diff options
| -rw-r--r-- | lib/pure/pegs.nim | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/lib/pure/pegs.nim b/lib/pure/pegs.nim index 23ed855a4..39c5790ed 100644 --- a/lib/pure/pegs.nim +++ b/lib/pure/pegs.nim @@ -1226,7 +1226,8 @@ proc skip(c: var PegLexer) = of ' ', '\t': inc(pos) of '#': - while not (buf[pos] in {'\c', '\L', '\0'}): inc(pos) + while (pos < c.buf.len) and + not (buf[pos] in {'\c', '\L', '\0'}): inc(pos) of '\c': pos = handleCR(c, pos) buf = c.buf @@ -1285,7 +1286,7 @@ proc getCharSet(c: var PegLexer, tok: var Token) = var ch: char case buf[pos] of ']': - inc(pos) + if pos < c.buf.len: inc(pos) break of '\\': c.bufpos = pos @@ -1304,7 +1305,10 @@ proc getCharSet(c: var PegLexer, tok: var Token) = incl(tok.charset, '-') inc(pos) else: - inc(pos) + if pos+1 < c.buf.len: + inc(pos) + else: + break var ch2: char case buf[pos] of '\\': @@ -1316,8 +1320,11 @@ proc getCharSet(c: var PegLexer, tok: var Token) = tok.kind = tkInvalid break else: - ch2 = buf[pos] - inc(pos) + if pos+1 < c.buf.len: + ch2 = buf[pos] + inc(pos) + else: + break for i in ord(ch)+1 .. ord(ch2): incl(tok.charset, chr(i)) c.bufpos = pos @@ -1334,7 +1341,7 @@ proc getSymbol(c: var PegLexer, tok: var Token) = tok.kind = tkIdentifier proc getBuiltin(c: var PegLexer, tok: var Token) = - if c.buf[c.bufpos+1] in strutils.Letters: + if c.bufpos+1 < c.buf.len and c.buf[c.bufpos+1] in strutils.Letters: inc(c.bufpos) getSymbol(c, tok) tok.kind = tkBuiltin @@ -1347,10 +1354,12 @@ proc getTok(c: var PegLexer, tok: var Token) = tok.modifier = modNone setLen(tok.literal, 0) skip(c) + case c.buf[c.bufpos] of '{': inc(c.bufpos) - if c.buf[c.bufpos] == '@' and c.buf[c.bufpos+1] == '}': + if c.buf[c.bufpos] == '@' and c.bufpos+2 < c.buf.len and + c.buf[c.bufpos+1] == '}': tok.kind = tkCurlyAt inc(c.bufpos, 2) add(tok.literal, "{@}") @@ -1383,13 +1392,11 @@ proc getTok(c: var PegLexer, tok: var Token) = getBuiltin(c, tok) of '\'', '"': getString(c, tok) of '$': getDollar(c, tok) - of '\0': - tok.kind = tkEof - tok.literal = "[EOF]" of 'a'..'z', 'A'..'Z', '\128'..'\255': getSymbol(c, tok) if c.buf[c.bufpos] in {'\'', '"'} or - c.buf[c.bufpos] == '$' and c.buf[c.bufpos+1] in {'0'..'9'}: + c.buf[c.bufpos] == '$' and c.bufpos+1 < c.buf.len and + c.buf[c.bufpos+1] in {'0'..'9'}: case tok.literal of "i": tok.modifier = modIgnoreCase of "y": tok.modifier = modIgnoreStyle @@ -1410,7 +1417,7 @@ proc getTok(c: var PegLexer, tok: var Token) = inc(c.bufpos) add(tok.literal, '+') of '<': - if c.buf[c.bufpos+1] == '-': + if c.bufpos+2 < c.buf.len and c.buf[c.bufpos+1] == '-': inc(c.bufpos, 2) tok.kind = tkArrow add(tok.literal, "<-") @@ -1445,6 +1452,9 @@ proc getTok(c: var PegLexer, tok: var Token) = inc(c.bufpos) add(tok.literal, '^') else: + if c.bufpos >= c.buf.len: + tok.kind = tkEof + tok.literal = "[EOF]" add(tok.literal, c.buf[c.bufpos]) inc(c.bufpos) |