static sl_node_base_t*
for_expression(sl_parse_state_t* ps)
{
sl_node_base_t *lval, *expr, *body, *else_body = NULL;
sl_node_seq_t* seq_lval;
sl_token_t* tok;
sl_parse_scope_t scope;
expect_token(ps, SL_TOK_FOR);
/* save current token to allow rewinding and erroring */
tok = peek_token(ps);
lval = call_expression(ps);
if(!sl_node_is_lval(lval)) {
unexpected(ps, tok);
}
if(peek_token(ps)->type == SL_TOK_COMMA || peek_token(ps)->type == SL_TOK_FAT_COMMA) {
seq_lval = sl_make_seq_node(ps);
seq_lval->nodes[seq_lval->node_count++] = lval;
while(peek_token(ps)->type == SL_TOK_COMMA || peek_token(ps)->type == SL_TOK_FAT_COMMA) {
next_token(ps);
if(seq_lval->node_count == seq_lval->node_capacity) {
seq_lval->node_capacity *= 2;
seq_lval->nodes = sl_realloc(ps->vm->arena, seq_lval->nodes, sizeof(sl_node_base_t*) * seq_lval->node_capacity);
}
tok = peek_token(ps);
lval = call_expression(ps);
if(!sl_node_is_lval(lval)) {
unexpected(ps, tok);
}
seq_lval->nodes[seq_lval->node_count++] = lval;
}
lval = sl_make_array_node(ps, seq_lval->node_count, seq_lval->nodes);
}
expect_token(ps, SL_TOK_IN);
expr = expression(ps);
scope.prev = ps->scope;
scope.flags = scope.prev->flags | SL_PF_CAN_NEXT_LAST;
ps->scope = &scope;
body = body_expression(ps);
ps->scope = scope.prev;
if(scope.flags & SL_PF_SCOPE_CLOSURE) {
ps->scope->flags |= SL_PF_SCOPE_CLOSURE;
}
if(peek_token(ps)->type == SL_TOK_ELSE) {
next_token(ps);
else_body = body_expression(ps);
}
return sl_make_for_node(ps, lval, expr, body, else_body);
}
static sl_node_base_t*
use_expression(sl_parse_state_t* ps)
{
expect_token(ps, SL_TOK_USE);
sl_node_base_t* node = call_expression(ps);
if(node->type != SL_NODE_CONST) {
error(ps, sl_make_cstring(ps->vm, "Expected constant reference in use expression"), token(ps));
}
for(sl_node_base_t* i = node; i && i->type == SL_NODE_CONST; i = ((sl_node_const_t*)i)->obj) {
i->type = SL_NODE_USE;
}
return node;
}
static sl_node_base_t*
inc_dec_expression(sl_parse_state_t* ps)
{
if(peek_token(ps)->type == SL_TOK_INCREMENT) {
next_token(ps);
return sl_make_prefix_mutate_node(ps, call_expression(ps), "succ");
}
if(peek_token(ps)->type == SL_TOK_DECREMENT) {
next_token(ps);
return sl_make_prefix_mutate_node(ps, call_expression(ps), "pred");
}
sl_node_base_t* lval = call_expression(ps);
if(sl_node_is_mutable_lval(lval)) {
if(peek_token(ps)->type == SL_TOK_INCREMENT) {
next_token(ps);
return sl_make_postfix_mutate_node(ps, lval, "succ");
}
if(peek_token(ps)->type == SL_TOK_DECREMENT) {
next_token(ps);
return sl_make_postfix_mutate_node(ps, lval, "pred");
}
}
return lval;
}
// Parse a postfix-expression.
//
// postfix-expression:
// primary-expression
// postfix-expression '.' id
// postfix-expression '(' [expression-list] ')'
// postfix-expression '[' expression ']'
//
// TODO: Add lots of stuff here.
Expr&
Parser::postfix_expression()
{
Expr* e = &primary_expression();
while (true) {
if (lookahead() == tk::dot_tok)
e = &dot_expression(*e);
else if (lookahead() == tk::lparen_tok)
e = &call_expression(*e);
else if (lookahead() == tk::lbracket_tok)
e = &subscript_expression(*e);
else
break;
}
return *e;
}