1 files changed, 140 insertions, 0 deletions
diff --git a/src/text/scanner/example_test.go b/src/text/scanner/example_test.go
new file mode 100644
index 0000000..5e8c3fb
--- /dev/null
+++ b/src/text/scanner/example_test.go
@@ -0,0 +1,140 @@
+// Copyright 2018 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.
+
+package scanner_test
+
+import (
+	"fmt"
+	"strings"
+	"text/scanner"
+	"unicode"
+)
+
+func Example() {
+	const src = `
+// This is scanned code.
+if a > 10 {
+	someParsable = text
+}`
+
+	var s scanner.Scanner
+	s.Init(strings.NewReader(src))
+	s.Filename = "example"
+	for tok := s.Scan(); tok != scanner.EOF; tok = s.Scan() {
+		fmt.Printf("%s: %s\n", s.Position, s.TokenText())
+	}
+
+	// Output:
+	// example:3:1: if
+	// example:3:4: a
+	// example:3:6: >
+	// example:3:8: 10
+	// example:3:11: {
+	// example:4:2: someParsable
+	// example:4:15: =
+	// example:4:17: text
+	// example:5:1: }
+}
+
+func Example_isIdentRune() {
+	const src = "%var1 var2%"
+
+	var s scanner.Scanner
+	s.Init(strings.NewReader(src))
+	s.Filename = "default"
+
+	for tok := s.Scan(); tok != scanner.EOF; tok = s.Scan() {
+		fmt.Printf("%s: %s\n", s.Position, s.TokenText())
+	}
+
+	fmt.Println()
+	s.Init(strings.NewReader(src))
+	s.Filename = "percent"
+
+	// treat leading '%' as part of an identifier
+	s.IsIdentRune = func(ch rune, i int) bool {
+		return ch == '%' && i == 0 || unicode.IsLetter(ch) || unicode.IsDigit(ch) && i > 0
+	}
+
+	for tok := s.Scan(); tok != scanner.EOF; tok = s.Scan() {
+		fmt.Printf("%s: %s\n", s.Position, s.TokenText())
+	}
+
+	// Output:
+	// default:1:1: %
+	// default:1:2: var1
+	// default:1:7: var2
+	// default:1:11: %
+	//
+	// percent:1:1: %var1
+	// percent:1:7: var2
+	// percent:1:11: %
+}
+
+func Example_mode() {
+	const src = `
+    // Comment begins at column 5.
+
+This line should not be included in the output.
+
+/*
+This multiline comment
+should be extracted in
+its entirety.
+*/
+`
+
+	var s scanner.Scanner
+	s.Init(strings.NewReader(src))
+	s.Filename = "comments"
+	s.Mode ^= scanner.SkipComments // don't skip comments
+
+	for tok := s.Scan(); tok != scanner.EOF; tok = s.Scan() {
+		txt := s.TokenText()
+		if strings.HasPrefix(txt, "//") || strings.HasPrefix(txt, "/*") {
+			fmt.Printf("%s: %s\n", s.Position, txt)
+		}
+	}
+
+	// Output:
+	// comments:2:5: // Comment begins at column 5.
+	// comments:6:1: /*
+	// This multiline comment
+	// should be extracted in
+	// its entirety.
+	// */
+}
+
+func Example_whitespace() {
+	// tab-separated values
+	const src = `aa	ab	ac	ad
+ba	bb	bc	bd
+ca	cb	cc	cd
+da	db	dc	dd`
+
+	var (
+		col, row int
+		s        scanner.Scanner
+		tsv      [4][4]string // large enough for example above
+	)
+	s.Init(strings.NewReader(src))
+	s.Whitespace ^= 1<<'\t' | 1<<'\n' // don't skip tabs and new lines
+
+	for tok := s.Scan(); tok != scanner.EOF; tok = s.Scan() {
+		switch tok {
+		case '\n':
+			row++
+			col = 0
+		case '\t':
+			col++
+		default:
+			tsv[row][col] = s.TokenText()
+		}
+	}
+
+	fmt.Print(tsv)
+
+	// Output:
+	// [[aa ab ac ad] [ba bb bc bd] [ca cb cc cd] [da db dc dd]]
+}