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go/doc/progs/interface2.go
Josh Bleecher Snyder 5451fff475 doc/progs: rewrite test driver in Go
The tests in doc/progs appear to have been originally written
for use with the old test driver. At some later point,
they acquired their own test driver.
Both ran tests in serial.

This CL rewrites the current test driver in Go,
runs tests concurrently, and cleans up
historical artifacts from the old drivers.

The primary motivation is to speed up all.bash.
On my laptop, using tip, this CL reduces doc/progs test
wall time from 26s to 7s. The savings will remain
even when the compiler gets faster. Using Go 1.4,
this CL reduces test wall time from 15s to 4s.

Change-Id: Iae945a8490222beee76e8a2118a0d7956092f543
Reviewed-on: https://go-review.googlesource.com/8410
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-04-07 00:41:59 +00:00

133 lines
2.6 KiB
Go

// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This file contains the code snippets included in "The Laws of Reflection."
package main
import (
"fmt"
"reflect"
)
func main() {
var x float64 = 3.4
fmt.Println("type:", reflect.TypeOf(x))
// STOP OMIT
// TODO(proppy): test output OMIT
}
// STOP main OMIT
func f1() {
// START f1 OMIT
var x float64 = 3.4
v := reflect.ValueOf(x)
fmt.Println("type:", v.Type())
fmt.Println("kind is float64:", v.Kind() == reflect.Float64)
fmt.Println("value:", v.Float())
// STOP OMIT
}
func f2() {
// START f2 OMIT
var x uint8 = 'x'
v := reflect.ValueOf(x)
fmt.Println("type:", v.Type()) // uint8.
fmt.Println("kind is uint8: ", v.Kind() == reflect.Uint8) // true.
x = uint8(v.Uint()) // v.Uint returns a uint64.
// STOP OMIT
}
func f3() {
// START f3 OMIT
type MyInt int
var x MyInt = 7
v := reflect.ValueOf(x)
// STOP OMIT
// START f3b OMIT
y := v.Interface().(float64) // y will have type float64.
fmt.Println(y)
// STOP OMIT
// START f3c OMIT
fmt.Println(v.Interface())
// STOP OMIT
// START f3d OMIT
fmt.Printf("value is %7.1e\n", v.Interface())
// STOP OMIT
}
func f4() {
// START f4 OMIT
var x float64 = 3.4
v := reflect.ValueOf(x)
v.SetFloat(7.1) // Error: will panic.
// STOP OMIT
}
func f5() {
// START f5 OMIT
var x float64 = 3.4
v := reflect.ValueOf(x)
fmt.Println("settability of v:", v.CanSet())
// STOP OMIT
}
func f6() {
// START f6 OMIT
var x float64 = 3.4
v := reflect.ValueOf(x)
// STOP OMIT
// START f6b OMIT
v.SetFloat(7.1)
// STOP OMIT
}
func f7() {
// START f7 OMIT
var x float64 = 3.4
p := reflect.ValueOf(&x) // Note: take the address of x.
fmt.Println("type of p:", p.Type())
fmt.Println("settability of p:", p.CanSet())
// STOP OMIT
// START f7b OMIT
v := p.Elem()
fmt.Println("settability of v:", v.CanSet())
// STOP OMIT
// START f7c OMIT
v.SetFloat(7.1)
fmt.Println(v.Interface())
fmt.Println(x)
// STOP OMIT
}
func f8() {
// START f8 OMIT
type T struct {
A int
B string
}
t := T{23, "skidoo"}
s := reflect.ValueOf(&t).Elem()
typeOfT := s.Type()
for i := 0; i < s.NumField(); i++ {
f := s.Field(i)
fmt.Printf("%d: %s %s = %v\n", i,
typeOfT.Field(i).Name, f.Type(), f.Interface())
}
// STOP OMIT
// START f8b OMIT
s.Field(0).SetInt(77)
s.Field(1).SetString("Sunset Strip")
fmt.Println("t is now", t)
// STOP OMIT
}
func f9() {
// START f9 OMIT
var x float64 = 3.4
fmt.Println("value:", reflect.ValueOf(x))
// STOP OMIT
}