col_style.go

package gobatis

import (
	"regexp"
	"strings"
)

// clone from https://raw.githubusercontent.com/iancoleman/strcase/master/snake.go

var numberSequence = regexp.MustCompile(`([a-zA-Z])(\d+)([a-zA-Z]?)`)
var numberReplacement = []byte(`$1 $2 $3`)

func addWordBoundariesToNumbers(s string) string {
	b := []byte(s)
	b = numberSequence.ReplaceAll(b, numberReplacement)
	return string(b)
}


// Converts a string to snake_case
func toSnake(s string) string {
	return toDelimited(s, '_')
}

// Converts a string to SCREAMING_SNAKE_CASE
func toScreamingSnake(s string) string {
	return toScreamingDelimited(s, '_', true)
}

// Converts a string to kebab-case
func toKebab(s string) string {
	return toDelimited(s, '-')
}

// Converts a string to SCREAMING-KEBAB-CASE
func toScreamingKebab(s string) string {
	return toScreamingDelimited(s, '-', true)
}

// Converts a string to delimited.snake.case (in this case `del = '.'`)
func toDelimited(s string, del uint8) string {
	return toScreamingDelimited(s, del, false)
}

func toScreamingDelimited(s string, del uint8, screaming bool) string {
	s = addWordBoundariesToNumbers(s)
	s = strings.Trim(s, " ")
	n := ""
	for i, v := range s {
		// treat acronyms as words, eg for JSONData -> JSON is a whole word
		nextCaseIsChanged := false
		if i+1 < len(s) {
			next := s[i+1]
			if (v >= 'A' && v <= 'Z' && next >= 'a' && next <= 'z') || (v >= 'a' && v <= 'z' && next >= 'A' && next <= 'Z') {
				nextCaseIsChanged = true
			}
		}

		if i > 0 && n[len(n)-1] != del && nextCaseIsChanged {
			// add underscore if next letter case type is changed
			if v >= 'A' && v <= 'Z' {
				n += string(del) + string(v)
			} else if v >= 'a' && v <= 'z' {
				n += string(v) + string(del)
			}
		} else if v == ' ' || v == '_' || v == '-' {
			// replace spaces/underscores with delimiters
			n += string(del)
		} else {
			n = n + string(v)
		}
	}

	if screaming {
		n = strings.ToUpper(n)
	} else {
		n = strings.ToLower(n)
	}
	return n
}


// Converts a string to CamelCase
func toCamelInitCase(s string, initCase bool) string {
	s = addWordBoundariesToNumbers(s)
	s = strings.Trim(s, " ")
	n := ""
	capNext := initCase
	for _, v := range s {
		if v >= 'A' && v <= 'Z' {
			n += string(v)
		}
		if v >= '0' && v <= '9' {
			n += string(v)
		}
		if v >= 'a' && v <= 'z' {
			if capNext {
				n += strings.ToUpper(string(v))
			} else {
				n += string(v)
			}
		}
		if v == '_' || v == ' ' || v == '-' {
			capNext = true
		} else {
			capNext = false
		}
	}
	return n
}

// Converts a string to CamelCase
func toCamel(s string) string {
	return toCamelInitCase(s, true)
}

// Converts a string to lowerCamelCase
func toLowerCamel(s string) string {
	if s == "" {
		return s
	}
	if r := rune(s[0]); r >= 'A' && r <= 'Z' {
		s = strings.ToLower(string(r)) + s[1:]
	}
	return toCamelInitCase(s, false)
}