erts: Improve readability of The Abstract Format

More verbose, but hopefully more readable than before.

1 files changed, 228 insertions, 192 deletions

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 @@
       <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>-module(Mod)</c>, then
-       Rep(F) = <c>{attribute,LINE,module,Mod}</c>.</item>
       <item>If F is an attribute <c>-behavior(Behavior)</c>, then
        Rep(F) = <c>{attribute,LINE,behavior,Behavior}</c>.</item>
       <item>If F is an attribute <c>-behaviour(Behaviour)</c>, then
        Rep(F) = <c>{attribute,LINE,behaviour,Behaviour}</c>.</item>
+      <item>If F is an attribute <c>-compile(Options)</c>, then
+       Rep(F) = <c>{attribute,LINE,compile,Options}</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>-export_type([Type_1/A_1, ..., Type_k/A_k])</c>, then
        Rep(F) = <c>{attribute,LINE,export_type,[{Type_1,A_1}, ..., {Type_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>-optional_callbacks([Fun_1/A_1, ..., Fun_k/A_k])</c>, then
        Rep(F) = <c>{attribute,LINE,optional_callbacks,[{Fun_1,A_1}, ..., {Fun_k,A_k}]}</c>.</item>
-      <item>If F is an attribute <c>-compile(Options)</c>, then
-       Rep(F) = <c>{attribute,LINE,compile,Options}</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 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>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>,
@@ -112,15 +107,20 @@
        <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>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>
     </list>
 
     <section>
@@ -160,15 +160,15 @@
     <p>There are five kinds of atomic literals, which are represented in the
       same way in patterns, expressions and guards:</p>
     <list type="bulleted">
-      <item>If L is an integer or character literal, then
-       Rep(L) = <c>{integer,LINE,L}</c>.</item>
+      <item>If L is an atom literal, then
+       Rep(L) = <c>{atom,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 or character 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>If L is an atom literal, then
-       Rep(L) = <c>{atom,LINE,L}</c>.</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>
@@ -182,45 +182,53 @@
     <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 binary pattern
+       <c>&lt;&lt;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 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>If P is a universal pattern <c>_</c>, then
-       Rep(P) = <c>{var,LINE,'_'}</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 nil pattern <c>[]</c>, then
-       Rep(P) = <c>{nil,LINE}</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 E is a binary pattern <c>&lt;&lt;P_1:Size_1/TSL_1, ..., P_k:Size_k/TSL_k>></c>, then
-       Rep(E) = <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</c> is represented by <c>default</c>. An omitted <c>TSL</c>
-       (type specifier list) is represented by <c>default</c>.</item>
-      <item>If P is <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 <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 record pattern <c>#Name{Field_1=P_1, ..., Field_k=P_k}</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 <c>#Name.Field</c>, then
-       Rep(P) = <c>{record_index,LINE,Name,Rep(Field)}</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 <c>( P_0 )</c>, then
+      <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, patterns cannot be distinguished from their bodies.</item>
+       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>
     </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>
@@ -233,36 +241,58 @@
     <p>An expression E is one of the following alternatives:</p>
     <list type="bulleted">
       <item>If E is an atomic literal <c>L</c>, then Rep(E) = Rep(L).</item>
-      <item>If E is <c>P = E_0</c>, then
-       Rep(E) = <c>{match,LINE,Rep(P),Rep(E_0)}</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>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 <c>[]</c>, then
-       Rep(E) = <c>{nil,LINE}</c>.</item>
+      <item>If E is a binary comprehension
+       <c>&lt;&lt;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 binary constructor <c>&lt;&lt;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 binary constructor <c>&lt;&lt;V_1:Size_1/TSL_1, ..., V_k:Size_k/TSL_k>></c>, then Rep(E) =
-       <c>{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)}]}</c>.
-       For Rep(TSL), see below.
-       An omitted <c>Size</c> is represented by <c>default</c>. An omitted <c>TSL</c>
-       (type specifier list) is represented by <c>default</c>.</item>
-      <item>If E is <c>E_1 Op E_2</c>, where <c>Op</c> is a binary operator,
-       then Rep(E) = <c>{op,LINE,Op,Rep(E_1),Rep(E_2)}</c>.</item>
-      <item>If E is <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 <c>#Name{Field_1=E_1, ..., Field_k=E_k}</c>,
+      <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>{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 <c>E_0#Name{Field_1=E_1, ..., Field_k=E_k}</c>, 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 <c>#Name.Field</c>, then
-       Rep(E) = <c>{record_index,LINE,Name,Rep(Field)}</c>.</item>
-      <item>If E is <c>E_0#Name.Field</c>, then
-       Rep(E) = <c>{record_field,LINE,Rep(E_0),Name,Rep(Field)}</c>.</item>
+       <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) =
@@ -273,95 +303,92 @@
        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 <c>catch E_0</c>, then
-       Rep(E) = <c>{'catch',LINE,Rep(E_0)}</c>.</item>
-      <item>If E is <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 <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 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 binary comprehension
-       <c>&lt;&lt;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 <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 <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 <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 <c>try B catch Tc_1 ; ... ; Tc_k end</c>,
+      <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 <c>try B of Cc_1 ; ... ; Cc_k catch Tc_1 ; ... ; Tc_n end</c>,
+      <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 <c>try B after A end</c>,
+      <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 <c>try B of Cc_1 ; ... ; Cc_k after A end</c>,
+      <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 <c>try B catch Tc_1 ; ... ; Tc_k after A end</c>,
+      <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 <c>try B of Cc_1 ; ... ; Cc_k  catch Tc_1 ; ... ; Tc_n after A end</c>,
+      <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 <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 <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 <c>fun Name / Arity</c>, then
-       Rep(E) = <c>{'fun',LINE,{function,Name,Arity}}</c>.</item>
-      <item>If E is <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 <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 <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 <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 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>
     </list>
 
     <section>
       <title>Qualifiers</title>
       <p>A qualifier Q is one of the following alternatives:</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 &lt;- 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 generator <c>P &lt;= 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>If Q is a filter <c>E</c>, where <c>E</c> is an expression, then
-         Rep(Q) = <c>Rep(E)</c>.</item>
       </list>
     </section>
 
@@ -399,16 +426,6 @@
       and catch clauses.</p>
     <p>A clause <c>C</c> is one of the following alternatives:</p>
     <list type="bulleted">
-      <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>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>
@@ -432,6 +449,16 @@
       <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>
     </list>
   </section>
 
@@ -446,33 +473,23 @@
     <p>A guard test <c>Gt</c> is one of the following alternatives:</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 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>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 <c>[]</c>, then Rep(Gt) = <c>{nil,LINE}</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 binary constructor
-       <c>&lt;&lt;Gt_1:Size_1/TSL_1, ..., Gt_k:Size_k/TSL_k>></c>, then
+       <c>&lt;&lt;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</c> is represented by <c>default</c>.
-       An omitted <c>TSL</c> (type specifier list) is represented
-       by <c>default</c>.</item>
-      <item>If Gt is <c>Gt_1 Op Gt_2</c>, where <c>Op</c>
-       is a binary operator, then Rep(Gt) =
-       <c>{op,LINE,Op,Rep(Gt_1),Rep(Gt_2)}</c>.</item>
-      <item>If Gt is <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 <c>#Name{Field_1=Gt_1, ..., Field_k=Gt_k}</c>, then
-       Rep(E) =
-      <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 <c>#Name.Field</c>, then
-       Rep(Gt) = <c>{record_index,LINE,Name,Rep(Field)}</c>.</item>
-      <item>If Gt is <c>Gt_0#Name.Field</c>, then
-       Rep(Gt) = <c>{record_field,LINE,Rep(Gt_0),Name,Rep(Field)}</c>.</item>
+       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) =
@@ -483,14 +500,33 @@
        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 <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 <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 <c>( Gt_0 )</c>, then
+      <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>
     </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>
@@ -504,15 +540,6 @@
        <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 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 a bitstring type <c>&lt;&lt;_: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>
@@ -535,6 +562,18 @@
        <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>
@@ -558,9 +597,6 @@
       <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>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>
     </list>
 
     <section>