struct token *lexer_read_substitution(struct lexer_book *bk)
{
int parenthesis = 0;
char c = lexer_next_peek(bk);
if(c != '$')
lexer_report_error(bk, "Expecting $ for variable substitution.");
lexer_next_char(bk); /* Jump $ */
if(lexer_next_peek(bk) == '(') {
lexer_next_char(bk); /* Jump ( */
parenthesis = 1;
}
struct token *name = lexer_read_syntax_name(bk);
name->type = SUBSTITUTION;
if(parenthesis) {
if(lexer_next_peek(bk) == ')')
lexer_next_char(bk); /* Jump ) */
else
lexer_report_error(bk, "Expecting ) for closing variable substitution.");
}
return name;
}
struct token *lexer_read_substitution(struct lexer *lx)
{
char closer = 0; //closer is either 0 (no closer), ) or }.
char c = lexer_next_peek(lx);
if(c != '$')
lexer_report_error(lx, "Expecting $ for variable substitution.");
lexer_next_char(lx); /* Jump $ */
if(lexer_next_peek(lx) == '(') {
lexer_next_char(lx); /* Jump ( */
closer = ')';
} else if(lexer_next_peek(lx) == '{') {
lexer_next_char(lx); /* Jump { */
closer = '}';
}
struct token *name = lexer_read_syntax_name(lx);
name->type = TOKEN_SUBSTITUTION;
if(closer) {
if(lexer_next_peek(lx) == closer)
lexer_next_char(lx); /* Jump ) */
else
lexer_report_error(lx, "Expecting %c for closing variable substitution.", closer);
}
return name;
}
accept_t lexer_read_syntax(struct lexer_book * bk)
{
lexer_discard_white_space(bk);
struct token *name = lexer_read_syntax_name(bk);
if(strcmp("export", name->lexeme) == 0)
return lexer_read_syntax_export(bk, name);
else if(lexer_unquoted_look_ahead_count(bk, "=") > -1)
return lexer_read_variable(bk, name);
else {
lexer_roll_back(bk, strlen(name->lexeme));
lexer_report_error(bk, "Unrecognized keyword: %s.", name->lexeme);
}
return NO;
}
accept_t lexer_read_syntax_export(struct lexer_book *bk, struct token *name)
{
lexer_discard_white_space(bk);
name->type = SYNTAX;
lexer_push_token(bk, name);
if(lexer_unquoted_look_ahead_count(bk, "=") > -1)
return lexer_read_variable(bk, lexer_read_syntax_name(bk));
else
return lexer_read_variable_list(bk);
return YES;
}
int lexer_read_syntax_or_variable(struct lexer * lx)
{
lexer_discard_white_space(lx);
struct token *name = lexer_read_syntax_name(lx);
if(strcmp("export", name->lexeme) == 0)
return lexer_read_syntax_export(lx, name);
else if(lexer_unquoted_look_ahead_count(lx, "=") > -1)
return lexer_read_variable(lx, name);
else {
lexer_roll_back(lx, strlen(name->lexeme));
lexer_report_error(lx, "Unrecognized keyword: %s.", name->lexeme);
}
return 1;
}
int lexer_read_syntax_export(struct lexer *lx, struct token *name)
{
lexer_discard_white_space(lx);
//name->lexeme is "export"
name->type = TOKEN_SYNTAX;
lexer_push_token(lx, name);
if(lexer_unquoted_look_ahead_count(lx, "=") > -1)
lexer_read_variable(lx, lexer_read_syntax_name(lx));
else
lexer_read_variable_list(lx);
lexer_push_token(lx, lexer_pack_token(lx, TOKEN_NEWLINE));
return 1;
}
int lexer_read_variable_list(struct lexer * lx)
{
int c;
while((c = lexer_next_peek(lx)) != '\n') {
lexer_discard_white_space(lx);
if(c == '#') {
lexer_discard_comments(lx);
lexer_roll_back(lx, 1); //Recover the newline
break;
}
lexer_push_token(lx, lexer_read_syntax_name(lx));
}
lexer_add_to_lexeme(lx, lexer_next_char(lx)); //Drop the newline
lexer_push_token(lx, lexer_pack_token(lx, TOKEN_NEWLINE));
return 1;
}
accept_t lexer_read_variable_list(struct lexer_book * bk)
{
int c;
while((c = lexer_next_peek(bk)) != '\n') {
lexer_discard_white_space(bk);
if(c == '#') {
lexer_discard_comments(bk);
lexer_roll_back(bk, 1); //Recover the newline
break;
}
lexer_push_token(bk, lexer_read_syntax_name(bk));
}
lexer_add_to_lexeme(bk, lexer_next_char(bk)); //Drop the newline
lexer_push_token(bk, lexer_pack_token(bk, NEWLINE));
return YES;
}
