bool expr_lambda(pass_opt_t* opt, ast_t** astp) { pony_assert(astp != NULL); ast_t* ast = *astp; pony_assert(ast != NULL); AST_GET_CHILDREN(ast, receiver_cap, name, t_params, params, captures, ret_type, raises, body, reference_cap); ast_t* annotation = ast_consumeannotation(ast); bool bare = ast_id(ast) == TK_BARELAMBDA; ast_t* members = ast_from(ast, TK_MEMBERS); ast_t* last_member = NULL; bool failed = false; if(bare) pony_assert(ast_id(captures) == TK_NONE); // Process captures for(ast_t* p = ast_child(captures); p != NULL; p = ast_sibling(p)) { ast_t* field = NULL; bool ok = make_capture_field(opt, p, &field); if(field != NULL) ast_list_append(members, &last_member, field); else if(!ok) // An error occurred, just keep going to potentially find more errors failed = true; } if(failed) { ast_free(members); return false; } // Stop the various elements being marked as preserve ast_clearflag(t_params, AST_FLAG_PRESERVE); ast_clearflag(params, AST_FLAG_PRESERVE); ast_clearflag(ret_type, AST_FLAG_PRESERVE); ast_clearflag(body, AST_FLAG_PRESERVE); const char* fn_name = "apply"; if(ast_id(name) == TK_ID) fn_name = ast_name(name); // Make the apply function BUILD(apply, ast, NODE(TK_FUN, AST_SCOPE ANNOTATE(annotation) TREE(receiver_cap) ID(fn_name) TREE(t_params) TREE(params) TREE(ret_type) TREE(raises) TREE(body) NONE // Doc string NONE)); // Guard ast_list_append(members, &last_member, apply); ast_setflag(members, AST_FLAG_PRESERVE); printbuf_t* buf = printbuf_new(); printbuf(buf, bare ? "@{(" : "{("); bool first = true; for(ast_t* p = ast_child(params); p != NULL; p = ast_sibling(p)) { if(first) first = false; else printbuf(buf, ", "); printbuf(buf, "%s", ast_print_type(ast_childidx(p, 1))); } printbuf(buf, ")"); if(ast_id(ret_type) != TK_NONE) printbuf(buf, ": %s", ast_print_type(ret_type)); if(ast_id(raises) != TK_NONE) printbuf(buf, " ?"); printbuf(buf, "}"); // Replace lambda with object literal REPLACE(astp, NODE(TK_OBJECT, DATA(stringtab(buf->m)) TREE(reference_cap) NONE // Provides list TREE(members))); printbuf_free(buf); if(bare) { BUILD(bare_annotation, *astp, NODE(TK_ANNOTATION, ID("ponyint_bare"))); // Record the syntax pass as done to avoid the error about internal // annotations. ast_pass_record(bare_annotation, PASS_SYNTAX); ast_setannotation(*astp, bare_annotation); } // Catch up passes if(ast_visit(astp, pass_syntax, NULL, opt, PASS_SYNTAX) != AST_OK) return false; return ast_passes_subtree(astp, opt, PASS_EXPR); }
bool expr_lambda(pass_opt_t* opt, ast_t** astp) { pony_assert(astp != NULL); ast_t* ast = *astp; pony_assert(ast != NULL); AST_GET_CHILDREN(ast, receiver_cap, name, t_params, params, captures, ret_type, raises, body, obj_cap); ast_t* annotation = ast_consumeannotation(ast); // Try to find an antecedent type, and find possible lambda interfaces in it. ast_t* antecedent_type = find_antecedent_type(opt, ast, NULL); astlist_t* possible_fun_defs = NULL; astlist_t* possible_obj_caps = NULL; if(!is_typecheck_error(antecedent_type)) find_possible_fun_defs(opt, antecedent_type, &possible_fun_defs, &possible_obj_caps); // If there's more than one possible fun defs, rule out impossible ones by // comparing each fun def by some basic criteria against the lambda, // creating a new list containing only the remaining possibilities. if(astlist_length(possible_fun_defs) > 1) { astlist_t* new_fun_defs = NULL; astlist_t* new_obj_caps = NULL; astlist_t* fun_def_cursor = possible_fun_defs; astlist_t* obj_cap_cursor = possible_obj_caps; for(; (fun_def_cursor != NULL) && (obj_cap_cursor != NULL); fun_def_cursor = astlist_next(fun_def_cursor), obj_cap_cursor = astlist_next(obj_cap_cursor)) { ast_t* fun_def = astlist_data(fun_def_cursor); ast_t* def_obj_cap = astlist_data(obj_cap_cursor); if(is_typecheck_error(fun_def)) continue; AST_GET_CHILDREN(fun_def, def_receiver_cap, def_name, def_t_params, def_params, def_ret_type, def_raises); // Must have the same number of parameters. if(ast_childcount(params) != ast_childcount(def_params)) continue; // Must have a supercap of the def's receiver cap (if present). if((ast_id(receiver_cap) != TK_NONE) && !is_cap_sub_cap( ast_id(def_receiver_cap), TK_NONE, ast_id(receiver_cap), TK_NONE) ) continue; // Must have a supercap of the def's object cap (if present). if((ast_id(obj_cap) != TK_NONE) && !is_cap_sub_cap(ast_id(obj_cap), TK_NONE, ast_id(def_obj_cap), TK_NONE)) continue; // TODO: This logic could potentially be expanded to do deeper // compatibility checks, but checks involving subtyping here would be // difficult, because the lambda's AST is not caught up yet in the passes. new_fun_defs = astlist_push(new_fun_defs, fun_def); new_obj_caps = astlist_push(new_obj_caps, def_obj_cap); } astlist_free(possible_fun_defs); astlist_free(possible_obj_caps); possible_fun_defs = new_fun_defs; possible_obj_caps = new_obj_caps; } if(astlist_length(possible_fun_defs) == 1) { ast_t* fun_def = astlist_data(possible_fun_defs); ast_t* def_obj_cap = astlist_data(possible_obj_caps); // Try to complete the lambda's type info by inferring from the lambda type. if(!is_typecheck_error(fun_def)) { // Infer the object cap, receiver cap, and return type if unspecified. if(ast_id(obj_cap) == TK_NONE) ast_replace(&obj_cap, def_obj_cap); if(ast_id(receiver_cap) == TK_NONE) ast_replace(&receiver_cap, ast_child(fun_def)); if(ast_id(ret_type) == TK_NONE) ast_replace(&ret_type, ast_childidx(fun_def, 4)); // Infer the type of any parameters that were left unspecified. ast_t* param = ast_child(params); ast_t* def_param = ast_child(ast_childidx(fun_def, 3)); while((param != NULL) && (def_param != NULL)) { ast_t* param_id = ast_child(param); ast_t* param_type = ast_sibling(param_id); // Convert a "_" parameter to whatever the expected parameter is. if(is_name_dontcare(ast_name(param_id))) { ast_replace(¶m_id, ast_child(def_param)); ast_replace(¶m_type, ast_childidx(def_param, 1)); } // Give a type-unspecified parameter the type of the expected parameter. else if(ast_id(param_type) == TK_NONE) { ast_replace(¶m_type, ast_childidx(def_param, 1)); } param = ast_sibling(param); def_param = ast_sibling(def_param); } } ast_free_unattached(fun_def); } astlist_free(possible_obj_caps); // If any parameters still have no type specified, it's an error. ast_t* param = ast_child(params); while(param != NULL) { if(ast_id(ast_childidx(param, 1)) == TK_NONE) { ast_error(opt->check.errors, param, "a lambda parameter must specify a type or be inferable from context"); if(astlist_length(possible_fun_defs) > 1) { for(astlist_t* fun_def_cursor = possible_fun_defs; fun_def_cursor != NULL; fun_def_cursor = astlist_next(fun_def_cursor)) { ast_error_continue(opt->check.errors, astlist_data(fun_def_cursor), "this lambda interface is inferred, but it's not the only one"); } } astlist_free(possible_fun_defs); return false; } param = ast_sibling(param); } astlist_free(possible_fun_defs); bool bare = ast_id(ast) == TK_BARELAMBDA; ast_t* members = ast_from(ast, TK_MEMBERS); ast_t* last_member = NULL; bool failed = false; if(bare) pony_assert(ast_id(captures) == TK_NONE); // Process captures for(ast_t* p = ast_child(captures); p != NULL; p = ast_sibling(p)) { ast_t* field = NULL; bool ok = make_capture_field(opt, p, &field); if(field != NULL) ast_list_append(members, &last_member, field); else if(!ok) // An error occurred, just keep going to potentially find more errors failed = true; } if(failed) { ast_free(members); return false; } // Stop the various elements being marked as preserve ast_clearflag(t_params, AST_FLAG_PRESERVE); ast_clearflag(params, AST_FLAG_PRESERVE); ast_clearflag(ret_type, AST_FLAG_PRESERVE); ast_clearflag(body, AST_FLAG_PRESERVE); const char* fn_name = "apply"; if(ast_id(name) == TK_ID) fn_name = ast_name(name); // Make the apply function BUILD(apply, ast, NODE(TK_FUN, AST_SCOPE ANNOTATE(annotation) TREE(receiver_cap) ID(fn_name) TREE(t_params) TREE(params) TREE(ret_type) TREE(raises) TREE(body) NONE)); // Doc string ast_list_append(members, &last_member, apply); ast_setflag(members, AST_FLAG_PRESERVE); printbuf_t* buf = printbuf_new(); printbuf(buf, bare ? "@{(" : "{("); bool first = true; for(ast_t* p = ast_child(params); p != NULL; p = ast_sibling(p)) { if(first) first = false; else printbuf(buf, ", "); printbuf(buf, "%s", ast_print_type(ast_childidx(p, 1))); } printbuf(buf, ")"); if(ast_id(ret_type) != TK_NONE) printbuf(buf, ": %s", ast_print_type(ret_type)); if(ast_id(raises) != TK_NONE) printbuf(buf, " ?"); printbuf(buf, "}"); // Replace lambda with object literal REPLACE(astp, NODE(TK_OBJECT, DATA(stringtab(buf->m)) TREE(obj_cap) NONE // Provides list TREE(members))); printbuf_free(buf); if(bare) { BUILD(bare_annotation, *astp, NODE(TK_ANNOTATION, ID("ponyint_bare"))); // Record the syntax pass as done to avoid the error about internal // annotations. ast_pass_record(bare_annotation, PASS_SYNTAX); ast_setannotation(*astp, bare_annotation); } // Catch up passes if(ast_visit(astp, pass_syntax, NULL, opt, PASS_SYNTAX) != AST_OK) return false; return ast_passes_subtree(astp, opt, PASS_EXPR); }