bool FloatParser::judge(const std::string& token)
{
size_t posE = std::min( token.find('e'), token.find('E'));
return (posE != token.npos) ? isSimpleFloat(token.substr(0,posE)) && isSimpleInt(token.substr(posE+1)) : isSimpleFloat(token);
}
bool
Lexer::getNextToken(Token *token, Error *error)
{
error->instance = ErrorInst::Null;
if (!(ungot_tokens.empty())) {
Token *popped_token = ungot_tokens.back();
ungot_tokens.pop_back();
popped_token->copyTo(token);
delete(popped_token);
return true;
}
/* Set when a token is hit: will be used for token begin position. */
int begin_line_count = current.getLineNumber();
int begin_col_count = current.getColumnNumber();
/* Set everytime: will be the last position for the token as well
* as the current position for the context. */
int end_line_count = begin_line_count;
int end_col_count = begin_col_count;
/* Current character. */
int c;
/* Current token type. */
int type = TokenType::Null;
/* Reset token string buffer. */
token->str_value.clear();
token->str_value.reserve(20);
for (;;) {
c = getchar_();
if (reset_position) {
begin_line_count = 1;
end_line_count = 1;
int col_diff = end_col_count - begin_col_count;
begin_col_count = 1;
end_col_count = col_diff + 1;
reset_position = false;
}
/* Single-line comments. */
if ((c == ';') && (token->str_value.compare("#\\"))) {
if (type) {
ungetchar_(c);
break;
}
while ((c = getchar_()) && c != EOF && c != '\n') {
}
end_line_count++;
end_col_count = 1;
begin_col_count = 1;
continue;
}
/* Multiple-line comments */
if ((c == '|') && !(token->str_value.compare("#"))) {
type = TokenType::Null;
int count = 1;
int last = c;
while ((c = getchar_()) && (c != EOF)) {
if (c == '\n') {
end_line_count++;
end_col_count = 1;
} else {
end_col_count++;
}
if ((last == '|') && (c == '#')) {
count--;
} else if ((last == '#') && (c == '|')) {
count++;
}
if (!count) {
break;
}
last = c;
}
if (c != EOF) {
getchar_();
}
end_col_count = 1;
begin_col_count = 1;
token->str_value.clear();
token->str_value.reserve(20);
continue;
}
/* String literals. */
if ((c == '"') && (token->str_value.compare("#\\"))) {
if (type) {
ungetchar_(c);
break;
}
type = TokenType::StringLiteral;
begin_line_count = end_line_count;
begin_col_count = end_col_count;
/* Read characters until you hit a double-quote. */
while ((c = getchar_())
&& c != EOF
&& ((c != '"')
|| (token->str_value.length() &&
(token->str_value[
token->str_value.length() - 1
] == '\\')))) {
if (c == '"') {
token->str_value[
token->str_value.length() - 1
] = c;
} else {
token->str_value.push_back(c);
}
end_col_count++;
}
if (c == EOF) {
error->instance =
ErrorInst::UnterminatedStringLiteral;
} else {
end_col_count++;
}
break;
}
/* Whitespace. */
if (isspace(c)) {
if (type) {
ungetchar_(c);
break;
}
if (c == '\n') {
end_line_count++;
end_col_count = 1;
begin_col_count = 1;
} else {
end_col_count++;
}
continue;
}
/* End-of-file. */
if (c == EOF) {
if (type) {
ungetchar_(c);
break;
}
type = TokenType::Eof;
break;
}
/* Left parenthesis. */
if (c == '(' && (token->str_value.compare("#\\"))) {
if (type) {
ungetchar_(c);
break;
}
type = TokenType::LeftParen;
begin_line_count = end_line_count;
begin_col_count = end_col_count;
end_col_count++;
break;
}
/* Right parenthesis. */
if (c == ')' && (token->str_value.compare("#\\"))) {
if (type) {
ungetchar_(c);
break;
}
type = TokenType::RightParen;
begin_line_count = end_line_count;
begin_col_count = end_col_count;
end_col_count++;
break;
}
/* Potential integer. */
if ((!type) && ((c == '-') || isdigit(c))) {
type = TokenType::Int;
begin_col_count = end_col_count;
begin_line_count = end_line_count;
}
/* Plain token. */
if (!type) {
type = TokenType::String;
begin_col_count = end_col_count;
begin_line_count = end_line_count;
}
token->str_value.push_back(c);
end_col_count++;
}
token->type = type;
if (type == TokenType::Int) {
if ((token->str_value.length() == 1)
&& (token->str_value[0] == '-')) {
token->type = TokenType::String;
} else if (strchr(token->str_value.c_str(), '.')) {
token->type = TokenType::FloatingPoint;
if (!isSimpleFloat(token->str_value.c_str())) {
error->instance =
ErrorInst::InvalidFloatingPointNumber;
}
} else {
if (!isSimpleInt(token->str_value.c_str())) {
error->instance = ErrorInst::InvalidInteger;
}
}
}
current.setLineAndColumn(end_line_count, end_col_count);
if (error->instance == ErrorInst::Null) {
token->begin.setLineAndColumn(
begin_line_count,
begin_col_count
);
current.copyTo(&(token->end));
return true;
} else {
error->begin.setLineAndColumn(
begin_line_count,
begin_col_count
);
current.copyTo(&(error->end));
return false;
}
}
