qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-21 20:04:44 -07:00
Code Releases Activity

undo CL 4428057 / 19e540fc7d7d

Browse Source 
The CL introduces inconsistencies with respect to
the use of parentheses/grouping of receive operations.

««« original CL description
spec: narrow syntax for expression and select statements

This is not a language change, it simply expresses the
accepted cases explicitly in the respective productions.

R=rsc, r, iant
CC=golang-dev
https://golang.org/cl/4428057
»»»

R=golang-dev, rsc1
CC=golang-dev
https://golang.org/cl/4444080
This commit is contained in:
Robert Griesemer 2011-04-29 12:20:31 -07:00
parent f5fa215d8a
commit c134718611
1 changed files with 7 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
doc/go_spec.html
View File

@ -1,5 +1,5 @@
<!-- title The Go Programming Language Specification --> <!-- title The Go Programming Language Specification -->
<!-- subtitle Version of Apr 29, 2011 --> <!-- subtitle Version of Apr 22, 2011 -->
<!-- <!--
TODO TODO
@ -3035,7 +3035,7 @@ f(&lt;-ch)
</pre> </pre>
<p> <p>
A receive operation used in an assignment or initialization of the form A receive expression used in an assignment or initialization of the form
</p> </p>
<pre> <pre>
@ -3521,14 +3521,13 @@ Error: log.Panic("error encountered")
<h3 id="Expression_statements">Expression statements</h3> <h3 id="Expression_statements">Expression statements</h3>
<p> <p>
Function calls, method calls, and Function calls, method calls, and receive operations
<a href="#Receive_operator">receive operations</a>
can appear in statement context. can appear in statement context.
</p> </p>
<pre class="ebnf"> <pre class="ebnf">
ExpressionStmt = PrimaryExpr Call | RecvExpr . ExpressionStmt = Expression .
RecvExpr = "&lt;-" UnaryExpr .
</pre> </pre>
<pre> <pre>
@ -4088,9 +4087,11 @@ SelectStmt = "select" "{" { CommClause } "}" .
CommClause = CommCase ":" { Statement ";" } . CommClause = CommCase ":" { Statement ";" } .
CommCase = "case" ( SendStmt | RecvStmt ) | "default" . CommCase = "case" ( SendStmt | RecvStmt ) | "default" .
RecvStmt = [ Expression [ "," Expression ] ( "=" | ":=" ) ] RecvExpr . RecvStmt = [ Expression [ "," Expression ] ( "=" | ":=" ) ] RecvExpr .
RecvExpr = Expression .
</pre> </pre>
<p> <p>
RecvExpr must be a <a href="#Receive_operator">receive operation</a>.
For all the cases in the "select" For all the cases in the "select"
statement, the channel expressions are evaluated in top-to-bottom order, along with statement, the channel expressions are evaluated in top-to-bottom order, along with
any expressions that appear on the right hand side of send statements. any expressions that appear on the right hand side of send statements.