package kv import ( "strconv" "strings" "codeberg.org/gruf/go-byteutil" "codeberg.org/gruf/go-kv/format" ) // AppendQuote will append (and escape/quote where necessary) a formatted field string. func AppendQuote(buf *byteutil.Buffer, str string) { switch { case len(str) == 0: // Append empty quotes. buf.B = append(buf.B, `""`...) return case len(str) == 1: // Append quote single byte. appendQuoteByte(buf, str[0]) return case len(str) > format.SingleTermLine || !format.IsSafeASCII(str): // Long line or contains non-ascii chars. buf.B = strconv.AppendQuote(buf.B, str) return case !isQuoted(str): // Single/double quoted already. // Get space / tab indices (if any). s := strings.IndexByte(str, ' ') t := strings.IndexByte(str, '\t') // Find first whitespace. sp0 := smallest(s, t) if sp0 < 0 { break } // Check if str is enclosed by braces. // (but without any key-value separator). if (enclosedBy(str, sp0, '{', '}') || enclosedBy(str, sp0, '[', ']') || enclosedBy(str, sp0, '(', ')')) && strings.IndexByte(str, '=') < 0 { break } if format.ContainsDoubleQuote(str) { // Contains double quote, double quote // and append escaped existing. buf.B = append(buf.B, '"') buf.B = format.AppendEscape(buf.B, str) buf.B = append(buf.B, '"') return } // Quote un-enclosed spaces. buf.B = append(buf.B, '"') buf.B = append(buf.B, str...) buf.B = append(buf.B, '"') return } // Double quoted, enclosed in braces, or // literally anything else: append as-is. buf.B = append(buf.B, str...) return } // appendEscapeByte will append byte to buffer, quoting and escaping where necessary. func appendQuoteByte(buf *byteutil.Buffer, c byte) { switch c { // Double quote space. case ' ': buf.B = append(buf.B, '"', c, '"') // Escape + double quote. case '\a': buf.B = append(buf.B, '"', '\\', 'a', '"') case '\b': buf.B = append(buf.B, '"', '\\', 'b', '"') case '\f': buf.B = append(buf.B, '"', '\\', 'f', '"') case '\n': buf.B = append(buf.B, '"', '\\', 'n', '"') case '\r': buf.B = append(buf.B, '"', '\\', 'r', '"') case '\t': buf.B = append(buf.B, '"', '\\', 't', '"') case '\v': buf.B = append(buf.B, '"', '\\', 'v', '"') // Append as-is. default: buf.B = append(buf.B, c) } } // isQuoted checks if string is single or double quoted. func isQuoted(str string) bool { return (str[0] == '"' && str[len(str)-1] == '"') || (str[0] == '\'' && str[len(str)-1] == '\'') } // smallest attempts to return the smallest positive value of those given. func smallest(i1, i2 int) int { if i1 >= 0 && (i2 < 0 || i1 < i2) { return i1 } return i2 } // enclosedBy will check if given string is enclosed by end, and at least non-whitespace up to start. func enclosedBy(str string, sp int, start, end byte) bool { // Check for ending char in string. if str[len(str)-1] != end { return false } // Check for starting char in string. i := strings.IndexByte(str, start) if i < 0 { return false } // Check before space. return i < sp }