fmt.Println(string(bytes.TrimFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
	// Output:
	// -gopher!
	// "go-gopher!"
	// go-gopher
	// go-gopher!
}

func ExampleTrimLeft() {
	fmt.Print(string(bytes.TrimLeft([]byte("453gopher8257"), "0123456789")))
	// Output:
	// gopher8257
}

func ExampleTrimLeftFunc() {
	fmt.Println(string(bytes.TrimLeftFunc([]byte("go-gopher"), unicode.IsLetter)))

package asm

import (
	"internal/buildcfg"
	"strings"
	"testing"

	"cmd/asm/internal/arch"
	"cmd/asm/internal/lex"
	"cmd/internal/obj"
)

// A simple in-out test: Do we print what we parse?

func setArch(goarch string) (*arch.Arch, *obj.Link) {
	buildcfg.GOOS = "linux" // obj can handle this OS for all architectures.
	buildcfg.GOARCH = goarch
	architecture := arch.Set(goarch, false)

	"math"
	"os"
	"os/exec"
	"strconv"
	"strings"
	"unicode"
	"unicode/utf8"

	"cmd/internal/quoted"
)

var debugDefine = flag.Bool("debug-define", false, "print relevant #defines")
var debugGcc = flag.Bool("debug-gcc", false, "print gcc invocations")

var nameToC = map[string]string{
	"schar":         "signed char",
	"uchar":         "unsigned char",
	"ushort":        "unsigned short",

<pre>
var a []int
var c, c1, c2, c3, c4 chan int
var i1, i2 int
select {
case i1 = &lt;-c1:
	print("received ", i1, " from c1\n")
case c2 &lt;- i2:
	print("sent ", i2, " to c2\n")
case i3, ok := (&lt;-c3):  // same as: i3, ok := &lt;-c3
	if ok {
		print("received ", i3, " from c3\n")
	} else {
		print("c3 is closed\n")
	}
case a[f()] = &lt;-c4:
	// same as:
	// case t := &lt;-c4
	//	a[f()] = t

	"internal/buildcfg"
	"os"
	"path/filepath"
	"regexp"
	"sort"
	"strconv"
	"strings"
	"testing"

	"cmd/asm/internal/lex"
	"cmd/internal/obj"
)

// An end-to-end test for the assembler: Do we print what we parse?
// Output is generated by, in effect, turning on -S and comparing the
// result against a golden file.

func testEndToEnd(t *testing.T, goarch, file string) {
	input := filepath.Join("testdata", file+".s")

				// An "unfortunate" case: the feature was once
				// included in the API (e.g. go1.txt), but was
				// subsequently removed. These are already
				// acknowledged by being in the file
				// "api/except.txt". No need to print them out
				// here.
			} else if portRemoved(feature) {
				// okay.
			} else if featureSet[featureWithoutContext(feature)] {
				// okay.
			} else {
				fmt.Fprintf(w, "-%s\n", feature)