Implement octal and hex escapes in strings.
diff --git a/py/lexer.c b/py/lexer.c
index daaeebf..af41302 100644
--- a/py/lexer.c
+++ b/py/lexer.c
@@ -126,6 +126,10 @@
return unichar_isdigit(lex->chr1);
}
+static bool is_following_odigit(mp_lexer_t *lex) {
+ return lex->chr1 >= '0' && lex->chr1 <= '7';
+}
+
// TODO UNICODE include unicode characters in definition of identifiers
static bool is_head_of_identifier(mp_lexer_t *lex) {
return is_letter(lex) || lex->chr0 == '_';
@@ -275,6 +279,32 @@
NULL,
};
+static int hex_digit(unichar c) {
+ // c is assumed to be hex digit
+ int n = c - '0';
+ if (n > 9) {
+ n &= ~('a' - 'A');
+ n -= ('A' - ('9' + 1));
+ }
+ return n;
+}
+
+// This is called with CUR_CHAR() before first hex digit, and should return with
+// it pointing to last hex digit
+static bool get_hex(mp_lexer_t *lex, int num_digits, uint *result) {
+ uint num = 0;
+ while (num_digits-- != 0) {
+ next_char(lex);
+ unichar c = CUR_CHAR(lex);
+ if (!unichar_isxdigit(c)) {
+ return false;
+ }
+ num = (num << 4) + hex_digit(c);
+ }
+ *result = num;
+ return true;
+}
+
static void mp_lexer_next_token_into(mp_lexer_t *lex, mp_token_t *tok, bool first_token) {
// skip white space and comments
bool had_physical_newline = false;
@@ -439,12 +469,34 @@
case 'v': c = 0x0b; break;
case 'f': c = 0x0c; break;
case 'r': c = 0x0d; break;
- // TODO \ooo octal
- case 'x': // TODO \xhh
- case 'N': // TODO \N{name} only in strings
- case 'u': // TODO \uxxxx only in strings
- case 'U': // TODO \Uxxxxxxxx only in strings
- default: break; // TODO error message
+ case 'x':
+ {
+ uint num;
+ if (!get_hex(lex, 2, &num)) {
+ // TODO error message
+ assert(0);
+ }
+ c = num;
+ break;
+ }
+ case 'N': break; // TODO \N{name} only in strings
+ case 'u': break; // TODO \uxxxx only in strings
+ case 'U': break; // TODO \Uxxxxxxxx only in strings
+ default:
+ if (c >= '0' && c <= '7') {
+ // Octal sequence, 1-3 chars
+ int digits = 3;
+ int num = c - '0';
+ while (is_following_odigit(lex) && --digits != 0) {
+ next_char(lex);
+ num = num * 8 + (CUR_CHAR(lex) - '0');
+ }
+ c = num;
+ } else {
+ // TODO error message
+ assert(0);
+ }
+ break;
}
if (c != MP_LEXER_CHAR_EOF) {
vstr_add_char(&lex->vstr, c);