Merge branch 'pan/otp_8086_ms_grammar' into dev

* pan/otp_8086_ms_grammar:
  Add match_specification grammar documentation specifically for ets

OTP-8086 Grammar for match specification describes tracing only

The grammar for match specifications in ERTS users guide only described the
tracing dialect of match specifications. An informal grammar for the ETS
dialect is added.

1 files changed, 49 insertions, 3 deletions

diff --git a/erts/doc/src/match_spec.xml b/erts/doc/src/match_spec.xml
index d6492198ca..f0390c9db8 100644
--- a/erts/doc/src/match_spec.xml
+++ b/erts/doc/src/match_spec.xml
@@ -60,7 +60,7 @@
 
   <section>
     <title>Grammar</title>
-    <p>A match_spec can be described in this <em>informal</em> grammar:</p>
+    <p>A match_spec used in tracing can be described in this <em>informal</em> grammar:</p>
     <list type="bulleted">
       <item>MatchExpression ::= [ MatchFunction, ... ]
       </item>
@@ -117,6 +117,52 @@
       <c><![CDATA[display]]></c> | <c><![CDATA[caller]]></c> | <c><![CDATA[set_tcw]]></c> |
       <c><![CDATA[silent]]></c></item>
     </list>
+
+    <p>A match_spec used in ets can be described in this <em>informal</em> grammar:</p>
+    <list type="bulleted">
+      <item>MatchExpression ::= [ MatchFunction, ... ]
+      </item>
+      <item>MatchFunction ::= { MatchHead, MatchConditions, MatchBody }
+      </item>
+      <item>MatchHead ::=  MatchVariable | <c><![CDATA['_']]></c> | { MatchHeadPart, ... }
+      </item>
+      <item>MatchHeadPart ::= term() | MatchVariable | <c><![CDATA['_']]></c></item>
+      <item>MatchVariable ::= '$&lt;number&gt;'
+      </item>
+      <item>MatchConditions ::= [ MatchCondition, ...] | <c><![CDATA[[]]]></c></item>
+      <item>MatchCondition ::= { GuardFunction } |
+       { GuardFunction, ConditionExpression, ... }
+      </item>
+      <item>BoolFunction ::= <c><![CDATA[is_atom]]></c> | <c><![CDATA[is_constant]]></c> |
+      <c><![CDATA[is_float]]></c> | <c><![CDATA[is_integer]]></c> | <c><![CDATA[is_list]]></c> |
+      <c><![CDATA[is_number]]></c> | <c><![CDATA[is_pid]]></c> | <c><![CDATA[is_port]]></c> |
+      <c><![CDATA[is_reference]]></c> | <c><![CDATA[is_tuple]]></c> | <c><![CDATA[is_binary]]></c> |
+      <c><![CDATA[is_function]]></c> | <c><![CDATA[is_record]]></c> | <c><![CDATA[is_seq_trace]]></c> |
+      <c><![CDATA['and']]></c> | <c><![CDATA['or']]></c> | <c><![CDATA['not']]></c> | <c><![CDATA['xor']]></c> |
+      <c><![CDATA[andalso]]></c> | <c><![CDATA[orelse]]></c></item>
+      <item>ConditionExpression ::= ExprMatchVariable | { GuardFunction } |
+       { GuardFunction, ConditionExpression, ... } | TermConstruct
+      </item>
+      <item>ExprMatchVariable ::= MatchVariable (bound in the MatchHead) |
+      <c><![CDATA['$_']]></c> | <c><![CDATA['$$']]></c></item>
+      <item>TermConstruct = {{}} | {{ ConditionExpression, ... }} |
+      <c><![CDATA[[]]]></c> | [ConditionExpression, ...] | NonCompositeTerm | Constant
+      </item>
+      <item>NonCompositeTerm ::= term() (not list or tuple)
+      </item>
+      <item>Constant ::= {<c><![CDATA[const]]></c>, term()}
+      </item>
+      <item>GuardFunction ::= BoolFunction | <c><![CDATA[abs]]></c> |
+      <c><![CDATA[element]]></c> | <c><![CDATA[hd]]></c> | <c><![CDATA[length]]></c> | <c><![CDATA[node]]></c> |
+      <c><![CDATA[round]]></c> | <c><![CDATA[size]]></c> | <c><![CDATA[tl]]></c> | <c><![CDATA[trunc]]></c> |
+      <c><![CDATA['+']]></c> | <c><![CDATA['-']]></c> | <c><![CDATA['*']]></c> | <c><![CDATA['div']]></c> |
+      <c><![CDATA['rem']]></c> | <c><![CDATA['band']]></c> | <c><![CDATA['bor']]></c> | <c><![CDATA['bxor']]></c> |
+      <c><![CDATA['bnot']]></c> | <c><![CDATA['bsl']]></c> | <c><![CDATA['bsr']]></c> | <c><![CDATA['>']]></c> |
+      <c><![CDATA['>=']]></c> | <c><![CDATA['<']]></c> | <c><![CDATA['=<']]></c> | <c><![CDATA['=:=']]></c> |
+      <c><![CDATA['==']]></c> | <c><![CDATA['=/=']]></c> | <c><![CDATA['/=']]></c> | <c><![CDATA[self]]></c> |
+      <c><![CDATA[get_tcw]]></c></item>
+      <item>MatchBody ::= [ ConditionExpression, ... ]</item>
+    </list>
   </section>
 
   <section>
@@ -453,8 +499,8 @@
   <section>
     <title>Differences between match specifications in ETS and tracing</title>
     <p>ETS match specifications are there to produce a return
-      value. Usually the expression contains one single
-      <c><![CDATA[ActionTerm]]></c> which defines the return value without having
+      value. Usually the <c><![CDATA[MatchBody]]></c> contains one single
+      <c><![CDATA[ConditionExpression]]></c> which defines the return value without having
       any side effects. Calls with side effects are not allowed in the
       ETS context.</p>
     <p>When tracing there is no return value to produce, the