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spec: examples of untyped boolean, string constants

This is a spec correction, not a language change.
The implementations have behaved like this for years
(and there are tests to that effect), and elsewhere in
the spec true and false are defined to be untyped
boolean constants.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5477047
This commit is contained in:
Russ Cox 2011-12-09 00:13:19 -05:00
parent 6a47bb4974
commit ef1c535727

View File

@ -3408,7 +3408,7 @@ untyped complex constant yields an untyped complex constant.
<p> <p>
A constant <a href="#Comparison_operators">comparison</a> always yields A constant <a href="#Comparison_operators">comparison</a> always yields
a constant of type <code>bool</code>. If the left operand of a constant an untyped boolean constant. If the left operand of a constant
<a href="#Operators">shift expression</a> is an untyped constant, the <a href="#Operators">shift expression</a> is an untyped constant, the
result is an integer constant; otherwise it is a constant of the same result is an integer constant; otherwise it is a constant of the same
type as the left operand, which must be of integer type type as the left operand, which must be of integer type
@ -3427,8 +3427,11 @@ const d = 1 &lt;&lt; 3.0 // d == 8 (untyped integer constant)
const e = 1.0 &lt;&lt; 3 // e == 8 (untyped integer constant) const e = 1.0 &lt;&lt; 3 // e == 8 (untyped integer constant)
const f = int32(1) &lt;&lt; 33 // f == 0 (type int32) const f = int32(1) &lt;&lt; 33 // f == 0 (type int32)
const g = float64(2) &gt;&gt; 1 // illegal (float64(2) is a typed floating-point constant) const g = float64(2) &gt;&gt; 1 // illegal (float64(2) is a typed floating-point constant)
const h = "foo" &gt; "bar" // h == true (type bool) const h = "foo" &gt; "bar" // h == true (untyped boolean constant)
const j = 'w' + 1 // j == 'x' (untyped character constant) const j = true // j == true (untyped boolean constant)
const k = 'w' + 1 // k == 'x' (untyped character constant)
const l = "hi" // l == "hi" (untyped string constant)
const m = string(k) // m == "x" (type string)
const Σ = 1 - 0.707 // (untyped complex constant) const Σ = 1 - 0.707 // (untyped complex constant)
const Δ = Σ + 2.0e-4 // (untyped complex constant) const Δ = Σ + 2.0e-4 // (untyped complex constant)
const Φ = iota*1i - 1/1i // (untyped complex constant) const Φ = iota*1i - 1/1i // (untyped complex constant)