mirror of
https://github.com/golang/go
synced 2024-11-21 18:04:40 -07:00
The final piece of the alternative to my parens proposal
(i.e., the status quo with braces in composite literals). DELTA=20 (16 added, 0 deleted, 4 changed) OCL=25640 CL=25646
This commit is contained in:
parent
49cc649e59
commit
7a5e97ba91
@ -1875,10 +1875,11 @@ ExprPair = Expression ":" Expression .
|
||||
|
||||
<p>
|
||||
The LiteralType must be a struct, array, slice, or map type.
|
||||
<font color=red>TODO: then why doesn't the grammar say that?</font>
|
||||
The types of the expressions must match the respective field, element, and
|
||||
key types of the LiteralType; there is no automatic type conversion.
|
||||
Given
|
||||
(The grammar enforces this constraint except when the type is given
|
||||
as a TypeName.)
|
||||
The types of the expressions must be assignment compatible to
|
||||
the respective field, element, and key types of the LiteralType;
|
||||
there is no additional conversion.
|
||||
</p>
|
||||
|
||||
<pre>
|
||||
@ -1936,6 +1937,21 @@ key-value pairs separated by a colon:
|
||||
m := map[string]int{"good": 0, "bad": 1, "indifferent": 7};
|
||||
</pre>
|
||||
|
||||
<p>
|
||||
A parsing ambiguity arises when a composite literal using the
|
||||
TypeName form of the LiteralType appears in the condition of an
|
||||
"if", "for", or "switch" statement, because the braces surrounding
|
||||
the expressions in the literal are confused with those introducing
|
||||
a block of statements. To resolve the ambiguity in this rare case,
|
||||
the composite literal must appear within
|
||||
parentheses.
|
||||
</p>
|
||||
|
||||
<pre>
|
||||
if x == (T{a,b,c}[i]) { ... }
|
||||
if (x == T{a,b,c}[i]) { ... }
|
||||
</pre>
|
||||
|
||||
<h3>Function literals</h3>
|
||||
|
||||
<p>
|
||||
|
Loading…
Reference in New Issue
Block a user