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* try_expression(sl_parse_state_t* ps) { sl_node_base_t *body, *lval = NULL, *catch_body = NULL; sl_token_t* tok; expect_token(ps, SL_TOK_TRY); body = body_expression(ps); expect_token(ps, SL_TOK_CATCH); tok = peek_token(ps); if(tok->type != SL_TOK_OPEN_BRACE) { lval = primary_expression(ps); if(!sl_node_is_lval(lval)) { unexpected(ps, tok); } } catch_body = body_expression(ps); return sl_make_try_node(ps, body, lval, catch_body); }
int sl_node_is_lval(sl_node_base_t* node) { switch(node->type) { case SL_NODE_VAR: return 1; case SL_NODE_IVAR: return 1; case SL_NODE_CVAR: return 1; case SL_NODE_CONST: return 1; case SL_NODE_SEND: return ((sl_node_send_t*)node)->arg_count == 0; case SL_NODE_ARRAY: { sl_node_array_t* ary = (sl_node_array_t*)node; for(size_t i = 0; i < ary->node_count; i++) { if(!sl_node_is_lval(ary->nodes[i])) { return 0; } } return 1; } default: return 0; } }