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Lex numeric escapes, needed for lib-str.rs (which now passes).

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This commit is contained in:
Graydon Hoare 2011-04-13 11:25:01 -07:00
parent 3e081d20e5
commit 8e0ecb4d1a
1 changed files with 77 additions and 13 deletions
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90
src/comp/front/lexer.rs
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@ -52,7 +52,7 @@ impure fn new_reader(io.reader rdr, str filename, codemap.filemap filemap)
if (pos < len) {ret _str.char_at(file, pos);}
else {ret -1 as char;}
}
impure fn init() {
if (pos < len) {
auto next = _str.char_range_at(file, pos);
@ -368,7 +368,7 @@ impure fn scan_exponent(reader rdr) -> option.t[str] {
}
impure fn scan_dec_digits(reader rdr) -> str {
auto c = rdr.curr();
let str res = "";
@ -417,11 +417,11 @@ impure fn scan_number(mutable char c, reader rdr) -> token.token {
dec_str = scan_dec_digits(rdr);
is_dec_integer = true;
}
if (is_dec_integer) {
accum_int = digits_to_string(dec_str);
}
c = rdr.curr();
n = rdr.next();
@ -526,6 +526,44 @@ impure fn scan_number(mutable char c, reader rdr) -> token.token {
}
}
impure fn scan_numeric_escape(reader rdr) -> char {
auto n_hex_digits = 0;
check (rdr.curr() == '\\');
alt (rdr.next()) {
case ('x') { n_hex_digits = 2; }
case ('u') { n_hex_digits = 4; }
case ('U') { n_hex_digits = 8; }
case (?c) {
log "unknown numeric character escape";
log c;
fail;
}
}
rdr.bump(); // advance curr past \
auto n = rdr.next();
auto accum_int = 0;
while (n_hex_digits != 0) {
if (!is_hex_digit(n)) {
log "illegal numeric character escape";
log n;
fail;
}
accum_int *= 16;
accum_int += hex_digit_val(n);
rdr.bump();
n = rdr.next();
n_hex_digits -= 1;
}
ret accum_int as char;
}
impure fn next_token(reader rdr) -> token.token {
auto accum_str = "";
@ -666,26 +704,31 @@ impure fn next_token(reader rdr) -> token.token {
auto c2 = rdr.curr();
if (c2 == '\\') {
alt (rdr.next()) {
case ('n') { rdr.bump(); c2 = '\n'; }
case ('r') { rdr.bump(); c2 = '\r'; }
case ('t') { rdr.bump(); c2 = '\t'; }
case ('\\') { rdr.bump(); c2 = '\\'; }
case ('\'') { rdr.bump(); c2 = '\''; }
// FIXME: unicode numeric escapes.
case ('n') { c2 = '\n'; }
case ('r') { c2 = '\r'; }
case ('t') { c2 = '\t'; }
case ('\\') { c2 = '\\'; }
case ('\'') { c2 = '\''; }
case ('x') { c2 = scan_numeric_escape(rdr); }
case ('u') { c2 = scan_numeric_escape(rdr); }
case ('U') { c2 = scan_numeric_escape(rdr); }
case (?c2) {
log "unknown character escape";
log c2;
fail;
}
}
rdr.bump();
}
if (rdr.next() != '\'') {
log "unterminated character constant";
fail;
}
rdr.bump();
rdr.bump();
rdr.bump(); // advance curr to closing '
rdr.bump(); // advance curr past token
ret token.LIT_CHAR(c2);
}
@ -715,7 +758,22 @@ impure fn next_token(reader rdr) -> token.token {
rdr.bump();
_str.push_byte(accum_str, '"' as u8);
}
// FIXME: unicode numeric escapes.
case ('x') {
_str.push_char(accum_str,
scan_numeric_escape(rdr));
}
case ('u') {
_str.push_char(accum_str,
scan_numeric_escape(rdr));
}
case ('U') {
_str.push_char(accum_str,
scan_numeric_escape(rdr));
}
case (?c2) {
log "unknown string escape";
log c2;
@ -782,6 +840,12 @@ impure fn next_token(reader rdr) -> token.token {
case ('%') {
ret binop(rdr, token.PERCENT);
}
case (?c) {
log "unkown start of token";
log c;
fail;
}
}
fail;