path.go

Documentation: golang.org/x/exp/cmd/gorelease

     1  // Copyright 2020 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 (
     8  	"path/filepath"
     9  	"strings"
    10  )
    11  
    12  // hasPathPrefix reports whether the slash-separated path s
    13  // begins with the elements in prefix.
    14  // Copied from cmd/go/internal/str.HasPathPrefix.
    15  func hasPathPrefix(s, prefix string) bool {
    16  	if len(s) == len(prefix) {
    17  		return s == prefix
    18  	}
    19  	if prefix == "" {
    20  		return true
    21  	}
    22  	if len(s) > len(prefix) {
    23  		if prefix[len(prefix)-1] == '/' || s[len(prefix)] == '/' {
    24  			return s[:len(prefix)] == prefix
    25  		}
    26  	}
    27  	return false
    28  }
    29  
    30  // hasFilePathPrefix reports whether the filesystem path s
    31  // begins with the elements in prefix.
    32  // Copied from cmd/go/internal/str.HasFilePathPrefix.
    33  func hasFilePathPrefix(s, prefix string) bool {
    34  	sv := strings.ToUpper(filepath.VolumeName(s))
    35  	pv := strings.ToUpper(filepath.VolumeName(prefix))
    36  	s = s[len(sv):]
    37  	prefix = prefix[len(pv):]
    38  	switch {
    39  	default:
    40  		return false
    41  	case pv != "" && sv != pv:
    42  		return false
    43  	case len(s) == len(prefix):
    44  		return s == prefix
    45  	case prefix == "":
    46  		return true
    47  	case len(s) > len(prefix):
    48  		if prefix[len(prefix)-1] == filepath.Separator {
    49  			return strings.HasPrefix(s, prefix)
    50  		}
    51  		return s[len(prefix)] == filepath.Separator && s[:len(prefix)] == prefix
    52  	}
    53  }
    54  
    55  // trimFilePathPrefix returns the given filesystem path s without the leading
    56  // prefix.
    57  func trimFilePathPrefix(s, prefix string) string {
    58  	sv := strings.ToUpper(filepath.VolumeName(s))
    59  	pv := strings.ToUpper(filepath.VolumeName(prefix))
    60  	s = s[len(sv):]
    61  	prefix = prefix[len(pv):]
    62  
    63  	if !hasFilePathPrefix(s, prefix) || len(prefix) == 0 {
    64  		return s
    65  	}
    66  	if len(s) == len(prefix) {
    67  		return ""
    68  	}
    69  	if prefix[len(prefix)-1] == filepath.Separator {
    70  		return strings.TrimPrefix(s, prefix)
    71  	}
    72  	return s[len(prefix)+1:]
    73  }
    74  
    75  // trimPathPrefix returns p without the leading prefix. Unlike
    76  // strings.TrimPrefix, the prefix will only match on slash-separted component
    77  // boundaries, so trimPathPrefix("aa/b", "aa") returns "b", but
    78  // trimPathPrefix("aa/b", "a") returns "aa/b".
    79  func trimPathPrefix(p, prefix string) string {
    80  	if prefix == "" {
    81  		return p
    82  	}
    83  	if prefix == p {
    84  		return ""
    85  	}
    86  	return strings.TrimPrefix(p, prefix+"/")
    87  }
    88
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