string.go

package jsondecoder

import (
	"strconv"
)

func isSpace(c byte) bool {
	return c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n')
}

// quoteChar formats c as a quoted character literal
func quoteChar(c byte) string {
	// special cases - different from quoted strings
	if c == '\'' {
		return `'\''`
	}
	if c == '"' {
		return `'"'`
	}

	// use quoted string with different quotation marks
	s := strconv.Quote(string(c))
	return "'" + s[1:len(s)-1] + "'"
}

// getu4 decodes \uXXXX from the beginning of s, returning the hex value,
// or it returns -1.
func getu4(s []byte) rune {
	if len(s) < 6 || s[0] != '\\' || s[1] != 'u' {
		return -1
	}
	var r rune
	for _, c := range s[2:6] {
		switch {
		case '0' <= c && c <= '9':
			c = c - '0'
		case 'a' <= c && c <= 'f':
			c = c - 'a' + 10
		case 'A' <= c && c <= 'F':
			c = c - 'A' + 10
		default:
			return -1
		}
		r = r*16 + rune(c)
	}
	return r
}