struct instruction *parse_instruction(void)
{
struct expr *expr;
struct instruction *res;
switch (lookahead[0]->type)
{
case WHILE: return parse_while();
case DO: return parse_do();
case IDENTIFIER: case LPAREN:
expr = parse_expression();
switch(lookahead[0]->type)
{
case ASSIGN: return parse_assignment_instr(expr);
case EOL:
if (expr->exprtype != funcalltype)
{
if (expr->exprtype == binopexprtype
&& expr->val.binopexpr.op == EQ)
{
error(expr->pos, "unexpected =, did you mean <- ?");
exit(1);
}
else
syntaxerror("expected instruction, not expression");
}
eat(EOL);
res = funcallinstr(expr->val.funcall.fun_ident,
expr->val.funcall.args, expr->pos);
free(expr);
return res;
default:
next();
syntaxerror("unexpected %s", tok->val);
return parse_instruction();
}
case RETURN:
eat(RETURN);
if (lookahead[0]->type == EOL)
{
eat(EOL);
return return_stmt(NULL);
}
else
{
expr = parse_expression(); eat(EOL);
return return_stmt(expr);
}
case FOR: return parse_for();
case IF: return parse_if();
case SWITCH: return parse_switch();
case ENDOFFILE: return NULL;
default:
next();
syntaxerror("expected instruction, not %s", tok->val);
return parse_instruction();
}
}
bool Parser::parse_statement(StatementList *list)
{
lexer.identify_keywords();
switch(lexeme())
{
case Lexeme::KW_IF:
parse_if(list);
break;
case Lexeme::KW_WHILE:
parse_while(list);
break;
case Lexeme::KW_DO:
parse_do(list);
parse_terminator();
break;
case Lexeme::KW_RETURN:
parse_return(list);
parse_terminator();
break;
case Lexeme::KW_BREAK:
parse_break(list);
parse_terminator();
break;
case Lexeme::KW_CONTINUE:
parse_continue(list);
parse_terminator();
break;
case Lexeme::KW_CONST:
step();
parse_local(true, parse_expression(), list);
parse_terminator();
break;
case Lexeme::BRACET_OPEN:
list->append(parse_block<true, false>(Scope::EMPTY));
break;
case Lexeme::SEMICOLON:
step();
break;
case Lexeme::END:
case Lexeme::BRACET_CLOSE:
return false;
default:
if(is_expression(lexeme()))
{
ExpressionNode *node = parse_expression();
if(lexeme() == Lexeme::IDENT && node->is_type_name(document, false))
parse_local(false, node, list);
else
list->append(node);
parse_terminator();
}
else
return false;
}
return true;
}
