Statement *ParserContext::parse_statement() {
Statement *statement = 0;
switch (curtok()->type()) {
case tok_while: {
statement = parse_while();
break;
}
case tok_if: {
statement = parse_if();
break;
}
case tok_return: {
statement = parse_return();
eat_token(tok_semicolon);
break;
}
case tok_def: {
statement = parse_def();
break;
}
default: {
Expression *expression = parse_expression();
if (expression) {
statement = new ExpressionStatement(expression);
eat_token(tok_semicolon);
} else {
throw UnexpectedToken("parse_statement", curtok());
}
break;
}
}
return statement;
}
static struct AstNode *parse_special(
struct DomNode *dom,
struct ParserState *state)
{
struct AstNode *result;
if ((!err_state() && (result = parse_do_block(dom, state))) ||
(!err_state() && (result = parse_match(dom, state))) ||
(!err_state() && (result = parse_if(dom, state))) ||
(!err_state() && (result = parse_while(dom, state))) ||
(!err_state() && (result = parse_func_def(dom, state))) ||
(!err_state() && (result = parse_min_nary(dom, 1, DOM_RES_AND, ast_make_spec_bool_and, state))) ||
(!err_state() && (result = parse_min_nary(dom, 1, DOM_RES_OR, ast_make_spec_bool_or, state))) ||
(!err_state() && (result = parse_min_nary(dom, 1, DOM_RES_SET_OF, ast_make_spec_set_of, state))) ||
(!err_state() && (result = parse_binary(dom, DOM_RES_RANGE_OF, ast_make_spec_range_of, state))) ||
(!err_state() && (result = parse_unary(dom, DOM_RES_ARRAY_OF, ast_make_spec_array_of, state))) ||
(!err_state() && (result = parse_min_nary(dom, 1, DOM_RES_TUPLE_OF, ast_make_spec_tuple_of, state))) ||
(!err_state() && (result = parse_unary(dom, DOM_RES_POINTER_TO, ast_make_spec_pointer_to, state))) ||
(!err_state() && (result = parse_min_nary(dom, 1, DOM_RES_FUNCTION, ast_make_spec_function_type, state))) ||
(!err_state() && (result = parse_unary(dom, DOM_RES_TYPE_PRODUCT, ast_make_spec_type_product, state))) ||
(!err_state() && (result = parse_unary(dom, DOM_RES_TYPE_UNION, ast_make_spec_type_union, state))) ||
(!err_state() && (result = parse_bind(dom, state))) ||
(!err_state() && (result = parse_unary(dom, DOM_RES_PTR, ast_make_spec_ptr, state))) ||
(!err_state() && (result = parse_unary(dom, DOM_RES_PEEK, ast_make_spec_peek, state))) ||
(!err_state() && (result = parse_binary(dom, DOM_RES_POKE, ast_make_spec_poke, state))) ||
(!err_state() && (result = parse_unary(dom, DOM_RES_BEGIN, ast_make_spec_begin, state))) ||
(!err_state() && (result = parse_unary(dom, DOM_RES_END, ast_make_spec_end, state))) ||
(!err_state() && (result = parse_unary(dom, DOM_RES_INC, ast_make_spec_inc, state))) ||
(!err_state() && (result = parse_unary(dom, DOM_RES_SUCC, ast_make_spec_succ, state)))) {
return result;
} else {
return NULL;
}
}
static statement_t* parse_statement(parser_t* p)
{
statement_t* statement = (statement_t*)malloc(sizeof(statement_t));
token_type_t tok = get_token(p->t);
unget_token(p->t);
switch (tok) {
case TT_IF:
statement->type = ST_IF;
statement->value = parse_if(p);
break;
case TT_WHILE:
statement->type = ST_WHILE;
statement->value = parse_while(p);
break;
case TT_RETURN:
statement->type = ST_RETURN;
match(p, TT_RETURN);
statement->value = parse_expression(p);
break;
case TT_PRINT:
statement->type = ST_PRINT;
match(p, TT_PRINT);
statement->value = parse_expression(p);
break;
default:
statement->type = ST_EXPRESSION;
statement->value = parse_expression(p);
}
return statement;
}
/*
parse_statement
Checks the current token to be able to parse the correct statement
Parameters: none
Return: none
*/
void parse_statement(Tree &cst){
cst.add_branch_node("statement");
if(!(curr_token -> desc).compare("print")){
parse_print(cst);
}
else if(!(curr_token -> type).compare("identifier")){
parse_assingment(cst);
}
else if(types.find(curr_token -> desc) != types.end()){
parse_var_decl(cst);
}
else if(!(curr_token -> desc).compare("while")){
parse_while(cst);
}
else if(!(curr_token -> desc).compare("if")){
parse_if(cst);
}
else if(!(curr_token -> type).compare("open_block")){
parse_block(cst);
}
else{
std::cout << "Parse Error on line " << curr_token -> line_number
<< ".\nExpected statement, found " << curr_token -> desc
<< "\nStatements begin with:\n\tprint\n\tidentifier -- [a-z]\n\t"
<< "int, string, boolean\n\twhile\n\tif\n\t{"
<< "\n\nCompilation unsuccessful" << std::endl;
exit(EXIT_FAILURE);
}
cst.kill_all_children();
}
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();
}
}
/** Parse statement.
*
* @param parse Parser object.
* @return New syntax tree node.
*/
stree_stat_t *parse_stat(parse_t *parse)
{
stree_stat_t *stat;
stree_vdecl_t *vdecl_s;
stree_if_t *if_s;
stree_switch_t *switch_s;
stree_while_t *while_s;
stree_for_t *for_s;
stree_raise_t *raise_s;
stree_break_t *break_s;
stree_return_t *return_s;
stree_wef_t *wef_s;
stree_exps_t *exp_s;
#ifdef DEBUG_PARSE_TRACE
printf("Parse statement.\n");
#endif
switch (lcur_lc(parse)) {
case lc_var:
vdecl_s = parse_vdecl(parse);
stat = stree_stat_new(st_vdecl);
stat->u.vdecl_s = vdecl_s;
break;
case lc_if:
if_s = parse_if(parse);
stat = stree_stat_new(st_if);
stat->u.if_s = if_s;
break;
case lc_switch:
switch_s = parse_switch(parse);
stat = stree_stat_new(st_switch);
stat->u.switch_s = switch_s;
break;
case lc_while:
while_s = parse_while(parse);
stat = stree_stat_new(st_while);
stat->u.while_s = while_s;
break;
case lc_for:
for_s = parse_for(parse);
stat = stree_stat_new(st_for);
stat->u.for_s = for_s;
break;
case lc_raise:
raise_s = parse_raise(parse);
stat = stree_stat_new(st_raise);
stat->u.raise_s = raise_s;
break;
case lc_break:
break_s = parse_break(parse);
stat = stree_stat_new(st_break);
stat->u.break_s = break_s;
break;
case lc_return:
return_s = parse_return(parse);
stat = stree_stat_new(st_return);
stat->u.return_s = return_s;
break;
case lc_do:
case lc_with:
wef_s = parse_wef(parse);
stat = stree_stat_new(st_wef);
stat->u.wef_s = wef_s;
break;
default:
exp_s = parse_exps(parse);
stat = stree_stat_new(st_exps);
stat->u.exp_s = exp_s;
break;
}
#ifdef DEBUG_PARSE_TRACE
printf("Parsed statement %p\n", stat);
#endif
return stat;
}
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;
}
