strcase/snake.go
2020-09-21 13:36:21 +10:00

115 lines
3.6 KiB
Go

/*
* The MIT License (MIT)
*
* Copyright (c) 2015 Ian Coleman
* Copyright (c) 2018 Ma_124, <github.com/Ma124>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, Subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or Substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package strcase
import (
"strings"
)
// ToSnake converts a string to snake_case
func ToSnake(s string) string {
return ToDelimited(s, '_')
}
func ToSnakeWithIgnore(s string, ignore uint8) string {
return ToScreamingDelimited(s, '_', ignore, false)
}
// ToScreamingSnake converts a string to SCREAMING_SNAKE_CASE
func ToScreamingSnake(s string) string {
return ToScreamingDelimited(s, '_', 0, true)
}
// ToKebab converts a string to kebab-case
func ToKebab(s string) string {
return ToDelimited(s, '-')
}
// ToScreamingKebab converts a string to SCREAMING-KEBAB-CASE
func ToScreamingKebab(s string) string {
return ToScreamingDelimited(s, '-', 0, true)
}
// ToDelimited converts a string to delimited.snake.case
// (in this case `delimiter = '.'`)
func ToDelimited(s string, delimiter uint8) string {
return ToScreamingDelimited(s, delimiter, 0, false)
}
// ToScreamingDelimited converts a string to SCREAMING.DELIMITED.SNAKE.CASE
// (in this case `delimiter = '.'; screaming = true`)
// or delimited.snake.case
// (in this case `delimiter = '.'; screaming = false`)
func ToScreamingDelimited(s string, delimiter uint8, ignore uint8, screaming bool) string {
s = strings.TrimSpace(s)
n := strings.Builder{}
n.Grow(len(s) + 2) // nominal 2 bytes of extra space for inserted delimiters
for i, v := range []byte(s) {
vIsCap := v >= 'A' && v <= 'Z'
vIsLow := v >= 'a' && v <= 'z'
if vIsLow && screaming {
v += 'A'
v -= 'a'
} else if vIsCap && !screaming {
v += 'a'
v -= 'A'
}
// treat acronyms as words, eg for JSONData -> JSON is a whole word
if i+1 < len(s) {
next := s[i+1]
vIsNum := v >= '0' && v <= '9'
nextIsCap := next >= 'A' && next <= 'Z'
nextIsLow := next >= 'a' && next <= 'z'
nextIsNum := next >= '0' && next <= '9'
// add underscore if next letter case type is changed
if (vIsCap && (nextIsLow || nextIsNum)) || (vIsLow && (nextIsCap || nextIsNum)) || (vIsNum && (nextIsCap || nextIsLow)) {
if prevIgnore := ignore > 0 && i > 0 && s[i-1] == ignore; !prevIgnore {
if vIsCap && nextIsLow {
if prevIsCap := i > 0 && s[i-1] >= 'A' && s[i-1] <= 'Z'; prevIsCap {
n.WriteByte(delimiter)
}
}
n.WriteByte(v)
if vIsLow || vIsNum || nextIsNum {
n.WriteByte(delimiter)
}
continue
}
}
}
if (v == ' ' || v == '_' || v == '-') && uint8(v) != ignore {
// replace space/underscore/hyphen with delimiter
n.WriteByte(delimiter)
} else {
n.WriteByte(v)
}
}
return n.String()
}