%% ``The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in %% compliance with the License. You should have received a copy of the %% Erlang Public License along with this software. If not, it can be %% retrieved via the world wide web at http://www.erlang.org/. %% %% Software distributed under the License is distributed on an "AS IS" %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See %% the License for the specific language governing rights and limitations %% under the License. %% %% The Initial Developer of the Original Code is Richard Carlsson. %% Copyright (C) 1999-2002 Richard Carlsson. %% Portions created by Ericsson are Copyright 2001, Ericsson Utvecklings %% AB. All Rights Reserved.'' %% %% $Id: cerl.erl,v 1.3 2010/03/04 13:54:20 maria Exp $ %% ===================================================================== %% @doc Core Erlang abstract syntax trees. %% %%

This module defines an abstract data type for representing Core %% Erlang source code as syntax trees.

%% %%

A recommended starting point for the first-time user is the %% documentation of the function type/1.

%% %%

NOTES:

%% %%

This module deals with the composition and decomposition of %% syntactic entities (as opposed to semantic ones); its %% purpose is to hide all direct references to the data structures %% used to represent these entities. With few exceptions, the %% functions in this module perform no semantic interpretation of %% their inputs, and in general, the user is assumed to pass %% type-correct arguments - if this is not done, the effects are not %% defined.

%% %%

The internal representations of abstract syntax trees are %% subject to change without notice, and should not be documented %% outside this module. Furthermore, we do not give any guarantees on %% how an abstract syntax tree may or may not be represented, with %% the following exceptions: no syntax tree is represented by a %% single atom, such as none, by a list constructor %% [X | Y], or by the empty list []. This %% can be relied on when writing functions that operate on syntax %% trees.

%% %% @type cerl(). An abstract Core Erlang syntax tree. %% %%

Every abstract syntax tree has a type, given by the %% function type/1. In addition, %% each syntax tree has a list of user annotations (cf. get_ann/1), which are included %% in the Core Erlang syntax.

-module(cerl). -export([abstract/1, add_ann/2, alias_pat/1, alias_var/1, ann_abstract/2, ann_c_alias/3, ann_c_apply/3, ann_c_atom/2, ann_c_call/4, ann_c_case/3, ann_c_catch/2, ann_c_char/2, ann_c_clause/3, ann_c_clause/4, ann_c_cons/3, ann_c_float/2, ann_c_fname/3, ann_c_fun/3, ann_c_int/2, ann_c_let/4, ann_c_letrec/3, ann_c_module/4, ann_c_module/5, ann_c_nil/1, ann_c_cons_skel/3, ann_c_tuple_skel/2, ann_c_primop/3, ann_c_receive/2, ann_c_receive/4, ann_c_seq/3, ann_c_string/2, ann_c_try/6, ann_c_tuple/2, ann_c_values/2, ann_c_var/2, ann_make_data/3, ann_make_list/2, ann_make_list/3, ann_make_data_skel/3, ann_make_tree/3, apply_args/1, apply_arity/1, apply_op/1, atom_lit/1, atom_name/1, atom_val/1, c_alias/2, c_apply/2, c_atom/1, c_call/3, c_case/2, c_catch/1, c_char/1, c_clause/2, c_clause/3, c_cons/2, c_float/1, c_fname/2, c_fun/2, c_int/1, c_let/3, c_letrec/2, c_module/3, c_module/4, c_nil/0, c_cons_skel/2, c_tuple_skel/1, c_primop/2, c_receive/1, c_receive/3, c_seq/2, c_string/1, c_try/5, c_tuple/1, c_values/1, c_var/1, call_args/1, call_arity/1, call_module/1, call_name/1, case_arg/1, case_arity/1, case_clauses/1, catch_body/1, char_lit/1, char_val/1, clause_arity/1, clause_body/1, clause_guard/1, clause_pats/1, clause_vars/1, concrete/1, cons_hd/1, cons_tl/1, copy_ann/2, data_arity/1, data_es/1, data_type/1, float_lit/1, float_val/1, fname_arity/1, fname_id/1, fold_literal/1, from_records/1, fun_arity/1, fun_body/1, fun_vars/1, get_ann/1, int_lit/1, int_val/1, is_c_alias/1, is_c_apply/1, is_c_atom/1, is_c_call/1, is_c_case/1, is_c_catch/1, is_c_char/1, is_c_clause/1, is_c_cons/1, is_c_float/1, is_c_fname/1, is_c_fun/1, is_c_int/1, is_c_let/1, is_c_letrec/1, is_c_list/1, is_c_module/1, is_c_nil/1, is_c_primop/1, is_c_receive/1, is_c_seq/1, is_c_string/1, is_c_try/1, is_c_tuple/1, is_c_values/1, is_c_var/1, is_data/1, is_leaf/1, is_literal/1, is_literal_term/1, is_print_char/1, is_print_string/1, let_arg/1, let_arity/1, let_body/1, let_vars/1, letrec_body/1, letrec_defs/1, letrec_vars/1, list_elements/1, list_length/1, make_data/2, make_list/1, make_list/2, make_data_skel/2, make_tree/2, meta/1, module_attrs/1, module_defs/1, module_exports/1, module_name/1, module_vars/1, pat_list_vars/1, pat_vars/1, primop_args/1, primop_arity/1, primop_name/1, receive_action/1, receive_clauses/1, receive_timeout/1, seq_arg/1, seq_body/1, set_ann/2, string_lit/1, string_val/1, subtrees/1, to_records/1, try_arg/1, try_body/1, try_vars/1, try_evars/1, try_handler/1, tuple_arity/1, tuple_es/1, type/1, unfold_literal/1, update_c_alias/3, update_c_apply/3, update_c_call/4, update_c_case/3, update_c_catch/2, update_c_clause/4, update_c_cons/3, update_c_cons_skel/3, update_c_fname/2, update_c_fname/3, update_c_fun/3, update_c_let/4, update_c_letrec/3, update_c_module/5, update_c_primop/3, update_c_receive/4, update_c_seq/3, update_c_try/6, update_c_tuple/2, update_c_tuple_skel/2, update_c_values/2, update_c_var/2, update_data/3, update_list/2, update_list/3, update_data_skel/3, update_tree/2, update_tree/3, values_arity/1, values_es/1, var_name/1, c_binary/1, update_c_binary/2, ann_c_binary/2, is_c_binary/1, binary_segments/1, c_bitstr/3, c_bitstr/4, c_bitstr/5, update_c_bitstr/5, update_c_bitstr/6, ann_c_bitstr/5, ann_c_bitstr/6, is_c_bitstr/1, bitstr_val/1, bitstr_size/1, bitstr_bitsize/1, bitstr_unit/1, bitstr_type/1, bitstr_flags/1]). -include("core_parse.hrl"). %% ===================================================================== %% Representation (general) %% %% All nodes are represented by tuples of arity 2 or (generally) %% greater, whose first element is an atom which uniquely identifies the %% type of the node, and whose second element is a (proper) list of %% annotation terms associated with the node - this is by default empty. %% %% For most node constructor functions, there are analogous functions %% named 'ann_...', taking one extra argument 'As' (always the first %% argument), specifying an annotation list at node creation time. %% Similarly, there are also functions named 'update_...', taking one %% extra argument 'Old', specifying a node from which all fields not %% explicitly given as arguments should be copied (generally, this is %% the annotation field only). %% ===================================================================== %% This defines the general representation of constant literals: -record(literal, {ann = [], val}). %% @spec type(Node::cerl()) -> atom() %% %% @doc Returns the type tag of Node. Current node types %% are: %% %%

%% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %%
aliasapplybinarybitstrcallcasecatch
clauseconsfunletletrecliteralmodule
primopreceiveseqtrytuplevaluesvar

%% %%

Note: The name of the primary constructor function for a node %% type is always the name of the type itself, prefixed by %% "c_"; recognizer predicates are correspondingly %% prefixed by "is_c_". Furthermore, to simplify %% preservation of annotations (cf. get_ann/1), there are %% analogous constructor functions prefixed by "ann_c_" %% and "update_c_", for setting the annotation list of %% the new node to either a specific value or to the annotations of an %% existing node, respectively.

%% %% @see abstract/1 %% @see c_alias/2 %% @see c_apply/2 %% @see c_binary/1 %% @see c_bitstr/5 %% @see c_call/3 %% @see c_case/2 %% @see c_catch/1 %% @see c_clause/3 %% @see c_cons/2 %% @see c_fun/2 %% @see c_let/3 %% @see c_letrec/2 %% @see c_module/3 %% @see c_primop/2 %% @see c_receive/1 %% @see c_seq/2 %% @see c_try/3 %% @see c_tuple/1 %% @see c_values/1 %% @see c_var/1 %% @see get_ann/1 %% @see to_records/1 %% @see from_records/1 %% @see data_type/1 %% @see subtrees/1 %% @see meta/1 type(Node) -> element(1, Node). %% @spec is_leaf(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is a leaf node, %% otherwise false. The current leaf node types are %% literal and var. %% %%

Note: all literals (cf. is_literal/1) are leaf %% nodes, even if they represent structured (constant) values such as %% {foo, [bar, baz]}. Also note that variables are leaf %% nodes but not literals.

%% %% @see type/1 %% @see is_literal/1 is_leaf(Node) -> case type(Node) of literal -> true; var -> true; _ -> false end. %% @spec get_ann(cerl()) -> [term()] %% %% @doc Returns the list of user annotations associated with a syntax %% tree node. For a newly created node, this is the empty list. The %% annotations may be any terms. %% %% @see set_ann/2 get_ann(Node) -> element(2, Node). %% @spec set_ann(Node::cerl(), Annotations::[term()]) -> cerl() %% %% @doc Sets the list of user annotations of Node to %% Annotations. %% %% @see get_ann/1 %% @see add_ann/2 %% @see copy_ann/2 set_ann(Node, List) -> setelement(2, Node, List). %% @spec add_ann(Annotations::[term()], Node::cerl()) -> cerl() %% %% @doc Appends Annotations to the list of user %% annotations of Node. %% %%

Note: this is equivalent to set_ann(Node, Annotations ++ %% get_ann(Node)), but potentially more efficient.

%% %% @see get_ann/1 %% @see set_ann/2 add_ann(Terms, Node) -> set_ann(Node, Terms ++ get_ann(Node)). %% @spec copy_ann(Source::cerl(), Target::cerl()) -> cerl() %% %% @doc Copies the list of user annotations from Source %% to Target. %% %%

Note: this is equivalent to set_ann(Target, %% get_ann(Source)), but potentially more efficient.

%% %% @see get_ann/1 %% @see set_ann/2 copy_ann(Source, Target) -> set_ann(Target, get_ann(Source)). %% @spec abstract(Term::term()) -> cerl() %% %% @doc Creates a syntax tree corresponding to an Erlang term. %% Term must be a literal term, i.e., one that can be %% represented as a source code literal. Thus, it may not contain a %% process identifier, port, reference, binary or function value as a %% subterm. %% %%

Note: This is a constant time operation.

%% %% @see ann_abstract/2 %% @see concrete/1 %% @see is_literal/1 %% @see is_literal_term/1 abstract(T) -> #literal{val = T}. %% @spec ann_abstract(Annotations::[term()], Term::term()) -> cerl() %% @see abstract/1 ann_abstract(As, T) -> #literal{val = T, ann = As}. %% @spec is_literal_term(Term::term()) -> boolean() %% %% @doc Returns true if Term can be %% represented as a literal, otherwise false. This %% function takes time proportional to the size of Term. %% %% @see abstract/1 is_literal_term(T) when integer(T) -> true; is_literal_term(T) when float(T) -> true; is_literal_term(T) when atom(T) -> true; is_literal_term([]) -> true; is_literal_term([H | T]) -> case is_literal_term(H) of true -> is_literal_term(T); false -> false end; is_literal_term(T) when tuple(T) -> is_literal_term_list(tuple_to_list(T)); is_literal_term(_) -> false. is_literal_term_list([T | Ts]) -> case is_literal_term(T) of true -> is_literal_term_list(Ts); false -> false end; is_literal_term_list([]) -> true. %% @spec concrete(Node::cerl()) -> term() %% %% @doc Returns the Erlang term represented by a syntax tree. An %% exception is thrown if Node does not represent a %% literal term. %% %%

Note: This is a constant time operation.

%% %% @see abstract/1 %% @see is_literal/1 %% Because the normal tuple and list constructor operations always %% return a literal if the arguments are literals, 'concrete' and %% 'is_literal' never need to traverse the structure. concrete(#literal{val = V}) -> V. %% @spec is_literal(Node::cerl()) -> boolean() %% %% @doc Returns true if Node represents a %% literal term, otherwise false. This function returns %% true if and only if the value of %% concrete(Node) is defined. %% %%

Note: This is a constant time operation.

%% %% @see abstract/1 %% @see concrete/1 %% @see fold_literal/1 is_literal(#literal{}) -> true; is_literal(_) -> false. %% @spec fold_literal(Node::cerl()) -> cerl() %% %% @doc Assures that literals have a compact representation. This is %% occasionally useful if c_cons_skel/2, %% c_tuple_skel/1 or unfold_literal/1 were %% used in the construction of Node, and you want to revert %% to the normal "folded" representation of literals. If %% Node represents a tuple or list constructor, its %% elements are rewritten recursively, and the node is reconstructed %% using c_cons/2 or c_tuple/1, respectively; %% otherwise, Node is not changed. %% %% @see is_literal/1 %% @see c_cons_skel/2 %% @see c_tuple_skel/1 %% @see c_cons/2 %% @see c_tuple/1 %% @see unfold_literal/1 fold_literal(Node) -> case type(Node) of tuple -> update_c_tuple(Node, fold_literal_list(tuple_es(Node))); cons -> update_c_cons(Node, fold_literal(cons_hd(Node)), fold_literal(cons_tl(Node))); _ -> Node end. fold_literal_list([E | Es]) -> [fold_literal(E) | fold_literal_list(Es)]; fold_literal_list([]) -> []. %% @spec unfold_literal(Node::cerl()) -> cerl() %% %% @doc Assures that literals have a fully expanded representation. If %% Node represents a literal tuple or list constructor, its %% elements are rewritten recursively, and the node is reconstructed %% using c_cons_skel/2 or c_tuple_skel/1, %% respectively; otherwise, Node is not changed. The {@link %% fold_literal/1} can be used to revert to the normal compact %% representation. %% %% @see is_literal/1 %% @see c_cons_skel/2 %% @see c_tuple_skel/1 %% @see c_cons/2 %% @see c_tuple/1 %% @see fold_literal/1 unfold_literal(Node) -> case type(Node) of literal -> copy_ann(Node, unfold_concrete(concrete(Node))); _ -> Node end. unfold_concrete(Val) -> case Val of _ when tuple(Val) -> c_tuple_skel(unfold_concrete_list(tuple_to_list(Val))); [H|T] -> c_cons_skel(unfold_concrete(H), unfold_concrete(T)); _ -> abstract(Val) end. unfold_concrete_list([E | Es]) -> [unfold_concrete(E) | unfold_concrete_list(Es)]; unfold_concrete_list([]) -> []. %% --------------------------------------------------------------------- -record(module, {ann = [], name, exports, attrs, defs}). %% @spec c_module(Name::cerl(), Exports, Definitions) -> cerl() %% %% Exports = [cerl()] %% Definitions = [{cerl(), cerl()}] %% %% @equiv c_module(Name, Exports, [], Definitions) c_module(Name, Exports, Es) -> #module{name = Name, exports = Exports, attrs = [], defs = Es}. %% @spec c_module(Name::cerl(), Exports, Attributes, Definitions) -> %% cerl() %% %% Exports = [cerl()] %% Attributes = [{cerl(), cerl()}] %% Definitions = [{cerl(), cerl()}] %% %% @doc Creates an abstract module definition. The result represents %%
%%   module Name [E1, ..., Ek]
%%     attributes [K1 = T1, ...,
%%                 Km = Tm]
%%     V1 = F1
%%     ...
%%     Vn = Fn
%%   end
%% %% if Exports = [E1, ..., Ek], %% Attributes = [{K1, T1}, ..., {Km, Tm}], %% and Definitions = [{V1, F1}, ..., {Vn, %% Fn}]. %% %%

Name and all the Ki must be atom %% literals, and all the Ti must be constant literals. All %% the Vi and Ei must have type %% var and represent function names. All the %% Fi must have type 'fun'.

%% %% @see c_module/3 %% @see module_name/1 %% @see module_exports/1 %% @see module_attrs/1 %% @see module_defs/1 %% @see module_vars/1 %% @see ann_c_module/4 %% @see ann_c_module/5 %% @see update_c_module/5 %% @see c_atom/1 %% @see c_var/1 %% @see c_fun/2 %% @see is_literal/1 c_module(Name, Exports, Attrs, Es) -> #module{name = Name, exports = Exports, attrs = Attrs, defs = Es}. %% @spec ann_c_module(As::[term()], Name::cerl(), Exports, %% Definitions) -> cerl() %% %% Exports = [cerl()] %% Definitions = [{cerl(), cerl()}] %% %% @see c_module/3 %% @see ann_c_module/5 ann_c_module(As, Name, Exports, Es) -> #module{name = Name, exports = Exports, attrs = [], defs = Es, ann = As}. %% @spec ann_c_module(As::[term()], Name::cerl(), Exports, %% Attributes, Definitions) -> cerl() %% %% Exports = [cerl()] %% Attributes = [{cerl(), cerl()}] %% Definitions = [{cerl(), cerl()}] %% %% @see c_module/4 %% @see ann_c_module/4 ann_c_module(As, Name, Exports, Attrs, Es) -> #module{name = Name, exports = Exports, attrs = Attrs, defs = Es, ann = As}. %% @spec update_c_module(Old::cerl(), Name::cerl(), Exports, %% Attributes, Definitions) -> cerl() %% %% Exports = [cerl()] %% Attributes = [{cerl(), cerl()}] %% Definitions = [{cerl(), cerl()}] %% %% @see c_module/4 update_c_module(Node, Name, Exports, Attrs, Es) -> #module{name = Name, exports = Exports, attrs = Attrs, defs = Es, ann = get_ann(Node)}. %% @spec is_c_module(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% module definition, otherwise false. %% %% @see type/1 is_c_module(#module{}) -> true; is_c_module(_) -> false. %% @spec module_name(Node::cerl()) -> cerl() %% %% @doc Returns the name subtree of an abstract module definition. %% %% @see c_module/4 module_name(Node) -> Node#module.name. %% @spec module_exports(Node::cerl()) -> [cerl()] %% %% @doc Returns the list of exports subtrees of an abstract module %% definition. %% %% @see c_module/4 module_exports(Node) -> Node#module.exports. %% @spec module_attrs(Node::cerl()) -> [{cerl(), cerl()}] %% %% @doc Returns the list of pairs of attribute key/value subtrees of %% an abstract module definition. %% %% @see c_module/4 module_attrs(Node) -> Node#module.attrs. %% @spec module_defs(Node::cerl()) -> [{cerl(), cerl()}] %% %% @doc Returns the list of function definitions of an abstract module %% definition. %% %% @see c_module/4 module_defs(Node) -> Node#module.defs. %% @spec module_vars(Node::cerl()) -> [cerl()] %% %% @doc Returns the list of left-hand side function variable subtrees %% of an abstract module definition. %% %% @see c_module/4 module_vars(Node) -> [F || {F, _} <- module_defs(Node)]. %% --------------------------------------------------------------------- %% @spec c_int(Value::integer()) -> cerl() %% %% %% @doc Creates an abstract integer literal. The lexical %% representation is the canonical decimal numeral of %% Value. %% %% @see ann_c_int/2 %% @see is_c_int/1 %% @see int_val/1 %% @see int_lit/1 %% @see c_char/1 c_int(Value) -> #literal{val = Value}. %% @spec ann_c_int(As::[term()], Value::integer()) -> cerl() %% @see c_int/1 ann_c_int(As, Value) -> #literal{val = Value, ann = As}. %% @spec is_c_int(Node::cerl()) -> boolean() %% %% @doc Returns true if Node represents an %% integer literal, otherwise false. %% @see c_int/1 is_c_int(#literal{val = V}) when integer(V) -> true; is_c_int(_) -> false. %% @spec int_val(cerl()) -> integer() %% %% @doc Returns the value represented by an integer literal node. %% @see c_int/1 int_val(Node) -> Node#literal.val. %% @spec int_lit(cerl()) -> string() %% %% @doc Returns the numeral string represented by an integer literal %% node. %% @see c_int/1 int_lit(Node) -> integer_to_list(int_val(Node)). %% --------------------------------------------------------------------- %% @spec c_float(Value::float()) -> cerl() %% %% @doc Creates an abstract floating-point literal. The lexical %% representation is the decimal floating-point numeral of %% Value. %% %% @see ann_c_float/2 %% @see is_c_float/1 %% @see float_val/1 %% @see float_lit/1 %% Note that not all floating-point numerals can be represented with %% full precision. c_float(Value) -> #literal{val = Value}. %% @spec ann_c_float(As::[term()], Value::float()) -> cerl() %% @see c_float/1 ann_c_float(As, Value) -> #literal{val = Value, ann = As}. %% @spec is_c_float(Node::cerl()) -> boolean() %% %% @doc Returns true if Node represents a %% floating-point literal, otherwise false. %% @see c_float/1 is_c_float(#literal{val = V}) when float(V) -> true; is_c_float(_) -> false. %% @spec float_val(cerl()) -> float() %% %% @doc Returns the value represented by a floating-point literal %% node. %% @see c_float/1 float_val(Node) -> Node#literal.val. %% @spec float_lit(cerl()) -> string() %% %% @doc Returns the numeral string represented by a floating-point %% literal node. %% @see c_float/1 float_lit(Node) -> float_to_list(float_val(Node)). %% --------------------------------------------------------------------- %% @spec c_atom(Name) -> cerl() %% Name = atom() | string() %% %% @doc Creates an abstract atom literal. The print name of the atom %% is the character sequence represented by Name. %% %%

Note: passing a string as argument to this function causes a %% corresponding atom to be created for the internal representation.

%% %% @see ann_c_atom/2 %% @see is_c_atom/1 %% @see atom_val/1 %% @see atom_name/1 %% @see atom_lit/1 c_atom(Name) when atom(Name) -> #literal{val = Name}; c_atom(Name) -> #literal{val = list_to_atom(Name)}. %% @spec ann_c_atom(As::[term()], Name) -> cerl() %% Name = atom() | string() %% @see c_atom/1 ann_c_atom(As, Name) when atom(Name) -> #literal{val = Name, ann = As}; ann_c_atom(As, Name) -> #literal{val = list_to_atom(Name), ann = As}. %% @spec is_c_atom(Node::cerl()) -> boolean() %% %% @doc Returns true if Node represents an %% atom literal, otherwise false. %% %% @see c_atom/1 is_c_atom(#literal{val = V}) when atom(V) -> true; is_c_atom(_) -> false. %% @spec atom_val(cerl())-> atom() %% %% @doc Returns the value represented by an abstract atom. %% %% @see c_atom/1 atom_val(Node) -> Node#literal.val. %% @spec atom_name(cerl()) -> string() %% %% @doc Returns the printname of an abstract atom. %% %% @see c_atom/1 atom_name(Node) -> atom_to_list(atom_val(Node)). %% @spec atom_lit(cerl()) -> string() %% %% @doc Returns the literal string represented by an abstract %% atom. This always includes surrounding single-quote characters. %% %%

Note that an abstract atom may have several literal %% representations, and that the representation yielded by this %% function is not fixed; e.g., %% atom_lit(c_atom("a\012b")) could yield the string %% "\'a\\nb\'".

%% %% @see c_atom/1 %% TODO: replace the use of the unofficial 'write_string/2'. atom_lit(Node) -> io_lib:write_string(atom_name(Node), $'). %' stupid Emacs. %% --------------------------------------------------------------------- %% @spec c_char(Value) -> cerl() %% %% Value = char() | integer() %% %% @doc Creates an abstract character literal. If the local %% implementation of Erlang defines char() as a subset of %% integer(), this function is equivalent to %% c_int/1. Otherwise, if the given value is an integer, %% it will be converted to the character with the corresponding %% code. The lexical representation of a character is %% "$Char", where Char is a single %% printing character or an escape sequence. %% %% @see c_int/1 %% @see c_string/1 %% @see ann_c_char/2 %% @see is_c_char/1 %% @see char_val/1 %% @see char_lit/1 %% @see is_print_char/1 c_char(Value) when integer(Value), Value >= 0 -> #literal{val = Value}. %% @spec ann_c_char(As::[term()], Value::char()) -> cerl() %% @see c_char/1 ann_c_char(As, Value) -> #literal{val = Value, ann = As}. %% @spec is_c_char(Node::cerl()) -> boolean() %% %% @doc Returns true if Node may represent a %% character literal, otherwise false. %% %%

If the local implementation of Erlang defines %% char() as a subset of integer(), then %% is_c_int(Node) will also yield %% true.

%% %% @see c_char/1 %% @see is_print_char/1 is_c_char(#literal{val = V}) when integer(V), V >= 0 -> is_char_value(V); is_c_char(_) -> false. %% @spec is_print_char(Node::cerl()) -> boolean() %% %% @doc Returns true if Node may represent a %% "printing" character, otherwise false. (Cf. %% is_c_char/1.) A "printing" character has either a %% given graphical representation, or a "named" escape sequence such %% as "\n". Currently, only ISO 8859-1 (Latin-1) %% character values are recognized. %% %% @see c_char/1 %% @see is_c_char/1 is_print_char(#literal{val = V}) when integer(V), V >= 0 -> is_print_char_value(V); is_print_char(_) -> false. %% @spec char_val(cerl()) -> char() %% %% @doc Returns the value represented by an abstract character literal. %% %% @see c_char/1 char_val(Node) -> Node#literal.val. %% @spec char_lit(cerl()) -> string() %% %% @doc Returns the literal string represented by an abstract %% character. This includes a leading $ %% character. Currently, all characters that are not in the set of ISO %% 8859-1 (Latin-1) "printing" characters will be escaped. %% %% @see c_char/1 char_lit(Node) -> io_lib:write_char(char_val(Node)). %% --------------------------------------------------------------------- %% @spec c_string(Value::string()) -> cerl() %% %% @doc Creates an abstract string literal. Equivalent to creating an %% abstract list of the corresponding character literals %% (cf. is_c_string/1), but is typically more %% efficient. The lexical representation of a string is %% ""Chars"", where Chars is a %% sequence of printing characters or spaces. %% %% @see c_char/1 %% @see ann_c_string/2 %% @see is_c_string/1 %% @see string_val/1 %% @see string_lit/1 %% @see is_print_string/1 c_string(Value) -> #literal{val = Value}. %% @spec ann_c_string(As::[term()], Value::string()) -> cerl() %% @see c_string/1 ann_c_string(As, Value) -> #literal{val = Value, ann = As}. %% @spec is_c_string(Node::cerl()) -> boolean() %% %% @doc Returns true if Node may represent a %% string literal, otherwise false. Strings are defined %% as lists of characters; see is_c_char/1 for details. %% %% @see c_string/1 %% @see is_c_char/1 %% @see is_print_string/1 is_c_string(#literal{val = V}) -> is_char_list(V); is_c_string(_) -> false. %% @spec is_print_string(Node::cerl()) -> boolean() %% %% @doc Returns true if Node may represent a %% string literal containing only "printing" characters, otherwise %% false. See is_c_string/1 and %% is_print_char/1 for details. Currently, only ISO %% 8859-1 (Latin-1) character values are recognized. %% %% @see c_string/1 %% @see is_c_string/1 %% @see is_print_char/1 is_print_string(#literal{val = V}) -> is_print_char_list(V); is_print_string(_) -> false. %% @spec string_val(cerl()) -> string() %% %% @doc Returns the value represented by an abstract string literal. %% %% @see c_string/1 string_val(Node) -> Node#literal.val. %% @spec string_lit(cerl()) -> string() %% %% @doc Returns the literal string represented by an abstract string. %% This includes surrounding double-quote characters %% "...". Currently, characters that are not in the set %% of ISO 8859-1 (Latin-1) "printing" characters will be escaped, %% except for spaces. %% %% @see c_string/1 string_lit(Node) -> io_lib:write_string(string_val(Node)). %% --------------------------------------------------------------------- %% @spec c_nil() -> cerl() %% %% @doc Creates an abstract empty list. The result represents %% "[]". The empty list is traditionally called "nil". %% %% @see ann_c_nil/1 %% @see is_c_list/1 %% @see c_cons/2 c_nil() -> #literal{val = []}. %% @spec ann_c_nil(As::[term()]) -> cerl() %% @see c_nil/0 ann_c_nil(As) -> #literal{val = [], ann = As}. %% @spec is_c_nil(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% empty list, otherwise false. is_c_nil(#literal{val = []}) -> true; is_c_nil(_) -> false. %% --------------------------------------------------------------------- %% @spec c_cons(Head::cerl(), Tail::cerl()) -> cerl() %% %% @doc Creates an abstract list constructor. The result represents %% "[Head | Tail]". Note that if both %% Head and Tail have type %% literal, then the result will also have type %% literal, and annotations on Head and %% Tail are lost. %% %%

Recall that in Erlang, the tail element of a list constructor is %% not necessarily a list.

%% %% @see ann_c_cons/3 %% @see update_c_cons/3 %% @see c_cons_skel/2 %% @see is_c_cons/1 %% @see cons_hd/1 %% @see cons_tl/1 %% @see is_c_list/1 %% @see c_nil/0 %% @see list_elements/1 %% @see list_length/1 %% @see make_list/2 -record(cons, {ann = [], hd, tl}). %% *Always* collapse literals. c_cons(#literal{val = Head}, #literal{val = Tail}) -> #literal{val = [Head | Tail]}; c_cons(Head, Tail) -> #cons{hd = Head, tl = Tail}. %% @spec ann_c_cons(As::[term()], Head::cerl(), Tail::cerl()) -> cerl() %% @see c_cons/2 ann_c_cons(As, #literal{val = Head}, #literal{val = Tail}) -> #literal{val = [Head | Tail], ann = As}; ann_c_cons(As, Head, Tail) -> #cons{hd = Head, tl = Tail, ann = As}. %% @spec update_c_cons(Old::cerl(), Head::cerl(), Tail::cerl()) -> %% cerl() %% @see c_cons/2 update_c_cons(Node, #literal{val = Head}, #literal{val = Tail}) -> #literal{val = [Head | Tail], ann = get_ann(Node)}; update_c_cons(Node, Head, Tail) -> #cons{hd = Head, tl = Tail, ann = get_ann(Node)}. %% @spec c_cons_skel(Head::cerl(), Tail::cerl()) -> cerl() %% %% @doc Creates an abstract list constructor skeleton. Does not fold %% constant literals, i.e., the result always has type %% cons, representing "[Head | %% Tail]". %% %%

This function is occasionally useful when it is necessary to have %% annotations on the subnodes of a list constructor node, even when the %% subnodes are constant literals. Note however that %% is_literal/1 will yield false and %% concrete/1 will fail if passed the result from this %% function.

%% %%

fold_literal/1 can be used to revert a node to the %% normal-form representation.

%% %% @see ann_c_cons_skel/3 %% @see update_c_cons_skel/3 %% @see c_cons/2 %% @see is_c_cons/1 %% @see is_c_list/1 %% @see c_nil/0 %% @see is_literal/1 %% @see fold_literal/1 %% @see concrete/1 %% *Never* collapse literals. c_cons_skel(Head, Tail) -> #cons{hd = Head, tl = Tail}. %% @spec ann_c_cons_skel(As::[term()], Head::cerl(), Tail::cerl()) -> %% cerl() %% @see c_cons_skel/2 ann_c_cons_skel(As, Head, Tail) -> #cons{hd = Head, tl = Tail, ann = As}. %% @spec update_c_cons_skel(Old::cerl(), Head::cerl(), Tail::cerl()) -> %% cerl() %% @see c_cons_skel/2 update_c_cons_skel(Node, Head, Tail) -> #cons{hd = Head, tl = Tail, ann = get_ann(Node)}. %% @spec is_c_cons(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% list constructor, otherwise false. is_c_cons(#cons{}) -> true; is_c_cons(#literal{val = [_ | _]}) -> true; is_c_cons(_) -> false. %% @spec cons_hd(cerl()) -> cerl() %% %% @doc Returns the head subtree of an abstract list constructor. %% %% @see c_cons/2 cons_hd(#cons{hd = Head}) -> Head; cons_hd(#literal{val = [Head | _]}) -> #literal{val = Head}. %% @spec cons_tl(cerl()) -> cerl() %% %% @doc Returns the tail subtree of an abstract list constructor. %% %%

Recall that the tail does not necessarily represent a proper %% list.

%% %% @see c_cons/2 cons_tl(#cons{tl = Tail}) -> Tail; cons_tl(#literal{val = [_ | Tail]}) -> #literal{val = Tail}. %% @spec is_c_list(Node::cerl()) -> boolean() %% %% @doc Returns true if Node represents a %% proper list, otherwise false. A proper list is either %% the empty list [], or a cons cell [Head | %% Tail], where recursively Tail is a %% proper list. %% %%

Note: Because Node is a syntax tree, the actual %% run-time values corresponding to its subtrees may often be partially %% or completely unknown. Thus, if Node represents e.g. %% "[... | Ns]" (where Ns is a variable), then %% the function will return false, because it is not known %% whether Ns will be bound to a list at run-time. If %% Node instead represents e.g. "[1, 2, 3]" or %% "[A | []]", then the function will return %% true.

%% %% @see c_cons/2 %% @see c_nil/0 %% @see list_elements/1 %% @see list_length/1 is_c_list(#cons{tl = Tail}) -> is_c_list(Tail); is_c_list(#literal{val = V}) -> is_proper_list(V); is_c_list(_) -> false. is_proper_list([_ | Tail]) -> is_proper_list(Tail); is_proper_list([]) -> true; is_proper_list(_) -> false. %% @spec list_elements(cerl()) -> [cerl()] %% %% @doc Returns the list of element subtrees of an abstract list. %% Node must represent a proper list. E.g., if %% Node represents "[X1, X2 | %% [X3, X4 | []]", then %% list_elements(Node) yields the list [X1, X2, X3, %% X4]. %% %% @see c_cons/2 %% @see c_nil/1 %% @see is_c_list/1 %% @see list_length/1 %% @see make_list/2 list_elements(#cons{hd = Head, tl = Tail}) -> [Head | list_elements(Tail)]; list_elements(#literal{val = V}) -> abstract_list(V). abstract_list([X | Xs]) -> [abstract(X) | abstract_list(Xs)]; abstract_list([]) -> []. %% @spec list_length(Node::cerl()) -> integer() %% %% @doc Returns the number of element subtrees of an abstract list. %% Node must represent a proper list. E.g., if %% Node represents "[X1 | [X2, X3 | [X4, X5, %% X6]]]", then list_length(Node) returns the %% integer 6. %% %%

Note: this is equivalent to %% length(list_elements(Node)), but potentially more %% efficient.

%% %% @see c_cons/2 %% @see c_nil/1 %% @see is_c_list/1 %% @see list_elements/1 list_length(L) -> list_length(L, 0). list_length(#cons{tl = Tail}, A) -> list_length(Tail, A + 1); list_length(#literal{val = V}, A) -> A + length(V). %% @spec make_list(List) -> Node %% @equiv make_list(List, none) make_list(List) -> ann_make_list([], List). %% @spec make_list(List::[cerl()], Tail) -> cerl() %% %% Tail = cerl() | none %% %% @doc Creates an abstract list from the elements in List %% and the optional Tail. If Tail is %% none, the result will represent a nil-terminated list, %% otherwise it represents "[... | Tail]". %% %% @see c_cons/2 %% @see c_nil/0 %% @see ann_make_list/3 %% @see update_list/3 %% @see list_elements/1 make_list(List, Tail) -> ann_make_list([], List, Tail). %% @spec update_list(Old::cerl(), List::[cerl()]) -> cerl() %% @equiv update_list(Old, List, none) update_list(Node, List) -> ann_make_list(get_ann(Node), List). %% @spec update_list(Old::cerl(), List::[cerl()], Tail) -> cerl() %% %% Tail = cerl() | none %% %% @see make_list/2 %% @see update_list/2 update_list(Node, List, Tail) -> ann_make_list(get_ann(Node), List, Tail). %% @spec ann_make_list(As::[term()], List::[cerl()]) -> cerl() %% @equiv ann_make_list(As, List, none) ann_make_list(As, List) -> ann_make_list(As, List, none). %% @spec ann_make_list(As::[term()], List::[cerl()], Tail) -> cerl() %% %% Tail = cerl() | none %% %% @see make_list/2 %% @see ann_make_list/2 ann_make_list(As, [H | T], Tail) -> ann_c_cons(As, H, make_list(T, Tail)); % `c_cons' folds literals ann_make_list(As, [], none) -> ann_c_nil(As); ann_make_list(_, [], Node) -> Node. %% --------------------------------------------------------------------- %% @spec c_tuple(Elements::[cerl()]) -> cerl() %% %% @doc Creates an abstract tuple. If Elements is %% [E1, ..., En], the result represents %% "{E1, ..., En}". Note that if all %% nodes in Elements have type literal, or if %% Elements is empty, then the result will also have type %% literal and annotations on nodes in %% Elements are lost. %% %%

Recall that Erlang has distinct 1-tuples, i.e., {X} %% is always distinct from X itself.

%% %% @see ann_c_tuple/2 %% @see update_c_tuple/2 %% @see is_c_tuple/1 %% @see tuple_es/1 %% @see tuple_arity/1 %% @see c_tuple_skel/1 -record(tuple, {ann = [], es}). %% *Always* collapse literals. c_tuple(Es) -> case is_lit_list(Es) of false -> #tuple{es = Es}; true -> #literal{val = list_to_tuple(lit_list_vals(Es))} end. %% @spec ann_c_tuple(As::[term()], Elements::[cerl()]) -> cerl() %% @see c_tuple/1 ann_c_tuple(As, Es) -> case is_lit_list(Es) of false -> #tuple{es = Es, ann = As}; true -> #literal{val = list_to_tuple(lit_list_vals(Es)), ann = As} end. %% @spec update_c_tuple(Old::cerl(), Elements::[cerl()]) -> cerl() %% @see c_tuple/1 update_c_tuple(Node, Es) -> case is_lit_list(Es) of false -> #tuple{es = Es, ann = get_ann(Node)}; true -> #literal{val = list_to_tuple(lit_list_vals(Es)), ann = get_ann(Node)} end. %% @spec c_tuple_skel(Elements::[cerl()]) -> cerl() %% %% @doc Creates an abstract tuple skeleton. Does not fold constant %% literals, i.e., the result always has type tuple, %% representing "{E1, ..., En}", if %% Elements is [E1, ..., En]. %% %%

This function is occasionally useful when it is necessary to have %% annotations on the subnodes of a tuple node, even when all the %% subnodes are constant literals. Note however that %% is_literal/1 will yield false and %% concrete/1 will fail if passed the result from this %% function.

%% %%

fold_literal/1 can be used to revert a node to the %% normal-form representation.

%% %% @see ann_c_tuple_skel/2 %% @see update_c_tuple_skel/2 %% @see c_tuple/1 %% @see tuple_es/1 %% @see is_c_tuple/1 %% @see is_literal/1 %% @see fold_literal/1 %% @see concrete/1 %% *Never* collapse literals. c_tuple_skel(Es) -> #tuple{es = Es}. %% @spec ann_c_tuple_skel(As::[term()], Elements::[cerl()]) -> cerl() %% @see c_tuple_skel/1 ann_c_tuple_skel(As, Es) -> #tuple{es = Es, ann = As}. %% @spec update_c_tuple_skel(Old::cerl(), Elements::[cerl()]) -> cerl() %% @see c_tuple_skel/1 update_c_tuple_skel(Old, Es) -> #tuple{es = Es, ann = get_ann(Old)}. %% @spec is_c_tuple(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% tuple, otherwise false. %% %% @see c_tuple/1 is_c_tuple(#tuple{}) -> true; is_c_tuple(#literal{val = V}) when tuple(V) -> true; is_c_tuple(_) -> false. %% @spec tuple_es(cerl()) -> [cerl()] %% %% @doc Returns the list of element subtrees of an abstract tuple. %% %% @see c_tuple/1 tuple_es(#tuple{es = Es}) -> Es; tuple_es(#literal{val = V}) -> make_lit_list(tuple_to_list(V)). %% @spec tuple_arity(Node::cerl()) -> integer() %% %% @doc Returns the number of element subtrees of an abstract tuple. %% %%

Note: this is equivalent to length(tuple_es(Node)), %% but potentially more efficient.

%% %% @see tuple_es/1 %% @see c_tuple/1 tuple_arity(#tuple{es = Es}) -> length(Es); tuple_arity(#literal{val = V}) when tuple(V) -> size(V). %% --------------------------------------------------------------------- %% @spec c_var(Name::var_name()) -> cerl() %% %% var_name() = integer() | atom() | {atom(), integer()} %% %% @doc Creates an abstract variable. A variable is identified by its %% name, given by the Name parameter. %% %%

If a name is given by a single atom, it should either be a %% "simple" atom which does not need to be single-quoted in Erlang, or %% otherwise its print name should correspond to a proper Erlang %% variable, i.e., begin with an uppercase character or an %% underscore. Names on the form {A, N} represent %% function name variables "A/N"; these %% are special variables which may be bound only in the function %% definitions of a module or a letrec. They may not be %% bound in let expressions and cannot occur in clause %% patterns. The atom A in a function name may be any %% atom; the integer N must be nonnegative. The functions %% c_fname/2 etc. are utilities for handling function %% name variables.

%% %%

When printing variable names, they must have the form of proper %% Core Erlang variables and function names. E.g., a name represented %% by an integer such as 42 could be formatted as %% "_42", an atom 'Xxx' simply as %% "Xxx", and an atom foo as %% "_foo". However, one must assure that any two valid %% distinct names are never mapped to the same strings. Tuples such %% as {foo, 2} representing function names can simply by %% formatted as "'foo'/2", with no risk of conflicts.

%% %% @see ann_c_var/2 %% @see update_c_var/2 %% @see is_c_var/1 %% @see var_name/1 %% @see c_fname/2 %% @see c_module/4 %% @see c_letrec/2 -record(var, {ann = [], name}). c_var(Name) -> #var{name = Name}. %% @spec ann_c_var(As::[term()], Name::var_name()) -> cerl() %% %% @see c_var/1 ann_c_var(As, Name) -> #var{name = Name, ann = As}. %% @spec update_c_var(Old::cerl(), Name::var_name()) -> cerl() %% %% @see c_var/1 update_c_var(Node, Name) -> #var{name = Name, ann = get_ann(Node)}. %% @spec is_c_var(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% variable, otherwise false. %% %% @see c_var/1 is_c_var(#var{}) -> true; is_c_var(_) -> false. %% @spec c_fname(Name::atom(), Arity::integer()) -> cerl() %% @equiv c_var({Name, Arity}) %% @see fname_id/1 %% @see fname_arity/1 %% @see is_c_fname/1 %% @see ann_c_fname/3 %% @see update_c_fname/3 c_fname(Atom, Arity) -> c_var({Atom, Arity}). %% @spec ann_c_fname(As::[term()], Name::atom(), Arity::integer()) -> %% cerl() %% @equiv ann_c_var(As, {Atom, Arity}) %% @see c_fname/2 ann_c_fname(As, Atom, Arity) -> ann_c_var(As, {Atom, Arity}). %% @spec update_c_fname(Old::cerl(), Name::atom()) -> cerl() %% @doc Like update_c_fname/3, but takes the arity from %% Node. %% @see update_c_fname/3 %% @see c_fname/2 update_c_fname(#var{name = {_, Arity}, ann = As}, Atom) -> #var{name = {Atom, Arity}, ann = As}. %% @spec update_c_fname(Old::cerl(), Name::atom(), Arity::integer()) -> %% cerl() %% @equiv update_c_var(Old, {Atom, Arity}) %% @see update_c_fname/2 %% @see c_fname/2 update_c_fname(Node, Atom, Arity) -> update_c_var(Node, {Atom, Arity}). %% @spec is_c_fname(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% function name variable, otherwise false. %% %% @see c_fname/2 %% @see c_var/1 %% @see c_var_name/1 is_c_fname(#var{name = {A, N}}) when atom(A), integer(N), N >= 0 -> true; is_c_fname(_) -> false. %% @spec var_name(cerl()) -> var_name() %% %% @doc Returns the name of an abstract variable. %% %% @see c_var/1 var_name(Node) -> Node#var.name. %% @spec fname_id(cerl()) -> atom() %% %% @doc Returns the identifier part of an abstract function name %% variable. %% %% @see fname_arity/1 %% @see c_fname/2 fname_id(#var{name={A,_}}) -> A. %% @spec fname_arity(cerl()) -> integer() %% %% @doc Returns the arity part of an abstract function name variable. %% %% @see fname_id/1 %% @see c_fname/2 fname_arity(#var{name={_,N}}) -> N. %% --------------------------------------------------------------------- %% @spec c_values(Elements::[cerl()]) -> cerl() %% %% @doc Creates an abstract value list. If Elements is %% [E1, ..., En], the result represents %% "<E1, ..., En>". %% %% @see ann_c_values/2 %% @see update_c_values/2 %% @see is_c_values/1 %% @see values_es/1 %% @see values_arity/1 -record(values, {ann = [], es}). c_values(Es) -> #values{es = Es}. %% @spec ann_c_values(As::[term()], Elements::[cerl()]) -> cerl() %% @see c_values/1 ann_c_values(As, Es) -> #values{es = Es, ann = As}. %% @spec update_c_values(Old::cerl(), Elements::[cerl()]) -> cerl() %% @see c_values/1 update_c_values(Node, Es) -> #values{es = Es, ann = get_ann(Node)}. %% @spec is_c_values(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% value list; otherwise false. %% %% @see c_values/1 is_c_values(#values{}) -> true; is_c_values(_) -> false. %% @spec values_es(cerl()) -> [cerl()] %% %% @doc Returns the list of element subtrees of an abstract value %% list. %% %% @see c_values/1 %% @see values_arity/1 values_es(Node) -> Node#values.es. %% @spec values_arity(Node::cerl()) -> integer() %% %% @doc Returns the number of element subtrees of an abstract value %% list. %% %%

Note: This is equivalent to %% length(values_es(Node)), but potentially more %% efficient.

%% %% @see c_values/1 %% @see values_es/1 values_arity(Node) -> length(values_es(Node)). %% --------------------------------------------------------------------- %% @spec c_binary(Segments::[cerl()]) -> cerl() %% %% @doc Creates an abstract binary-template. A binary object is a %% sequence of 8-bit bytes. It is specified by zero or more bit-string %% template segments of arbitrary lengths (in number of bits), %% such that the sum of the lengths is evenly divisible by 8. If %% Segments is [S1, ..., Sn], the result %% represents "#{S1, ..., Sn}#". All the %% Si must have type bitstr. %% %% @see ann_c_binary/2 %% @see update_c_binary/2 %% @see is_c_binary/1 %% @see binary_segments/1 %% @see c_bitstr/5 -record(binary, {ann = [], segments}). c_binary(Segments) -> #binary{segments = Segments}. %% @spec ann_c_binary(As::[term()], Segments::[cerl()]) -> cerl() %% @see c_binary/1 ann_c_binary(As, Segments) -> #binary{segments = Segments, ann = As}. %% @spec update_c_binary(Old::cerl(), Segments::[cerl()]) -> cerl() %% @see c_binary/1 update_c_binary(Node, Segments) -> #binary{segments = Segments, ann = get_ann(Node)}. %% @spec is_c_binary(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% binary-template; otherwise false. %% %% @see c_binary/1 is_c_binary(#binary{}) -> true; is_c_binary(_) -> false. %% @spec binary_segments(cerl()) -> [cerl()] %% %% @doc Returns the list of segment subtrees of an abstract %% binary-template. %% %% @see c_binary/1 %% @see c_bitstr/5 binary_segments(Node) -> Node#binary.segments. %% @spec c_bitstr(Value::cerl(), Size::cerl(), Unit::cerl(), %% Type::cerl(), Flags::cerl()) -> cerl() %% %% @doc Creates an abstract bit-string template. These can only occur as %% components of an abstract binary-template (see {@link c_binary/1}). %% The result represents "#<Value>(Size, %% Unit, Type, Flags)", where %% Unit must represent a positive integer constant, %% Type must represent a constant atom (one of %% 'integer', 'float', or %% 'binary'), and Flags must represent a %% constant list "[F1, ..., Fn]" where %% all the Fi are atoms. %% %% @see c_binary/1 %% @see ann_c_bitstr/6 %% @see update_c_bitstr/6 %% @see is_c_bitstr/1 %% @see bitstr_val/1 %% @see bitstr_size/1 %% @see bitstr_unit/1 %% @see bitstr_type/1 %% @see bitstr_flags/1 -record(bitstr, {ann = [], val, size, unit, type, flags}). c_bitstr(Val, Size, Unit, Type, Flags) -> #bitstr{val = Val, size = Size, unit = Unit, type = Type, flags = Flags}. %% @spec c_bitstr(Value::cerl(), Size::cerl(), Type::cerl(), %% Flags::cerl()) -> cerl() %% @equiv c_bitstr(Value, Size, abstract(1), Type, Flags) c_bitstr(Val, Size, Type, Flags) -> c_bitstr(Val, Size, abstract(1), Type, Flags). %% @spec c_bitstr(Value::cerl(), Type::cerl(), %% Flags::cerl()) -> cerl() %% @equiv c_bitstr(Value, abstract(all), abstract(1), Type, Flags) c_bitstr(Val, Type, Flags) -> c_bitstr(Val, abstract(all), abstract(1), Type, Flags). %% @spec ann_c_bitstr(As::[term()], Value::cerl(), Size::cerl(), %% Unit::cerl(), Type::cerl(), Flags::cerl()) -> cerl() %% @see c_bitstr/5 %% @see ann_c_bitstr/5 ann_c_bitstr(As, Val, Size, Unit, Type, Flags) -> #bitstr{val = Val, size = Size, unit = Unit, type = Type, flags = Flags, ann = As}. %% @spec ann_c_bitstr(As::[term()], Value::cerl(), Size::cerl(), %% Type::cerl(), Flags::cerl()) -> cerl() %% @equiv ann_c_bitstr(As, Value, Size, abstract(1), Type, Flags) ann_c_bitstr(As, Value, Size, Type, Flags) -> ann_c_bitstr(As, Value, Size, abstract(1), Type, Flags). %% @spec update_c_bitstr(Old::cerl(), Value::cerl(), Size::cerl(), %% Unit::cerl(), Type::cerl(), Flags::cerl()) -> cerl() %% @see c_bitstr/5 %% @see update_c_bitstr/5 update_c_bitstr(Node, Val, Size, Unit, Type, Flags) -> #bitstr{val = Val, size = Size, unit = Unit, type = Type, flags = Flags, ann = get_ann(Node)}. %% @spec update_c_bitstr(Old::cerl(), Value::cerl(), Size::cerl(), %% Type::cerl(), Flags::cerl()) -> cerl() %% @equiv update_c_bitstr(Node, Value, Size, abstract(1), Type, Flags) update_c_bitstr(Node, Value, Size, Type, Flags) -> update_c_bitstr(Node, Value, Size, abstract(1), Type, Flags). %% @spec is_c_bitstr(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% bit-string template; otherwise false. %% %% @see c_bitstr/5 is_c_bitstr(#bitstr{}) -> true; is_c_bitstr(_) -> false. %% @spec bitstr_val(cerl()) -> cerl() %% %% @doc Returns the value subtree of an abstract bit-string template. %% %% @see c_bitstr/5 bitstr_val(Node) -> Node#bitstr.val. %% @spec bitstr_size(cerl()) -> cerl() %% %% @doc Returns the size subtree of an abstract bit-string template. %% %% @see c_bitstr/5 bitstr_size(Node) -> Node#bitstr.size. %% @spec bitstr_bitsize(cerl()) -> integer() | any | all %% %% @doc Returns the total size in bits of an abstract bit-string %% template. If the size field is an integer literal, the result is the %% product of the size and unit values; if the size field is the atom %% literal all, the atom all is returned; in %% all other cases, the atom any is returned. %% %% @see c_bitstr/5 bitstr_bitsize(Node) -> Size = Node#bitstr.size, case is_literal(Size) of true -> case concrete(Size) of all -> all; S when integer(S) -> S*concrete(Node#bitstr.unit); true -> any end; false -> any end. %% @spec bitstr_unit(cerl()) -> cerl() %% %% @doc Returns the unit subtree of an abstract bit-string template. %% %% @see c_bitstr/5 bitstr_unit(Node) -> Node#bitstr.unit. %% @spec bitstr_type(cerl()) -> cerl() %% %% @doc Returns the type subtree of an abstract bit-string template. %% %% @see c_bitstr/5 bitstr_type(Node) -> Node#bitstr.type. %% @spec bitstr_flags(cerl()) -> cerl() %% %% @doc Returns the flags subtree of an abstract bit-string template. %% %% @see c_bitstr/5 bitstr_flags(Node) -> Node#bitstr.flags. %% --------------------------------------------------------------------- %% @spec c_fun(Variables::[cerl()], Body::cerl()) -> cerl() %% %% @doc Creates an abstract fun-expression. If Variables %% is [V1, ..., Vn], the result represents "fun %% (V1, ..., Vn) -> Body". All the %% Vi must have type var. %% %% @see ann_c_fun/3 %% @see update_c_fun/3 %% @see is_c_fun/1 %% @see fun_vars/1 %% @see fun_body/1 %% @see fun_arity/1 -record('fun', {ann = [], vars, body}). c_fun(Variables, Body) -> #'fun'{vars = Variables, body = Body}. %% @spec ann_c_fun(As::[term()], Variables::[cerl()], Body::cerl()) -> %% cerl() %% @see c_fun/2 ann_c_fun(As, Variables, Body) -> #'fun'{vars = Variables, body = Body, ann = As}. %% @spec update_c_fun(Old::cerl(), Variables::[cerl()], %% Body::cerl()) -> cerl() %% @see c_fun/2 update_c_fun(Node, Variables, Body) -> #'fun'{vars = Variables, body = Body, ann = get_ann(Node)}. %% @spec is_c_fun(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% fun-expression, otherwise false. %% %% @see c_fun/2 is_c_fun(#'fun'{}) -> true; % Now this is fun! is_c_fun(_) -> false. %% @spec fun_vars(cerl()) -> [cerl()] %% %% @doc Returns the list of parameter subtrees of an abstract %% fun-expression. %% %% @see c_fun/2 %% @see fun_arity/1 fun_vars(Node) -> Node#'fun'.vars. %% @spec fun_body(cerl()) -> cerl() %% %% @doc Returns the body subtree of an abstract fun-expression. %% %% @see c_fun/2 fun_body(Node) -> Node#'fun'.body. %% @spec fun_arity(Node::cerl()) -> integer() %% %% @doc Returns the number of parameter subtrees of an abstract %% fun-expression. %% %%

Note: this is equivalent to length(fun_vars(Node)), %% but potentially more efficient.

%% %% @see c_fun/2 %% @see fun_vars/1 fun_arity(Node) -> length(fun_vars(Node)). %% --------------------------------------------------------------------- %% @spec c_seq(Argument::cerl(), Body::cerl()) -> cerl() %% %% @doc Creates an abstract sequencing expression. The result %% represents "do Argument Body". %% %% @see ann_c_seq/3 %% @see update_c_seq/3 %% @see is_c_seq/1 %% @see seq_arg/1 %% @see seq_body/1 -record(seq, {ann = [], arg, body}). c_seq(Argument, Body) -> #seq{arg = Argument, body = Body}. %% @spec ann_c_seq(As::[term()], Argument::cerl(), Body::cerl()) -> %% cerl() %% @see c_seq/2 ann_c_seq(As, Argument, Body) -> #seq{arg = Argument, body = Body, ann = As}. %% @spec update_c_seq(Old::cerl(), Argument::cerl(), Body::cerl()) -> %% cerl() %% @see c_seq/2 update_c_seq(Node, Argument, Body) -> #seq{arg = Argument, body = Body, ann = get_ann(Node)}. %% @spec is_c_seq(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% sequencing expression, otherwise false. %% %% @see c_seq/2 is_c_seq(#seq{}) -> true; is_c_seq(_) -> false. %% @spec seq_arg(cerl()) -> cerl() %% %% @doc Returns the argument subtree of an abstract sequencing %% expression. %% %% @see c_seq/2 seq_arg(Node) -> Node#seq.arg. %% @spec seq_body(cerl()) -> cerl() %% %% @doc Returns the body subtree of an abstract sequencing expression. %% %% @see c_seq/2 seq_body(Node) -> Node#seq.body. %% --------------------------------------------------------------------- %% @spec c_let(Variables::[cerl()], Argument::cerl(), Body::cerl()) -> %% cerl() %% %% @doc Creates an abstract let-expression. If Variables %% is [V1, ..., Vn], the result represents "let %% <V1, ..., Vn> = Argument in %% Body". All the Vi must have type %% var. %% %% @see ann_c_let/4 %% @see update_c_let/4 %% @see is_c_let/1 %% @see let_vars/1 %% @see let_arg/1 %% @see let_body/1 %% @see let_arity/1 -record('let', {ann = [], vars, arg, body}). c_let(Variables, Argument, Body) -> #'let'{vars = Variables, arg = Argument, body = Body}. %% ann_c_let(As, Variables, Argument, Body) -> Node %% @see c_let/3 ann_c_let(As, Variables, Argument, Body) -> #'let'{vars = Variables, arg = Argument, body = Body, ann = As}. %% update_c_let(Old, Variables, Argument, Body) -> Node %% @see c_let/3 update_c_let(Node, Variables, Argument, Body) -> #'let'{vars = Variables, arg = Argument, body = Body, ann = get_ann(Node)}. %% @spec is_c_let(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% let-expression, otherwise false. %% %% @see c_let/3 is_c_let(#'let'{}) -> true; is_c_let(_) -> false. %% @spec let_vars(cerl()) -> [cerl()] %% %% @doc Returns the list of left-hand side variables of an abstract %% let-expression. %% %% @see c_let/3 %% @see let_arity/1 let_vars(Node) -> Node#'let'.vars. %% @spec let_arg(cerl()) -> cerl() %% %% @doc Returns the argument subtree of an abstract let-expression. %% %% @see c_let/3 let_arg(Node) -> Node#'let'.arg. %% @spec let_body(cerl()) -> cerl() %% %% @doc Returns the body subtree of an abstract let-expression. %% %% @see c_let/3 let_body(Node) -> Node#'let'.body. %% @spec let_arity(Node::cerl()) -> integer() %% %% @doc Returns the number of left-hand side variables of an abstract %% let-expression. %% %%

Note: this is equivalent to length(let_vars(Node)), %% but potentially more efficient.

%% %% @see c_let/3 %% @see let_vars/1 let_arity(Node) -> length(let_vars(Node)). %% --------------------------------------------------------------------- %% @spec c_letrec(Definitions::[{cerl(), cerl()}], Body::cerl()) -> %% cerl() %% %% @doc Creates an abstract letrec-expression. If %% Definitions is [{V1, F1}, ..., {Vn, Fn}], %% the result represents "letrec V1 = F1 %% ... Vn = Fn in Body. All the %% Vi must have type var and represent %% function names. All the Fi must have type %% 'fun'. %% %% @see ann_c_letrec/3 %% @see update_c_letrec/3 %% @see is_c_letrec/1 %% @see letrec_defs/1 %% @see letrec_body/1 %% @see letrec_vars/1 -record(letrec, {ann = [], defs, body}). c_letrec(Defs, Body) -> #letrec{defs = Defs, body = Body}. %% @spec ann_c_letrec(As::[term()], Definitions::[{cerl(), cerl()}], %% Body::cerl()) -> cerl() %% @see c_letrec/2 ann_c_letrec(As, Defs, Body) -> #letrec{defs = Defs, body = Body, ann = As}. %% @spec update_c_letrec(Old::cerl(), %% Definitions::[{cerl(), cerl()}], %% Body::cerl()) -> cerl() %% @see c_letrec/2 update_c_letrec(Node, Defs, Body) -> #letrec{defs = Defs, body = Body, ann = get_ann(Node)}. %% @spec is_c_letrec(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% letrec-expression, otherwise false. %% %% @see c_letrec/2 is_c_letrec(#letrec{}) -> true; is_c_letrec(_) -> false. %% @spec letrec_defs(Node::cerl()) -> [{cerl(), cerl()}] %% %% @doc Returns the list of definitions of an abstract %% letrec-expression. If Node represents "letrec %% V1 = F1 ... Vn = Fn in %% Body", the returned value is [{V1, F1}, ..., %% {Vn, Fn}]. %% %% @see c_letrec/2 letrec_defs(Node) -> Node#letrec.defs. %% @spec letrec_body(cerl()) -> cerl() %% %% @doc Returns the body subtree of an abstract letrec-expression. %% %% @see c_letrec/2 letrec_body(Node) -> Node#letrec.body. %% @spec letrec_vars(cerl()) -> [cerl()] %% %% @doc Returns the list of left-hand side function variable subtrees %% of a letrec-expression. If Node represents %% "letrec V1 = F1 ... Vn = %% Fn in Body", the returned value is %% [V1, ..., Vn]. %% %% @see c_letrec/2 letrec_vars(Node) -> [F || {F, _} <- letrec_defs(Node)]. %% --------------------------------------------------------------------- %% @spec c_case(Argument::cerl(), Clauses::[cerl()]) -> cerl() %% %% @doc Creates an abstract case-expression. If Clauses %% is [C1, ..., Cn], the result represents "case %% Argument of C1 ... Cn %% end". Clauses must not be empty. %% %% @see ann_c_case/3 %% @see update_c_case/3 %% @see is_c_case/1 %% @see c_clause/3 %% @see case_arg/1 %% @see case_clauses/1 %% @see case_arity/1 -record('case', {ann = [], arg, clauses}). c_case(Expr, Clauses) -> #'case'{arg = Expr, clauses = Clauses}. %% @spec ann_c_case(As::[term()], Argument::cerl(), %% Clauses::[cerl()]) -> cerl() %% @see c_case/2 ann_c_case(As, Expr, Clauses) -> #'case'{arg = Expr, clauses = Clauses, ann = As}. %% @spec update_c_case(Old::cerl(), Argument::cerl(), %% Clauses::[cerl()]) -> cerl() %% @see c_case/2 update_c_case(Node, Expr, Clauses) -> #'case'{arg = Expr, clauses = Clauses, ann = get_ann(Node)}. %% is_c_case(Node) -> boolean() %% %% Node = cerl() %% %% @doc Returns true if Node is an abstract %% case-expression; otherwise false. %% %% @see c_case/2 is_c_case(#'case'{}) -> true; is_c_case(_) -> false. %% @spec case_arg(cerl()) -> cerl() %% %% @doc Returns the argument subtree of an abstract case-expression. %% %% @see c_case/2 case_arg(Node) -> Node#'case'.arg. %% @spec case_clauses(cerl()) -> [cerl()] %% %% @doc Returns the list of clause subtrees of an abstract %% case-expression. %% %% @see c_case/2 %% @see case_arity/1 case_clauses(Node) -> Node#'case'.clauses. %% @spec case_arity(Node::cerl()) -> integer() %% %% @doc Equivalent to %% clause_arity(hd(case_clauses(Node))), but potentially %% more efficient. %% %% @see c_case/2 %% @see case_clauses/1 %% @see clause_arity/1 case_arity(Node) -> clause_arity(hd(case_clauses(Node))). %% --------------------------------------------------------------------- %% @spec c_clause(Patterns::[cerl()], Body::cerl()) -> cerl() %% @equiv c_clause(Patterns, c_atom(true), Body) %% @see c_atom/1 c_clause(Patterns, Body) -> c_clause(Patterns, c_atom(true), Body). %% @spec c_clause(Patterns::[cerl()], Guard::cerl(), Body::cerl()) -> %% cerl() %% %% @doc Creates an an abstract clause. If Patterns is %% [P1, ..., Pn], the result represents %% "<P1, ..., Pn> when Guard -> %% Body". %% %% @see c_clause/2 %% @see ann_c_clause/4 %% @see update_c_clause/4 %% @see is_c_clause/1 %% @see c_case/2 %% @see c_receive/3 %% @see clause_pats/1 %% @see clause_guard/1 %% @see clause_body/1 %% @see clause_arity/1 %% @see clause_vars/1 -record(clause, {ann = [], pats, guard, body}). c_clause(Patterns, Guard, Body) -> #clause{pats = Patterns, guard = Guard, body = Body}. %% @spec ann_c_clause(As::[term()], Patterns::[cerl()], %% Body::cerl()) -> cerl() %% @equiv ann_c_clause(As, Patterns, c_atom(true), Body) %% @see c_clause/3 ann_c_clause(As, Patterns, Body) -> ann_c_clause(As, Patterns, c_atom(true), Body). %% @spec ann_c_clause(As::[term()], Patterns::[cerl()], Guard::cerl(), %% Body::cerl()) -> cerl() %% @see ann_c_clause/3 %% @see c_clause/3 ann_c_clause(As, Patterns, Guard, Body) -> #clause{pats = Patterns, guard = Guard, body = Body, ann = As}. %% @spec update_c_clause(Old::cerl(), Patterns::[cerl()], %% Guard::cerl(), Body::cerl()) -> cerl() %% @see c_clause/3 update_c_clause(Node, Patterns, Guard, Body) -> #clause{pats = Patterns, guard = Guard, body = Body, ann = get_ann(Node)}. %% @spec is_c_clause(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% clause, otherwise false. %% %% @see c_clause/3 is_c_clause(#clause{}) -> true; is_c_clause(_) -> false. %% @spec clause_pats(cerl()) -> [cerl()] %% %% @doc Returns the list of pattern subtrees of an abstract clause. %% %% @see c_clause/3 %% @see clause_arity/1 clause_pats(Node) -> Node#clause.pats. %% @spec clause_guard(cerl()) -> cerl() %% %% @doc Returns the guard subtree of an abstract clause. %% %% @see c_clause/3 clause_guard(Node) -> Node#clause.guard. %% @spec clause_body(cerl()) -> cerl() %% %% @doc Returns the body subtree of an abstract clause. %% %% @see c_clause/3 clause_body(Node) -> Node#clause.body. %% @spec clause_arity(Node::cerl()) -> integer() %% %% @doc Returns the number of pattern subtrees of an abstract clause. %% %%

Note: this is equivalent to %% length(clause_pats(Node)), but potentially more %% efficient.

%% %% @see c_clause/3 %% @see clause_pats/1 clause_arity(Node) -> length(clause_pats(Node)). %% @spec clause_vars(cerl()) -> [cerl()] %% %% @doc Returns the list of all abstract variables in the patterns of %% an abstract clause. The order of listing is not defined. %% %% @see c_clause/3 %% @see pat_list_vars/1 clause_vars(Clause) -> pat_list_vars(clause_pats(Clause)). %% @spec pat_vars(Pattern::cerl()) -> [cerl()] %% %% @doc Returns the list of all abstract variables in a pattern. An %% exception is thrown if Node does not represent a %% well-formed Core Erlang clause pattern. The order of listing is not %% defined. %% %% @see pat_list_vars/1 %% @see clause_vars/1 pat_vars(Node) -> pat_vars(Node, []). pat_vars(Node, Vs) -> case type(Node) of var -> [Node | Vs]; literal -> Vs; cons -> pat_vars(cons_hd(Node), pat_vars(cons_tl(Node), Vs)); tuple -> pat_list_vars(tuple_es(Node), Vs); binary -> pat_list_vars(binary_segments(Node), Vs); bitstr -> pat_vars(bitstr_val(Node), Vs); alias -> pat_vars(alias_pat(Node), [alias_var(Node) | Vs]) end. %% @spec pat_list_vars(Patterns::[cerl()]) -> [cerl()] %% %% @doc Returns the list of all abstract variables in the given %% patterns. An exception is thrown if some element in %% Patterns does not represent a well-formed Core Erlang %% clause pattern. The order of listing is not defined. %% %% @see pat_vars/1 %% @see clause_vars/1 pat_list_vars(Ps) -> pat_list_vars(Ps, []). pat_list_vars([P | Ps], Vs) -> pat_list_vars(Ps, pat_vars(P, Vs)); pat_list_vars([], Vs) -> Vs. %% --------------------------------------------------------------------- %% @spec c_alias(Variable::cerl(), Pattern::cerl()) -> cerl() %% %% @doc Creates an abstract pattern alias. The result represents %% "Variable = Pattern". %% %% @see ann_c_alias/3 %% @see update_c_alias/3 %% @see is_c_alias/1 %% @see alias_var/1 %% @see alias_pat/1 %% @see c_clause/3 -record(alias, {ann = [], var, pat}). c_alias(Var, Pattern) -> #alias{var = Var, pat = Pattern}. %% @spec ann_c_alias(As::[term()], Variable::cerl(), %% Pattern::cerl()) -> cerl() %% @see c_alias/2 ann_c_alias(As, Var, Pattern) -> #alias{var = Var, pat = Pattern, ann = As}. %% @spec update_c_alias(Old::cerl(), Variable::cerl(), %% Pattern::cerl()) -> cerl() %% @see c_alias/2 update_c_alias(Node, Var, Pattern) -> #alias{var = Var, pat = Pattern, ann = get_ann(Node)}. %% @spec is_c_alias(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% pattern alias, otherwise false. %% %% @see c_alias/2 is_c_alias(#alias{}) -> true; is_c_alias(_) -> false. %% @spec alias_var(cerl()) -> cerl() %% %% @doc Returns the variable subtree of an abstract pattern alias. %% %% @see c_alias/2 alias_var(Node) -> Node#alias.var. %% @spec alias_pat(cerl()) -> cerl() %% %% @doc Returns the pattern subtree of an abstract pattern alias. %% %% @see c_alias/2 alias_pat(Node) -> Node#alias.pat. %% --------------------------------------------------------------------- %% @spec c_receive(Clauses::[cerl()]) -> cerl() %% @equiv c_receive(Clauses, c_atom(infinity), c_atom(true)) %% @see c_atom/1 c_receive(Clauses) -> c_receive(Clauses, c_atom(infinity), c_atom(true)). %% @spec c_receive(Clauses::[cerl()], Timeout::cerl(), %% Action::cerl()) -> cerl() %% %% @doc Creates an abstract receive-expression. If %% Clauses is [C1, ..., Cn], the result %% represents "receive C1 ... Cn after %% Timeout -> Action end". %% %% @see c_receive/1 %% @see ann_c_receive/4 %% @see update_c_receive/4 %% @see is_c_receive/1 %% @see receive_clauses/1 %% @see receive_timeout/1 %% @see receive_action/1 -record('receive', {ann = [], clauses, timeout, action}). c_receive(Clauses, Timeout, Action) -> #'receive'{clauses = Clauses, timeout = Timeout, action = Action}. %% @spec ann_c_receive(As::[term()], Clauses::[cerl()]) -> cerl() %% @equiv ann_c_receive(As, Clauses, c_atom(infinity), c_atom(true)) %% @see c_receive/3 %% @see c_atom/1 ann_c_receive(As, Clauses) -> ann_c_receive(As, Clauses, c_atom(infinity), c_atom(true)). %% @spec ann_c_receive(As::[term()], Clauses::[cerl()], %% Timeout::cerl(), Action::cerl()) -> cerl() %% @see ann_c_receive/2 %% @see c_receive/3 ann_c_receive(As, Clauses, Timeout, Action) -> #'receive'{clauses = Clauses, timeout = Timeout, action = Action, ann = As}. %% @spec update_c_receive(Old::cerl(), Clauses::[cerl()], %% Timeout::cerl(), Action::cerl()) -> cerl() %% @see c_receive/3 update_c_receive(Node, Clauses, Timeout, Action) -> #'receive'{clauses = Clauses, timeout = Timeout, action = Action, ann = get_ann(Node)}. %% @spec is_c_receive(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% receive-expression, otherwise false. %% %% @see c_receive/3 is_c_receive(#'receive'{}) -> true; is_c_receive(_) -> false. %% @spec receive_clauses(cerl()) -> [cerl()] %% %% @doc Returns the list of clause subtrees of an abstract %% receive-expression. %% %% @see c_receive/3 receive_clauses(Node) -> Node#'receive'.clauses. %% @spec receive_timeout(cerl()) -> cerl() %% %% @doc Returns the timeout subtree of an abstract receive-expression. %% %% @see c_receive/3 receive_timeout(Node) -> Node#'receive'.timeout. %% @spec receive_action(cerl()) -> cerl() %% %% @doc Returns the action subtree of an abstract receive-expression. %% %% @see c_receive/3 receive_action(Node) -> Node#'receive'.action. %% --------------------------------------------------------------------- %% @spec c_apply(Operator::cerl(), Arguments::[cerl()]) -> cerl() %% %% @doc Creates an abstract function application. If %% Arguments is [A1, ..., An], the result %% represents "apply Operator(A1, ..., %% An)". %% %% @see ann_c_apply/3 %% @see update_c_apply/3 %% @see is_c_apply/1 %% @see apply_op/1 %% @see apply_args/1 %% @see apply_arity/1 %% @see c_call/3 %% @see c_primop/2 -record(apply, {ann = [], op, args}). c_apply(Operator, Arguments) -> #apply{op = Operator, args = Arguments}. %% @spec ann_c_apply(As::[term()], Operator::cerl(), %% Arguments::[cerl()]) -> cerl() %% @see c_apply/2 ann_c_apply(As, Operator, Arguments) -> #apply{op = Operator, args = Arguments, ann = As}. %% @spec update_c_apply(Old::cerl(), Operator::cerl(), %% Arguments::[cerl()]) -> cerl() %% @see c_apply/2 update_c_apply(Node, Operator, Arguments) -> #apply{op = Operator, args = Arguments, ann = get_ann(Node)}. %% @spec is_c_apply(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% function application, otherwise false. %% %% @see c_apply/2 is_c_apply(#apply{}) -> true; is_c_apply(_) -> false. %% @spec apply_op(cerl()) -> cerl() %% %% @doc Returns the operator subtree of an abstract function %% application. %% %% @see c_apply/2 apply_op(Node) -> Node#apply.op. %% @spec apply_args(cerl()) -> [cerl()] %% %% @doc Returns the list of argument subtrees of an abstract function %% application. %% %% @see c_apply/2 %% @see apply_arity/1 apply_args(Node) -> Node#apply.args. %% @spec apply_arity(Node::cerl()) -> integer() %% %% @doc Returns the number of argument subtrees of an abstract %% function application. %% %%

Note: this is equivalent to %% length(apply_args(Node)), but potentially more %% efficient.

%% %% @see c_apply/2 %% @see apply_args/1 apply_arity(Node) -> length(apply_args(Node)). %% --------------------------------------------------------------------- %% @spec c_call(Module::cerl(), Name::cerl(), Arguments::[cerl()]) -> %% cerl() %% %% @doc Creates an abstract inter-module call. If %% Arguments is [A1, ..., An], the result %% represents "call Module:Name(A1, %% ..., An)". %% %% @see ann_c_call/4 %% @see update_c_call/4 %% @see is_c_call/1 %% @see call_module/1 %% @see call_name/1 %% @see call_args/1 %% @see call_arity/1 %% @see c_apply/2 %% @see c_primop/2 -record(call, {ann = [], module, name, args}). c_call(Module, Name, Arguments) -> #call{module = Module, name = Name, args = Arguments}. %% @spec ann_c_call(As::[term()], Module::cerl(), Name::cerl(), %% Arguments::[cerl()]) -> cerl() %% @see c_call/3 ann_c_call(As, Module, Name, Arguments) -> #call{module = Module, name = Name, args = Arguments, ann = As}. %% @spec update_c_call(Old::cerl(), Module::cerl(), Name::cerl(), %% Arguments::[cerl()]) -> cerl() %% @see c_call/3 update_c_call(Node, Module, Name, Arguments) -> #call{module = Module, name = Name, args = Arguments, ann = get_ann(Node)}. %% @spec is_c_call(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% inter-module call expression; otherwise false. %% %% @see c_call/3 is_c_call(#call{}) -> true; is_c_call(_) -> false. %% @spec call_module(cerl()) -> cerl() %% %% @doc Returns the module subtree of an abstract inter-module call. %% %% @see c_call/3 call_module(Node) -> Node#call.module. %% @spec call_name(cerl()) -> cerl() %% %% @doc Returns the name subtree of an abstract inter-module call. %% %% @see c_call/3 call_name(Node) -> Node#call.name. %% @spec call_args(cerl()) -> [cerl()] %% %% @doc Returns the list of argument subtrees of an abstract %% inter-module call. %% %% @see c_call/3 %% @see call_arity/1 call_args(Node) -> Node#call.args. %% @spec call_arity(Node::cerl()) -> integer() %% %% @doc Returns the number of argument subtrees of an abstract %% inter-module call. %% %%

Note: this is equivalent to %% length(call_args(Node)), but potentially more %% efficient.

%% %% @see c_call/3 %% @see call_args/1 call_arity(Node) -> length(call_args(Node)). %% --------------------------------------------------------------------- %% @spec c_primop(Name::cerl(), Arguments::[cerl()]) -> cerl() %% %% @doc Creates an abstract primitive operation call. If %% Arguments is [A1, ..., An], the result %% represents "primop Name(A1, ..., %% An)". Name must be an atom literal. %% %% @see ann_c_primop/3 %% @see update_c_primop/3 %% @see is_c_primop/1 %% @see primop_name/1 %% @see primop_args/1 %% @see primop_arity/1 %% @see c_apply/2 %% @see c_call/3 -record(primop, {ann = [], name, args}). c_primop(Name, Arguments) -> #primop{name = Name, args = Arguments}. %% @spec ann_c_primop(As::[term()], Name::cerl(), %% Arguments::[cerl()]) -> cerl() %% @see c_primop/2 ann_c_primop(As, Name, Arguments) -> #primop{name = Name, args = Arguments, ann = As}. %% @spec update_c_primop(Old::cerl(), Name::cerl(), %% Arguments::[cerl()]) -> cerl() %% @see c_primop/2 update_c_primop(Node, Name, Arguments) -> #primop{name = Name, args = Arguments, ann = get_ann(Node)}. %% @spec is_c_primop(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% primitive operation call, otherwise false. %% %% @see c_primop/2 is_c_primop(#primop{}) -> true; is_c_primop(_) -> false. %% @spec primop_name(cerl()) -> cerl() %% %% @doc Returns the name subtree of an abstract primitive operation %% call. %% %% @see c_primop/2 primop_name(Node) -> Node#primop.name. %% @spec primop_args(cerl()) -> [cerl()] %% %% @doc Returns the list of argument subtrees of an abstract primitive %% operation call. %% %% @see c_primop/2 %% @see primop_arity/1 primop_args(Node) -> Node#primop.args. %% @spec primop_arity(Node::cerl()) -> integer() %% %% @doc Returns the number of argument subtrees of an abstract %% primitive operation call. %% %%

Note: this is equivalent to %% length(primop_args(Node)), but potentially more %% efficient.

%% %% @see c_primop/2 %% @see primop_args/1 primop_arity(Node) -> length(primop_args(Node)). %% --------------------------------------------------------------------- %% @spec c_try(Argument::cerl(), Variables::[cerl()], Body::cerl(), %% ExceptionVars::[cerl()], Handler::cerl()) -> cerl() %% %% @doc Creates an abstract try-expression. If Variables is %% [V1, ..., Vn] and ExceptionVars is %% [X1, ..., Xm], the result represents "try %% Argument of <V1, ..., Vn> -> %% Body catch <X1, ..., Xm> -> %% Handler". All the Vi and Xi %% must have type var. %% %% @see ann_c_try/6 %% @see update_c_try/6 %% @see is_c_try/1 %% @see try_arg/1 %% @see try_vars/1 %% @see try_body/1 %% @see c_catch/1 -record('try', {ann = [], arg, vars, body, evars, handler}). c_try(Expr, Vs, Body, Evs, Handler) -> #'try'{arg = Expr, vars = Vs, body = Body, evars = Evs, handler = Handler}. %% @spec ann_c_try(As::[term()], Expression::cerl(), %% Variables::[cerl()], Body::cerl(), %% EVars::[cerl()], EBody::[cerl()]) -> cerl() %% @see c_try/3 ann_c_try(As, Expr, Vs, Body, Evs, Handler) -> #'try'{arg = Expr, vars = Vs, body = Body, evars = Evs, handler = Handler, ann = As}. %% @spec update_c_try(Old::cerl(), Expression::cerl(), %% Variables::[cerl()], Body::cerl(), %% EVars::[cerl()], EBody::[cerl()]) -> cerl() %% @see c_try/3 update_c_try(Node, Expr, Vs, Body, Evs, Handler) -> #'try'{arg = Expr, vars = Vs, body = Body, evars = Evs, handler = Handler, ann = get_ann(Node)}. %% @spec is_c_try(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% try-expression, otherwise false. %% %% @see c_try/3 is_c_try(#'try'{}) -> true; is_c_try(_) -> false. %% @spec try_arg(cerl()) -> cerl() %% %% @doc Returns the expression subtree of an abstract try-expression. %% %% @see c_try/3 try_arg(Node) -> Node#'try'.arg. %% @spec try_vars(cerl()) -> [cerl()] %% %% @doc Returns the list of success variable subtrees of an abstract %% try-expression. %% %% @see c_try/3 try_vars(Node) -> Node#'try'.vars. %% @spec try_body(cerl()) -> cerl() %% %% @doc Returns the success body subtree of an abstract try-expression. %% %% @see c_try/3 try_body(Node) -> Node#'try'.body. %% @spec try_evars(cerl()) -> [cerl()] %% %% @doc Returns the list of exception variable subtrees of an abstract %% try-expression. %% %% @see c_try/3 try_evars(Node) -> Node#'try'.evars. %% @spec try_handler(cerl()) -> cerl() %% %% @doc Returns the exception body subtree of an abstract %% try-expression. %% %% @see c_try/3 try_handler(Node) -> Node#'try'.handler. %% --------------------------------------------------------------------- %% @spec c_catch(Body::cerl()) -> cerl() %% %% @doc Creates an abstract catch-expression. The result represents %% "catch Body". %% %%

Note: catch-expressions can be rewritten as try-expressions, and %% will eventually be removed from Core Erlang.

%% %% @see ann_c_catch/2 %% @see update_c_catch/2 %% @see is_c_catch/1 %% @see catch_body/1 %% @see c_try/3 -record('catch', {ann = [], body}). c_catch(Body) -> #'catch'{body = Body}. %% @spec ann_c_catch(As::[term()], Body::cerl()) -> cerl() %% @see c_catch/1 ann_c_catch(As, Body) -> #'catch'{body = Body, ann = As}. %% @spec update_c_catch(Old::cerl(), Body::cerl()) -> cerl() %% @see c_catch/1 update_c_catch(Node, Body) -> #'catch'{body = Body, ann = get_ann(Node)}. %% @spec is_c_catch(Node::cerl()) -> boolean() %% %% @doc Returns true if Node is an abstract %% catch-expression, otherwise false. %% %% @see c_catch/1 is_c_catch(#'catch'{}) -> true; is_c_catch(_) -> false. %% @spec catch_body(Node::cerl()) -> cerl() %% %% @doc Returns the body subtree of an abstract catch-expression. %% %% @see c_catch/1 catch_body(Node) -> Node#'catch'.body. %% --------------------------------------------------------------------- %% @spec to_records(Tree::cerl()) -> record(record_types()) %% %% @doc Translates an abstract syntax tree to a corresponding explicit %% record representation. The records are defined in the file %% "cerl.hrl". %% %%

Note: Compound constant literals are always unfolded in the %% record representation.

%% %% @see type/1 %% @see from_records/1 to_records(Node) -> A = get_ann(Node), case type(Node) of literal -> lit_to_records(concrete(Node), A); binary -> #c_binary{anno = A, segments = list_to_records(binary_segments(Node))}; bitstr -> #c_bitstr{anno = A, val = to_records(bitstr_val(Node)), size = to_records(bitstr_size(Node)), unit = to_records(bitstr_unit(Node)), type = to_records(bitstr_type(Node)), flags = to_records(bitstr_flags(Node))}; cons -> #c_cons{anno = A, hd = to_records(cons_hd(Node)), tl = to_records(cons_tl(Node))}; tuple -> #c_tuple{anno = A, es = list_to_records(tuple_es(Node))}; var -> case is_c_fname(Node) of true -> #c_fname{anno = A, id = fname_id(Node), arity = fname_arity(Node)}; false -> #c_var{anno = A, name = var_name(Node)} end; values -> #c_values{anno = A, es = list_to_records(values_es(Node))}; 'fun' -> #c_fun{anno = A, vars = list_to_records(fun_vars(Node)), body = to_records(fun_body(Node))}; seq -> #c_seq{anno = A, arg = to_records(seq_arg(Node)), body = to_records(seq_body(Node))}; 'let' -> #c_let{anno = A, vars = list_to_records(let_vars(Node)), arg = to_records(let_arg(Node)), body = to_records(let_body(Node))}; letrec -> #c_letrec{anno = A, defs = [#c_def{name = to_records(N), val = to_records(F)} || {N, F} <- letrec_defs(Node)], body = to_records(letrec_body(Node))}; 'case' -> #c_case{anno = A, arg = to_records(case_arg(Node)), clauses = list_to_records(case_clauses(Node))}; clause -> #c_clause{anno = A, pats = list_to_records(clause_pats(Node)), guard = to_records(clause_guard(Node)), body = to_records(clause_body(Node))}; alias -> #c_alias{anno = A, var = to_records(alias_var(Node)), pat = to_records(alias_pat(Node))}; 'receive' -> #c_receive{anno = A, clauses = list_to_records(receive_clauses(Node)), timeout = to_records(receive_timeout(Node)), action = to_records(receive_action(Node))}; apply -> #c_apply{anno = A, op = to_records(apply_op(Node)), args = list_to_records(apply_args(Node))}; call -> #c_call{anno = A, module = to_records(call_module(Node)), name = to_records(call_name(Node)), args = list_to_records(call_args(Node))}; primop -> #c_primop{anno = A, name = to_records(primop_name(Node)), args = list_to_records(primop_args(Node))}; 'try' -> #c_try{anno = A, arg = to_records(try_arg(Node)), vars = list_to_records(try_vars(Node)), body = to_records(try_body(Node)), evars = list_to_records(try_evars(Node)), handler = to_records(try_handler(Node))}; 'catch' -> #c_catch{anno = A, body = to_records(catch_body(Node))}; module -> #c_module{anno = A, name = to_records(module_name(Node)), exports = list_to_records( module_exports(Node)), attrs = [#c_def{name = to_records(K), val = to_records(V)} || {K, V} <- module_attrs(Node)], defs = [#c_def{name = to_records(N), val = to_records(F)} || {N, F} <- module_defs(Node)]} end. list_to_records([T | Ts]) -> [to_records(T) | list_to_records(Ts)]; list_to_records([]) -> []. lit_to_records(V, A) when integer(V) -> #c_int{anno = A, val = V}; lit_to_records(V, A) when float(V) -> #c_float{anno = A, val = V}; lit_to_records(V, A) when atom(V) -> #c_atom{anno = A, val = V}; lit_to_records([H | T] = V, A) -> case is_print_char_list(V) of true -> #c_string{anno = A, val = V}; false -> #c_cons{anno = A, hd = lit_to_records(H, []), tl = lit_to_records(T, [])} end; lit_to_records([], A) -> #c_nil{anno = A}; lit_to_records(V, A) when tuple(V) -> #c_tuple{anno = A, es = lit_list_to_records(tuple_to_list(V))}. lit_list_to_records([T | Ts]) -> [lit_to_records(T, []) | lit_list_to_records(Ts)]; lit_list_to_records([]) -> []. %% @spec from_records(Tree::record(record_types())) -> cerl() %% %% record_types() = c_alias | c_apply | c_call | c_case | c_catch | %% c_clause | c_cons | c_def| c_fun | c_let | %% c_letrec |c_lit | c_module | c_primop | %% c_receive | c_seq | c_try | c_tuple | %% c_values | c_var %% %% @doc Translates an explicit record representation to a %% corresponding abstract syntax tree. The records are defined in the %% file "cerl.hrl". %% %%

Note: Compound constant literals are folded, discarding %% annotations on subtrees. There are no c_def nodes in %% the abstract representation; annotations on c_def %% records are discarded.

%% %% @see type/1 %% @see to_records/1 from_records(#c_int{val = V, anno = As}) -> ann_c_int(As, V); from_records(#c_float{val = V, anno = As}) -> ann_c_float(As, V); from_records(#c_atom{val = V, anno = As}) -> ann_c_atom(As, V); from_records(#c_char{val = V, anno = As}) -> ann_c_char(As, V); from_records(#c_string{val = V, anno = As}) -> ann_c_string(As, V); from_records(#c_nil{anno = As}) -> ann_c_nil(As); from_records(#c_binary{segments = Ss, anno = As}) -> ann_c_binary(As, from_records_list(Ss)); from_records(#c_bitstr{val = V, size = S, unit = U, type = T, flags = Fs, anno = As}) -> ann_c_bitstr(As, from_records(V), from_records(S), from_records(U), from_records(T), from_records(Fs)); from_records(#c_cons{hd = H, tl = T, anno = As}) -> ann_c_cons(As, from_records(H), from_records(T)); from_records(#c_tuple{es = Es, anno = As}) -> ann_c_tuple(As, from_records_list(Es)); from_records(#c_var{name = Name, anno = As}) -> ann_c_var(As, Name); from_records(#c_fname{id = Id, arity = Arity, anno = As}) -> ann_c_fname(As, Id, Arity); from_records(#c_values{es = Es, anno = As}) -> ann_c_values(As, from_records_list(Es)); from_records(#c_fun{vars = Vs, body = B, anno = As}) -> ann_c_fun(As, from_records_list(Vs), from_records(B)); from_records(#c_seq{arg = A, body = B, anno = As}) -> ann_c_seq(As, from_records(A), from_records(B)); from_records(#c_let{vars = Vs, arg = A, body = B, anno = As}) -> ann_c_let(As, from_records_list(Vs), from_records(A), from_records(B)); from_records(#c_letrec{defs = Fs, body = B, anno = As}) -> ann_c_letrec(As, [{from_records(N), from_records(F)} || #c_def{name = N, val = F} <- Fs], from_records(B)); from_records(#c_case{arg = A, clauses = Cs, anno = As}) -> ann_c_case(As, from_records(A), from_records_list(Cs)); from_records(#c_clause{pats = Ps, guard = G, body = B, anno = As}) -> ann_c_clause(As, from_records_list(Ps), from_records(G), from_records(B)); from_records(#c_alias{var = V, pat = P, anno = As}) -> ann_c_alias(As, from_records(V), from_records(P)); from_records(#c_receive{clauses = Cs, timeout = T, action = A, anno = As}) -> ann_c_receive(As, from_records_list(Cs), from_records(T), from_records(A)); from_records(#c_apply{op = Op, args = Es, anno = As}) -> ann_c_apply(As, from_records(Op), from_records_list(Es)); from_records(#c_call{module = M, name = N, args = Es, anno = As}) -> ann_c_call(As, from_records(M), from_records(N), from_records_list(Es)); from_records(#c_primop{name = N, args = Es, anno = As}) -> ann_c_primop(As, from_records(N), from_records_list(Es)); from_records(#c_try{arg = E, vars = Vs, body = B, evars = Evs, handler = H, anno = As}) -> ann_c_try(As, from_records(E), from_records_list(Vs), from_records(B), from_records_list(Evs), from_records(H)); from_records(#c_catch{body = B, anno = As}) -> ann_c_catch(As, from_records(B)); from_records(#c_module{name = N, exports = Es, attrs = Ds, defs = Fs, anno = As}) -> ann_c_module(As, from_records(N), from_records_list(Es), [{from_records(K), from_records(V)} || #c_def{name = K, val = V} <- Ds], [{from_records(V), from_records(F)} || #c_def{name = V, val = F} <- Fs]). from_records_list([T | Ts]) -> [from_records(T) | from_records_list(Ts)]; from_records_list([]) -> []. %% --------------------------------------------------------------------- %% @spec is_data(Node::cerl()) -> boolean() %% %% @doc Returns true if Node represents a %% data constructor, otherwise false. Data constructors %% are cons cells, tuples, and atomic literals. %% %% @see data_type/1 %% @see data_es/1 %% @see data_arity/1 is_data(#literal{}) -> true; is_data(#cons{}) -> true; is_data(#tuple{}) -> true; is_data(_) -> false. %% @spec data_type(Node::cerl()) -> dtype() %% %% dtype() = cons | tuple | {'atomic', Value} %% Value = integer() | float() | atom() | [] %% %% @doc Returns a type descriptor for a data constructor %% node. (Cf. is_data/1.) This is mainly useful for %% comparing types and for constructing new nodes of the same type %% (cf. make_data/2). If Node represents an %% integer, floating-point number, atom or empty list, the result is %% {'atomic', Value}, where Value is the value %% of concrete(Node), otherwise the result is either %% cons or tuple. %% %%

Type descriptors can be compared for equality or order (in the %% Erlang term order), but remember that floating-point values should %% in general never be tested for equality.

%% %% @see is_data/1 %% @see make_data/2 %% @see type/1 %% @see concrete/1 data_type(#literal{val = V}) -> case V of [_ | _] -> cons; _ when tuple(V) -> tuple; _ -> {'atomic', V} end; data_type(#cons{}) -> cons; data_type(#tuple{}) -> tuple. %% @spec data_es(Node::cerl()) -> [cerl()] %% %% @doc Returns the list of subtrees of a data constructor node. If %% the arity of the constructor is zero, the result is the empty list. %% %%

Note: if data_type(Node) is cons, the %% number of subtrees is exactly two. If data_type(Node) %% is {'atomic', Value}, the number of subtrees is %% zero.

%% %% @see is_data/1 %% @see data_type/1 %% @see data_arity/1 %% @see make_data/2 data_es(#literal{val = V}) -> case V of [Head | Tail] -> [#literal{val = Head}, #literal{val = Tail}]; _ when tuple(V) -> make_lit_list(tuple_to_list(V)); _ -> [] end; data_es(#cons{hd = H, tl = T}) -> [H, T]; data_es(#tuple{es = Es}) -> Es. %% @spec data_arity(Node::cerl()) -> integer() %% %% @doc Returns the number of subtrees of a data constructor %% node. This is equivalent to length(data_es(Node)), but %% potentially more efficient. %% %% @see is_data/1 %% @see data_es/1 data_arity(#literal{val = V}) -> case V of [_ | _] -> 2; _ when tuple(V) -> size(V); _ -> 0 end; data_arity(#cons{}) -> 2; data_arity(#tuple{es = Es}) -> length(Es). %% @spec make_data(Type::dtype(), Elements::[cerl()]) -> cerl() %% %% @doc Creates a data constructor node with the specified type and %% subtrees. (Cf. data_type/1.) An exception is thrown %% if the length of Elements is invalid for the given %% Type; see data_es/1 for arity constraints %% on constructor types. %% %% @see data_type/1 %% @see data_es/1 %% @see ann_make_data/3 %% @see update_data/3 %% @see make_data_skel/2 make_data(CType, Es) -> ann_make_data([], CType, Es). %% @spec ann_make_data(As::[term()], Type::dtype(), %% Elements::[cerl()]) -> cerl() %% @see make_data/2 ann_make_data(As, {'atomic', V}, []) -> #literal{val = V, ann = As}; ann_make_data(As, cons, [H, T]) -> ann_c_cons(As, H, T); ann_make_data(As, tuple, Es) -> ann_c_tuple(As, Es). %% @spec update_data(Old::cerl(), Type::dtype(), %% Elements::[cerl()]) -> cerl() %% @see make_data/2 update_data(Node, CType, Es) -> ann_make_data(get_ann(Node), CType, Es). %% @spec make_data_skel(Type::dtype(), Elements::[cerl()]) -> cerl() %% %% @doc Like make_data/2, but analogous to %% c_tuple_skel/1 and c_cons_skel/2. %% %% @see ann_make_data_skel/3 %% @see update_data_skel/3 %% @see make_data/2 %% @see c_tuple_skel/1 %% @see c_cons_skel/2 make_data_skel(CType, Es) -> ann_make_data_skel([], CType, Es). %% @spec ann_make_data_skel(As::[term()], Type::dtype(), %% Elements::[cerl()]) -> cerl() %% @see make_data_skel/2 ann_make_data_skel(As, {'atomic', V}, []) -> #literal{val = V, ann = As}; ann_make_data_skel(As, cons, [H, T]) -> ann_c_cons_skel(As, H, T); ann_make_data_skel(As, tuple, Es) -> ann_c_tuple_skel(As, Es). %% @spec update_data_skel(Old::cerl(), Type::dtype(), %% Elements::[cerl()]) -> cerl() %% @see make_data_skel/2 update_data_skel(Node, CType, Es) -> ann_make_data_skel(get_ann(Node), CType, Es). %% --------------------------------------------------------------------- %% @spec subtrees(Node::cerl()) -> [[cerl()]] %% %% @doc Returns the grouped list of all subtrees of a node. If %% Node is a leaf node (cf. is_leaf/1), this %% is the empty list, otherwise the result is always a nonempty list, %% containing the lists of subtrees of Node, in %% left-to-right order as they occur in the printed program text, and %% grouped by category. Often, each group contains only a single %% subtree. %% %%

Depending on the type of Node, the size of some %% groups may be variable (e.g., the group consisting of all the %% elements of a tuple), while others always contain the same number %% of elements - usually exactly one (e.g., the group containing the %% argument expression of a case-expression). Note, however, that the %% exact structure of the returned list (for a given node type) should %% in general not be depended upon, since it might be subject to %% change without notice.

%% %%

The function subtrees/1 and the constructor functions %% make_tree/2 and update_tree/2 can be a %% great help if one wants to traverse a syntax tree, visiting all its %% subtrees, but treat nodes of the tree in a uniform way in most or all %% cases. Using these functions makes this simple, and also assures that %% your code is not overly sensitive to extensions of the syntax tree %% data type, because any node types not explicitly handled by your code %% can be left to a default case.

%% %%

For example: %%

%%   postorder(F, Tree) ->
%%       F(case subtrees(Tree) of
%%           [] -> Tree;
%%           List -> update_tree(Tree,
%%                               [[postorder(F, Subtree)
%%                                 || Subtree <- Group]
%%                                || Group <- List])
%%         end).
%% 
%% maps the function F on Tree and all its %% subtrees, doing a post-order traversal of the syntax tree. (Note %% the use of update_tree/2 to preserve annotations.) For %% a simple function like: %%
%%   f(Node) ->
%%       case type(Node) of
%%           atom -> atom("a_" ++ atom_name(Node));
%%           _ -> Node
%%       end.
%% 
%% the call postorder(fun f/1, Tree) will yield a new %% representation of Tree in which all atom names have %% been extended with the prefix "a_", but nothing else (including %% annotations) has been changed.

%% %% @see is_leaf/1 %% @see make_tree/2 %% @see update_tree/2 subtrees(T) -> case is_leaf(T) of true -> []; false -> case type(T) of values -> [values_es(T)]; binary -> [binary_segments(T)]; bitstr -> [[bitstr_val(T)], [bitstr_size(T)], [bitstr_unit(T)], [bitstr_type(T)], [bitstr_flags(T)]]; cons -> [[cons_hd(T)], [cons_tl(T)]]; tuple -> [tuple_es(T)]; 'let' -> [let_vars(T), [let_arg(T)], [let_body(T)]]; seq -> [[seq_arg(T)], [seq_body(T)]]; apply -> [[apply_op(T)], apply_args(T)]; call -> [[call_module(T)], [call_name(T)], call_args(T)]; primop -> [[primop_name(T)], primop_args(T)]; 'case' -> [[case_arg(T)], case_clauses(T)]; clause -> [clause_pats(T), [clause_guard(T)], [clause_body(T)]]; alias -> [[alias_var(T)], [alias_pat(T)]]; 'fun' -> [fun_vars(T), [fun_body(T)]]; 'receive' -> [receive_clauses(T), [receive_timeout(T)], [receive_action(T)]]; 'try' -> [[try_arg(T)], try_vars(T), [try_body(T)], try_evars(T), [try_handler(T)]]; 'catch' -> [[catch_body(T)]]; letrec -> Es = unfold_tuples(letrec_defs(T)), [Es, [letrec_body(T)]]; module -> As = unfold_tuples(module_attrs(T)), Es = unfold_tuples(module_defs(T)), [[module_name(T)], module_exports(T), As, Es] end end. %% @spec update_tree(Old::cerl(), Groups::[[cerl()]]) -> cerl() %% %% @doc Creates a syntax tree with the given subtrees, and the same %% type and annotations as the Old node. This is %% equivalent to ann_make_tree(get_ann(Node), type(Node), %% Groups), but potentially more efficient. %% %% @see update_tree/3 %% @see ann_make_tree/3 %% @see get_ann/1 %% @see type/1 update_tree(Node, Gs) -> ann_make_tree(get_ann(Node), type(Node), Gs). %% @spec update_tree(Old::cerl(), Type::atom(), Groups::[[cerl()]]) -> %% cerl() %% %% @doc Creates a syntax tree with the given type and subtrees, and %% the same annotations as the Old node. This is %% equivalent to ann_make_tree(get_ann(Node), Type, %% Groups), but potentially more efficient. %% %% @see update_tree/2 %% @see ann_make_tree/3 %% @see get_ann/1 update_tree(Node, Type, Gs) -> ann_make_tree(get_ann(Node), Type, Gs). %% @spec make_tree(Type::atom(), Groups::[[cerl()]]) -> cerl() %% %% @doc Creates a syntax tree with the given type and subtrees. %% Type must be a node type name %% (cf. type/1) that does not denote a leaf node type %% (cf. is_leaf/1). Groups must be a %% nonempty list of groups of syntax trees, representing the %% subtrees of a node of the given type, in left-to-right order as %% they would occur in the printed program text, grouped by category %% as done by subtrees/1. %% %%

The result of ann_make_tree(get_ann(Node), type(Node), %% subtrees(Node)) (cf. update_tree/2) represents %% the same source code text as the original Node, %% assuming that subtrees(Node) yields a nonempty %% list. However, it does not necessarily have the exact same data %% representation as Node.

%% %% @see ann_make_tree/3 %% @see type/1 %% @see is_leaf/1 %% @see subtrees/1 %% @see update_tree/2 make_tree(Type, Gs) -> ann_make_tree([], Type, Gs). %% @spec ann_make_tree(As::[term()], Type::atom(), %% Groups::[[cerl()]]) -> cerl() %% %% @doc Creates a syntax tree with the given annotations, type and %% subtrees. See make_tree/2 for details. %% %% @see make_tree/2 ann_make_tree(As, values, [Es]) -> ann_c_values(As, Es); ann_make_tree(As, binary, [Ss]) -> ann_c_binary(As, Ss); ann_make_tree(As, bitstr, [[V],[S],[U],[T],[Fs]]) -> ann_c_bitstr(As, V, S, U, T, Fs); ann_make_tree(As, cons, [[H], [T]]) -> ann_c_cons(As, H, T); ann_make_tree(As, tuple, [Es]) -> ann_c_tuple(As, Es); ann_make_tree(As, 'let', [Vs, [A], [B]]) -> ann_c_let(As, Vs, A, B); ann_make_tree(As, seq, [[A], [B]]) -> ann_c_seq(As, A, B); ann_make_tree(As, apply, [[Op], Es]) -> ann_c_apply(As, Op, Es); ann_make_tree(As, call, [[M], [N], Es]) -> ann_c_call(As, M, N, Es); ann_make_tree(As, primop, [[N], Es]) -> ann_c_primop(As, N, Es); ann_make_tree(As, 'case', [[A], Cs]) -> ann_c_case(As, A, Cs); ann_make_tree(As, clause, [Ps, [G], [B]]) -> ann_c_clause(As, Ps, G, B); ann_make_tree(As, alias, [[V], [P]]) -> ann_c_alias(As, V, P); ann_make_tree(As, 'fun', [Vs, [B]]) -> ann_c_fun(As, Vs, B); ann_make_tree(As, 'receive', [Cs, [T], [A]]) -> ann_c_receive(As, Cs, T, A); ann_make_tree(As, 'try', [[E], Vs, [B], Evs, [H]]) -> ann_c_try(As, E, Vs, B, Evs, H); ann_make_tree(As, 'catch', [[B]]) -> ann_c_catch(As, B); ann_make_tree(As, letrec, [Es, [B]]) -> ann_c_letrec(As, fold_tuples(Es), B); ann_make_tree(As, module, [[N], Xs, Es, Ds]) -> ann_c_module(As, N, Xs, fold_tuples(Es), fold_tuples(Ds)). %% --------------------------------------------------------------------- %% @spec meta(Tree::cerl()) -> cerl() %% %% @doc Creates a meta-representation of a syntax tree. The result %% represents an Erlang expression "MetaTree" %% which, if evaluated, will yield a new syntax tree representing the %% same source code text as Tree (although the actual %% data representation may be different). The expression represented %% by MetaTree is implementation independent %% with regard to the data structures used by the abstract syntax tree %% implementation. %% %%

Any node in Tree whose node type is %% var (cf. type/1), and whose list of %% annotations (cf. get_ann/1) contains the atom %% meta_var, will remain unchanged in the resulting tree, %% except that exactly one occurrence of meta_var is %% removed from its annotation list.

%% %%

The main use of the function meta/1 is to transform %% a data structure Tree, which represents a piece of %% program code, into a form that is representation independent %% when printed. E.g., suppose Tree represents a %% variable named "V". Then (assuming a function print/1 %% for printing syntax trees), evaluating %% print(abstract(Tree)) - simply using %% abstract/1 to map the actual data structure onto a %% syntax tree representation - would output a string that might look %% something like "{var, ..., 'V'}", which is obviously %% dependent on the implementation of the abstract syntax trees. This %% could e.g. be useful for caching a syntax tree in a file. However, %% in some situations like in a program generator generator (with two %% "generator"), it may be unacceptable. Using %% print(meta(Tree)) instead would output a %% representation independent syntax tree generating %% expression; in the above case, something like %% "cerl:c_var('V')".

%% %%

The implementation tries to generate compact code with respect %% to literals and lists.

%% %% @see abstract/1 %% @see type/1 %% @see get_ann/1 meta(Node) -> %% First of all we check for metavariables: case type(Node) of var -> case lists:member(meta_var, get_ann(Node)) of false -> meta_0(var, Node); true -> %% A meta-variable: remove the first found %% 'meta_var' annotation, but otherwise leave %% the node unchanged. set_ann(Node, lists:delete(meta_var, get_ann(Node))) end; Type -> meta_0(Type, Node) end. meta_0(Type, Node) -> case get_ann(Node) of [] -> meta_1(Type, Node); As -> meta_call(set_ann, [meta_1(Type, Node), abstract(As)]) end. meta_1(literal, Node) -> %% We handle atomic literals separately, to get a bit %% more compact code. For the rest, we use 'abstract'. case concrete(Node) of V when atom(V) -> meta_call(c_atom, [Node]); V when integer(V) -> meta_call(c_int, [Node]); V when float(V) -> meta_call(c_float, [Node]); [] -> meta_call(c_nil, []); _ -> meta_call(abstract, [Node]) end; meta_1(var, Node) -> %% A normal variable or function name. meta_call(c_var, [abstract(var_name(Node))]); meta_1(values, Node) -> meta_call(c_values, [make_list(meta_list(values_es(Node)))]); meta_1(binary, Node) -> meta_call(c_binary, [make_list(meta_list(binary_segments(Node)))]); meta_1(bitstr, Node) -> meta_call(c_bitstr, [meta(bitstr_val(Node)), meta(bitstr_size(Node)), meta(bitstr_unit(Node)), meta(bitstr_type(Node)), meta(bitstr_flags(Node))]); meta_1(cons, Node) -> %% The list is split up if some sublist has annotatations. If %% we get exactly one element, we generate a 'c_cons' call %% instead of 'make_list' to reconstruct the node. case split_list(Node) of {[H], none} -> meta_call(c_cons, [meta(H), meta(c_nil())]); {[H], Node1} -> meta_call(c_cons, [meta(H), meta(Node1)]); {L, none} -> meta_call(make_list, [make_list(meta_list(L))]); {L, Node1} -> meta_call(make_list, [make_list(meta_list(L)), meta(Node1)]) end; meta_1(tuple, Node) -> meta_call(c_tuple, [make_list(meta_list(tuple_es(Node)))]); meta_1('let', Node) -> meta_call(c_let, [make_list(meta_list(let_vars(Node))), meta(let_arg(Node)), meta(let_body(Node))]); meta_1(seq, Node) -> meta_call(c_seq, [meta(seq_arg(Node)), meta(seq_body(Node))]); meta_1(apply, Node) -> meta_call(c_apply, [meta(apply_op(Node)), make_list(meta_list(apply_args(Node)))]); meta_1(call, Node) -> meta_call(c_call, [meta(call_module(Node)), meta(call_name(Node)), make_list(meta_list(call_args(Node)))]); meta_1(primop, Node) -> meta_call(c_primop, [meta(primop_name(Node)), make_list(meta_list(primop_args(Node)))]); meta_1('case', Node) -> meta_call(c_case, [meta(case_arg(Node)), make_list(meta_list(case_clauses(Node)))]); meta_1(clause, Node) -> meta_call(c_clause, [make_list(meta_list(clause_pats(Node))), meta(clause_guard(Node)), meta(clause_body(Node))]); meta_1(alias, Node) -> meta_call(c_alias, [meta(alias_var(Node)), meta(alias_pat(Node))]); meta_1('fun', Node) -> meta_call(c_fun, [make_list(meta_list(fun_vars(Node))), meta(fun_body(Node))]); meta_1('receive', Node) -> meta_call(c_receive, [make_list(meta_list(receive_clauses(Node))), meta(receive_timeout(Node)), meta(receive_action(Node))]); meta_1('try', Node) -> meta_call(c_try, [meta(try_arg(Node)), make_list(meta_list(try_vars(Node))), meta(try_body(Node)), make_list(meta_list(try_evars(Node))), meta(try_handler(Node))]); meta_1('catch', Node) -> meta_call(c_catch, [meta(catch_body(Node))]); meta_1(letrec, Node) -> meta_call(c_letrec, [make_list([c_tuple([meta(N), meta(F)]) || {N, F} <- letrec_defs(Node)]), meta(letrec_body(Node))]); meta_1(module, Node) -> meta_call(c_module, [meta(module_name(Node)), make_list(meta_list(module_exports(Node))), make_list([c_tuple([meta(A), meta(V)]) || {A, V} <- module_attrs(Node)]), make_list([c_tuple([meta(N), meta(F)]) || {N, F} <- module_defs(Node)])]). meta_call(F, As) -> c_call(c_atom(?MODULE), c_atom(F), As). meta_list([T | Ts]) -> [meta(T) | meta_list(Ts)]; meta_list([]) -> []. split_list(Node) -> split_list(set_ann(Node, []), []). split_list(Node, L) -> A = get_ann(Node), case type(Node) of cons when A == [] -> split_list(cons_tl(Node), [cons_hd(Node) | L]); nil when A == [] -> {lists:reverse(L), none}; _ -> {lists:reverse(L), Node} end. %% --------------------------------------------------------------------- %% General utilities is_lit_list([#literal{} | Es]) -> is_lit_list(Es); is_lit_list([_ | _]) -> false; is_lit_list([]) -> true. lit_list_vals([#literal{val = V} | Es]) -> [V | lit_list_vals(Es)]; lit_list_vals([]) -> []. make_lit_list([V | Vs]) -> [#literal{val = V} | make_lit_list(Vs)]; make_lit_list([]) -> []. %% The following tests are the same as done by 'io_lib:char_list' and %% 'io_lib:printable_list', respectively, but for a single character. is_char_value(V) when V >= $\000, V =< $\377 -> true; is_char_value(_) -> false. is_print_char_value(V) when V >= $\040, V =< $\176 -> true; is_print_char_value(V) when V >= $\240, V =< $\377 -> true; is_print_char_value(V) when V =:= $\b -> true; is_print_char_value(V) when V =:= $\d -> true; is_print_char_value(V) when V =:= $\e -> true; is_print_char_value(V) when V =:= $\f -> true; is_print_char_value(V) when V =:= $\n -> true; is_print_char_value(V) when V =:= $\r -> true; is_print_char_value(V) when V =:= $\s -> true; is_print_char_value(V) when V =:= $\t -> true; is_print_char_value(V) when V =:= $\v -> true; is_print_char_value(V) when V =:= $\" -> true; is_print_char_value(V) when V =:= $\' -> true; is_print_char_value(V) when V =:= $\\ -> true; is_print_char_value(_) -> false. is_char_list([V | Vs]) when integer(V) -> case is_char_value(V) of true -> is_char_list(Vs); false -> false end; is_char_list([]) -> true; is_char_list(_) -> false. is_print_char_list([V | Vs]) when integer(V) -> case is_print_char_value(V) of true -> is_print_char_list(Vs); false -> false end; is_print_char_list([]) -> true; is_print_char_list(_) -> false. unfold_tuples([{X, Y} | Ps]) -> [X, Y | unfold_tuples(Ps)]; unfold_tuples([]) -> []. fold_tuples([X, Y | Es]) -> [{X, Y} | fold_tuples(Es)]; fold_tuples([]) -> [].