From 6e2d941bf278191c11f6d1cebdfab5e51419d734 Mon Sep 17 00:00:00 2001 From: Hans Bolinder Date: Wed, 20 Jan 2016 09:55:21 +0100 Subject: erts: Improve readability of The Abstract Format More verbose, but hopefully more readable than before. --- erts/doc/src/absform.xml | 420 +++++++++++++++++++++++++---------------------- 1 file changed, 228 insertions(+), 192 deletions(-) (limited to 'erts/doc') diff --git a/erts/doc/src/absform.xml b/erts/doc/src/absform.xml index 3f47b3061b..ccdecf44ec 100644 --- a/erts/doc/src/absform.xml +++ b/erts/doc/src/absform.xml @@ -68,34 +68,29 @@ If D is a module declaration consisting of the forms F_1, ..., F_k, then Rep(D) = [Rep(F_1), ..., Rep(F_k)]. - If F is an attribute -module(Mod), then - Rep(F) = {attribute,LINE,module,Mod}. If F is an attribute -behavior(Behavior), then Rep(F) = {attribute,LINE,behavior,Behavior}. If F is an attribute -behaviour(Behaviour), then Rep(F) = {attribute,LINE,behaviour,Behaviour}. + If F is an attribute -compile(Options), then + Rep(F) = {attribute,LINE,compile,Options}. If F is an attribute -export([Fun_1/A_1, ..., Fun_k/A_k]), then Rep(F) = {attribute,LINE,export,[{Fun_1,A_1}, ..., {Fun_k,A_k}]}. - If F is an attribute -import(Mod,[Fun_1/A_1, ..., Fun_k/A_k]), then - Rep(F) = {attribute,LINE,import,{Mod,[{Fun_1,A_1}, ..., {Fun_k,A_k}]}}. If F is an attribute -export_type([Type_1/A_1, ..., Type_k/A_k]), then Rep(F) = {attribute,LINE,export_type,[{Type_1,A_1}, ..., {Type_k,A_k}]}. + If F is an attribute -import(Mod,[Fun_1/A_1, ..., Fun_k/A_k]), then + Rep(F) = {attribute,LINE,import,{Mod,[{Fun_1,A_1}, ..., {Fun_k,A_k}]}}. + If F is an attribute -module(Mod), then + Rep(F) = {attribute,LINE,module,Mod}. If F is an attribute -optional_callbacks([Fun_1/A_1, ..., Fun_k/A_k]), then Rep(F) = {attribute,LINE,optional_callbacks,[{Fun_1,A_1}, ..., {Fun_k,A_k}]}. - If F is an attribute -compile(Options), then - Rep(F) = {attribute,LINE,compile,Options}. If F is an attribute -file(File,Line), then Rep(F) = {attribute,LINE,file,{File,Line}}. - If F is a record declaration - -record(Name,{V_1, ..., V_k}), - where each V_i is a record field, then Rep(F) = - {attribute,LINE,record,{Name,[Rep(V_1), ..., Rep(V_k)]}}. - For Rep(V), see below. - If F is a type declaration - -Type Name(V_1, ..., V_k) :: T, where - Type is either the atom type or the atom opaque, - each V_i is a variable, and T is a type, then Rep(F) = - {attribute,LINE,Type,{Name,Rep(T),[Rep(V_1), ..., Rep(V_k)]}}. + If F is a function declaration + Name Fc_1 ; ... ; Name Fc_k, + where each Fc_i is a function clause with a + pattern sequence of the same length Arity, then + Rep(F) = {function,LINE,Name,Arity,[Rep(Fc_1), ...,Rep(Fc_k)]}. If F is a function specification -Spec Name Ft_1; ...; Ft_k, @@ -112,15 +107,20 @@ Arity, then Rep(F) = {attribute,Line,spec,{{Mod,Name,Arity},[Rep(Ft_1), ..., Rep(Ft_k)]}}. + If F is a record declaration + -record(Name,{V_1, ..., V_k}), + where each V_i is a record field, then Rep(F) = + {attribute,LINE,record,{Name,[Rep(V_1), ..., Rep(V_k)]}}. + For Rep(V), see below. + If F is a type declaration + -Type Name(V_1, ..., V_k) :: T, where + Type is either the atom type or the atom opaque, + each V_i is a variable, and T is a type, then Rep(F) = + {attribute,LINE,Type,{Name,Rep(T),[Rep(V_1), ..., Rep(V_k)]}}. + If F is a wild attribute -A(T), then Rep(F) = {attribute,LINE,A,T}.

- If F is a function declaration - Name Fc_1 ; ... ; Name Fc_k, - where each Fc_i is a function clause with a - pattern sequence of the same length Arity, then - Rep(F) = {function,LINE,Name,Arity,[Rep(Fc_1), ...,Rep(Fc_k)]}. -
@@ -160,15 +160,15 @@

There are five kinds of atomic literals, which are represented in the same way in patterns, expressions and guards:

- If L is an integer or character literal, then - Rep(L) = {integer,LINE,L}. + If L is an atom literal, then + Rep(L) = {atom,LINE,L}. If L is a float literal, then Rep(L) = {float,LINE,L}. + If L is an integer or character literal, then + Rep(L) = {integer,LINE,L}. If L is a string literal consisting of the characters C_1, ..., C_k, then Rep(L) = {string,LINE,[C_1, ..., C_k]}. - If L is an atom literal, then - Rep(L) = {atom,LINE,L}.

Note that negative integer and float literals do not occur as such; they are parsed as an application of the unary negation operator.

@@ -182,45 +182,53 @@

Individual patterns are represented as follows:

If P is an atomic literal L, then Rep(P) = Rep(L). + If P is a binary pattern + <<P_1:Size_1/TSL_1, ..., P_k:Size_k/TSL_k>>, where each + Size_i is an expression that can be evaluated to an integer + and each TSL_i is a type specificer list, then + Rep(P) = {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)}]}. + For Rep(TSL), see below. + An omitted Size_i is represented by default. + An omitted TSL_i is represented by default. If P is a compound pattern P_1 = P_2, then Rep(P) = {match,LINE,Rep(P_1),Rep(P_2)}. - If P is a variable pattern V, then - Rep(P) = {var,LINE,A}, - where A is an atom with a printname consisting of the same characters as - V. - If P is a universal pattern _, then - Rep(P) = {var,LINE,'_'}. - If P is a tuple pattern {P_1, ..., P_k}, then - Rep(P) = {tuple,LINE,[Rep(P_1), ..., Rep(P_k)]}. - If P is a nil pattern [], then - Rep(P) = {nil,LINE}. If P is a cons pattern [P_h | P_t], then Rep(P) = {cons,LINE,Rep(P_h),Rep(P_t)}. - If E is a binary pattern <<P_1:Size_1/TSL_1, ..., P_k:Size_k/TSL_k>>, then - Rep(E) = {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)}]}. - For Rep(TSL), see below. - An omitted Size is represented by default. An omitted TSL - (type specifier list) is represented by default. - If P is P_1 Op P_2, where Op is a binary operator (this - is either an occurrence of ++ 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) = {op,LINE,Op,Rep(P_1),Rep(P_2)}. - If P is Op P_0, where Op is a unary operator (this is an - occurrence of an expression that can be evaluated to a number at compile - time), then Rep(P) = {op,LINE,Op,Rep(P_0)}. - If P is a record pattern #Name{Field_1=P_1, ..., Field_k=P_k}, - then Rep(P) = - {record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(P_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(P_k)}]}. - If P is #Name.Field, then - Rep(P) = {record_index,LINE,Name,Rep(Field)}. If P is a map pattern #{A_1, ..., A_k}, where each A_i is an association P_i_1 := P_i_2, then Rep(P) = {map,LINE,[Rep(A_1), ..., Rep(A_k)]}. For Rep(A), see below. - If P is ( P_0 ), then + If P is a nil pattern [], then + Rep(P) = {nil,LINE}. + If P is an operator pattern P_1 Op P_2, + where Op is a binary operator (this is either an occurrence + of ++ 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) = {op,LINE,Op,Rep(P_1),Rep(P_2)}. + If P is an operator pattern Op P_0, + where Op is a unary operator (this is an occurrence of + an expression that can be evaluated to a number at compile + time), then Rep(P) = {op,LINE,Op,Rep(P_0)}. + If P is a parenthesized pattern ( P_0 ), then Rep(P) = Rep(P_0), - that is, patterns cannot be distinguished from their bodies. + that is, parenthesized patterns cannot be distinguished from their + bodies. + If P is a record field index pattern #Name.Field, + where Field is an atom, then + Rep(P) = {record_index,LINE,Name,Rep(Field)}. + If P is a record pattern + #Name{Field_1=P_1, ..., Field_k=P_k}, + where each Field_i is an atom or _, then Rep(P) = + {record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(P_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(P_k)}]}. + If P is a tuple pattern {P_1, ..., P_k}, then + Rep(P) = {tuple,LINE,[Rep(P_1), ..., Rep(P_k)]}. + If P is a universal pattern _, then + Rep(P) = {var,LINE,'_'}. + If P is a variable pattern V, then + Rep(P) = {var,LINE,A}, + where A is an atom with a printname consisting of the same characters as + V.

Note that every pattern has the same source form as some expression, and is represented the same way as the corresponding expression.

@@ -233,36 +241,58 @@

An expression E is one of the following alternatives:

If E is an atomic literal L, then Rep(E) = Rep(L). - If E is P = E_0, then - Rep(E) = {match,LINE,Rep(P),Rep(E_0)}. - If E is a variable V, then Rep(E) = {var,LINE,A}, - where A is an atom with a printname consisting of the same - characters as V. - If E is a tuple skeleton {E_1, ..., E_k}, then - Rep(E) = {tuple,LINE,[Rep(E_1), ..., Rep(E_k)]}. - If E is [], then - Rep(E) = {nil,LINE}. + If E is a binary comprehension + <<E_0 || Q_1, ..., Q_k>>, + where each Q_i is a qualifier, then + Rep(E) = {bc,LINE,Rep(E_0),[Rep(Q_1), ..., Rep(Q_k)]}. + For Rep(Q), see below. + If E is a binary constructor <<E_1:Size_1/TSL_1, ..., E_k:Size_k/TSL_k>>, + where each Size_i is an expression and each + TSL_i is a type specificer list, then Rep(E) = + {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)}]}. + For Rep(TSL), see below. + An omitted Size_i is represented by default. + An omitted TSL_i is represented by default. + If E is a block expression begin B end, + where B is a body, then + Rep(E) = {block,LINE,Rep(B)}. + If E is a case expression case E_0 of Cc_1 ; ... ; Cc_k end, + where E_0 is an expression and each Cc_i is a + case clause then Rep(E) = + {'case',LINE,Rep(E_0),[Rep(Cc_1), ..., Rep(Cc_k)]}. + If E is a catch expression catch E_0, then + Rep(E) = {'catch',LINE,Rep(E_0)}. If E is a cons skeleton [E_h | E_t], then Rep(E) = {cons,LINE,Rep(E_h),Rep(E_t)}. - If E is a binary constructor <<V_1:Size_1/TSL_1, ..., V_k:Size_k/TSL_k>>, then Rep(E) = - {bin,LINE,[{bin_element,LINE,Rep(V_1),Rep(Size_1),Rep(TSL_1)}, ..., {bin_element,LINE,Rep(V_k),Rep(Size_k),Rep(TSL_k)}]}. - For Rep(TSL), see below. - An omitted Size is represented by default. An omitted TSL - (type specifier list) is represented by default. - If E is E_1 Op E_2, where Op is a binary operator, - then Rep(E) = {op,LINE,Op,Rep(E_1),Rep(E_2)}. - If E is Op E_0, where Op is a unary operator, then - Rep(E) = {op,LINE,Op,Rep(E_0)}. - If E is #Name{Field_1=E_1, ..., Field_k=E_k}, + If E is a fun expression fun Name/Arity, then + Rep(E) = {'fun',LINE,{function,Name,Arity}}. + If E is a fun expression + fun Module:Name/Arity, then Rep(E) = + {'fun',LINE,{function,Rep(Module),Rep(Name),Rep(Arity)}}. + (Before the R15 release: Rep(E) = + {'fun',LINE,{function,Module,Name,Arity}}.) + If E is a fun expression fun Fc_1 ; ... ; Fc_k end, + where each Fc_i is a function clause then Rep(E) = + {'fun',LINE,{clauses,[Rep(Fc_1), ..., Rep(Fc_k)]}}. + If E is a fun expression + fun Name Fc_1 ; ... ; Name Fc_k end, + where Name is a variable and each + Fc_i is a function clause then Rep(E) = + {named_fun,LINE,Name,[Rep(Fc_1), ..., Rep(Fc_k)]}. + + If E is a function call E_0(E_1, ..., E_k), then + Rep(E) = {call,LINE,Rep(E_0),[Rep(E_1), ..., Rep(E_k)]}. + If E is a function call E_m:E_0(E_1, ..., E_k), then Rep(E) = - {record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(E_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(E_k)}]}. - If E is E_0#Name{Field_1=E_1, ..., Field_k=E_k}, then - Rep(E) = - {record,LINE,Rep(E_0),Name,[{record_field,LINE,Rep(Field_1),Rep(E_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(E_k)}]}. - If E is #Name.Field, then - Rep(E) = {record_index,LINE,Name,Rep(Field)}. - If E is E_0#Name.Field, then - Rep(E) = {record_field,LINE,Rep(E_0),Name,Rep(Field)}. + {call,LINE,{remote,LINE,Rep(E_m),Rep(E_0)},[Rep(E_1), ..., Rep(E_k)]}. + + If E is an if expression if Ic_1 ; ... ; Ic_k end, + where each Ic_i is an if clause then Rep(E) = + {'if',LINE,[Rep(Ic_1), ..., Rep(Ic_k)]}. + If E is a list comprehension [E_0 || Q_1, ..., Q_k], + where each Q_i is a qualifier, then Rep(E) = + {lc,LINE,Rep(E_0),[Rep(Q_1), ..., Rep(Q_k)]}. For Rep(Q), see + below. If E is a map creation #{A_1, ..., A_k}, where each A_i is an association E_i_1 => E_i_2 or E_i_1 := E_i_2, then Rep(E) = @@ -273,95 +303,92 @@ or E_i_1 := E_i_2, then Rep(E) = {map,LINE,Rep(E_0),[Rep(A_1), ..., Rep(A_k)]}. For Rep(A), see below. - If E is catch E_0, then - Rep(E) = {'catch',LINE,Rep(E_0)}. - If E is E_0(E_1, ..., E_k), then - Rep(E) = {call,LINE,Rep(E_0),[Rep(E_1), ..., Rep(E_k)]}. - If E is E_m:E_0(E_1, ..., E_k), then Rep(E) = - {call,LINE,{remote,LINE,Rep(E_m),Rep(E_0)},[Rep(E_1), ..., Rep(E_k)]}. - - If E is a list comprehension [E_0 || Q_1, ..., Q_k], - where each Q_i is a qualifier, then Rep(E) = - {lc,LINE,Rep(E_0),[Rep(Q_1), ..., Rep(Q_k)]}. For Rep(Q), see - below. - If E is a binary comprehension - <<E_0 || Q_1, ..., Q_k>>, - where each Q_i is a qualifier, then - Rep(E) = {bc,LINE,Rep(E_0),[Rep(Q_1), ..., Rep(Q_k)]}. - For Rep(Q), see below. - If E is begin B end, where B is a body, then - Rep(E) = {block,LINE,Rep(B)}. - If E is if Ic_1 ; ... ; Ic_k end, - where each Ic_i is an if clause then Rep(E) = - {'if',LINE,[Rep(Ic_1), ..., Rep(Ic_k)]}. - If E is case E_0 of Cc_1 ; ... ; Cc_k end, - where E_0 is an expression and each Cc_i is a - case clause then Rep(E) = - {'case',LINE,Rep(E_0),[Rep(Cc_1), ..., Rep(Cc_k)]}. - If E is try B catch Tc_1 ; ... ; Tc_k end, + If E is a match operator expression P = E_0, + where P is a pattern, then + Rep(E) = {match,LINE,Rep(P),Rep(E_0)}. + If E is nil, [], then + Rep(E) = {nil,LINE}. + If E is an operator expression E_1 Op E_2, + where Op is a binary operator other than the match + operator =, then + Rep(E) = {op,LINE,Op,Rep(E_1),Rep(E_2)}. + If E is an operator expression Op E_0, + where Op is a unary operator, then + Rep(E) = {op,LINE,Op,Rep(E_0)}. + If E is a parenthesized expression ( E_0 ), then + Rep(E) = Rep(E_0), that is, parenthesized + expressions cannot be distinguished from their bodies. + If E is a receive expression receive Cc_1 ; ... ; Cc_k end, + where each Cc_i is a case clause then Rep(E) = + {'receive',LINE,[Rep(Cc_1), ..., Rep(Cc_k)]}. + If E is a receive expression + receive Cc_1 ; ... ; Cc_k after E_0 -> B_t end, + where each Cc_i is a case clause, + E_0 is an expression and B_t is a body, then Rep(E) = + {'receive',LINE,[Rep(Cc_1), ..., Rep(Cc_k)],Rep(E_0),Rep(B_t)}. + If E is a record creation + #Name{Field_1=E_1, ..., Field_k=E_k}, + where each Field_i is an atom or _, then Rep(E) = + {record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(E_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(E_k)}]}. + If E is a record field access E_0#Name.Field, + where Field is an atom, then + Rep(E) = {record_field,LINE,Rep(E_0),Name,Rep(Field)}. + If E is a record field index #Name.Field, + where Field is an atom, then + Rep(E) = {record_index,LINE,Name,Rep(Field)}. + If E is a record update + E_0#Name{Field_1=E_1, ..., Field_k=E_k}, + where each Field_i is an atom, then Rep(E) = + {record,LINE,Rep(E_0),Name,[{record_field,LINE,Rep(Field_1),Rep(E_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(E_k)}]}. + If E is a tuple skeleton {E_1, ..., E_k}, then + Rep(E) = {tuple,LINE,[Rep(E_1), ..., Rep(E_k)]}. + If E is a try expression try B catch Tc_1 ; ... ; Tc_k end, where B is a body and each Tc_i is a catch clause then Rep(E) = {'try',LINE,Rep(B),[],[Rep(Tc_1), ..., Rep(Tc_k)],[]}. - If E is try B of Cc_1 ; ... ; Cc_k catch Tc_1 ; ... ; Tc_n end, + If E is a try expression + try B of Cc_1 ; ... ; Cc_k catch Tc_1 ; ... ; Tc_n end, where B is a body, each Cc_i is a case clause and each Tc_j is a catch clause then Rep(E) = {'try',LINE,Rep(B),[Rep(Cc_1), ..., Rep(Cc_k)],[Rep(Tc_1), ..., Rep(Tc_n)],[]}. - If E is try B after A end, + If E is a try expression try B after A end, where B and A are bodies then Rep(E) = {'try',LINE,Rep(B),[],[],Rep(A)}. - If E is try B of Cc_1 ; ... ; Cc_k after A end, + If E is a try expression + try B of Cc_1 ; ... ; Cc_k after A end, where B and A are a bodies and each Cc_i is a case clause then Rep(E) = {'try',LINE,Rep(B),[Rep(Cc_1), ..., Rep(Cc_k)],[],Rep(A)}. - If E is try B catch Tc_1 ; ... ; Tc_k after A end, + If E is a try expression + try B catch Tc_1 ; ... ; Tc_k after A end, where B and A are bodies and each Tc_i is a catch clause then Rep(E) = {'try',LINE,Rep(B),[],[Rep(Tc_1), ..., Rep(Tc_k)],Rep(A)}. - If E is try B of Cc_1 ; ... ; Cc_k catch Tc_1 ; ... ; Tc_n after A end, + If E is a try expression + try B of Cc_1 ; ... ; Cc_k catch Tc_1 ; ... ; Tc_n after A end, where B and A are a bodies, each Cc_i is a case clause, and each Tc_j is a catch clause then Rep(E) = {'try',LINE,Rep(B),[Rep(Cc_1), ..., Rep(Cc_k)],[Rep(Tc_1), ..., Rep(Tc_n)],Rep(A)}. - If E is receive Cc_1 ; ... ; Cc_k end, - where each Cc_i is a case clause then Rep(E) = - {'receive',LINE,[Rep(Cc_1), ..., Rep(Cc_k)]}. - If E is receive Cc_1 ; ... ; Cc_k after E_0 -> B_t end, - where each Cc_i is a case clause, - E_0 is an expression and B_t is a body, then Rep(E) = - {'receive',LINE,[Rep(Cc_1), ..., Rep(Cc_k)],Rep(E_0),Rep(B_t)}. - If E is fun Name / Arity, then - Rep(E) = {'fun',LINE,{function,Name,Arity}}. - If E is fun Module:Name/Arity, then Rep(E) = - {'fun',LINE,{function,Rep(Module),Rep(Name),Rep(Arity)}}. - (Before the R15 release: Rep(E) = - {'fun',LINE,{function,Module,Name,Arity}}.) - If E is fun Fc_1 ; ... ; Fc_k end, - where each Fc_i is a function clause then Rep(E) = - {'fun',LINE,{clauses,[Rep(Fc_1), ..., Rep(Fc_k)]}}. - If E is fun Name Fc_1 ; ... ; Name Fc_k end, - where Name is a variable and each - Fc_i is a function clause then Rep(E) = - {named_fun,LINE,Name,[Rep(Fc_1), ..., Rep(Fc_k)]}. - - If E is ( E_0 ), then - Rep(E) = Rep(E_0), that is, parenthesized - expressions cannot be distinguished from their bodies. + If E is a variable V, then Rep(E) = {var,LINE,A}, + where A is an atom with a printname consisting of the same + characters as V.
Qualifiers

A qualifier Q is one of the following alternatives:

+ If Q is a filter E, where E is an expression, then + Rep(Q) = Rep(E). If Q is a generator P <- E, where P is a pattern and E is an expression, then Rep(Q) = {generate,LINE,Rep(P),Rep(E)}. If Q is a generator P <= E, where P is a pattern and E is an expression, then Rep(Q) = {b_generate,LINE,Rep(P),Rep(E)}. - If Q is a filter E, where E is an expression, then - Rep(Q) = Rep(E).
@@ -399,16 +426,6 @@ and catch clauses.

A clause C is one of the following alternatives:

- If C is a function clause ( Ps ) -> B, - where Ps is a pattern sequence and B is a body, then - Rep(C) = {clause,LINE,Rep(Ps),[],Rep(B)}. - If C is a function clause ( Ps ) when Gs -> B, - where Ps is a pattern sequence, - Gs is a guard sequence and B is a body, then - Rep(C) = {clause,LINE,Rep(Ps),Rep(Gs),Rep(B)}. - If C is an if clause Gs -> B, - where Gs is a guard sequence and B is a body, then - Rep(C) = {clause,LINE,[],Rep(Gs),Rep(B)}. If C is a case clause P -> B, where P is a pattern and B is a body, then Rep(C) = {clause,LINE,[Rep(P)],[],Rep(B)}. @@ -432,6 +449,16 @@ P is a pattern, Gs is a guard sequence, and B is a body, then Rep(C) = {clause,LINE,[Rep({X,P,_})],Rep(Gs),Rep(B)}. + If C is a function clause ( Ps ) -> B, + where Ps is a pattern sequence and B is a body, then + Rep(C) = {clause,LINE,Rep(Ps),[],Rep(B)}. + If C is a function clause ( Ps ) when Gs -> B, + where Ps is a pattern sequence, + Gs is a guard sequence and B is a body, then + Rep(C) = {clause,LINE,Rep(Ps),Rep(Gs),Rep(B)}. + If C is an if clause Gs -> B, + where Gs is a guard sequence and B is a body, then + Rep(C) = {clause,LINE,[],Rep(Gs),Rep(B)}.
@@ -446,33 +473,23 @@

A guard test Gt is one of the following alternatives:

If Gt is an atomic literal L, then Rep(Gt) = Rep(L). - If Gt is a variable pattern V, then - Rep(Gt) = {var,LINE,A}, where A is an atom with - a printname consisting of the same characters as V. - If Gt is a tuple skeleton {Gt_1, ..., Gt_k}, then - Rep(Gt) = {tuple,LINE,[Rep(Gt_1), ..., Rep(Gt_k)]}. - If Gt is [], then Rep(Gt) = {nil,LINE}. - If Gt is a cons skeleton [Gt_h | Gt_t], then - Rep(Gt) = {cons,LINE,Rep(Gt_h),Rep(Gt_t)}. If Gt is a binary constructor - <<Gt_1:Size_1/TSL_1, ..., Gt_k:Size_k/TSL_k>>, then + <<Gt_1:Size_1/TSL_1, ..., Gt_k:Size_k/TSL_k>>, + where each Size_i is a guard test and each + TSL_i is a type specificer list, then Rep(Gt) = {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)}]}. For Rep(TSL), see above. - An omitted Size is represented by default. - An omitted TSL (type specifier list) is represented - by default. - If Gt is Gt_1 Op Gt_2, where Op - is a binary operator, then Rep(Gt) = - {op,LINE,Op,Rep(Gt_1),Rep(Gt_2)}. - If Gt is Op Gt_0, where Op is a unary operator, then - Rep(Gt) = {op,LINE,Op,Rep(Gt_0)}. - If Gt is #Name{Field_1=Gt_1, ..., Field_k=Gt_k}, then - Rep(E) = - {record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(Gt_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(Gt_k)}]}. - If Gt is #Name.Field, then - Rep(Gt) = {record_index,LINE,Name,Rep(Field)}. - If Gt is Gt_0#Name.Field, then - Rep(Gt) = {record_field,LINE,Rep(Gt_0),Name,Rep(Field)}. + An omitted Size_i is represented by default. + An omitted TSL_i is represented by default. + If Gt is a cons skeleton [Gt_h | Gt_t], then + Rep(Gt) = {cons,LINE,Rep(Gt_h),Rep(Gt_t)}. + If Gt is a function call A(Gt_1, ..., Gt_k), + where A is an atom, then Rep(Gt) = + {call,LINE,Rep(A),[Rep(Gt_1), ..., Rep(Gt_k)]}. + If Gt is a function call A_m:A(Gt_1, ..., Gt_k), + where A_m is the atom erlang and A is + an atom or an operator, then Rep(Gt) = + {call,LINE,{remote,LINE,Rep(A_m),Rep(A)},[Rep(Gt_1), ..., Rep(Gt_k)]}. If Gt is a map creation #{A_1, ..., A_k}, where each A_i is an association Gt_i_1 => Gt_i_2 or Gt_i_1 := Gt_i_2, then Rep(Gt) = @@ -483,14 +500,33 @@ or Gt_i_1 := Gt_i_2, then Rep(Gt) = {map,LINE,Rep(Gt_0),[Rep(A_1), ..., Rep(A_k)]}. For Rep(A), see above. - If Gt is A(Gt_1, ..., Gt_k), where A is an atom, then - Rep(Gt) = {call,LINE,Rep(A),[Rep(Gt_1), ..., Rep(Gt_k)]}. - If Gt is A_m:A(Gt_1, ..., Gt_k), where A_m is - the atom erlang and A is an atom or an operator, then - Rep(Gt) = {call,LINE,{remote,LINE,Rep(A_m),Rep(A)},[Rep(Gt_1), ..., Rep(Gt_k)]}. - If Gt is ( Gt_0 ), then + If Gt is nil, [], + then Rep(Gt) = {nil,LINE}. + If Gt is an operator guard test Gt_1 Op Gt_2, + where Op is a binary operator other than the match + operator =, then + Rep(Gt) = {op,LINE,Op,Rep(Gt_1),Rep(Gt_2)}. + If Gt is an operator guard test Op Gt_0, + where Op is a unary operator, then + Rep(Gt) = {op,LINE,Op,Rep(Gt_0)}. + If Gt is a parenthesized guard test ( Gt_0 ), then Rep(Gt) = Rep(Gt_0), that is, parenthesized guard tests cannot be distinguished from their bodies. + If Gt is a record creation + #Name{Field_1=Gt_1, ..., Field_k=Gt_k}, + where each Field_i is an atom or _, then Rep(Gt) = + {record,LINE,Name,[{record_field,LINE,Rep(Field_1),Rep(Gt_1)}, ..., {record_field,LINE,Rep(Field_k),Rep(Gt_k)}]}. + If Gt is a record field access Gt_0#Name.Field, + where Field is an atom, then + Rep(Gt) = {record_field,LINE,Rep(Gt_0),Name,Rep(Field)}. + If Gt is a record field index #Name.Field, + where Field is an atom, then + Rep(Gt) = {record_index,LINE,Name,Rep(Field)}. + If Gt is a tuple skeleton {Gt_1, ..., Gt_k}, then + Rep(Gt) = {tuple,LINE,[Rep(Gt_1), ..., Rep(Gt_k)]}. + If Gt is a variable pattern V, then + Rep(Gt) = {var,LINE,A}, where A is an atom with + a printname consisting of the same characters as V.

Note that every guard test has the same source form as some expression, and is represented the same way as the corresponding expression.

@@ -504,15 +540,6 @@ {ann_type,LINE,[Rep(A),Rep(T_0)]}. If T is an atom or integer literal L, then Rep(T) = Rep(L). - If T is an operator type T_1 Op T_2, - where Op is a binary operator (this is an occurrence of - an expression that can be evaluated to an integer at compile - time), then - Rep(T) = {op,LINE,Op,Rep(T_1),Rep(T_2)}. - If T is an operator type Op T_0, where Op is a - unary operator (this is an occurrence of - an expression that can be evaluated to an integer at compile time), - then Rep(T) = {op,LINE,Op,Rep(T_0)}. If T is a bitstring type <<_:M,_:_*N>>, where M and N are singleton integer types, then Rep(T) = {type,LINE,binary,[Rep(M),Rep(N)]}. @@ -535,6 +562,18 @@ A_i is an association type, then Rep(T) = {type,LINE,map,[Rep(A_1), ..., Rep(A_k)]}. For Rep(A), see below. + If T is an operator type T_1 Op T_2, + where Op is a binary operator (this is an occurrence of + an expression that can be evaluated to an integer at compile + time), then + Rep(T) = {op,LINE,Op,Rep(T_1),Rep(T_2)}. + If T is an operator type Op T_0, where Op is a + unary operator (this is an occurrence of + an expression that can be evaluated to an integer at compile time), + then Rep(T) = {op,LINE,Op,Rep(T_0)}. + If T is ( T_0 ), then Rep(T) = Rep(T_0), + that is, parenthesized types cannot be distinguished from their + bodies. If T is a predefined (or built-in) type N(T_1, ..., T_k), then Rep(T) = {type,LINE,N,[Rep(T_1), ..., Rep(T_k)]}. @@ -558,9 +597,6 @@ If T is a user-defined type N(T_1, ..., T_k), then Rep(T) = {user_type,LINE,N,[Rep(T_1), ..., Rep(T_k)]}. - If T is ( T_0 ), then Rep(T) = Rep(T_0), - that is, parenthesized types cannot be distinguished from their - bodies.
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