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.
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.
%% %%Currently, the internal data structure used is the same as %% the record-based data structures used traditionally in the Beam %% compiler.
%% %%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.
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.
Node. Current node types
%% are:
%%
%% | alias | %%apply | %%binary | %%bitstr | %%call | %%case | %%catch | %%clause | %%
| cons | %%fun | %%let | %%letrec | %%literal | %%map | %%map_pair | %%module | %%
| primop | %%receive | %%seq | %%try | %%tuple | %%values | %%var | %%
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.
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.
Node to
%% Annotations.
%%
%% @see get_ann/1
%% @see add_ann/2
%% @see copy_ann/2
-spec set_ann(cerl(), [term()]) -> cerl().
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.
Source
%% to Target.
%%
%% Note: this is equivalent to set_ann(Target,
%% get_ann(Source)), but potentially more efficient.
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 -spec abstract(term()) -> c_literal(). abstract(T) -> #c_literal{val = T}. %% @spec ann_abstract(Annotations::[term()], Term::term()) -> cerl() %% @see abstract/1 -spec ann_abstract([term()], term()) -> c_literal(). ann_abstract(As, T) -> #c_literal{val = T, anno = As}. %% @spec is_literal_term(Term::term()) -> boolean() %% %% @doc Returnstrue if Term can be
%% represented as a literal, otherwise false. This
%% function takes time proportional to the size of Term.
%%
%% @see abstract/1
-spec is_literal_term(term()) -> boolean().
is_literal_term(T) when is_integer(T) -> true;
is_literal_term(T) when is_float(T) -> true;
is_literal_term(T) when is_atom(T) -> true;
is_literal_term([]) -> true;
is_literal_term([H | T]) ->
is_literal_term(H) andalso is_literal_term(T);
is_literal_term(T) when is_tuple(T) ->
is_literal_term_list(tuple_to_list(T));
is_literal_term(B) when is_bitstring(B) -> true;
is_literal_term(_) ->
false.
-spec is_literal_term_list([term()]) -> boolean().
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. -spec concrete(c_literal()) -> term(). concrete(#c_literal{val = V}) -> V. %% @spec is_literal(Node::cerl()) -> boolean() %% %% @doc Returnstrue 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 -spec is_literal(cerl()) -> boolean(). is_literal(#c_literal{}) -> true; is_literal(_) -> false. %% @spec fold_literal(Node::cerl()) -> cerl() %% %% @doc Assures that literals have a compact representation. This is %% occasionally useful ifc_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
-spec fold_literal(cerl()) -> cerl().
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
-spec unfold_literal(cerl()) -> cerl().
unfold_literal(Node) ->
case type(Node) of
literal ->
copy_ann(Node, unfold_concrete(concrete(Node)));
_ ->
Node
end.
unfold_concrete(Val) ->
case Val of
_ when is_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([]) ->
[].
%% ---------------------------------------------------------------------
%% @spec c_module(Name::cerl(), Exports, Definitions) -> cerl()
%%
%% Exports = [cerl()]
%% Definitions = [{cerl(), cerl()}]
%%
%% @equiv c_module(Name, Exports, [], Definitions)
-spec c_module(cerl(), [cerl()], [{cerl(), cerl()}]) -> c_module().
c_module(Name, Exports, Es) ->
#c_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'.
true if Node is an abstract
%% module definition, otherwise false.
%%
%% @see type/1
-spec is_c_module(cerl()) -> boolean().
is_c_module(#c_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
-spec module_name(c_module()) -> cerl().
module_name(Node) ->
Node#c_module.name.
%% @spec module_exports(Node::cerl()) -> [cerl()]
%%
%% @doc Returns the list of exports subtrees of an abstract module
%% definition.
%%
%% @see c_module/4
-spec module_exports(c_module()) -> [cerl()].
module_exports(Node) ->
Node#c_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
-spec module_attrs(c_module()) -> [{cerl(), cerl()}].
module_attrs(Node) ->
Node#c_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
-spec module_defs(c_module()) -> [{cerl(), cerl()}].
module_defs(Node) ->
Node#c_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
-spec module_vars(c_module()) -> [cerl()].
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
-spec c_int(integer()) -> c_literal().
c_int(Value) ->
#c_literal{val = Value}.
%% @spec ann_c_int(As::[term()], Value::integer()) -> cerl()
%% @see c_int/1
-spec ann_c_int([term()], integer()) -> c_literal().
ann_c_int(As, Value) ->
#c_literal{val = Value, anno = As}.
%% @spec is_c_int(Node::cerl()) -> boolean()
%%
%% @doc Returns true if Node represents an
%% integer literal, otherwise false.
%% @see c_int/1
-spec is_c_int(cerl()) -> boolean().
is_c_int(#c_literal{val = V}) when is_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
-spec int_val(c_literal()) -> integer().
int_val(Node) ->
Node#c_literal.val.
%% @spec int_lit(cerl()) -> string()
%%
%% @doc Returns the numeral string represented by an integer literal
%% node.
%% @see c_int/1
-spec int_lit(c_literal()) -> string().
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.
-spec c_float(float()) -> c_literal().
c_float(Value) ->
#c_literal{val = Value}.
%% @spec ann_c_float(As::[term()], Value::float()) -> cerl()
%% @see c_float/1
-spec ann_c_float([term()], float()) -> c_literal().
ann_c_float(As, Value) ->
#c_literal{val = Value, anno = As}.
%% @spec is_c_float(Node::cerl()) -> boolean()
%%
%% @doc Returns true if Node represents a
%% floating-point literal, otherwise false.
%% @see c_float/1
-spec is_c_float(cerl()) -> boolean().
is_c_float(#c_literal{val = V}) when is_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
-spec float_val(c_literal()) -> float().
float_val(Node) ->
Node#c_literal.val.
%% @spec float_lit(cerl()) -> string()
%%
%% @doc Returns the numeral string represented by a floating-point
%% literal node.
%% @see c_float/1
-spec float_lit(c_literal()) -> string().
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 -spec c_atom(atom() | string()) -> c_literal(). c_atom(Name) when is_atom(Name) -> #c_literal{val = Name}; c_atom(Name) -> #c_literal{val = list_to_atom(Name)}. %% @spec ann_c_atom(As::[term()], Name) -> cerl() %% Name = atom() | string() %% @see c_atom/1 -spec ann_c_atom([term()], atom() | string()) -> c_literal(). ann_c_atom(As, Name) when is_atom(Name) -> #c_literal{val = Name, anno = As}; ann_c_atom(As, Name) -> #c_literal{val = list_to_atom(Name), anno = As}. %% @spec is_c_atom(Node::cerl()) -> boolean() %% %% @doc Returnstrue if Node represents an
%% atom literal, otherwise false.
%%
%% @see c_atom/1
-spec is_c_atom(cerl()) -> boolean().
is_c_atom(#c_literal{val = V}) when is_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
-spec atom_val(c_literal()) -> atom().
atom_val(Node) ->
Node#c_literal.val.
%% @spec atom_name(cerl()) -> string()
%%
%% @doc Returns the printname of an abstract atom.
%%
%% @see c_atom/1
-spec atom_name(c_literal()) -> string().
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\'".
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
-spec c_char(non_neg_integer()) -> c_literal().
c_char(Value) when is_integer(Value), Value >= 0 ->
#c_literal{val = Value}.
%% @spec ann_c_char(As::[term()], Value::char()) -> cerl()
%% @see c_char/1
-spec ann_c_char([term()], char()) -> c_literal().
ann_c_char(As, Value) ->
#c_literal{val = Value, anno = 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.
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
-spec is_print_char(cerl()) -> boolean().
is_print_char(#c_literal{val = V}) when is_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
-spec char_val(c_literal()) -> char().
char_val(Node) ->
Node#c_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
-spec char_lit(c_literal()) -> nonempty_string().
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
-spec c_string(string()) -> c_literal().
c_string(Value) ->
#c_literal{val = Value}.
%% @spec ann_c_string(As::[term()], Value::string()) -> cerl()
%% @see c_string/1
-spec ann_c_string([term()], string()) -> c_literal().
ann_c_string(As, Value) ->
#c_literal{val = Value, anno = 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
-spec is_c_string(cerl()) -> boolean().
is_c_string(#c_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
-spec is_print_string(cerl()) -> boolean().
is_print_string(#c_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
-spec string_val(c_literal()) -> string().
string_val(Node) ->
Node#c_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
-spec string_lit(c_literal()) -> nonempty_string().
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
-spec c_nil() -> c_literal().
c_nil() ->
#c_literal{val = []}.
%% @spec ann_c_nil(As::[term()]) -> cerl()
%% @see c_nil/0
-spec ann_c_nil([term()]) -> c_literal().
ann_c_nil(As) ->
#c_literal{val = [], anno = As}.
%% @spec is_c_nil(Node::cerl()) -> boolean()
%%
%% @doc Returns true if Node is an abstract
%% empty list, otherwise false.
-spec is_c_nil(cerl()) -> boolean().
is_c_nil(#c_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 %% *Always* collapse literals. -spec c_cons(cerl(), cerl()) -> c_literal() | c_cons(). c_cons(#c_literal{val = Head}, #c_literal{val = Tail}) -> #c_literal{val = [Head | Tail]}; c_cons(Head, Tail) -> #c_cons{hd = Head, tl = Tail}. %% @spec ann_c_cons(As::[term()], Head::cerl(), Tail::cerl()) -> cerl() %% @see c_cons/2 -spec ann_c_cons([term()], cerl(), cerl()) -> c_literal() | c_cons(). ann_c_cons(As, #c_literal{val = Head}, #c_literal{val = Tail}) -> #c_literal{val = [Head | Tail], anno = As}; ann_c_cons(As, Head, Tail) -> #c_cons{hd = Head, tl = Tail, anno = As}. %% @spec update_c_cons(Old::cerl(), Head::cerl(), Tail::cerl()) -> %% cerl() %% @see c_cons/2 -spec update_c_cons(c_literal() | c_cons(), cerl(), cerl()) -> c_literal() | c_cons(). update_c_cons(Node, #c_literal{val = Head}, #c_literal{val = Tail}) -> #c_literal{val = [Head | Tail], anno = get_ann(Node)}; update_c_cons(Node, Head, Tail) -> #c_cons{hd = Head, tl = Tail, anno = 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.
true if Node is an abstract
%% list constructor, otherwise false.
-spec is_c_cons(cerl()) -> boolean().
is_c_cons(#c_cons{}) ->
true;
is_c_cons(#c_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
-spec cons_hd(c_cons() | c_literal()) -> cerl().
cons_hd(#c_cons{hd = Head}) ->
Head;
cons_hd(#c_literal{val = [Head | _]}) ->
#c_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 -spec cons_tl(c_cons() | c_literal()) -> cerl(). cons_tl(#c_cons{tl = Tail}) -> Tail; cons_tl(#c_literal{val = [_ | Tail]}) -> #c_literal{val = Tail}. %% @spec is_c_list(Node::cerl()) -> boolean() %% %% @doc Returnstrue 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.
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
-spec list_elements(c_cons() | c_literal()) -> [cerl()].
list_elements(#c_cons{hd = Head, tl = Tail}) ->
[Head | list_elements(Tail)];
list_elements(#c_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.
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
-spec make_list([cerl()], cerl() | 'none') -> cerl().
make_list(List, Tail) ->
ann_make_list([], List, Tail).
%% @spec update_list(Old::cerl(), List::[cerl()]) -> cerl()
%% @equiv update_list(Old, List, none)
-spec update_list(cerl(), [cerl()]) -> cerl().
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
-spec update_list(cerl(), [cerl()], cerl() | 'none') -> cerl().
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)
-spec ann_make_list([term()], [cerl()]) -> cerl().
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
-spec ann_make_list([term()], [cerl()], cerl() | 'none') -> cerl().
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.
%% ---------------------------------------------------------------------
%% maps
-spec map_es(c_map()) -> [c_map_pair()].
map_es(#c_map{es = Es}) ->
Es.
-spec map_arg(c_map()) -> c_map() | c_literal().
map_arg(#c_map{arg=M}) ->
M.
-spec c_map([c_map_pair()]) -> c_map().
c_map(Pairs) ->
ann_c_map([], Pairs).
-spec c_map_pattern([c_map_pair()]) -> c_map().
c_map_pattern(Pairs) ->
#c_map{es=Pairs, is_pat=true}.
-spec ann_c_map_pattern([term()], [c_map_pair()]) -> c_map().
ann_c_map_pattern(As, Pairs) ->
#c_map{anno=As, es=Pairs, is_pat=true}.
-spec is_c_map_empty(c_map() | c_literal()) -> boolean().
is_c_map_empty(#c_map{ es=[] }) -> true;
is_c_map_empty(#c_literal{val=M}) when is_map(M),map_size(M) =:= 0 -> true;
is_c_map_empty(_) -> false.
-spec ann_c_map([term()], [c_map_pair()]) -> c_map() | c_literal().
ann_c_map(As, Es) ->
ann_c_map(As, #c_literal{val=#{}}, Es).
-spec ann_c_map([term()], c_map() | c_literal(), [c_map_pair()]) -> c_map() | c_literal().
ann_c_map(As,#c_literal{val=M},Es) when is_map(M) ->
fold_map_pairs(As,Es,M);
ann_c_map(As,M,Es) ->
#c_map{arg=M, es=Es, anno=As }.
fold_map_pairs(As,[],M) -> #c_literal{anno=As,val=M};
%% M#{ K => V}
fold_map_pairs(As,[#c_map_pair{op=#c_literal{val=assoc},key=Ck,val=Cv}=E|Es],M) ->
case is_lit_list([Ck,Cv]) of
true ->
[K,V] = lit_list_vals([Ck,Cv]),
fold_map_pairs(As,Es,maps:put(K,V,M));
false ->
#c_map{arg=#c_literal{val=M,anno=As}, es=[E|Es], anno=As }
end;
%% M#{ K := V}
fold_map_pairs(As,[#c_map_pair{op=#c_literal{val=exact},key=Ck,val=Cv}=E|Es],M) ->
case is_lit_list([Ck,Cv]) of
true ->
[K,V] = lit_list_vals([Ck,Cv]),
case maps:is_key(K,M) of
true -> fold_map_pairs(As,Es,maps:put(K,V,M));
false ->
#c_map{arg=#c_literal{val=M,anno=As}, es=[E|Es], anno=As }
end;
false ->
#c_map{arg=#c_literal{val=M,anno=As}, es=[E|Es], anno=As }
end.
-spec update_c_map(c_map(), cerl(), [cerl()]) -> c_map() | c_literal().
update_c_map(#c_map{is_pat=true}=Old, M, Es) ->
Old#c_map{arg=M, es=Es};
update_c_map(#c_map{is_pat=false}=Old, M, Es) ->
ann_c_map(get_ann(Old), M, Es).
map_pair_key(#c_map_pair{key=K}) -> K.
map_pair_val(#c_map_pair{val=V}) -> V.
map_pair_op(#c_map_pair{op=Op}) -> Op.
-spec c_map_pair(cerl(), cerl()) -> c_map_pair().
c_map_pair(Key,Val) ->
#c_map_pair{op=#c_literal{val=assoc},key=Key,val=Val}.
-spec ann_c_map_pair([term()], cerl(), cerl(), cerl()) ->
c_map_pair().
ann_c_map_pair(As,Op,K,V) ->
#c_map_pair{op=Op, key = K, val=V, anno = As}.
update_c_map_pair(Old,Op,K,V) ->
#c_map_pair{op=Op, key=K, val=V, anno = get_ann(Old)}.
%% ---------------------------------------------------------------------
%% @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.
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.
true if Node is an abstract
%% tuple, otherwise false.
%%
%% @see c_tuple/1
-spec is_c_tuple(cerl()) -> boolean().
is_c_tuple(#c_tuple{}) ->
true;
is_c_tuple(#c_literal{val = V}) when is_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
-spec tuple_es(c_tuple() | c_literal()) -> [cerl()].
tuple_es(#c_tuple{es = Es}) ->
Es;
tuple_es(#c_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.
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.
true if Node is an abstract
%% variable, otherwise false.
%%
%% @see c_var/1
-spec is_c_var(cerl()) -> boolean().
is_c_var(#c_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
-spec c_fname(atom(), non_neg_integer()) -> c_var().
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
-spec ann_c_fname([term()], atom(), non_neg_integer()) -> c_var().
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
-spec update_c_fname(c_var(), atom()) -> c_var().
update_c_fname(#c_var{name = {_, Arity}, anno = As}, Atom) ->
#c_var{name = {Atom, Arity}, anno = 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
-spec update_c_fname(c_var(), atom(), integer()) -> c_var().
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
-spec is_c_fname(cerl()) -> boolean().
is_c_fname(#c_var{name = {A, N}}) when is_atom(A), is_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
-spec var_name(c_var()) -> var_name().
var_name(Node) ->
Node#c_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
-spec fname_id(c_var()) -> atom().
fname_id(#c_var{name={A,_}}) ->
A.
%% @spec fname_arity(cerl()) -> byte()
%%
%% @doc Returns the arity part of an abstract function name variable.
%%
%% @see fname_id/1
%% @see c_fname/2
-spec fname_arity(c_var()) -> byte().
fname_arity(#c_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
-spec c_values([cerl()]) -> c_values().
c_values(Es) ->
#c_values{es = Es}.
%% @spec ann_c_values(As::[term()], Elements::[cerl()]) -> cerl()
%% @see c_values/1
-spec ann_c_values([term()], [cerl()]) -> c_values().
ann_c_values(As, Es) ->
#c_values{es = Es, anno = As}.
%% @spec update_c_values(Old::cerl(), Elements::[cerl()]) -> cerl()
%% @see c_values/1
-spec update_c_values(c_values(), [cerl()]) -> c_values().
update_c_values(Node, Es) ->
#c_values{es = Es, anno = 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
-spec is_c_values(cerl()) -> boolean().
is_c_values(#c_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
-spec values_es(c_values()) -> [cerl()].
values_es(Node) ->
Node#c_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.
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
-spec c_binary([cerl()]) -> c_binary().
c_binary(Segments) ->
#c_binary{segments = Segments}.
%% @spec ann_c_binary(As::[term()], Segments::[cerl()]) -> cerl()
%% @see c_binary/1
-spec ann_c_binary([term()], [cerl()]) -> c_binary().
ann_c_binary(As, Segments) ->
#c_binary{segments = Segments, anno = As}.
%% @spec update_c_binary(Old::cerl(), Segments::[cerl()]) -> cerl()
%% @see c_binary/1
-spec update_c_binary(c_binary(), [cerl()]) -> c_binary().
update_c_binary(Node, Segments) ->
#c_binary{segments = Segments, anno = 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
-spec is_c_binary(cerl()) -> boolean().
is_c_binary(#c_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
-spec binary_segments(c_binary()) -> [cerl()].
binary_segments(Node) ->
Node#c_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
-spec c_bitstr(cerl(), cerl(), cerl(), cerl(), cerl()) -> c_bitstr().
c_bitstr(Val, Size, Unit, Type, Flags) ->
#c_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)
-spec c_bitstr(cerl(), cerl(), cerl(), cerl()) -> c_bitstr().
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)
-spec c_bitstr(cerl(), cerl(), cerl()) -> c_bitstr().
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
-spec ann_c_bitstr([term()], cerl(), cerl(), cerl(), cerl(), cerl()) ->
c_bitstr().
ann_c_bitstr(As, Val, Size, Unit, Type, Flags) ->
#c_bitstr{val = Val, size = Size, unit = Unit, type = Type,
flags = Flags, anno = 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)
-spec ann_c_bitstr([term()], cerl(), cerl(), cerl(), cerl()) -> c_bitstr().
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
-spec update_c_bitstr(c_bitstr(), cerl(), cerl(), cerl(), cerl(), cerl()) ->
c_bitstr().
update_c_bitstr(Node, Val, Size, Unit, Type, Flags) ->
#c_bitstr{val = Val, size = Size, unit = Unit, type = Type,
flags = Flags, anno = 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)
-spec update_c_bitstr(c_bitstr(), cerl(), cerl(), cerl(), cerl()) -> c_bitstr().
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
-spec is_c_bitstr(cerl()) -> boolean().
is_c_bitstr(#c_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
-spec bitstr_val(c_bitstr()) -> cerl().
bitstr_val(Node) ->
Node#c_bitstr.val.
%% @spec bitstr_size(cerl()) -> cerl()
%%
%% @doc Returns the size subtree of an abstract bit-string template.
%%
%% @see c_bitstr/5
-spec bitstr_size(c_bitstr()) -> cerl().
bitstr_size(Node) ->
Node#c_bitstr.size.
%% @spec bitstr_bitsize(cerl()) -> any | all | utf | integer()
%%
%% @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.
%% If the size is not a literal, the atom any is returned.
%%
%% @see c_bitstr/5
-spec bitstr_bitsize(c_bitstr()) -> 'all' | 'any' | 'utf' | non_neg_integer().
bitstr_bitsize(Node) ->
Size = Node#c_bitstr.size,
case is_literal(Size) of
true ->
case concrete(Size) of
all ->
all;
undefined ->
%% just an assertion below
"utf" ++ _ = atom_to_list(concrete(Node#c_bitstr.type)),
utf;
S when is_integer(S) ->
S * concrete(Node#c_bitstr.unit)
end;
false ->
any
end.
%% @spec bitstr_unit(cerl()) -> cerl()
%%
%% @doc Returns the unit subtree of an abstract bit-string template.
%%
%% @see c_bitstr/5
-spec bitstr_unit(c_bitstr()) -> cerl().
bitstr_unit(Node) ->
Node#c_bitstr.unit.
%% @spec bitstr_type(cerl()) -> cerl()
%%
%% @doc Returns the type subtree of an abstract bit-string template.
%%
%% @see c_bitstr/5
-spec bitstr_type(c_bitstr()) -> cerl().
bitstr_type(Node) ->
Node#c_bitstr.type.
%% @spec bitstr_flags(cerl()) -> cerl()
%%
%% @doc Returns the flags subtree of an abstract bit-string template.
%%
%% @see c_bitstr/5
-spec bitstr_flags(c_bitstr()) -> cerl().
bitstr_flags(Node) ->
Node#c_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
-spec c_fun([cerl()], cerl()) -> c_fun().
c_fun(Variables, Body) ->
#c_fun{vars = Variables, body = Body}.
%% @spec ann_c_fun(As::[term()], Variables::[cerl()], Body::cerl()) ->
%% cerl()
%% @see c_fun/2
-spec ann_c_fun([term()], [cerl()], cerl()) -> c_fun().
ann_c_fun(As, Variables, Body) ->
#c_fun{vars = Variables, body = Body, anno = As}.
%% @spec update_c_fun(Old::cerl(), Variables::[cerl()],
%% Body::cerl()) -> cerl()
%% @see c_fun/2
-spec update_c_fun(c_fun(), [cerl()], cerl()) -> c_fun().
update_c_fun(Node, Variables, Body) ->
#c_fun{vars = Variables, body = Body, anno = 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
-spec is_c_fun(cerl()) -> boolean().
is_c_fun(#c_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
-spec fun_vars(c_fun()) -> [cerl()].
fun_vars(Node) ->
Node#c_fun.vars.
%% @spec fun_body(cerl()) -> cerl()
%%
%% @doc Returns the body subtree of an abstract fun-expression.
%%
%% @see c_fun/2
-spec fun_body(c_fun()) -> cerl().
fun_body(Node) ->
Node#c_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.
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
-spec c_seq(cerl(), cerl()) -> c_seq().
c_seq(Argument, Body) ->
#c_seq{arg = Argument, body = Body}.
%% @spec ann_c_seq(As::[term()], Argument::cerl(), Body::cerl()) ->
%% cerl()
%% @see c_seq/2
-spec ann_c_seq([term()], cerl(), cerl()) -> c_seq().
ann_c_seq(As, Argument, Body) ->
#c_seq{arg = Argument, body = Body, anno = As}.
%% @spec update_c_seq(Old::cerl(), Argument::cerl(), Body::cerl()) ->
%% cerl()
%% @see c_seq/2
-spec update_c_seq(c_seq(), cerl(), cerl()) -> c_seq().
update_c_seq(Node, Argument, Body) ->
#c_seq{arg = Argument, body = Body, anno = 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
-spec is_c_seq(cerl()) -> boolean().
is_c_seq(#c_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
-spec seq_arg(c_seq()) -> cerl().
seq_arg(Node) ->
Node#c_seq.arg.
%% @spec seq_body(cerl()) -> cerl()
%%
%% @doc Returns the body subtree of an abstract sequencing expression.
%%
%% @see c_seq/2
-spec seq_body(c_seq()) -> cerl().
seq_body(Node) ->
Node#c_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
-spec c_let([cerl()], cerl(), cerl()) -> c_let().
c_let(Variables, Argument, Body) ->
#c_let{vars = Variables, arg = Argument, body = Body}.
%% ann_c_let(As, Variables, Argument, Body) -> Node
%% @see c_let/3
-spec ann_c_let([term()], [cerl()], cerl(), cerl()) -> c_let().
ann_c_let(As, Variables, Argument, Body) ->
#c_let{vars = Variables, arg = Argument, body = Body, anno = As}.
%% update_c_let(Old, Variables, Argument, Body) -> Node
%% @see c_let/3
-spec update_c_let(c_let(), [cerl()], cerl(), cerl()) -> c_let().
update_c_let(Node, Variables, Argument, Body) ->
#c_let{vars = Variables, arg = Argument, body = Body,
anno = 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
-spec is_c_let(cerl()) -> boolean().
is_c_let(#c_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
-spec let_vars(c_let()) -> [cerl()].
let_vars(Node) ->
Node#c_let.vars.
%% @spec let_arg(cerl()) -> cerl()
%%
%% @doc Returns the argument subtree of an abstract let-expression.
%%
%% @see c_let/3
-spec let_arg(c_let()) -> cerl().
let_arg(Node) ->
Node#c_let.arg.
%% @spec let_body(cerl()) -> cerl()
%%
%% @doc Returns the body subtree of an abstract let-expression.
%%
%% @see c_let/3
-spec let_body(c_let()) -> cerl().
let_body(Node) ->
Node#c_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.
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
-spec c_letrec([{cerl(), cerl()}], cerl()) -> c_letrec().
c_letrec(Defs, Body) ->
#c_letrec{defs = Defs, body = Body}.
%% @spec ann_c_letrec(As::[term()], Definitions::[{cerl(), cerl()}],
%% Body::cerl()) -> cerl()
%% @see c_letrec/2
-spec ann_c_letrec([term()], [{cerl(), cerl()}], cerl()) -> c_letrec().
ann_c_letrec(As, Defs, Body) ->
#c_letrec{defs = Defs, body = Body, anno = As}.
%% @spec update_c_letrec(Old::cerl(),
%% Definitions::[{cerl(), cerl()}],
%% Body::cerl()) -> cerl()
%% @see c_letrec/2
-spec update_c_letrec(c_letrec(), [{cerl(), cerl()}], cerl()) -> c_letrec().
update_c_letrec(Node, Defs, Body) ->
#c_letrec{defs = Defs, body = Body, anno = 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
-spec is_c_letrec(cerl()) -> boolean().
is_c_letrec(#c_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
-spec letrec_defs(c_letrec()) -> [{cerl(), cerl()}].
letrec_defs(Node) ->
Node#c_letrec.defs.
%% @spec letrec_body(cerl()) -> cerl()
%%
%% @doc Returns the body subtree of an abstract letrec-expression.
%%
%% @see c_letrec/2
-spec letrec_body(c_letrec()) -> cerl().
letrec_body(Node) ->
Node#c_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
-spec letrec_vars(c_letrec()) -> [cerl()].
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
-spec c_case(cerl(), [cerl()]) -> c_case().
c_case(Expr, Clauses) ->
#c_case{arg = Expr, clauses = Clauses}.
%% @spec ann_c_case(As::[term()], Argument::cerl(),
%% Clauses::[cerl()]) -> cerl()
%% @see c_case/2
-spec ann_c_case([term()], cerl(), [cerl()]) -> c_case().
ann_c_case(As, Expr, Clauses) ->
#c_case{arg = Expr, clauses = Clauses, anno = As}.
%% @spec update_c_case(Old::cerl(), Argument::cerl(),
%% Clauses::[cerl()]) -> cerl()
%% @see c_case/2
-spec update_c_case(c_case(), cerl(), [cerl()]) -> c_case().
update_c_case(Node, Expr, Clauses) ->
#c_case{arg = Expr, clauses = Clauses, anno = 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
-spec is_c_case(cerl()) -> boolean().
is_c_case(#c_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
-spec case_arg(c_case()) -> cerl().
case_arg(Node) ->
Node#c_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
-spec case_clauses(c_case()) -> [cerl()].
case_clauses(Node) ->
Node#c_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
-spec case_arity(c_case()) -> non_neg_integer().
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
-spec c_clause([cerl()], cerl()) -> c_clause().
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
-spec c_clause([cerl()], cerl(), cerl()) -> c_clause().
c_clause(Patterns, Guard, Body) ->
#c_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
-spec ann_c_clause([term()], [cerl()], cerl()) -> c_clause().
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
-spec ann_c_clause([term()], [cerl()], cerl(), cerl()) -> c_clause().
ann_c_clause(As, Patterns, Guard, Body) ->
#c_clause{pats = Patterns, guard = Guard, body = Body, anno = As}.
%% @spec update_c_clause(Old::cerl(), Patterns::[cerl()],
%% Guard::cerl(), Body::cerl()) -> cerl()
%% @see c_clause/3
-spec update_c_clause(c_clause(), [cerl()], cerl(), cerl()) -> c_clause().
update_c_clause(Node, Patterns, Guard, Body) ->
#c_clause{pats = Patterns, guard = Guard, body = Body,
anno = 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
-spec is_c_clause(cerl()) -> boolean().
is_c_clause(#c_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
-spec clause_pats(c_clause()) -> [cerl()].
clause_pats(Node) ->
Node#c_clause.pats.
%% @spec clause_guard(cerl()) -> cerl()
%%
%% @doc Returns the guard subtree of an abstract clause.
%%
%% @see c_clause/3
-spec clause_guard(c_clause()) -> cerl().
clause_guard(Node) ->
Node#c_clause.guard.
%% @spec clause_body(cerl()) -> cerl()
%%
%% @doc Returns the body subtree of an abstract clause.
%%
%% @see c_clause/3
-spec clause_body(c_clause()) -> cerl().
clause_body(Node) ->
Node#c_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.
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
-spec pat_vars(cerl()) -> [cerl()].
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);
map ->
pat_list_vars(map_es(Node), Vs);
map_pair ->
%% map_pair_key is not a pattern var, excluded
pat_list_vars([map_pair_op(Node),map_pair_val(Node)],Vs);
binary ->
pat_list_vars(binary_segments(Node), Vs);
bitstr ->
%% bitstr_size is not a pattern var, excluded
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
-spec pat_list_vars([cerl()]) -> [cerl()].
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
-spec c_alias(c_var(), cerl()) -> c_alias().
c_alias(Var, Pattern) ->
#c_alias{var = Var, pat = Pattern}.
%% @spec ann_c_alias(As::[term()], Variable::cerl(),
%% Pattern::cerl()) -> cerl()
%% @see c_alias/2
-spec ann_c_alias([term()], c_var(), cerl()) -> c_alias().
ann_c_alias(As, Var, Pattern) ->
#c_alias{var = Var, pat = Pattern, anno = As}.
%% @spec update_c_alias(Old::cerl(), Variable::cerl(),
%% Pattern::cerl()) -> cerl()
%% @see c_alias/2
-spec update_c_alias(c_alias(), cerl(), cerl()) -> c_alias().
update_c_alias(Node, Var, Pattern) ->
#c_alias{var = Var, pat = Pattern, anno = 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
-spec is_c_alias(cerl()) -> boolean().
is_c_alias(#c_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
-spec alias_var(c_alias()) -> c_var().
alias_var(Node) ->
Node#c_alias.var.
%% @spec alias_pat(cerl()) -> cerl()
%%
%% @doc Returns the pattern subtree of an abstract pattern alias.
%%
%% @see c_alias/2
-spec alias_pat(c_alias()) -> cerl().
alias_pat(Node) ->
Node#c_alias.pat.
%% ---------------------------------------------------------------------
%% @spec c_receive(Clauses::[cerl()]) -> cerl()
%% @equiv c_receive(Clauses, c_atom(infinity), c_atom(true))
%% @see c_atom/1
-spec c_receive([cerl()]) -> c_receive().
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
-spec c_receive([cerl()], cerl(), cerl()) -> c_receive().
c_receive(Clauses, Timeout, Action) ->
#c_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
-spec ann_c_receive([term()], [cerl()]) -> c_receive().
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
-spec ann_c_receive([term()], [cerl()], cerl(), cerl()) -> c_receive().
ann_c_receive(As, Clauses, Timeout, Action) ->
#c_receive{clauses = Clauses, timeout = Timeout, action = Action,
anno = As}.
%% @spec update_c_receive(Old::cerl(), Clauses::[cerl()],
%% Timeout::cerl(), Action::cerl()) -> cerl()
%% @see c_receive/3
-spec update_c_receive(c_receive(), [cerl()], cerl(), cerl()) -> c_receive().
update_c_receive(Node, Clauses, Timeout, Action) ->
#c_receive{clauses = Clauses, timeout = Timeout, action = Action,
anno = 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
-spec is_c_receive(cerl()) -> boolean().
is_c_receive(#c_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
-spec receive_clauses(c_receive()) -> [cerl()].
receive_clauses(Node) ->
Node#c_receive.clauses.
%% @spec receive_timeout(cerl()) -> cerl()
%%
%% @doc Returns the timeout subtree of an abstract receive-expression.
%%
%% @see c_receive/3
-spec receive_timeout(c_receive()) -> cerl().
receive_timeout(Node) ->
Node#c_receive.timeout.
%% @spec receive_action(cerl()) -> cerl()
%%
%% @doc Returns the action subtree of an abstract receive-expression.
%%
%% @see c_receive/3
-spec receive_action(c_receive()) -> cerl().
receive_action(Node) ->
Node#c_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
-spec c_apply(cerl(), [cerl()]) -> c_apply().
c_apply(Operator, Arguments) ->
#c_apply{op = Operator, args = Arguments}.
%% @spec ann_c_apply(As::[term()], Operator::cerl(),
%% Arguments::[cerl()]) -> cerl()
%% @see c_apply/2
-spec ann_c_apply([term()], cerl(), [cerl()]) -> c_apply().
ann_c_apply(As, Operator, Arguments) ->
#c_apply{op = Operator, args = Arguments, anno = As}.
%% @spec update_c_apply(Old::cerl(), Operator::cerl(),
%% Arguments::[cerl()]) -> cerl()
%% @see c_apply/2
-spec update_c_apply(c_apply(), cerl(), [cerl()]) -> c_apply().
update_c_apply(Node, Operator, Arguments) ->
#c_apply{op = Operator, args = Arguments, anno = 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
-spec is_c_apply(cerl()) -> boolean().
is_c_apply(#c_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
-spec apply_op(c_apply()) -> cerl().
apply_op(Node) ->
Node#c_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
-spec apply_args(c_apply()) -> [cerl()].
apply_args(Node) ->
Node#c_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.
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
-spec c_call(cerl(), cerl(), [cerl()]) -> c_call().
c_call(Module, Name, Arguments) ->
#c_call{module = Module, name = Name, args = Arguments}.
%% @spec ann_c_call(As::[term()], Module::cerl(), Name::cerl(),
%% Arguments::[cerl()]) -> cerl()
%% @see c_call/3
-spec ann_c_call([term()], cerl(), cerl(), [cerl()]) -> c_call().
ann_c_call(As, Module, Name, Arguments) ->
#c_call{module = Module, name = Name, args = Arguments, anno = As}.
%% @spec update_c_call(Old::cerl(), Module::cerl(), Name::cerl(),
%% Arguments::[cerl()]) -> cerl()
%% @see c_call/3
-spec update_c_call(cerl(), cerl(), cerl(), [cerl()]) -> c_call().
update_c_call(Node, Module, Name, Arguments) ->
#c_call{module = Module, name = Name, args = Arguments,
anno = 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
-spec is_c_call(cerl()) -> boolean().
is_c_call(#c_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
-spec call_module(c_call()) -> cerl().
call_module(Node) ->
Node#c_call.module.
%% @spec call_name(cerl()) -> cerl()
%%
%% @doc Returns the name subtree of an abstract inter-module call.
%%
%% @see c_call/3
-spec call_name(c_call()) -> cerl().
call_name(Node) ->
Node#c_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
-spec call_args(c_call()) -> [cerl()].
call_args(Node) ->
Node#c_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.
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
-spec c_primop(cerl(), [cerl()]) -> c_primop().
c_primop(Name, Arguments) ->
#c_primop{name = Name, args = Arguments}.
%% @spec ann_c_primop(As::[term()], Name::cerl(),
%% Arguments::[cerl()]) -> cerl()
%% @see c_primop/2
-spec ann_c_primop([term()], cerl(), [cerl()]) -> c_primop().
ann_c_primop(As, Name, Arguments) ->
#c_primop{name = Name, args = Arguments, anno = As}.
%% @spec update_c_primop(Old::cerl(), Name::cerl(),
%% Arguments::[cerl()]) -> cerl()
%% @see c_primop/2
-spec update_c_primop(cerl(), cerl(), [cerl()]) -> c_primop().
update_c_primop(Node, Name, Arguments) ->
#c_primop{name = Name, args = Arguments, anno = 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
-spec is_c_primop(cerl()) -> boolean().
is_c_primop(#c_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
-spec primop_name(c_primop()) -> cerl().
primop_name(Node) ->
Node#c_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
-spec primop_args(c_primop()) -> [cerl()].
primop_args(Node) ->
Node#c_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.
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
-spec c_try(cerl(), [cerl()], cerl(), [cerl()], cerl()) -> c_try().
c_try(Expr, Vs, Body, Evs, Handler) ->
#c_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()], Handler::cerl()) -> cerl()
%% @see c_try/3
-spec ann_c_try([term()], cerl(), [cerl()], cerl(), [cerl()], cerl()) ->
c_try().
ann_c_try(As, Expr, Vs, Body, Evs, Handler) ->
#c_try{arg = Expr, vars = Vs, body = Body,
evars = Evs, handler = Handler, anno = As}.
%% @spec update_c_try(Old::cerl(), Expression::cerl(),
%% Variables::[cerl()], Body::cerl(),
%% EVars::[cerl()], Handler::cerl()) -> cerl()
%% @see c_try/3
-spec update_c_try(c_try(), cerl(), [cerl()], cerl(), [cerl()], cerl()) ->
c_try().
update_c_try(Node, Expr, Vs, Body, Evs, Handler) ->
#c_try{arg = Expr, vars = Vs, body = Body,
evars = Evs, handler = Handler, anno = 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
-spec is_c_try(cerl()) -> boolean().
is_c_try(#c_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
-spec try_arg(c_try()) -> cerl().
try_arg(Node) ->
Node#c_try.arg.
%% @spec try_vars(cerl()) -> [cerl()]
%%
%% @doc Returns the list of success variable subtrees of an abstract
%% try-expression.
%%
%% @see c_try/3
-spec try_vars(c_try()) -> [cerl()].
try_vars(Node) ->
Node#c_try.vars.
%% @spec try_body(cerl()) -> cerl()
%%
%% @doc Returns the success body subtree of an abstract try-expression.
%%
%% @see c_try/3
-spec try_body(c_try()) -> cerl().
try_body(Node) ->
Node#c_try.body.
%% @spec try_evars(cerl()) -> [cerl()]
%%
%% @doc Returns the list of exception variable subtrees of an abstract
%% try-expression.
%%
%% @see c_try/3
-spec try_evars(c_try()) -> [cerl()].
try_evars(Node) ->
Node#c_try.evars.
%% @spec try_handler(cerl()) -> cerl()
%%
%% @doc Returns the exception body subtree of an abstract
%% try-expression.
%%
%% @see c_try/3
-spec try_handler(c_try()) -> cerl().
try_handler(Node) ->
Node#c_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 -spec c_catch(cerl()) -> c_catch(). c_catch(Body) -> #c_catch{body = Body}. %% @spec ann_c_catch(As::[term()], Body::cerl()) -> cerl() %% @see c_catch/1 -spec ann_c_catch([term()], cerl()) -> c_catch(). ann_c_catch(As, Body) -> #c_catch{body = Body, anno = As}. %% @spec update_c_catch(Old::cerl(), Body::cerl()) -> cerl() %% @see c_catch/1 -spec update_c_catch(c_catch(), cerl()) -> c_catch(). update_c_catch(Node, Body) -> #c_catch{body = Body, anno = get_ann(Node)}. %% @spec is_c_catch(Node::cerl()) -> boolean() %% %% @doc Returnstrue if Node is an abstract
%% catch-expression, otherwise false.
%%
%% @see c_catch/1
-spec is_c_catch(cerl()) -> boolean().
is_c_catch(#c_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
-spec catch_body(c_catch()) -> cerl().
catch_body(Node) ->
Node#c_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".
%%
%% @see type/1
%% @see from_records/1
-spec to_records(cerl()) -> cerl().
to_records(Node) ->
Node.
%% @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_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 "core_parse.hrl".
%%
%% @see type/1
%% @see to_records/1
-spec from_records(cerl()) -> cerl().
from_records(Node) ->
Node.
%% ---------------------------------------------------------------------
%% @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
-spec is_data(cerl()) -> boolean().
is_data(#c_literal{}) ->
true;
is_data(#c_cons{}) ->
true;
is_data(#c_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 -type value() :: integer() | float() | atom() | []. -type dtype() :: 'cons' | 'tuple' | {'atomic', value()}. -type c_lct() :: c_literal() | c_cons() | c_tuple(). -spec data_type(c_lct()) -> dtype(). data_type(#c_literal{val = V}) -> case V of [_ | _] -> cons; _ when is_tuple(V) -> tuple; _ -> {atomic, V} end; data_type(#c_cons{}) -> cons; data_type(#c_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.
length(data_es(Node)), but
%% potentially more efficient.
%%
%% @see is_data/1
%% @see data_es/1
-spec data_arity(c_lct()) -> non_neg_integer().
data_arity(#c_literal{val = V}) ->
case V of
[_ | _] ->
2;
_ when is_tuple(V) ->
tuple_size(V);
_ ->
0
end;
data_arity(#c_cons{}) ->
2;
data_arity(#c_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
-spec make_data(dtype(), [cerl()]) -> c_lct().
make_data(CType, Es) ->
ann_make_data([], CType, Es).
%% @spec ann_make_data(As::[term()], Type::dtype(),
%% Elements::[cerl()]) -> cerl()
%% @see make_data/2
-spec ann_make_data([term()], dtype(), [cerl()]) -> c_lct().
ann_make_data(As, {atomic, V}, []) -> #c_literal{val = V, anno = 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
-spec update_data(cerl(), dtype(), [cerl()]) -> c_lct().
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
-spec make_data_skel(dtype(), [cerl()]) -> c_lct().
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
-spec ann_make_data_skel([term()], dtype(), [cerl()]) -> c_lct().
ann_make_data_skel(As, {atomic, V}, []) -> #c_literal{val = V, anno = 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
-spec update_data_skel(cerl(), dtype(), [cerl()]) -> c_lct().
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
-spec subtrees(cerl()) -> [[cerl()]].
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)];
map ->
[map_es(T)];
map_pair ->
[[map_pair_op(T)],[map_pair_key(T)],[map_pair_val(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
-spec update_tree(cerl(), [[cerl()],...]) -> cerl().
update_tree(Node, Gs) ->
ann_make_tree(get_ann(Node), type(Node), Gs).
%% @spec update_tree(Old::cerl(), Type::ctype(), 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
-spec update_tree(cerl(), ctype(), [[cerl()],...]) -> cerl().
update_tree(Node, Type, Gs) ->
ann_make_tree(get_ann(Node), Type, Gs).
%% @spec make_tree(Type::ctype(), 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.
make_tree/2 for details.
%%
%% @see make_tree/2
-spec ann_make_tree([term()], ctype(), [[cerl()],...]) -> cerl().
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, map, [Es]) -> ann_c_map(As, Es);
ann_make_tree(As, map, [[A], Es]) -> ann_c_map(As, A, Es);
ann_make_tree(As, map_pair, [[Op], [K], [V]]) -> ann_c_map_pair(As, Op, K, V);
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 -spec meta(cerl()) -> cerl(). 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 is_atom(V) -> meta_call(c_atom, [Node]); V when is_integer(V) -> meta_call(c_int, [Node]); V when is_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], Node1} -> meta_call(c_cons, [meta(H), meta(Node1)]); {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]); _ -> {lists:reverse(L), Node} end. %% --------------------------------------------------------------------- %% General utilities is_lit_list([#c_literal{} | Es]) -> is_lit_list(Es); is_lit_list([_ | _]) -> false; is_lit_list([]) -> true. lit_list_vals([#c_literal{val = V} | Es]) -> [V | lit_list_vals(Es)]; lit_list_vals([]) -> []. -spec make_lit_list([_]) -> [#c_literal{}]. % XXX: cerl() instead of _ ? make_lit_list([V | Vs]) -> [#c_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 is_integer(V) -> is_char_value(V) andalso is_char_list(Vs); is_char_list([]) -> true; is_char_list(_) -> false. is_print_char_list([V | Vs]) when is_integer(V) -> is_print_char_value(V) andalso is_print_char_list(Vs); 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([]) -> [].