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diff --git a/erts/doc/src/absform.xml b/erts/doc/src/absform.xml index 0b04f8f70e..2ada903edb 100644 --- a/erts/doc/src/absform.xml +++ b/erts/doc/src/absform.xml @@ -4,7 +4,7 @@ <chapter> <header> <copyright> - <year>2001</year><year>2016</year> + <year>2001</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -26,144 +26,206 @@ <prepared>Arndt Jonasson</prepared> <responsible>Kenneth Lundin</responsible> <docno>1</docno> - <approved>Jultomten</approved> + <approved></approved> <checked></checked> - <date>00-12-01</date> + <date>2000-12-01</date> <rev>A</rev> <file>absform.xml</file> </header> - <p></p> - <p>This document describes the standard representation of parse trees for Erlang - programs as Erlang terms. This representation is known as the <em>abstract format</em>. - Functions dealing with such parse trees are <c>compile:forms/[1,2]</c> - and functions in the modules - <c>epp</c>, - <c>erl_eval</c>, - <c>erl_lint</c>, - <c>erl_pp</c>, - <c>erl_parse</c>, - and - <c>io</c>. - They are also used as input and output for parse transforms (see the module - <c>compile</c>).</p> + <p>This section describes the standard representation of parse trees for Erlang + programs as Erlang terms. This representation is known as the <em>abstract + format</em>. Functions dealing with such parse trees are + <seealso marker="compiler:compile#forms/1"> + <c>compile:forms/1,2</c></seealso> and functions in the following + modules:</p> + + <list type="bulleted"> + <item><seealso marker="stdlib:epp"> + <c>epp(3)</c></seealso></item> + <item><seealso marker="stdlib:erl_eval"> + <c>erl_eval(3)</c></seealso></item> + <item><seealso marker="stdlib:erl_lint"> + <c>erl_lint(3)</c></seealso></item> + <item><seealso marker="stdlib:erl_parse"> + <c>erl_parse(3)</c></seealso></item> + <item><seealso marker="stdlib:erl_pp"> + <c>erl_pp(3)</c></seealso></item> + <item><seealso marker="stdlib:io"> + <c>io(3)</c></seealso></item> + </list> + + <p>The functions are also used as input and output for parse transforms, see + the <seealso marker="compiler:compile"><c>compile(3)</c></seealso> + module.</p> + <p>We use the function <c>Rep</c> to denote the mapping from an Erlang source construct <c>C</c> to its abstract format representation <c>R</c>, and write - <c>R = Rep(C)</c>. - </p> - <p>The word <c>LINE</c> below represents an integer, and denotes the + <c>R = Rep(C)</c>.</p> + + <p>The word <c>LINE</c> in this section represents an integer, and denotes the number of the line in the source file where the construction occurred. - Several instances of <c>LINE</c> in the same construction may denote + Several instances of <c>LINE</c> in the same construction can denote different lines.</p> - <p>Since operators are not terms in their own right, when operators are - mentioned below, the representation of an operator should be taken to + + <p>As operators are not terms in their own right, when operators are + mentioned below, the representation of an operator is to be taken to be the atom with a printname consisting of the same characters as the - operator. - </p> + operator.</p> <section> <title>Module Declarations and Forms</title> - <p>A module declaration consists of a sequence of forms that are either + <p>A module declaration consists of a sequence of forms, which are either function declarations or attributes.</p> + <list type="bulleted"> - <item>If D is a module declaration consisting of the forms - <c>F_1</c>, ..., <c>F_k</c>, then - Rep(D) = <c>[Rep(F_1), ..., Rep(F_k)]</c>.</item> - <item>If F is an attribute <c>-export([Fun_1/A_1, ..., Fun_k/A_k])</c>, then - Rep(F) = <c>{attribute,LINE,export,[{Fun_1,A_1}, ..., {Fun_k,A_k}]}</c>.</item> - <item>If F is an attribute <c>-import(Mod,[Fun_1/A_1, ..., Fun_k/A_k])</c>, then - Rep(F) = <c>{attribute,LINE,import,{Mod,[{Fun_1,A_1}, ..., {Fun_k,A_k}]}}</c>.</item> - <item>If F is an attribute <c>-module(Mod)</c>, then - Rep(F) = <c>{attribute,LINE,module,Mod}</c>.</item> - <item>If F is an attribute <c>-file(File,Line)</c>, then - Rep(F) = <c>{attribute,LINE,file,{File,Line}}</c>.</item> - <item>If F is a function declaration - <c>Name Fc_1 ; ... ; Name Fc_k</c>, - where each <c>Fc_i</c> is a function clause with a - pattern sequence of the same length <c>Arity</c>, then - Rep(F) = <c>{function,LINE,Name,Arity,[Rep(Fc_1), ...,Rep(Fc_k)]}</c>. - </item> - <item>If F is a function specification - <c>-Spec Name Ft_1; ...; Ft_k</c>, - where <c>Spec</c> is either the atom <c>spec</c> or the atom - <c>callback</c>, and each <c>Ft_i</c> is a possibly constrained - function type with an argument sequence of the same length - <c>Arity</c>, then Rep(F) = - <c>{attribute,Line,Spec,{{Name,Arity},[Rep(Ft_1), ..., Rep(Ft_k)]}}</c>. - </item> - <item>If F is a function specification - <c>-spec Mod:Name Ft_1; ...; Ft_k</c>, - where each <c>Ft_i</c> is a possibly constrained - function type with an argument sequence of the same length - <c>Arity</c>, then Rep(F) = - <c>{attribute,Line,spec,{{Mod,Name,Arity},[Rep(Ft_1), ..., Rep(Ft_k)]}}</c>. - </item> - <item>If F is a record declaration - <c>-record(Name,{V_1, ..., V_k})</c>, - where each <c>V_i</c> is a record field, then Rep(F) = - <c>{attribute,LINE,record,{Name,[Rep(V_1), ..., Rep(V_k)]}}</c>. - For Rep(V), see below.</item> - <item>If F is a type declaration - <c>-Type Name(V_1, ..., V_k) :: T</c>, where - <c>Type</c> is either the atom <c>type</c> or the atom <c>opaque</c>, - each <c>V_i</c> is a variable, and <c>T</c> is a type, then Rep(F) = - <c>{attribute,LINE,Type,{Name,Rep(T),[Rep(V_1), ..., Rep(V_k)]}}</c>. - </item> - <item>If F is a wild attribute <c>-A(T)</c>, then - Rep(F) = <c>{attribute,LINE,A,T}</c>. - <br></br></item> + <item> + <p>If D is a module declaration consisting of the forms + <c>F_1</c>, ..., <c>F_k</c>, then + Rep(D) = <c>[Rep(F_1), ..., Rep(F_k)]</c>.</p> + </item> + <item> + <p>If F is an attribute <c>-export([Fun_1/A_1, ..., Fun_k/A_k])</c>, + then Rep(F) = + <c>{attribute,LINE,export,[{Fun_1,A_1}, ..., {Fun_k,A_k}]}</c>.</p> + </item> + <item> + <p>If F is an attribute <c>-import(Mod,[Fun_1/A_1, ..., Fun_k/A_k])</c>, + then Rep(F) = + <c>{attribute,LINE,import,{Mod,[{Fun_1,A_1}, ..., + {Fun_k,A_k}]}}</c>.</p> + </item> + <item> + <p>If F is an attribute <c>-module(Mod)</c>, then + Rep(F) = <c>{attribute,LINE,module,Mod}</c>.</p> + </item> + <item> + <p>If F is an attribute <c>-file(File,Line)</c>, then + Rep(F) = <c>{attribute,LINE,file,{File,Line}}</c>.</p> + </item> + <item> + <p>If F is a function declaration <c>Name Fc_1 ; ... ; Name Fc_k</c>, + where each <c>Fc_i</c> is a function clause with a pattern sequence of + the same length <c>Arity</c>, then Rep(F) = + <c>{function,LINE,Name,Arity,[Rep(Fc_1), ...,Rep(Fc_k)]}</c>.</p> + </item> + <item> + <p>If F is a function specification <c>-Spec Name Ft_1; ...; Ft_k</c>, + where <c>Spec</c> is either the atom <c>spec</c> or the atom + <c>callback</c>, and each <c>Ft_i</c> is a possibly constrained + function type with an argument sequence of the same length + <c>Arity</c>, then Rep(F) = + <c>{attribute,Line,Spec,{{Name,Arity},[Rep(Ft_1), ..., + Rep(Ft_k)]}}</c>.</p> + </item> + <item> + <p>If F is a function specification + <c>-spec Mod:Name Ft_1; ...; Ft_k</c>, where each <c>Ft_i</c> is a + possibly constrained function type with an argument sequence of the + same length <c>Arity</c>, then Rep(F) = + <c>{attribute,Line,spec,{{Mod,Name,Arity},[Rep(Ft_1), ..., + Rep(Ft_k)]}}</c>.</p> + </item> + <item> + <p>If F is a record declaration <c>-record(Name,{V_1, ..., V_k})</c>, + where each <c>V_i</c> is a record field, then Rep(F) = + <c>{attribute,LINE,record,{Name,[Rep(V_1), ..., Rep(V_k)]}}</c>. + For Rep(V), see below.</p> + </item> + <item> + <p>If F is a type declaration <c>-Type Name(V_1, ..., V_k) :: T</c>, + where <c>Type</c> is either the atom <c>type</c> or the atom + <c>opaque</c>, each <c>V_i</c> is a variable, and <c>T</c> is a type, + then Rep(F) = + <c>{attribute,LINE,Type,{Name,Rep(T),[Rep(V_1), ..., + Rep(V_k)]}}</c>.</p> + </item> + <item> + <p>If F is a wild attribute <c>-A(T)</c>, then + Rep(F) = <c>{attribute,LINE,A,T}</c>.</p> + </item> </list> <section> <title>Record Fields</title> - <p>Each field in a record declaration may have an optional - explicit default initializer expression, as well as an + <p>Each field in a record declaration can have an optional, + explicit, default initializer expression, and an optional type.</p> + <list type="bulleted"> - <item>If V is <c>A</c>, then - Rep(V) = <c>{record_field,LINE,Rep(A)}</c>.</item> - <item>If V is <c>A = E</c>, - where <c>E</c> is an expression, then - Rep(V) = <c>{record_field,LINE,Rep(A),Rep(E)}</c>.</item> - <item>If V is <c>A :: T</c>, where <c>T</c> is a type, then Rep(V) = - <c>{typed_record_field,{record_field,LINE,Rep(A)},Rep(T)}</c>. - </item> - <item>If V is <c>A = E :: T</c>, where - <c>E</c> is an expression and <c>T</c> is a type, then Rep(V) = - <c>{typed_record_field,{record_field,LINE,Rep(A),Rep(E)},Rep(T)}</c>. + <item> + <p>If V is <c>A</c>, then + Rep(V) = <c>{record_field,LINE,Rep(A)}</c>.</p> + </item> + <item> + <p>If V is <c>A = E</c>, where <c>E</c> is an expression, then + Rep(V) = <c>{record_field,LINE,Rep(A),Rep(E)}</c>.</p> + </item> + <item> + <p>If V is <c>A :: T</c>, where <c>T</c> is a type, then Rep(V) = + <c>{typed_record_field,{record_field,LINE,Rep(A)},Rep(T)}</c>.</p> + </item> + <item> + <p>If V is <c>A = E :: T</c>, where + <c>E</c> is an expression and <c>T</c> is a type, then Rep(V) = + <c>{typed_record_field,{record_field,LINE,Rep(A),Rep(E)},Rep(T)}</c>. + </p> </item> </list> </section> <section> - <title>Representation of Parse Errors and End-of-file</title> + <title>Representation of Parse Errors and End-of-File</title> <p>In addition to the representations of forms, the list that represents - a module declaration (as returned by functions in <c>erl_parse</c> and - <c>epp</c>) may contain tuples <c>{error,E}</c> and - <c>{warning,W}</c>, denoting syntactically incorrect forms and - warnings, and <c>{eof,LINE}</c>, denoting an end-of-stream - encountered before a complete form had been parsed.</p> + a module declaration (as returned by functions in + <seealso marker="stdlib:epp"><c>epp(3)</c></seealso> and + <seealso marker="stdlib:erl_parse"><c>erl_parse(3)</c></seealso>) + can contain the following:</p> + + <list type="bulleted"> + <item> + <p>Tuples <c>{error,E}</c> and <c>{warning,W}</c>, denoting + syntactically incorrect forms and warnings. + </p> + </item> + <item> + <p><c>{eof,LOCATION}</c>, denoting an end-of-stream + encountered before a complete form had been parsed. + The word <c>LOCATION</c> represents an integer, and denotes the + number of the last line in the source file. + </p> + </item> + </list> </section> </section> <section> <title>Atomic Literals</title> <p>There are five kinds of atomic literals, which are represented in the - same way in patterns, expressions and guards:</p> + same way in patterns, expressions, and guards:</p> + <list type="bulleted"> - <item>If L is an atom literal, then - Rep(L) = <c>{atom,LINE,L}</c>.</item> - <item>If L is a character literal, then - Rep(L) = <c>{char,LINE,L}</c>.</item> - <item>If L is a float literal, then - Rep(L) = <c>{float,LINE,L}</c>.</item> - <item>If L is an integer literal, then - Rep(L) = <c>{integer,LINE,L}</c>.</item> - <item>If L is a string literal consisting of the characters - <c>C_1</c>, ..., <c>C_k</c>, then - Rep(L) = <c>{string,LINE,[C_1, ..., C_k]}</c>.</item> + <item> + <p>If L is an atom literal, then Rep(L) = <c>{atom,LINE,L}</c>.</p> + </item> + <item> + <p>If L is a character literal, then Rep(L) = <c>{char,LINE,L}</c>.</p> + </item> + <item> + <p>If L is a float literal, then Rep(L) = <c>{float,LINE,L}</c>.</p> + </item> + <item> + <p>If L is an integer literal, then + Rep(L) = <c>{integer,LINE,L}</c>.</p> + </item> + <item> + <p>If L is a string literal consisting of the characters + <c>C_1</c>, ..., <c>C_k</c>, then + Rep(L) = <c>{string,LINE,[C_1, ..., C_k]}</c>.</p> + </item> </list> - <p>Note that negative integer and float literals do not occur as such; they are - parsed as an application of the unary negation operator.</p> + + <p>Notice that negative integer and float literals do not occur as such; + they are parsed as an application of the unary negation operator.</p> </section> <section> @@ -171,288 +233,456 @@ <p>If Ps is a sequence of patterns <c>P_1, ..., P_k</c>, then Rep(Ps) = <c>[Rep(P_1), ..., Rep(P_k)]</c>. Such sequences occur as the list of arguments to a function or fun.</p> + <p>Individual patterns are represented as follows:</p> + <list type="bulleted"> - <item>If P is an atomic literal <c>L</c>, then Rep(P) = Rep(L).</item> - <item>If P is a bit string pattern - <c><<P_1:Size_1/TSL_1, ..., P_k:Size_k/TSL_k>></c>, where each - <c>Size_i</c> is an expression that can be evaluated to an integer - and each <c>TSL_i</c> is a type specificer list, then - Rep(P) = <c>{bin,LINE,[{bin_element,LINE,Rep(P_1),Rep(Size_1),Rep(TSL_1)}, ..., {bin_element,LINE,Rep(P_k),Rep(Size_k),Rep(TSL_k)}]}</c>. - For Rep(TSL), see below. - An omitted <c>Size_i</c> is represented by <c>default</c>. - An omitted <c>TSL_i</c> is represented by <c>default</c>.</item> - <item>If P is a compound pattern <c>P_1 = P_2</c>, then - Rep(P) = <c>{match,LINE,Rep(P_1),Rep(P_2)}</c>.</item> - <item>If P is a cons pattern <c>[P_h | P_t]</c>, then - Rep(P) = <c>{cons,LINE,Rep(P_h),Rep(P_t)}</c>.</item> - <item>If P is a map pattern <c>#{A_1, ..., A_k}</c>, where each - <c>A_i</c> is an association <c>P_i_1 := P_i_2</c>, then Rep(P) = - <c>{map,LINE,[Rep(A_1), ..., Rep(A_k)]}</c>. For Rep(A), see - below.</item> - <item>If P is a nil pattern <c>[]</c>, then - Rep(P) = <c>{nil,LINE}</c>.</item> - <item>If P is an operator pattern <c>P_1 Op P_2</c>, - where <c>Op</c> is a binary operator (this is either an occurrence - of <c>++</c> applied to a literal string or character - list, or an occurrence of an expression that can be evaluated to a number - at compile time), - then Rep(P) = <c>{op,LINE,Op,Rep(P_1),Rep(P_2)}</c>.</item> - <item>If P is an operator pattern <c>Op P_0</c>, - where <c>Op</c> is a unary operator (this is an occurrence of - an expression that can be evaluated to a number at compile - time), then Rep(P) = <c>{op,LINE,Op,Rep(P_0)}</c>.</item> - <item>If P is a parenthesized pattern <c>( P_0 )</c>, then - Rep(P) = <c>Rep(P_0)</c>, - that is, parenthesized patterns cannot be distinguished from their - bodies.</item> - <item>If P is a record field index pattern <c>#Name.Field</c>, - where <c>Field</c> is an atom, then - Rep(P) = <c>{record_index,LINE,Name,Rep(Field)}</c>.</item> - <item>If P is a record pattern - <c>#Name{Field_1=P_1, ..., Field_k=P_k}</c>, - where each <c>Field_i</c> is an atom or <c>_</c>, then Rep(P) = - <c>{record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(P_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(P_k)}]}</c>.</item> - <item>If P is a tuple pattern <c>{P_1, ..., P_k}</c>, then - Rep(P) = <c>{tuple,LINE,[Rep(P_1), ..., Rep(P_k)]}</c>.</item> - <item>If P is a universal pattern <c>_</c>, then - Rep(P) = <c>{var,LINE,'_'}</c>.</item> - <item>If P is a variable pattern <c>V</c>, then - Rep(P) = <c>{var,LINE,A}</c>, - where A is an atom with a printname consisting of the same characters as - <c>V</c>.</item> + <item> + <p>If P is an atomic literal <c>L</c>, then Rep(P) = Rep(L).</p> + </item> + <item> + <p>If P is a bitstring pattern + <c><<P_1:Size_1/TSL_1, ..., P_k:Size_k/TSL_k>></c>, where each + <c>Size_i</c> is an expression that can be evaluated to an integer, + and each <c>TSL_i</c> is a type specificer list, then Rep(P) = + <c>{bin,LINE,[{bin_element,LINE,Rep(P_1),Rep(Size_1),Rep(TSL_1)}, + ..., {bin_element,LINE,Rep(P_k),Rep(Size_k),Rep(TSL_k)}]}</c>. + For Rep(TSL), see below. + An omitted <c>Size_i</c> is represented by <c>default</c>. + An omitted <c>TSL_i</c> is represented by <c>default</c>.</p> + </item> + <item> + <p>If P is a compound pattern <c>P_1 = P_2</c>, then Rep(P) = + <c>{match,LINE,Rep(P_1),Rep(P_2)}</c>.</p> + </item> + <item> + <p>If P is a cons pattern <c>[P_h | P_t]</c>, then Rep(P) = + <c>{cons,LINE,Rep(P_h),Rep(P_t)}</c>.</p> + </item> + <item> + <p>If P is a map pattern <c>#{A_1, ..., A_k}</c>, where each + <c>A_i</c> is an association <c>P_i_1 := P_i_2</c>, then Rep(P) = + <c>{map,LINE,[Rep(A_1), ..., Rep(A_k)]}</c>. + For Rep(A), see below.</p> + </item> + <item> + <p>If P is a nil pattern <c>[]</c>, then Rep(P) = + <c>{nil,LINE}</c>.</p> + </item> + <item> + <p>If P is an operator pattern <c>P_1 Op P_2</c>, where <c>Op</c> is a + binary operator (this is either an occurrence of <c>++</c> applied to + a literal string or character list, or an occurrence of an expression + that can be evaluated to a number at compile time), then Rep(P) = + <c>{op,LINE,Op,Rep(P_1),Rep(P_2)}</c>.</p> + </item> + <item> + <p>If P is an operator pattern <c>Op P_0</c>, where <c>Op</c> is a + unary operator (this is an occurrence of an expression that can be + evaluated to a number at compile time), then Rep(P) = + <c>{op,LINE,Op,Rep(P_0)}</c>.</p> + </item> + <item> + <p>If P is a parenthesized pattern <c>( P_0 )</c>, then Rep(P) = + <c>Rep(P_0)</c>, that is, parenthesized patterns cannot be + distinguished from their bodies.</p> + </item> + <item> + <p>If P is a record field index pattern <c>#Name.Field</c>, + where <c>Field</c> is an atom, then Rep(P) = + <c>{record_index,LINE,Name,Rep(Field)}</c>.</p> + </item> + <item> + <p>If P is a record pattern <c>#Name{Field_1=P_1, ..., Field_k=P_k}</c>, + where each <c>Field_i</c> is an atom or <c>_</c>, then Rep(P) = + <c>{record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(P_1)}, ..., + {record_field,LINE,Rep(Field_k),Rep(P_k)}]}</c>.</p> + </item> + <item> + <p>If P is a tuple pattern <c>{P_1, ..., P_k}</c>, then Rep(P) = + <c>{tuple,LINE,[Rep(P_1), ..., Rep(P_k)]}</c>.</p> + </item> + <item> + <p>If P is a universal pattern <c>_</c>, then Rep(P) = + <c>{var,LINE,'_'}</c>.</p></item> + <item> + <p>If P is a variable pattern <c>V</c>, then Rep(P) = + <c>{var,LINE,A}</c>, where A is an atom with a printname consisting + of the same characters as <c>V</c>.</p> + </item> </list> - <p>Note that every pattern has the same source form as some expression, and is - represented the same way as the corresponding expression.</p> + + <p>Notice that every pattern has the same source form as some expression, + and is represented in the same way as the corresponding expression.</p> </section> <section> <title>Expressions</title> - <p>A body B is a nonempty sequence of expressions <c>E_1, ..., E_k</c>, + <p>A body B is a non-empty sequence of expressions <c>E_1, ..., E_k</c>, and Rep(B) = <c>[Rep(E_1), ..., Rep(E_k)]</c>.</p> - <p>An expression E is one of the following alternatives:</p> + + <p>An expression E is one of the following:</p> + <list type="bulleted"> - <item>If E is an atomic literal <c>L</c>, then Rep(E) = Rep(L).</item> - <item>If E is a bit string comprehension - <c><<E_0 || Q_1, ..., Q_k>></c>, - where each <c>Q_i</c> is a qualifier, then - Rep(E) = <c>{bc,LINE,Rep(E_0),[Rep(Q_1), ..., Rep(Q_k)]}</c>. - For Rep(Q), see below.</item> - <item>If E is a bit string constructor - <c><<E_1:Size_1/TSL_1, ..., E_k:Size_k/TSL_k>></c>, - where each <c>Size_i</c> is an expression and each - <c>TSL_i</c> is a type specificer list, then Rep(E) = - <c>{bin,LINE,[{bin_element,LINE,Rep(E_1),Rep(Size_1),Rep(TSL_1)}, ..., {bin_element,LINE,Rep(E_k),Rep(Size_k),Rep(TSL_k)}]}</c>. - For Rep(TSL), see below. - An omitted <c>Size_i</c> is represented by <c>default</c>. - An omitted <c>TSL_i</c> is represented by <c>default</c>.</item> - <item>If E is a block expression <c>begin B end</c>, - where <c>B</c> is a body, then - Rep(E) = <c>{block,LINE,Rep(B)}</c>.</item> - <item>If E is a case expression <c>case E_0 of Cc_1 ; ... ; Cc_k end</c>, - where <c>E_0</c> is an expression and each <c>Cc_i</c> is a - case clause then Rep(E) = - <c>{'case',LINE,Rep(E_0),[Rep(Cc_1), ..., Rep(Cc_k)]}</c>.</item> - <item>If E is a catch expression <c>catch E_0</c>, then - Rep(E) = <c>{'catch',LINE,Rep(E_0)}</c>.</item> - <item>If E is a cons skeleton <c>[E_h | E_t]</c>, then - Rep(E) = <c>{cons,LINE,Rep(E_h),Rep(E_t)}</c>.</item> - <item>If E is a fun expression <c>fun Name/Arity</c>, then - Rep(E) = <c>{'fun',LINE,{function,Name,Arity}}</c>.</item> - <item>If E is a fun expression - <c>fun Module:Name/Arity</c>, then Rep(E) = - <c>{'fun',LINE,{function,Rep(Module),Rep(Name),Rep(Arity)}}</c>. - (Before the R15 release: Rep(E) = - <c>{'fun',LINE,{function,Module,Name,Arity}}</c>.)</item> - <item>If E is a fun expression <c>fun Fc_1 ; ... ; Fc_k end</c>, - where each <c>Fc_i</c> is a function clause then Rep(E) = - <c>{'fun',LINE,{clauses,[Rep(Fc_1), ..., Rep(Fc_k)]}}</c>.</item> - <item>If E is a fun expression - <c>fun Name Fc_1 ; ... ; Name Fc_k end</c>, - where <c>Name</c> is a variable and each - <c>Fc_i</c> is a function clause then Rep(E) = - <c>{named_fun,LINE,Name,[Rep(Fc_1), ..., Rep(Fc_k)]}</c>. - </item> - <item>If E is a function call <c>E_0(E_1, ..., E_k)</c>, then - Rep(E) = <c>{call,LINE,Rep(E_0),[Rep(E_1), ..., Rep(E_k)]}</c>.</item> - <item>If E is a function call <c>E_m:E_0(E_1, ..., E_k)</c>, - then Rep(E) = - <c>{call,LINE,{remote,LINE,Rep(E_m),Rep(E_0)},[Rep(E_1), ..., Rep(E_k)]}</c>. - </item> - <item>If E is an if expression <c>if Ic_1 ; ... ; Ic_k end</c>, - where each <c>Ic_i</c> is an if clause then Rep(E) = - <c>{'if',LINE,[Rep(Ic_1), ..., Rep(Ic_k)]}</c>.</item> - <item>If E is a list comprehension <c>[E_0 || Q_1, ..., Q_k]</c>, - where each <c>Q_i</c> is a qualifier, then Rep(E) = - <c>{lc,LINE,Rep(E_0),[Rep(Q_1), ..., Rep(Q_k)]}</c>. For Rep(Q), see - below.</item> - <item>If E is a map creation <c>#{A_1, ..., A_k}</c>, - where each <c>A_i</c> is an association <c>E_i_1 => E_i_2</c> - or <c>E_i_1 := E_i_2</c>, then Rep(E) = - <c>{map,LINE,[Rep(A_1), ..., Rep(A_k)]}</c>. For Rep(A), see - below.</item> - <item>If E is a map update <c>E_0#{A_1, ..., A_k}</c>, - where each <c>A_i</c> is an association <c>E_i_1 => E_i_2</c> - or <c>E_i_1 := E_i_2</c>, then Rep(E) = - <c>{map,LINE,Rep(E_0),[Rep(A_1), ..., Rep(A_k)]}</c>. - For Rep(A), see below.</item> - <item>If E is a match operator expression <c>P = E_0</c>, - where <c>P</c> is a pattern, then - Rep(E) = <c>{match,LINE,Rep(P),Rep(E_0)}</c>.</item> - <item>If E is nil, <c>[]</c>, then - Rep(E) = <c>{nil,LINE}</c>.</item> - <item>If E is an operator expression <c>E_1 Op E_2</c>, - where <c>Op</c> is a binary operator other than the match - operator <c>=</c>, then - Rep(E) = <c>{op,LINE,Op,Rep(E_1),Rep(E_2)}</c>.</item> - <item>If E is an operator expression <c>Op E_0</c>, - where <c>Op</c> is a unary operator, then - Rep(E) = <c>{op,LINE,Op,Rep(E_0)}</c>.</item> - <item>If E is a parenthesized expression <c>( E_0 )</c>, then - Rep(E) = <c>Rep(E_0)</c>, that is, parenthesized - expressions cannot be distinguished from their bodies.</item> - <item>If E is a receive expression <c>receive Cc_1 ; ... ; Cc_k end</c>, - where each <c>Cc_i</c> is a case clause then Rep(E) = - <c>{'receive',LINE,[Rep(Cc_1), ..., Rep(Cc_k)]}</c>.</item> - <item>If E is a receive expression - <c>receive Cc_1 ; ... ; Cc_k after E_0 -> B_t end</c>, - where each <c>Cc_i</c> is a case clause, - <c>E_0</c> is an expression and <c>B_t</c> is a body, then Rep(E) = - <c>{'receive',LINE,[Rep(Cc_1), ..., Rep(Cc_k)],Rep(E_0),Rep(B_t)}</c>.</item> - <item>If E is a record creation - <c>#Name{Field_1=E_1, ..., Field_k=E_k}</c>, - where each <c>Field_i</c> is an atom or <c>_</c>, then Rep(E) = - <c>{record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(E_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(E_k)}]}</c>.</item> - <item>If E is a record field access <c>E_0#Name.Field</c>, - where <c>Field</c> is an atom, then - Rep(E) = <c>{record_field,LINE,Rep(E_0),Name,Rep(Field)}</c>.</item> - <item>If E is a record field index <c>#Name.Field</c>, - where <c>Field</c> is an atom, then - Rep(E) = <c>{record_index,LINE,Name,Rep(Field)}</c>.</item> - <item>If E is a record update - <c>E_0#Name{Field_1=E_1, ..., Field_k=E_k}</c>, - where each <c>Field_i</c> is an atom, then Rep(E) = - <c>{record,LINE,Rep(E_0),Name,[{record_field,LINE,Rep(Field_1),Rep(E_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(E_k)}]}</c>.</item> - <item>If E is a tuple skeleton <c>{E_1, ..., E_k}</c>, then - Rep(E) = <c>{tuple,LINE,[Rep(E_1), ..., Rep(E_k)]}</c>.</item> - <item>If E is a try expression <c>try B catch Tc_1 ; ... ; Tc_k end</c>, - where <c>B</c> is a body and each <c>Tc_i</c> is a catch clause then - Rep(E) = - <c>{'try',LINE,Rep(B),[],[Rep(Tc_1), ..., Rep(Tc_k)],[]}</c>.</item> - <item>If E is a try expression - <c>try B of Cc_1 ; ... ; Cc_k catch Tc_1 ; ... ; Tc_n end</c>, - where <c>B</c> is a body, - each <c>Cc_i</c> is a case clause and - each <c>Tc_j</c> is a catch clause then Rep(E) = - <c>{'try',LINE,Rep(B),[Rep(Cc_1), ..., Rep(Cc_k)],[Rep(Tc_1), ..., Rep(Tc_n)],[]}</c>.</item> - <item>If E is a try expression <c>try B after A end</c>, - where <c>B</c> and <c>A</c> are bodies then Rep(E) = - <c>{'try',LINE,Rep(B),[],[],Rep(A)}</c>.</item> - <item>If E is a try expression - <c>try B of Cc_1 ; ... ; Cc_k after A end</c>, - where <c>B</c> and <c>A</c> are a bodies and - each <c>Cc_i</c> is a case clause then Rep(E) = - <c>{'try',LINE,Rep(B),[Rep(Cc_1), ..., Rep(Cc_k)],[],Rep(A)}</c>.</item> - <item>If E is a try expression - <c>try B catch Tc_1 ; ... ; Tc_k after A end</c>, - where <c>B</c> and <c>A</c> are bodies and - each <c>Tc_i</c> is a catch clause then Rep(E) = - <c>{'try',LINE,Rep(B),[],[Rep(Tc_1), ..., Rep(Tc_k)],Rep(A)}</c>.</item> - <item>If E is a try expression - <c>try B of Cc_1 ; ... ; Cc_k catch Tc_1 ; ... ; Tc_n after A end</c>, - where <c>B</c> and <c>A</c> are a bodies, - each <c>Cc_i</c> is a case clause, and - each <c>Tc_j</c> is a catch clause then - Rep(E) = - <c>{'try',LINE,Rep(B),[Rep(Cc_1), ..., Rep(Cc_k)],[Rep(Tc_1), ..., Rep(Tc_n)],Rep(A)}</c>.</item> - <item>If E is a variable <c>V</c>, then Rep(E) = <c>{var,LINE,A}</c>, - where <c>A</c> is an atom with a printname consisting of the same - characters as <c>V</c>.</item> + <item> + <p>If E is an atomic literal <c>L</c>, then Rep(E) = Rep(L).</p> + </item> + <item> + <p>If E is a bitstring comprehension + <c><<E_0 || Q_1, ..., Q_k>></c>, + where each <c>Q_i</c> is a qualifier, then Rep(E) = + <c>{bc,LINE,Rep(E_0),[Rep(Q_1), ..., Rep(Q_k)]}</c>. + For Rep(Q), see below.</p> + </item> + <item> + <p>If E is a bitstring constructor + <c><<E_1:Size_1/TSL_1, ..., E_k:Size_k/TSL_k>></c>, + where each <c>Size_i</c> is an expression and each + <c>TSL_i</c> is a type specificer list, then Rep(E) = + <c>{bin,LINE,[{bin_element,LINE,Rep(E_1),Rep(Size_1),Rep(TSL_1)}, + ..., {bin_element,LINE,Rep(E_k),Rep(Size_k),Rep(TSL_k)}]}</c>. + For Rep(TSL), see below. + An omitted <c>Size_i</c> is represented by <c>default</c>. + An omitted <c>TSL_i</c> is represented by <c>default</c>.</p> + </item> + <item> + <p>If E is a block expression <c>begin B end</c>, + where <c>B</c> is a body, then Rep(E) = + <c>{block,LINE,Rep(B)}</c>.</p> + </item> + <item> + <p>If E is a case expression <c>case E_0 of Cc_1 ; ... ; Cc_k end</c>, + where <c>E_0</c> is an expression and each <c>Cc_i</c> is a + case clause, then Rep(E) = + <c>{'case',LINE,Rep(E_0),[Rep(Cc_1), ..., Rep(Cc_k)]}</c>.</p> + </item> + <item> + <p>If E is a catch expression <c>catch E_0</c>, then Rep(E) = + <c>{'catch',LINE,Rep(E_0)}</c>.</p> + </item> + <item> + <p>If E is a cons skeleton <c>[E_h | E_t]</c>, then Rep(E) = + <c>{cons,LINE,Rep(E_h),Rep(E_t)}</c>.</p> + </item> + <item> + <p>If E is a fun expression <c>fun Name/Arity</c>, then Rep(E) = + <c>{'fun',LINE,{function,Name,Arity}}</c>.</p> + </item> + <item> + <p>If E is a fun expression <c>fun Module:Name/Arity</c>, then Rep(E) = + <c>{'fun',LINE,{function,Rep(Module),Rep(Name),Rep(Arity)}}</c>. + (Before Erlang/OTP R15: Rep(E) = + <c>{'fun',LINE,{function,Module,Name,Arity}}</c>.)</p> + </item> + <item> + <p>If E is a fun expression <c>fun Fc_1 ; ... ; Fc_k end</c>, + where each <c>Fc_i</c> is a function clause, then Rep(E) = + <c>{'fun',LINE,{clauses,[Rep(Fc_1), ..., Rep(Fc_k)]}}</c>.</p> + </item> + <item> + <p>If E is a fun expression <c>fun Name Fc_1 ; ... ; Name Fc_k end</c>, + where <c>Name</c> is a variable and each + <c>Fc_i</c> is a function clause, then Rep(E) = + <c>{named_fun,LINE,Name,[Rep(Fc_1), ..., Rep(Fc_k)]}</c>.</p> + </item> + <item> + <p>If E is a function call <c>E_0(E_1, ..., E_k)</c>, then Rep(E) = + <c>{call,LINE,Rep(E_0),[Rep(E_1), ..., Rep(E_k)]}</c>.</p> + </item> + <item> + <p>If E is a function call <c>E_m:E_0(E_1, ..., E_k)</c>, then Rep(E) = + <c>{call,LINE,{remote,LINE,Rep(E_m),Rep(E_0)},[Rep(E_1), ..., + Rep(E_k)]}</c>.</p> + </item> + <item> + <p>If E is an if expression <c>if Ic_1 ; ... ; Ic_k end</c>, + where each <c>Ic_i</c> is an if clause, then Rep(E) = + <c>{'if',LINE,[Rep(Ic_1), ..., Rep(Ic_k)]}</c>.</p> + </item> + <item> + <p>If E is a list comprehension <c>[E_0 || Q_1, ..., Q_k]</c>, + where each <c>Q_i</c> is a qualifier, then Rep(E) = + <c>{lc,LINE,Rep(E_0),[Rep(Q_1), ..., Rep(Q_k)]}</c>. + For Rep(Q), see below.</p> + </item> + <item> + <p>If E is a map creation <c>#{A_1, ..., A_k}</c>, + where each <c>A_i</c> is an association <c>E_i_1 => E_i_2</c> + or <c>E_i_1 := E_i_2</c>, then Rep(E) = + <c>{map,LINE,[Rep(A_1), ..., Rep(A_k)]}</c>. + For Rep(A), see below.</p> + </item> + <item> + <p>If E is a map update <c>E_0#{A_1, ..., A_k}</c>, + where each <c>A_i</c> is an association <c>E_i_1 => E_i_2</c> + or <c>E_i_1 := E_i_2</c>, then Rep(E) = + <c>{map,LINE,Rep(E_0),[Rep(A_1), ..., Rep(A_k)]}</c>. + For Rep(A), see below.</p> + </item> + <item> + <p>If E is a match operator expression <c>P = E_0</c>, + where <c>P</c> is a pattern, then Rep(E) = + <c>{match,LINE,Rep(P),Rep(E_0)}</c>.</p> + </item> + <item> + <p>If E is nil, <c>[]</c>, then Rep(E) = <c>{nil,LINE}</c>.</p> + </item> + <item> + <p>If E is an operator expression <c>E_1 Op E_2</c>, + where <c>Op</c> is a binary operator other than match operator + <c>=</c>, then Rep(E) = + <c>{op,LINE,Op,Rep(E_1),Rep(E_2)}</c>.</p> + </item> + <item> + <p>If E is an operator expression <c>Op E_0</c>, + where <c>Op</c> is a unary operator, then Rep(E) = + <c>{op,LINE,Op,Rep(E_0)}</c>.</p> + </item> + <item> + <p>If E is a parenthesized expression <c>( E_0 )</c>, then Rep(E) = + <c>Rep(E_0)</c>, that is, parenthesized expressions cannot be + distinguished from their bodies.</p> + </item> + <item> + <p>If E is a receive expression <c>receive Cc_1 ; ... ; Cc_k end</c>, + where each <c>Cc_i</c> is a case clause, then Rep(E) = + <c>{'receive',LINE,[Rep(Cc_1), ..., Rep(Cc_k)]}</c>.</p> + </item> + <item> + <p>If E is a receive expression + <c>receive Cc_1 ; ... ; Cc_k after E_0 -> B_t end</c>, + where each <c>Cc_i</c> is a case clause, <c>E_0</c> is an expression, + and <c>B_t</c> is a body, then Rep(E) = + <c>{'receive',LINE,[Rep(Cc_1), ..., + Rep(Cc_k)],Rep(E_0),Rep(B_t)}</c>.</p> + </item> + <item> + <p>If E is a record creation + <c>#Name{Field_1=E_1, ..., Field_k=E_k}</c>, + where each <c>Field_i</c> is an atom or <c>_</c>, then Rep(E) = + <c>{record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(E_1)}, + ..., {record_field,LINE,Rep(Field_k),Rep(E_k)}]}</c>.</p> + </item> + <item> + <p>If E is a record field access <c>E_0#Name.Field</c>, + where <c>Field</c> is an atom, then Rep(E) = + <c>{record_field,LINE,Rep(E_0),Name,Rep(Field)}</c>.</p> + </item> + <item> + <p>If E is a record field index <c>#Name.Field</c>, + where <c>Field</c> is an atom, then Rep(E) = + <c>{record_index,LINE,Name,Rep(Field)}</c>.</p></item> + <item> + <p>If E is a record update + <c>E_0#Name{Field_1=E_1, ..., Field_k=E_k}</c>, + where each <c>Field_i</c> is an atom, then Rep(E) = + <c>{record,LINE,Rep(E_0),Name,[{record_field,LINE,Rep(Field_1),Rep(E_1)}, + ..., {record_field,LINE,Rep(Field_k),Rep(E_k)}]}</c>.</p> + </item> + <item> + <p>If E is a tuple skeleton <c>{E_1, ..., E_k}</c>, then Rep(E) = + <c>{tuple,LINE,[Rep(E_1), ..., Rep(E_k)]}</c>.</p> + </item> + <item> + <p>If E is a try expression <c>try B catch Tc_1 ; ... ; Tc_k end</c>, + where <c>B</c> is a body and each <c>Tc_i</c> is a catch clause, + then Rep(E) = + <c>{'try',LINE,Rep(B),[],[Rep(Tc_1), ..., Rep(Tc_k)],[]}</c>.</p> + </item> + <item> + <p>If E is a try expression + <c>try B of Cc_1 ; ... ; Cc_k catch Tc_1 ; ... ; Tc_n end</c>, + where <c>B</c> is a body, each <c>Cc_i</c> is a case clause, and + each <c>Tc_j</c> is a catch clause, then Rep(E) = + <c>{'try',LINE,Rep(B),[Rep(Cc_1), ..., Rep(Cc_k)],[Rep(Tc_1), ..., + Rep(Tc_n)],[]}</c>.</p> + </item> + <item> + <p>If E is a try expression <c>try B after A end</c>, + where <c>B</c> and <c>A</c> are bodies, then Rep(E) = + <c>{'try',LINE,Rep(B),[],[],Rep(A)}</c>.</p> + </item> + <item> + <p>If E is a try expression + <c>try B of Cc_1 ; ... ; Cc_k after A end</c>, + where <c>B</c> and <c>A</c> are a bodies, + and each <c>Cc_i</c> is a case clause, then Rep(E) = + <c>{'try',LINE,Rep(B),[Rep(Cc_1), ..., + Rep(Cc_k)],[],Rep(A)}</c>.</p> + </item> + <item> + <p>If E is a try expression + <c>try B catch Tc_1 ; ... ; Tc_k after A end</c>, + where <c>B</c> and <c>A</c> are bodies, + and each <c>Tc_i</c> is a catch clause, then Rep(E) = + <c>{'try',LINE,Rep(B),[],[Rep(Tc_1), ..., + Rep(Tc_k)],Rep(A)}</c>.</p> + </item> + <item> + <p>If E is a try expression + <c>try B of Cc_1 ; ... ; Cc_k catch Tc_1 ; ... ; Tc_n after A + end</c>, where <c>B</c> and <c>A</c> are a bodies, + each <c>Cc_i</c> is a case clause, + and each <c>Tc_j</c> is a catch clause, then Rep(E) = + <c>{'try',LINE,Rep(B),[Rep(Cc_1), ..., Rep(Cc_k)],[Rep(Tc_1), ..., + Rep(Tc_n)],Rep(A)}</c>.</p> + </item> + <item> + <p>If E is a variable <c>V</c>, then Rep(E) = <c>{var,LINE,A}</c>, + where <c>A</c> is an atom with a printname consisting of the same + characters as <c>V</c>.</p> + </item> </list> <section> <title>Qualifiers</title> - <p>A qualifier Q is one of the following alternatives:</p> + <p>A qualifier Q is one of the following:</p> + <list type="bulleted"> - <item>If Q is a filter <c>E</c>, where <c>E</c> is an expression, then - Rep(Q) = <c>Rep(E)</c>.</item> - <item>If Q is a generator <c>P <- E</c>, where <c>P</c> is - a pattern and <c>E</c> is an expression, then - Rep(Q) = <c>{generate,LINE,Rep(P),Rep(E)}</c>.</item> - <item>If Q is a bit string generator - <c>P <= E</c>, where <c>P</c> is - a pattern and <c>E</c> is an expression, then - Rep(Q) = <c>{b_generate,LINE,Rep(P),Rep(E)}</c>.</item> + <item> + <p>If Q is a filter <c>E</c>, where <c>E</c> is an expression, then + Rep(Q) = <c>Rep(E)</c>.</p> + </item> + <item> + <p>If Q is a generator <c>P <- E</c>, where <c>P</c> is + a pattern and <c>E</c> is an expression, then Rep(Q) = + <c>{generate,LINE,Rep(P),Rep(E)}</c>.</p> + </item> + <item> + <p>If Q is a bitstring generator <c>P <= E</c>, where <c>P</c> is + a pattern and <c>E</c> is an expression, then Rep(Q) = + <c>{b_generate,LINE,Rep(P),Rep(E)}</c>.</p> + </item> </list> </section> <section> - <title>Bit String Element Type Specifiers</title> - <p>A type specifier list TSL for a bit string element is a sequence + <title>Bitstring Element Type Specifiers</title> + <p>A type specifier list TSL for a bitstring element is a sequence of type specifiers <c>TS_1 - ... - TS_k</c>, and Rep(TSL) = <c>[Rep(TS_1), ..., Rep(TS_k)]</c>.</p> + <list type="bulleted"> - <item>If TS is a type specifier <c>A</c>, where <c>A</c> is an atom, - then Rep(TS) = <c>A</c>.</item> - <item>If TS is a type specifier <c>A:Value</c>, - where <c>A</c> is an atom and <c>Value</c> is an integer, - then Rep(TS) = <c>{A,Value}</c>.</item> + <item> + <p>If TS is a type specifier <c>A</c>, where <c>A</c> is an atom, + then Rep(TS) = <c>A</c>.</p> + </item> + <item> + <p>If TS is a type specifier <c>A:Value</c>, + where <c>A</c> is an atom and <c>Value</c> is an integer, + then Rep(TS) = <c>{A,Value}</c>.</p> + </item> </list> </section> <section> <title>Associations</title> - <p>An association A is one of the following alternatives:</p> + <p>An association A is one of the following:</p> + <list type="bulleted"> - <item>If A is an association <c>K => V</c>, - then Rep(A) = <c>{map_field_assoc,LINE,Rep(K),Rep(V)}</c>. - </item> - <item>If A is an association <c>K := V</c>, - then Rep(A) = <c>{map_field_exact,LINE,Rep(K),Rep(V)}</c>. - </item> + <item> + <p>If A is an association <c>K => V</c>, + then Rep(A) = <c>{map_field_assoc,LINE,Rep(K),Rep(V)}</c>.</p> + </item> + <item> + <p>If A is an association <c>K := V</c>, + then Rep(A) = <c>{map_field_exact,LINE,Rep(K),Rep(V)}</c>.</p> + </item> </list> </section> </section> <section> <title>Clauses</title> - <p>There are function clauses, if clauses, case clauses + <p>There are function clauses, if clauses, case clauses, and catch clauses.</p> - <p>A clause <c>C</c> is one of the following alternatives:</p> + + <p>A clause C is one of the following:</p> + <list type="bulleted"> - <item>If C is a case clause <c>P -> B</c>, - where <c>P</c> is a pattern and <c>B</c> is a body, then - Rep(C) = <c>{clause,LINE,[Rep(P)],[],Rep(B)}</c>.</item> - <item>If C is a case clause <c>P when Gs -> B</c>, - where <c>P</c> is a pattern, - <c>Gs</c> is a guard sequence and <c>B</c> is a body, then - Rep(C) = <c>{clause,LINE,[Rep(P)],Rep(Gs),Rep(B)}</c>.</item> - <item>If C is a catch clause <c>P -> B</c>, - where <c>P</c> is a pattern and <c>B</c> is a body, then - Rep(C) = <c>{clause,LINE,[Rep({throw,P,_})],[],Rep(B)}</c>.</item> - <item>If C is a catch clause <c>X : P -> B</c>, - where <c>X</c> is an atomic literal or a variable pattern, - <c>P</c> is a pattern, and <c>B</c> is a body, then - Rep(C) = <c>{clause,LINE,[Rep({X,P,_})],[],Rep(B)}</c>.</item> - <item>If C is a catch clause <c>P when Gs -> B</c>, - where <c>P</c> is a pattern, <c>Gs</c> is a guard sequence, - and <c>B</c> is a body, then - Rep(C) = <c>{clause,LINE,[Rep({throw,P,_})],Rep(Gs),Rep(B)}</c>.</item> - <item>If C is a catch clause <c>X : P when Gs -> B</c>, - where <c>X</c> is an atomic literal or a variable pattern, - <c>P</c> is a pattern, <c>Gs</c> is a guard sequence, - and <c>B</c> is a body, then - Rep(C) = <c>{clause,LINE,[Rep({X,P,_})],Rep(Gs),Rep(B)}</c>.</item> - <item>If C is a function clause <c>( Ps ) -> B</c>, - where <c>Ps</c> is a pattern sequence and <c>B</c> is a body, then - Rep(C) = <c>{clause,LINE,Rep(Ps),[],Rep(B)}</c>.</item> - <item>If C is a function clause <c>( Ps ) when Gs -> B</c>, - where <c>Ps</c> is a pattern sequence, - <c>Gs</c> is a guard sequence and <c>B</c> is a body, then - Rep(C) = <c>{clause,LINE,Rep(Ps),Rep(Gs),Rep(B)}</c>.</item> - <item>If C is an if clause <c>Gs -> B</c>, - where <c>Gs</c> is a guard sequence and <c>B</c> is a body, then - Rep(C) = <c>{clause,LINE,[],Rep(Gs),Rep(B)}</c>.</item> + <item> + <p>If C is a case clause <c>P -> B</c>, + where <c>P</c> is a pattern and <c>B</c> is a body, then + Rep(C) = <c>{clause,LINE,[Rep(P)],[],Rep(B)}</c>.</p> + </item> + <item> + <p>If C is a case clause <c>P when Gs -> B</c>, + where <c>P</c> is a pattern, + <c>Gs</c> is a guard sequence, and <c>B</c> is a body, then + Rep(C) = <c>{clause,LINE,[Rep(P)],Rep(Gs),Rep(B)}</c>.</p> + </item> + <item> + <p>If C is a catch clause <c>P -> B</c>, + where <c>P</c> is a pattern and <c>B</c> is a body, then + Rep(C) = <c>{clause,LINE,[Rep({throw,P,_})],[],Rep(B)}</c>, + that is, a catch clause with an explicit exception class + <c>throw</c> and with or without an explicit stacktrace + variable <c>_</c> cannot be distinguished from a catch clause + without an explicit exception class and without an explicit + stacktrace variable.</p> + </item> + <item> + <p>If C is a catch clause <c>X : P -> B</c>, + where <c>X</c> is an atomic literal or a variable pattern, + <c>P</c> is a pattern, and <c>B</c> is a body, then + Rep(C) = <c>{clause,LINE,[Rep({X,P,_})],[],Rep(B)}</c>, + that is, a catch clause with an explicit exception class and + with an explicit stacktrace variable <c>_</c> cannot be + distinguished from a catch clause with an explicit exception + class and without an explicit stacktrace variable.</p> + </item> + <item> + <p>If C is a catch clause <c>X : P : S -> B</c>, + where <c>X</c> is an atomic literal or a variable pattern, + <c>P</c> is a pattern, <c>S</c> is a variable, and <c>B</c> + is a body, then + Rep(C) = <c>{clause,LINE,[Rep({X,P,S})],[],Rep(B)}</c>.</p> + </item> + <item> + <p>If C is a catch clause <c>P when Gs -> B</c>, + where <c>P</c> is a pattern, <c>Gs</c> is a guard sequence, + and <c>B</c> is a body, then + Rep(C) = <c>{clause,LINE,[Rep({throw,P,_})],Rep(Gs),Rep(B)}</c>, + that is, a catch clause with an explicit exception class + <c>throw</c> and with or without an explicit stacktrace + variable <c>_</c> cannot be distinguished from a catch clause + without an explicit exception class and without an explicit + stacktrace variable.</p> + </item> + <item> + <p>If C is a catch clause <c>X : P when Gs -> B</c>, + where <c>X</c> is an atomic literal or a variable pattern, + <c>P</c> is a pattern, <c>Gs</c> is a guard sequence, + and <c>B</c> is a body, then + Rep(C) = <c>{clause,LINE,[Rep({X,P,_})],Rep(Gs),Rep(B)}</c>, + that is, a catch clause with an explicit exception class and + with an explicit stacktrace variable <c>_</c> cannot be + distinguished from a catch clause with an explicit exception + class and without an explicit stacktrace variable.</p> + </item> + <item> + <p>If C is a catch clause <c>X : P : S when Gs -> B</c>, + where <c>X</c> is an atomic literal or a variable pattern, + <c>P</c> is a pattern, <c>Gs</c> is a guard sequence, + <c>S</c> is a variable, and <c>B</c> is a body, then + Rep(C) = <c>{clause,LINE,[Rep({X,P,S})],Rep(Gs),Rep(B)}</c>.</p> + </item> + <item> + <p>If C is a function clause <c>( Ps ) -> B</c>, + where <c>Ps</c> is a pattern sequence and <c>B</c> is a body, then + Rep(C) = <c>{clause,LINE,Rep(Ps),[],Rep(B)}</c>.</p> + </item> + <item> + <p>If C is a function clause <c>( Ps ) when Gs -> B</c>, + where <c>Ps</c> is a pattern sequence, + <c>Gs</c> is a guard sequence and <c>B</c> is a body, then + Rep(C) = <c>{clause,LINE,Rep(Ps),Rep(Gs),Rep(B)}</c>.</p> + </item> + <item> + <p>If C is an if clause <c>Gs -> B</c>, + where <c>Gs</c> is a guard sequence and <c>B</c> is a body, then + Rep(C) = <c>{clause,LINE,[],Rep(Gs),Rep(B)}</c>.</p> + </item> </list> </section> @@ -460,205 +690,292 @@ <title>Guards</title> <p>A guard sequence Gs is a sequence of guards <c>G_1; ...; G_k</c>, and Rep(Gs) = <c>[Rep(G_1), ..., Rep(G_k)]</c>. If the guard sequence is - empty, Rep(Gs) = <c>[]</c>.</p> - <p>A guard G is a nonempty sequence of guard tests + empty, then Rep(Gs) = <c>[]</c>.</p> + + <p>A guard G is a non-empty sequence of guard tests <c>Gt_1, ..., Gt_k</c>, and Rep(G) = <c>[Rep(Gt_1), ..., Rep(Gt_k)]</c>.</p> - <p>A guard test <c>Gt</c> is one of the following alternatives:</p> + + <p>A guard test Gt is one of the following:</p> + <list type="bulleted"> - <item>If Gt is an atomic literal <c>L</c>, then Rep(Gt) = Rep(L).</item> - <item>If Gt is a bit string constructor - <c><<Gt_1:Size_1/TSL_1, ..., Gt_k:Size_k/TSL_k>></c>, - where each <c>Size_i</c> is a guard test and each - <c>TSL_i</c> is a type specificer list, then - Rep(Gt) = <c>{bin,LINE,[{bin_element,LINE,Rep(Gt_1),Rep(Size_1),Rep(TSL_1)}, ..., {bin_element,LINE,Rep(Gt_k),Rep(Size_k),Rep(TSL_k)}]}</c>. - For Rep(TSL), see above. - An omitted <c>Size_i</c> is represented by <c>default</c>. - An omitted <c>TSL_i</c> is represented by <c>default</c>.</item> - <item>If Gt is a cons skeleton <c>[Gt_h | Gt_t]</c>, then - Rep(Gt) = <c>{cons,LINE,Rep(Gt_h),Rep(Gt_t)}</c>.</item> - <item>If Gt is a function call <c>A(Gt_1, ..., Gt_k)</c>, - where <c>A</c> is an atom, then Rep(Gt) = - <c>{call,LINE,Rep(A),[Rep(Gt_1), ..., Rep(Gt_k)]}</c>.</item> - <item>If Gt is a function call <c>A_m:A(Gt_1, ..., Gt_k)</c>, - where <c>A_m</c> is the atom <c>erlang</c> and <c>A</c> is - an atom or an operator, then Rep(Gt) = - <c>{call,LINE,{remote,LINE,Rep(A_m),Rep(A)},[Rep(Gt_1), ..., Rep(Gt_k)]}</c>.</item> - <item>If Gt is a map creation <c>#{A_1, ..., A_k}</c>, - where each <c>A_i</c> is an association <c>Gt_i_1 => Gt_i_2</c> - or <c>Gt_i_1 := Gt_i_2</c>, then Rep(Gt) = - <c>{map,LINE,[Rep(A_1), ..., Rep(A_k)]}</c>. For Rep(A), see - above.</item> - <item>If Gt is a map update <c>Gt_0#{A_1, ..., A_k}</c>, where each - <c>A_i</c> is an association <c>Gt_i_1 => Gt_i_2</c> - or <c>Gt_i_1 := Gt_i_2</c>, then Rep(Gt) = - <c>{map,LINE,Rep(Gt_0),[Rep(A_1), ..., Rep(A_k)]}</c>. - For Rep(A), see above.</item> - <item>If Gt is nil, <c>[]</c>, - then Rep(Gt) = <c>{nil,LINE}</c>.</item> - <item>If Gt is an operator guard test <c>Gt_1 Op Gt_2</c>, - where <c>Op</c> is a binary operator other than the match - operator <c>=</c>, then - Rep(Gt) = <c>{op,LINE,Op,Rep(Gt_1),Rep(Gt_2)}</c>.</item> - <item>If Gt is an operator guard test <c>Op Gt_0</c>, - where <c>Op</c> is a unary operator, then - Rep(Gt) = <c>{op,LINE,Op,Rep(Gt_0)}</c>.</item> - <item>If Gt is a parenthesized guard test <c>( Gt_0 )</c>, then - Rep(Gt) = <c>Rep(Gt_0)</c>, that is, parenthesized - guard tests cannot be distinguished from their bodies.</item> - <item>If Gt is a record creation - <c>#Name{Field_1=Gt_1, ..., Field_k=Gt_k}</c>, - where each <c>Field_i</c> is an atom or <c>_</c>, then Rep(Gt) = - <c>{record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(Gt_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(Gt_k)}]}</c>.</item> - <item>If Gt is a record field access <c>Gt_0#Name.Field</c>, - where <c>Field</c> is an atom, then - Rep(Gt) = <c>{record_field,LINE,Rep(Gt_0),Name,Rep(Field)}</c>.</item> - <item>If Gt is a record field index <c>#Name.Field</c>, - where <c>Field</c> is an atom, then - Rep(Gt) = <c>{record_index,LINE,Name,Rep(Field)}</c>.</item> - <item>If Gt is a tuple skeleton <c>{Gt_1, ..., Gt_k}</c>, then - Rep(Gt) = <c>{tuple,LINE,[Rep(Gt_1), ..., Rep(Gt_k)]}</c>.</item> - <item>If Gt is a variable pattern <c>V</c>, then - Rep(Gt) = <c>{var,LINE,A}</c>, where A is an atom with - a printname consisting of the same characters as <c>V</c>.</item> + <item> + <p>If Gt is an atomic literal <c>L</c>, then Rep(Gt) = Rep(L).</p> + </item> + <item> + <p>If Gt is a bitstring constructor + <c><<Gt_1:Size_1/TSL_1, ..., Gt_k:Size_k/TSL_k>></c>, + where each <c>Size_i</c> is a guard test and each + <c>TSL_i</c> is a type specificer list, then Rep(Gt) = + <c>{bin,LINE,[{bin_element,LINE,Rep(Gt_1),Rep(Size_1),Rep(TSL_1)}, + ..., {bin_element,LINE,Rep(Gt_k),Rep(Size_k),Rep(TSL_k)}]}</c>. + For Rep(TSL), see above. + An omitted <c>Size_i</c> is represented by <c>default</c>. + An omitted <c>TSL_i</c> is represented by <c>default</c>.</p> + </item> + <item> + <p>If Gt is a cons skeleton <c>[Gt_h | Gt_t]</c>, then Rep(Gt) = + <c>{cons,LINE,Rep(Gt_h),Rep(Gt_t)}</c>.</p> + </item> + <item> + <p>If Gt is a function call <c>A(Gt_1, ..., Gt_k)</c>, + where <c>A</c> is an atom, then Rep(Gt) = + <c>{call,LINE,Rep(A),[Rep(Gt_1), ..., Rep(Gt_k)]}</c>.</p> + </item> + <item> + <p>If Gt is a function call <c>A_m:A(Gt_1, ..., Gt_k)</c>, + where <c>A_m</c> is the atom <c>erlang</c> and <c>A</c> is + an atom or an operator, then Rep(Gt) = + <c>{call,LINE,{remote,LINE,Rep(A_m),Rep(A)},[Rep(Gt_1), ..., + Rep(Gt_k)]}</c>.</p> + </item> + <item> + <p>If Gt is a map creation <c>#{A_1, ..., A_k}</c>, + where each <c>A_i</c> is an association <c>Gt_i_1 => Gt_i_2</c> + or <c>Gt_i_1 := Gt_i_2</c>, then Rep(Gt) = + <c>{map,LINE,[Rep(A_1), ..., Rep(A_k)]}</c>. + For Rep(A), see above.</p> + </item> + <item> + <p>If Gt is a map update <c>Gt_0#{A_1, ..., A_k}</c>, + where each <c>A_i</c> is an association <c>Gt_i_1 => Gt_i_2</c> + or <c>Gt_i_1 := Gt_i_2</c>, then Rep(Gt) = + <c>{map,LINE,Rep(Gt_0),[Rep(A_1), ..., Rep(A_k)]}</c>. + For Rep(A), see above.</p> + </item> + <item> + <p>If Gt is nil, <c>[]</c>, then Rep(Gt) = <c>{nil,LINE}</c>.</p> + </item> + <item> + <p>If Gt is an operator guard test <c>Gt_1 Op Gt_2</c>, + where <c>Op</c> is a binary operator other than match + operator <c>=</c>, then Rep(Gt) = + <c>{op,LINE,Op,Rep(Gt_1),Rep(Gt_2)}</c>.</p> + </item> + <item> + <p>If Gt is an operator guard test <c>Op Gt_0</c>, + where <c>Op</c> is a unary operator, then Rep(Gt) = + <c>{op,LINE,Op,Rep(Gt_0)}</c>.</p> + </item> + <item> + <p>If Gt is a parenthesized guard test <c>( Gt_0 )</c>, then Rep(Gt) = + <c>Rep(Gt_0)</c>, that is, parenthesized + guard tests cannot be distinguished from their bodies.</p> + </item> + <item> + <p>If Gt is a record creation + <c>#Name{Field_1=Gt_1, ..., Field_k=Gt_k}</c>, + where each <c>Field_i</c> is an atom or <c>_</c>, then Rep(Gt) = + <c>{record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(Gt_1)}, + ..., {record_field,LINE,Rep(Field_k),Rep(Gt_k)}]}</c>.</p> + </item> + <item> + <p>If Gt is a record field access <c>Gt_0#Name.Field</c>, + where <c>Field</c> is an atom, then Rep(Gt) = + <c>{record_field,LINE,Rep(Gt_0),Name,Rep(Field)}</c>.</p> + </item> + <item> + <p>If Gt is a record field index <c>#Name.Field</c>, + where <c>Field</c> is an atom, then Rep(Gt) = + <c>{record_index,LINE,Name,Rep(Field)}</c>.</p> + </item> + <item> + <p>If Gt is a tuple skeleton <c>{Gt_1, ..., Gt_k}</c>, then Rep(Gt) = + <c>{tuple,LINE,[Rep(Gt_1), ..., Rep(Gt_k)]}</c>.</p> + </item> + <item> + <p>If Gt is a variable pattern <c>V</c>, then Rep(Gt) = + <c>{var,LINE,A}</c>, where A is an atom with + a printname consisting of the same characters as <c>V</c>.</p> + </item> </list> - <p>Note that every guard test has the same source form as some expression, - and is represented the same way as the corresponding expression.</p> + + <p>Notice that every guard test has the same source form as some expression, + and is represented in the same way as the corresponding expression.</p> </section> <section> <title>Types</title> <list type="bulleted"> - <item>If T is an annotated type <c>A :: T_0</c>, - where <c>A</c> is a variable, then Rep(T) = - <c>{ann_type,LINE,[Rep(A),Rep(T_0)]}</c>.</item> - <item>If T is an atom or integer literal L, then Rep(T) = Rep(L). - </item> - <item>If T is a bit string type <c><<_:M,_:_*N>></c>, - where <c>M</c> and <c>N</c> are singleton integer types, then Rep(T) = - <c>{type,LINE,binary,[Rep(M),Rep(N)]}</c>.</item> - <item>If T is the empty list type <c>[]</c>, then Rep(T) = - <c>{type,Line,nil,[]}</c>.</item> - <item>If T is a fun type <c>fun()</c>, then Rep(T) = - <c>{type,LINE,'fun',[]}</c>.</item> - <item>If T is a fun type <c>fun((...) -> T_0)</c>, then - Rep(T) = <c>{type,LINE,'fun',[{type,LINE,any},Rep(T_0)]}</c>. - </item> - <item>If T is a fun type <c>fun(Ft)</c>, where - <c>Ft</c> is a function type, - then Rep(T) = <c>Rep(Ft)</c>. For Rep(Ft), see below.</item> - <item>If T is an integer range type <c>L .. H</c>, - where <c>L</c> and <c>H</c> are singleton integer types, then - Rep(T) = <c>{type,LINE,range,[Rep(L),Rep(H)]}</c>.</item> - <item>If T is a map type <c>map()</c>, then Rep(T) = - <c>{type,LINE,map,any}</c>.</item> - <item>If T is a map type <c>#{A_1, ..., A_k}</c>, where each - <c>A_i</c> is an association type, then Rep(T) = - <c>{type,LINE,map,[Rep(A_1), ..., Rep(A_k)]}</c>. - For Rep(A), see below.</item> - <item>If T is an operator type <c>T_1 Op T_2</c>, - where <c>Op</c> is a binary operator (this is an occurrence of - an expression that can be evaluated to an integer at compile - time), then - Rep(T) = <c>{op,LINE,Op,Rep(T_1),Rep(T_2)}</c>.</item> - <item>If T is an operator type <c>Op T_0</c>, where <c>Op</c> is a - unary operator (this is an occurrence of - an expression that can be evaluated to an integer at compile time), - then Rep(T) = <c>{op,LINE,Op,Rep(T_0)}</c>.</item> - <item>If T is <c>( T_0 )</c>, then Rep(T) = <c>Rep(T_0)</c>, - that is, parenthesized types cannot be distinguished from their - bodies.</item> - <item>If T is a predefined (or built-in) type <c>N(T_1, ..., T_k)</c>, - then Rep(T) = - <c>{type,LINE,N,[Rep(T_1), ..., Rep(T_k)]}</c>.</item> - <item>If T is a record type <c>#Name{F_1, ..., F_k}</c>, - where each <c>F_i</c> is a record field type, then Rep(T) = - <c>{type,LINE,record,[Rep(Name),Rep(F_1), ..., Rep(F_k)]}</c>. - For Rep(F), see below.</item> - <item>If T is a remote type <c>M:N(T_1, ..., T_k)</c>, then Rep(T) = - <c>{remote_type,LINE,[Rep(M),Rep(N),[Rep(T_1), ..., Rep(T_k)]]}</c>. - </item> - <item>If T is a tuple type <c>tuple()</c>, then Rep(T) = - <c>{type,LINE,tuple,any}</c>.</item> - <item>If T is a tuple type <c>{T_1, ..., T_k}</c>, then Rep(T) = - <c>{type,LINE,tuple,[Rep(T_1), ..., Rep(T_k)]}</c>.</item> - <item>If T is a type union <c>T_1 | ... | T_k</c>, then Rep(T) = - <c>{type,LINE,union,[Rep(T_1), ..., Rep(T_k)]}</c>.</item> - <item>If T is a type variable <c>V</c>, then Rep(T) = - <c>{var,LINE,A}</c>, where <c>A</c> is an atom with a printname - consisting of the same characters as <c>V</c>. A type variable - is any variable except underscore (<c>_</c>).</item> - <item>If T is a user-defined type <c>N(T_1, ..., T_k)</c>, - then Rep(T) = - <c>{user_type,LINE,N,[Rep(T_1), ..., Rep(T_k)]}</c>.</item> + <item> + <p>If T is an annotated type <c>A :: T_0</c>, + where <c>A</c> is a variable, then Rep(T) = + <c>{ann_type,LINE,[Rep(A),Rep(T_0)]}</c>.</p> + </item> + <item> + <p>If T is an atom or integer literal L, then Rep(T) = Rep(L).</p> + </item> + <item> + <p>If T is a bitstring type <c><<_:M,_:_*N>></c>, + where <c>M</c> and <c>N</c> are singleton integer types, then Rep(T) = + <c>{type,LINE,binary,[Rep(M),Rep(N)]}</c>.</p> + </item> + <item> + <p>If T is the empty list type <c>[]</c>, then Rep(T) = + <c>{type,Line,nil,[]}</c>.</p> + </item> + <item> + <p>If T is a fun type <c>fun()</c>, then Rep(T) = + <c>{type,LINE,'fun',[]}</c>.</p> + </item> + <item> + <p>If T is a fun type <c>fun((...) -> T_0)</c>, then Rep(T) = + <c>{type,LINE,'fun',[{type,LINE,any},Rep(T_0)]}</c>.</p> + </item> + <item> + <p>If T is a fun type <c>fun(Ft)</c>, where + <c>Ft</c> is a function type, then Rep(T) = <c>Rep(Ft)</c>. + For Rep(Ft), see below.</p> + </item> + <item> + <p>If T is an integer range type <c>L .. H</c>, + where <c>L</c> and <c>H</c> are singleton integer types, then Rep(T) = + <c>{type,LINE,range,[Rep(L),Rep(H)]}</c>.</p> + </item> + <item> + <p>If T is a map type <c>map()</c>, then Rep(T) = + <c>{type,LINE,map,any}</c>.</p> + </item> + <item> + <p>If T is a map type <c>#{A_1, ..., A_k}</c>, where each + <c>A_i</c> is an association type, then Rep(T) = + <c>{type,LINE,map,[Rep(A_1), ..., Rep(A_k)]}</c>. + For Rep(A), see below.</p> + </item> + <item> + <p>If T is an operator type <c>T_1 Op T_2</c>, + where <c>Op</c> is a binary operator (this is an occurrence of + an expression that can be evaluated to an integer at compile + time), then Rep(T) = + <c>{op,LINE,Op,Rep(T_1),Rep(T_2)}</c>.</p> + </item> + <item> + <p>If T is an operator type <c>Op T_0</c>, where <c>Op</c> is a + unary operator (this is an occurrence of an expression that can + be evaluated to an integer at compile time), then Rep(T) = + <c>{op,LINE,Op,Rep(T_0)}</c>.</p> + </item> + <item> + <p>If T is <c>( T_0 )</c>, then Rep(T) = <c>Rep(T_0)</c>, that is, + parenthesized types cannot be distinguished from their bodies.</p> + </item> + <item> + <p>If T is a predefined (or built-in) type <c>N(T_1, ..., T_k)</c>, + then Rep(T) = <c>{type,LINE,N,[Rep(T_1), ..., Rep(T_k)]}</c>.</p> + </item> + <item> + <p>If T is a record type <c>#Name{F_1, ..., F_k}</c>, + where each <c>F_i</c> is a record field type, then Rep(T) = + <c>{type,LINE,record,[Rep(Name),Rep(F_1), ..., Rep(F_k)]}</c>. + For Rep(F), see below.</p> + </item> + <item> + <p>If T is a remote type <c>M:N(T_1, ..., T_k)</c>, then Rep(T) = + <c>{remote_type,LINE,[Rep(M),Rep(N),[Rep(T_1), ..., + Rep(T_k)]]}</c>.</p> + </item> + <item> + <p>If T is a tuple type <c>tuple()</c>, then Rep(T) = + <c>{type,LINE,tuple,any}</c>.</p> + </item> + <item> + <p>If T is a tuple type <c>{T_1, ..., T_k}</c>, then Rep(T) = + <c>{type,LINE,tuple,[Rep(T_1), ..., Rep(T_k)]}</c>.</p> + </item> + <item> + <p>If T is a type union <c>T_1 | ... | T_k</c>, then Rep(T) = + <c>{type,LINE,union,[Rep(T_1), ..., Rep(T_k)]}</c>.</p> + </item> + <item> + <p>If T is a type variable <c>V</c>, then Rep(T) = + <c>{var,LINE,A}</c>, where <c>A</c> is an atom with a printname + consisting of the same characters as <c>V</c>. A type variable + is any variable except underscore (<c>_</c>).</p> + </item> + <item> + <p>If T is a user-defined type <c>N(T_1, ..., T_k)</c>, then Rep(T) = + <c>{user_type,LINE,N,[Rep(T_1), ..., Rep(T_k)]}</c>.</p> + </item> </list> <section> <title>Function Types</title> - <p>A function type Ft is one of the following alternatives:</p> + <p>A function type Ft is one of the following:</p> + <list type="bulleted"> - <item>If Ft is a constrained function type <c>Ft_1 when Fc</c>, - where <c>Ft_1</c> is a function type and - <c>Fc</c> is a function constraint, then Rep(T) = - <c>{type,LINE,bounded_fun,[Rep(Ft_1),Rep(Fc)]}</c>. - For Rep(Fc), see below.</item> - <item>If Ft is a function type <c>(T_1, ..., T_n) -> T_0</c>, - where each <c>T_i</c> is a type, then - Rep(Ft) = <c>{type,LINE,'fun',[{type,LINE,product,[Rep(T_1), - ..., Rep(T_n)]},Rep(T_0)]}</c>.</item> + <item> + <p>If Ft is a constrained function type <c>Ft_1 when Fc</c>, + where <c>Ft_1</c> is a function type and + <c>Fc</c> is a function constraint, then Rep(T) = + <c>{type,LINE,bounded_fun,[Rep(Ft_1),Rep(Fc)]}</c>. + For Rep(Fc), see below.</p> + </item> + <item> + <p>If Ft is a function type <c>(T_1, ..., T_n) -> T_0</c>, + where each <c>T_i</c> is a type, then Rep(Ft) = + <c>{type,LINE,'fun',[{type,LINE,product,[Rep(T_1), ..., + Rep(T_n)]},Rep(T_0)]}</c>.</p> + </item> </list> </section> <section> <title>Function Constraints</title> - <p>A function constraint Fc is a nonempty sequence of constraints - <c>C_1, ..., C_k</c>, and - Rep(Fc) = <c>[Rep(C_1), ..., Rep(C_k)]</c>.</p> + <p>A function constraint Fc is a non-empty sequence of constraints + <c>C_1, ..., C_k</c>, and + Rep(Fc) = <c>[Rep(C_1), ..., Rep(C_k)]</c>.</p> + <list type="bulleted"> - <item>If C is a constraint <c>is_subtype(V, T)</c> or <c>V :: T</c>, - where <c>V</c> is a type variable and <c>T</c> is a type, then - Rep(C) = <c>{type,LINE,constraint,[{atom,LINE,is_subtype},[Rep(V),Rep(T)]]}</c>. - </item> + <item>If C is a constraint <c>V :: T</c>, + where <c>V</c> is a type variable + and <c>T</c> is a type, then Rep(C) = + <c>{type,LINE,constraint,[{atom,LINE,is_subtype},[Rep(V),Rep(T)]]}</c>. + </item> </list> </section> <section> <title>Association Types</title> <list type="bulleted"> - <item>If A is an association type <c>K => V</c>, where - <c>K</c> and <c>V</c> are types, then Rep(A) = - <c>{type,LINE,map_field_assoc,[Rep(K),Rep(V)]}</c>.</item> - <item>If A is an association type <c>K := V</c>, where - <c>K</c> and <c>V</c> are types, then Rep(A) = - <c>{type,LINE,map_field_exact,[Rep(K),Rep(V)]}</c>.</item> + <item> + <p>If A is an association type <c>K => V</c>, + where <c>K</c> and <c>V</c> are types, then Rep(A) = + <c>{type,LINE,map_field_assoc,[Rep(K),Rep(V)]}</c>.</p> + </item> + <item> + <p>If A is an association type <c>K := V</c>, + where <c>K</c> and <c>V</c> are types, then Rep(A) = + <c>{type,LINE,map_field_exact,[Rep(K),Rep(V)]}</c>.</p> + </item> </list> </section> <section> <title>Record Field Types</title> <list type="bulleted"> - <item>If F is a record field type <c>Name :: Type</c>, - where <c>Type</c> is a type, then Rep(F) = - <c>{type,LINE,field_type,[Rep(Name),Rep(Type)]}</c>.</item> + <item>If F is a record field type <c>Name :: Type</c>, + where <c>Type</c> is a type, then Rep(F) = + <c>{type,LINE,field_type,[Rep(Name),Rep(Type)]}</c>. + </item> </list> </section> </section> <section> - <title>The Abstract Format After Preprocessing</title> - <p>The compilation option <c>debug_info</c> can be given to the + <title>The Abstract Format after Preprocessing</title> + <p>The compilation option <c>debug_info</c> can be specified to the compiler to have the abstract code stored in - the <c>abstract_code</c> chunk in the BEAM file + the <c>abstract_code</c> chunk in the Beam file (for debugging purposes).</p> - <p>In OTP R9C and later, the <c>abstract_code</c> chunk will - contain</p> - <p><c>{raw_abstract_v1,AbstractCode}</c></p> - <p>where <c>AbstractCode</c> is the abstract code as described - in this document.</p> - <p>In releases of OTP prior to R9C, the abstract code after some more - processing was stored in the BEAM file. The first element of the - tuple would be either <c>abstract_v1</c> (R7B) or <c>abstract_v2</c> - (R8B).</p> + + <p>As from Erlang/OTP R9C, the <c>abstract_code</c> chunk contains + <c>{raw_abstract_v1,AbstractCode}</c>, where <c>AbstractCode</c> is the + abstract code as described in this section.</p> + + <p>In OTP releases before R9C, the abstract code after some more + processing was stored in the Beam file. The first element of the + tuple would be either <c>abstract_v1</c> (in OTP R7B) or + <c>abstract_v2</c> (in OTP R8B).</p> </section> </chapter> |