/* Reading the pattern itself */
static int
lex_pattern(usenet_parser_t self, int ch)
{
/* Watch for EOF or linefeed */
if (ch == EOF || ch == '\n') {
/* Null-terminate the token */
if (append_char(self, '\0') < 0) {
return -1;
}
/* Do something interesting with the expression */
if (accept_expression(self, self->field, self->operator,
self->token) < 0) {
return -1;
}
/* This is also the end of the group entry */
if (accept_group(self, self->has_not, self->group) < 0) {
return -1;
}
free(self->group);
/* Let the start state deal with the EOF or linefeed */
return lex_start(self, ch);
}
/* Watch for the escape character */
if (ch == '\\') {
self->state = lex_pattern_esc;
return 0;
}
/* Watch for other whitespace */
if (isspace(ch)) {
/* Record the position of the whitespace for later trimming */
self->token_mark = self->token_pointer;
self->state = lex_pattern_ws;
return append_char(self, ch);
}
/* Watch for a separator */
if (ch == '/') {
/* Null-terminate the token */
if (append_char(self, '\0') < 0) {
return -1;
}
/* Do something interesting with the expression */
self->token_pointer = self->token;
self->state = lex_field_start;
return accept_expression(self, self->field, self->operator,
self->token);
}
/* Anything else is part of the pattern */
return append_char(self, ch);
}
/* Reading trailing whitespace after a pattern */
static int
lex_pattern_ws(usenet_parser_t self, int ch)
{
/* Watch for EOF and newline */
if (ch == EOF || ch == '\n') {
/* Trim off the trailing whitespace */
*self->token_mark = '\0';
/* Do something interesting with the expression */
if (accept_expression(self, self->field, self->operator,
self->token) < 0) {
return -1;
}
/* This is also the end of the group entry */
if (accept_group(self, self->has_not, self->group) < 0) {
return -1;
}
free(self->group);
/* Let the start state deal with the EOF or newline */
return lex_start(self, ch);
}
/* Skip any other whitespace */
if (isspace(ch)) {
return append_char(self, ch);
}
/* Watch for an escape character */
if (ch == '\\') {
self->state = lex_pattern_esc;
return 0;
}
/* Watch for a separator */
if (ch == '/') {
/* Trim off the trailing whitespace */
*self->token_mark = '\0';
/* Do something interesting with the expression */
self->token_pointer = self->token;
self->state = lex_field_start;
return accept_expression(self, self->field, self->operator,
self->token);
}
/* Anything else is more of the pattern */
self->state = lex_pattern;
return append_char(self, ch);
}
shared_ptr<Statement>
Parser::accept_var_statement(const shared_ptr<Environment> environment) {
if (!accept(Token(Token::IDENTIFIER, "var")))
return nullptr;
Token identifier;
expect(Token::IDENTIFIER, identifier);
shared_ptr<Expression> initializer = make_shared<UndefinedValue>();
if (accept(Token(Token::OPERATOR, "="))
&& !(initializer = accept_expression(environment)))
expected("initializer");
expect(Token::SEMICOLON);
return make_shared<VarStatement>(identifier.string, initializer);
}
