core/lexer/runes.go

package lexer

import (
	"strings"
	"unicode"
)

// NewIsNot generates a rune condition checker that reverses the
// decision of the given checker.
func NewIsNot(cond func(rune) bool) func(rune) bool {
	return func(r rune) bool {
		return !cond(r)
	}
}

// NewIsIn generates a rune condition checker that accepts runes
// contained on the provided string
func NewIsIn(s string) func(rune) bool {
	return func(r rune) bool {
		return strings.ContainsRune(s, r)
	}
}

// NewIsOneOf generates a run condition checker that accepts runes
// accepted by any of the given checkers
func NewIsOneOf(s ...func(rune) bool) func(rune) bool {
	return func(r rune) bool {
		for _, cond := range s {
			if cond(r) {
				return true
			}
		}
		return false
	}
}

// IsSpace reports whether the rune is a space character as
// defined by Unicode's White Space property
func IsSpace(r rune) bool {
	return unicode.IsSpace(r)
}