example_test.go

Documentation: go/scanner

		 1  // Copyright 2012 The Go Authors. All rights reserved.
		 2  // Use of this source code is governed by a BSD-style
		 3  // license that can be found in the LICENSE file.
		 4  
		 5  package scanner_test
		 6  
		 7  import (
		 8  	"fmt"
		 9  	"go/scanner"
		10  	"go/token"
		11  )
		12  
		13  func ExampleScanner_Scan() {
		14  	// src is the input that we want to tokenize.
		15  	src := []byte("cos(x) + 1i*sin(x) // Euler")
		16  
		17  	// Initialize the scanner.
		18  	var s scanner.Scanner
		19  	fset := token.NewFileSet()											// positions are relative to fset
		20  	file := fset.AddFile("", fset.Base(), len(src)) // register input "file"
		21  	s.Init(file, src, nil /* no error handler */, scanner.ScanComments)
		22  
		23  	// Repeated calls to Scan yield the token sequence found in the input.
		24  	for {
		25  		pos, tok, lit := s.Scan()
		26  		if tok == token.EOF {
		27  			break
		28  		}
		29  		fmt.Printf("%s\t%s\t%q\n", fset.Position(pos), tok, lit)
		30  	}
		31  
		32  	// output:
		33  	// 1:1	IDENT	"cos"
		34  	// 1:4	(	""
		35  	// 1:5	IDENT	"x"
		36  	// 1:6	)	""
		37  	// 1:8	+	""
		38  	// 1:10	IMAG	"1i"
		39  	// 1:12	*	""
		40  	// 1:13	IDENT	"sin"
		41  	// 1:16	(	""
		42  	// 1:17	IDENT	"x"
		43  	// 1:18	)	""
		44  	// 1:20	;	"\n"
		45  	// 1:20	COMMENT	"// Euler"
		46  }
		47
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