k3s/vendor/github.com/lithammer/dedent/dedent.go

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2019-01-12 04:58:27 +00:00
package dedent
import (
"regexp"
"strings"
)
var (
whitespaceOnly = regexp.MustCompile("(?m)^[ \t]+$")
leadingWhitespace = regexp.MustCompile("(?m)(^[ \t]*)(?:[^ \t\n])")
)
// Dedent removes any common leading whitespace from every line in text.
//
// This can be used to make multiline strings to line up with the left edge of
// the display, while still presenting them in the source code in indented
// form.
func Dedent(text string) string {
var margin string
text = whitespaceOnly.ReplaceAllString(text, "")
indents := leadingWhitespace.FindAllStringSubmatch(text, -1)
// Look for the longest leading string of spaces and tabs common to all
// lines.
for i, indent := range indents {
if i == 0 {
margin = indent[1]
} else if strings.HasPrefix(indent[1], margin) {
// Current line more deeply indented than previous winner:
// no change (previous winner is still on top).
continue
} else if strings.HasPrefix(margin, indent[1]) {
// Current line consistent with and no deeper than previous winner:
// it's the new winner.
margin = indent[1]
} else {
// Current line and previous winner have no common whitespace:
// there is no margin.
margin = ""
break
}
}
if margin != "" {
text = regexp.MustCompile("(?m)^"+margin).ReplaceAllString(text, "")
}
return text
}