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effective go: tweak the words about semicolons, parens in control structures,

and make and new.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/4699043
This commit is contained in:
Rob Pike 2011-07-12 23:45:10 +10:00
parent 9f4c288c16
commit 4c63129545

View File

@ -116,7 +116,7 @@ Some formatting details remain. Very briefly,
<dt>Parentheses</dt> <dt>Parentheses</dt>
<dd> <dd>
Go needs fewer parentheses: control structures (<code>if</code>, Go needs fewer parentheses: control structures (<code>if</code>,
<code>for</code>, <code>switch</code>) do not require parentheses in <code>for</code>, <code>switch</code>) do not have parentheses in
their syntax. their syntax.
Also, the operator precedence hierarchy is shorter and clearer, so Also, the operator precedence hierarchy is shorter and clearer, so
<pre> <pre>
@ -405,7 +405,7 @@ break continue fallthrough return ++ -- ) }
<p> <p>
the lexer always inserts a semicolon after the token. the lexer always inserts a semicolon after the token.
This could be summarized as, &ldquo;if the newline comes This could be summarized as, &ldquo;if the newline comes
after a token that could end a statement, add a semicolon&rdquo;. after a token that could end a statement, insert a semicolon&rdquo;.
</p> </p>
<p> <p>
@ -461,7 +461,7 @@ initialization statement like that of <code>for</code>;
and there are new control structures including a type switch and a and there are new control structures including a type switch and a
multiway communications multiplexer, <code>select</code>. multiway communications multiplexer, <code>select</code>.
The syntax is also slightly different: The syntax is also slightly different:
parentheses are not required there are no parentheses
and the bodies must always be brace-delimited. and the bodies must always be brace-delimited.
</p> </p>
@ -564,7 +564,7 @@ for i := 0; i &lt; 10; i++ {
<p> <p>
If you're looping over an array, slice, string, or map, If you're looping over an array, slice, string, or map,
or reading from a channel, a <code>range</code> clause can or reading from a channel, a <code>range</code> clause can
manage the loop for you. manage the loop.
</p> </p>
<pre> <pre>
var m map[string]int var m map[string]int
@ -943,8 +943,11 @@ Go has two allocation primitives, the built-in functions
They do different things and apply to different types, which can be confusing, They do different things and apply to different types, which can be confusing,
but the rules are simple. but the rules are simple.
Let's talk about <code>new</code> first. Let's talk about <code>new</code> first.
It's a built-in function essentially the same as its namesakes It's a built-in function that allocates memory, but unlike its namesakes
in other languages: <code>new(T)</code> allocates zeroed storage for a new item of type in some other languages it does not <em>initialize</em> the memory,
it only <em>zeroes</em> it.
That is,
<code>new(T)</code> allocates zeroed storage for a new item of type
<code>T</code> and returns its address, a value of type <code>*T</code>. <code>T</code> and returns its address, a value of type <code>*T</code>.
In Go terminology, it returns a pointer to a newly allocated zero value of type In Go terminology, it returns a pointer to a newly allocated zero value of type
<code>T</code>. <code>T</code>.