github.com/adwpc/xmobile@v0.0.0-20231212131043-3f9720cf0e99/cmd/gomobile/strings_flag.go (about)

     1  // Copyright 2015 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 main
     6  
     7  import "fmt"
     8  
     9  type stringsFlag []string
    10  
    11  func (v *stringsFlag) Set(s string) error {
    12  	var err error
    13  	*v, err = splitQuotedFields(s)
    14  	if *v == nil {
    15  		*v = []string{}
    16  	}
    17  	return err
    18  }
    19  
    20  func isSpaceByte(c byte) bool {
    21  	return c == ' ' || c == '\t' || c == '\n' || c == '\r'
    22  }
    23  
    24  func splitQuotedFields(s string) ([]string, error) {
    25  	// Split fields allowing '' or "" around elements.
    26  	// Quotes further inside the string do not count.
    27  	var f []string
    28  	for len(s) > 0 {
    29  		for len(s) > 0 && isSpaceByte(s[0]) {
    30  			s = s[1:]
    31  		}
    32  		if len(s) == 0 {
    33  			break
    34  		}
    35  		// Accepted quoted string. No unescaping inside.
    36  		if s[0] == '"' || s[0] == '\'' {
    37  			quote := s[0]
    38  			s = s[1:]
    39  			i := 0
    40  			for i < len(s) && s[i] != quote {
    41  				i++
    42  			}
    43  			if i >= len(s) {
    44  				return nil, fmt.Errorf("unterminated %c string", quote)
    45  			}
    46  			f = append(f, s[:i])
    47  			s = s[i+1:]
    48  			continue
    49  		}
    50  		i := 0
    51  		for i < len(s) && !isSpaceByte(s[i]) {
    52  			i++
    53  		}
    54  		f = append(f, s[:i])
    55  		s = s[i:]
    56  	}
    57  	return f, nil
    58  }
    59  
    60  func (v *stringsFlag) String() string {
    61  	return "<stringsFlag>"
    62  }