103 lines
2.2 KiB
Go
103 lines
2.2 KiB
Go
// Package aghstrings contains utilities dealing with strings.
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package aghstrings
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import (
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"strings"
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)
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// CloneSliceOrEmpty returns the copy of a or empty strings slice if a is nil.
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func CloneSliceOrEmpty(a []string) (b []string) {
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return append([]string{}, a...)
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}
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// CloneSlice returns the exact copy of a.
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func CloneSlice(a []string) (b []string) {
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if a == nil {
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return nil
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}
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return CloneSliceOrEmpty(a)
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}
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// Coalesce returns the first non-empty string. It is named after the function
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// COALESCE in SQL except that since strings in Go are non-nullable, it uses an
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// empty string as a NULL value. If strs is empty, it returns an empty string.
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func Coalesce(strs ...string) (res string) {
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for _, s := range strs {
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if s != "" {
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return s
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}
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}
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return ""
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}
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// FilterOut returns a copy of strs with all strings for which f returned true
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// removed.
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func FilterOut(strs []string, f func(s string) (ok bool)) (filtered []string) {
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for _, s := range strs {
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if !f(s) {
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filtered = append(filtered, s)
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}
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}
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return filtered
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}
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// InSlice checks if string is in the slice of strings.
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func InSlice(strs []string, str string) (ok bool) {
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for _, s := range strs {
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if s == str {
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return true
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}
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}
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return false
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}
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// IsCommentOrEmpty returns true of the string starts with a "#" character or is
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// an empty string.
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func IsCommentOrEmpty(s string) (ok bool) {
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return len(s) == 0 || s[0] == '#'
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}
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// SplitNext splits string by a byte and returns the first chunk skipping empty
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// ones. Whitespaces are trimmed.
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func SplitNext(s *string, sep rune) (chunk string) {
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if s == nil {
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return chunk
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}
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i := strings.IndexByte(*s, byte(sep))
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if i == -1 {
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chunk = *s
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*s = ""
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return strings.TrimSpace(chunk)
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}
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chunk = (*s)[:i]
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*s = (*s)[i+1:]
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var j int
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var r rune
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for j, r = range *s {
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if r != sep {
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break
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}
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}
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*s = (*s)[j:]
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return strings.TrimSpace(chunk)
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}
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// WriteToBuilder is a convenient wrapper for strings.(*Builder).WriteString
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// that deals with multiple strings and ignores errors that are guaranteed to be
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// nil.
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func WriteToBuilder(b *strings.Builder, strs ...string) {
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// TODO(e.burkov): Recover from panic?
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for _, s := range strs {
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_, _ = b.WriteString(s)
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}
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}
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