// Sugar for partial application, which we convert to a lambda.
static bool partial_application(pass_opt_t* opt, ast_t** astp)
{
/* Example that we refer to throughout this function.
* ```pony
* class C
* fun f[T](a: A, b: B = b_default): R
*
* let recv: T = ...
* recv~f[T2](foo)
* ```
*
* Partial call is converted to:
* ```pony
* {(b: B = b_default)($0 = recv, a = foo): R => $0.f[T2](a, consume b) }
* ```
*/
ast_t* ast = *astp;
typecheck_t* t = &opt->check;
if(!method_application(opt, ast, true))
return false;
AST_GET_CHILDREN(ast, positional, namedargs, question, lhs);
// LHS must be an application, possibly wrapped in another application
// if the method had type parameters for qualification.
pony_assert(ast_id(lhs) == TK_FUNAPP || ast_id(lhs) == TK_BEAPP ||
ast_id(lhs) == TK_NEWAPP);
AST_GET_CHILDREN(lhs, receiver, method);
ast_t* type_args = NULL;
if(ast_id(receiver) == ast_id(lhs))
{
type_args = method;
AST_GET_CHILDREN_NO_DECL(receiver, receiver, method);
}
// Look up the original method definition for this method call.
ast_t* method_def = lookup(opt, lhs, ast_type(receiver), ast_name(method));
pony_assert(ast_id(method_def) == TK_FUN || ast_id(method_def) == TK_BE ||
ast_id(method_def) == TK_NEW);
// The TK_FUNTYPE of the LHS.
ast_t* type = ast_type(lhs);
pony_assert(ast_id(type) == TK_FUNTYPE);
if(is_typecheck_error(type))
return false;
AST_GET_CHILDREN(type, cap, type_params, target_params, result);
bool bare = ast_id(cap) == TK_AT;
token_id apply_cap = TK_AT;
if(!bare)
apply_cap = partial_application_cap(opt, type, receiver, positional);
token_id can_error = ast_id(ast_childidx(method_def, 5));
const char* recv_name = package_hygienic_id(t);
// Build lambda expression.
ast_t* call_receiver = NULL;
if(bare)
{
ast_t* arg = ast_child(positional);
while(arg != NULL)
{
if(ast_id(arg) != TK_NONE)
{
ast_error(opt->check.errors, arg, "the partial application of a bare "
"method cannot take arguments");
return false;
}
arg = ast_sibling(arg);
}
ast_t* receiver_type = ast_type(receiver);
if(is_bare(receiver_type))
{
// Partial application on a bare object, simply return the object itself.
ast_replace(astp, receiver);
return true;
}
AST_GET_CHILDREN(receiver_type, recv_type_package, recv_type_name);
const char* recv_package_str = ast_name(recv_type_package);
const char* recv_name_str = ast_name(recv_type_name);
ast_t* module = ast_nearest(ast, TK_MODULE);
ast_t* package = ast_parent(module);
ast_t* pkg_id = package_id(package);
const char* pkg_str = ast_name(pkg_id);
const char* pkg_alias = NULL;
if(recv_package_str != pkg_str)
pkg_alias = package_alias_from_id(module, recv_package_str);
ast_free_unattached(pkg_id);
if(pkg_alias != NULL)
{
// `package.Type.f`
BUILD_NO_DECL(call_receiver, ast,
NODE(TK_DOT,
NODE(TK_DOT,
NODE(TK_REFERENCE, ID(pkg_alias))
ID(recv_name_str))
TREE(method)));
} else {
// `Type.f`
BUILD_NO_DECL(call_receiver, ast,
NODE(TK_DOT,
NODE(TK_REFERENCE, ID(recv_name_str))
TREE(method)));
}
} else {
// `$0.f`
BUILD_NO_DECL(call_receiver, ast,
NODE(TK_DOT,
NODE(TK_REFERENCE, ID(recv_name))
TREE(method)));
}
ast_t* captures = NULL;
if(bare)
{
captures = ast_from(receiver, TK_NONE);
} else {
// Build captures. We always have at least one capture, for receiver.
// Capture: `$0 = recv`
BUILD_NO_DECL(captures, receiver,
NODE(TK_LAMBDACAPTURES,
NODE(TK_LAMBDACAPTURE,
ID(recv_name)
NONE // Infer type.
TREE(receiver))));
}
// Process arguments.
ast_t* target_param = ast_child(target_params);
ast_t* lambda_params = ast_from(target_params, TK_NONE);
ast_t* lambda_call_args = ast_from(positional, TK_NONE);
ast_t* given_arg = ast_child(positional);
while(given_arg != NULL)
{
pony_assert(target_param != NULL);
const char* target_p_name = ast_name(ast_child(target_param));
if(ast_id(given_arg) == TK_NONE)
{
// This argument is not supplied already, must be a lambda parameter.
// Like `b` in example above.
// Build a new a new TK_PARAM node rather than copying the target one,
// since the target has already been processed to expr pass, and we need
// a clean one.
AST_GET_CHILDREN(target_param, p_id, p_type, p_default);
// Parameter: `b: B = b_default`
BUILD(lambda_param, target_param,
NODE(TK_PARAM,
TREE(p_id)
TREE(sanitise_type(p_type))
TREE(p_default)));
ast_append(lambda_params, lambda_param);
ast_setid(lambda_params, TK_PARAMS);
// Argument: `consume b`
BUILD(target_arg, lambda_param,
NODE(TK_SEQ,
NODE(TK_CONSUME,
NONE
NODE(TK_REFERENCE, ID(target_p_name)))));
ast_append(lambda_call_args, target_arg);
ast_setid(lambda_call_args, TK_POSITIONALARGS);
}
else
{
// This argument is supplied to the partial, capture it.
// Like `a` in example above.
// Capture: `a = foo`
BUILD(capture, given_arg,
NODE(TK_LAMBDACAPTURE,
ID(target_p_name)
NONE
TREE(given_arg)));
ast_append(captures, capture);
// Argument: `a`
BUILD(target_arg, given_arg,
NODE(TK_SEQ,
NODE(TK_REFERENCE, ID(target_p_name))));
ast_append(lambda_call_args, target_arg);
ast_setid(lambda_call_args, TK_POSITIONALARGS);
}
given_arg = ast_sibling(given_arg);
target_param = ast_sibling(target_param);
}
pony_assert(target_param == NULL);
if(type_args != NULL)
{
// The partial call has type args, add them to the actual call in apply().
// `$0.f[T2]`
BUILD(qualified, type_args,
NODE(TK_QUALIFY,
TREE(call_receiver)
TREE(type_args)));
call_receiver = qualified;
}
REPLACE(astp,
NODE((bare ? TK_BARELAMBDA : TK_LAMBDA),
NODE(apply_cap)
NONE // Lambda function name.
NONE // Lambda type params.
TREE(lambda_params)
TREE(captures)
TREE(sanitise_type(result))
NODE(can_error)
NODE(TK_SEQ,
NODE(TK_CALL,
TREE(lambda_call_args)
NONE // Named args.
NODE(can_error)
TREE(call_receiver)))
NONE)); // Lambda reference capability.
// Need to preserve various lambda children.
ast_setflag(ast_childidx(*astp, 2), AST_FLAG_PRESERVE); // Type params.
ast_setflag(ast_childidx(*astp, 3), AST_FLAG_PRESERVE); // Parameters.
ast_setflag(ast_childidx(*astp, 5), AST_FLAG_PRESERVE); // Return type.
ast_setflag(ast_childidx(*astp, 7), AST_FLAG_PRESERVE); // Body.
// Catch up to this pass.
return ast_passes_subtree(astp, opt, PASS_EXPR);
}
// Sugar for partial application, which we convert to a lambda.
static bool partial_application(pass_opt_t* opt, ast_t** astp)
{
/* Example that we refer to throughout this function.
* ```pony
* class C
* fun f[T](a: A, b: B = b_default): R
*
* let recv: T = ...
* recv~f[T2](foo)
* ```
*
* Partial call is converted to:
* ```pony
* lambda(b: B = b_default)($0 = recv, a = foo): R => $0.f[T2](a, consume b)
* ```
*/
ast_t* ast = *astp;
typecheck_t* t = &opt->check;
if(!method_application(opt, ast, true))
return false;
AST_GET_CHILDREN(ast, positional, namedargs, lhs);
assert(ast_id(lhs) == TK_FUNAPP || ast_id(lhs) == TK_BEAPP ||
ast_id(lhs) == TK_NEWAPP);
// LHS must be a TK_TILDE, possibly contained in a TK_QUALIFY.
AST_GET_CHILDREN(lhs, receiver, method);
ast_t* type_args = NULL;
switch(ast_id(receiver))
{
case TK_NEWAPP:
case TK_BEAPP:
case TK_FUNAPP:
type_args = method;
AST_GET_CHILDREN_NO_DECL(receiver, receiver, method);
break;
default: {}
}
// The TK_FUNTYPE of the LHS.
ast_t* type = ast_type(lhs);
if(is_typecheck_error(type))
return false;
token_id apply_cap = partial_application_cap(opt, type, receiver,
positional);
AST_GET_CHILDREN(type, cap, type_params, target_params, result);
token_id can_error = ast_canerror(lhs) ? TK_QUESTION : TK_NONE;
const char* recv_name = package_hygienic_id(t);
// Build captures. We always have at least one capture, for receiver.
// Capture: `$0 = recv`
BUILD(captures, receiver,
NODE(TK_LAMBDACAPTURES,
NODE(TK_LAMBDACAPTURE,
ID(recv_name)
NONE // Infer type.
TREE(receiver))));
// Process arguments.
ast_t* given_arg = ast_child(positional);
ast_t* target_param = ast_child(target_params);
ast_t* lambda_params = ast_from(target_params, TK_NONE);
ast_t* lambda_call_args = ast_from(positional, TK_NONE);
while(given_arg != NULL)
{
assert(target_param != NULL);
const char* target_p_name = ast_name(ast_child(target_param));
if(ast_id(given_arg) == TK_NONE)
{
// This argument is not supplied already, must be a lambda parameter.
// Like `b` in example above.
// Build a new a new TK_PARAM node rather than copying the target one,
// since the target has already been processed to expr pass, and we need
// a clean one.
AST_GET_CHILDREN(target_param, p_id, p_type, p_default);
// Parameter: `b: B = b_default`
BUILD(lambda_param, target_param,
NODE(TK_PARAM,
TREE(p_id)
TREE(sanitise_type(p_type))
TREE(p_default)));
ast_append(lambda_params, lambda_param);
ast_setid(lambda_params, TK_PARAMS);
// Argument: `consume b`
BUILD(target_arg, lambda_param,
NODE(TK_SEQ,
NODE(TK_CONSUME,
NONE
NODE(TK_REFERENCE, ID(target_p_name)))));
ast_append(lambda_call_args, target_arg);
ast_setid(lambda_call_args, TK_POSITIONALARGS);
}
else
{
// This argument is supplied to the partial, capture it.
// Like `a` in example above.
// Capture: `a = foo`
BUILD(capture, given_arg,
NODE(TK_LAMBDACAPTURE,
ID(target_p_name)
NONE
TREE(given_arg)));
ast_append(captures, capture);
// Argument: `a`
BUILD(target_arg, given_arg,
NODE(TK_SEQ,
NODE(TK_REFERENCE, ID(target_p_name))));
ast_append(lambda_call_args, target_arg);
ast_setid(lambda_call_args, TK_POSITIONALARGS);
}
given_arg = ast_sibling(given_arg);
target_param = ast_sibling(target_param);
}
assert(target_param == NULL);
// Build lambda expression.
// `$0.f`
BUILD(call_receiver, ast,
NODE(TK_DOT,
NODE(TK_REFERENCE, ID(recv_name))
TREE(method)));
if(type_args != NULL)
{
// The partial call has type args, add them to the actual call in apply().
// `$0.f[T2]`
BUILD(qualified, type_args,
NODE(TK_QUALIFY,
TREE(call_receiver)
TREE(type_args)));
call_receiver = qualified;
}
REPLACE(astp,
NODE(TK_LAMBDA,
NODE(apply_cap)
NONE // Lambda function name.
NONE // Lambda type params.
TREE(lambda_params)
TREE(captures)
TREE(sanitise_type(result))
NODE(can_error)
NODE(TK_SEQ,
NODE(TK_CALL,
TREE(lambda_call_args)
NONE // Named args.
TREE(call_receiver)))));
// Need to preserve various lambda children.
ast_setflag(ast_childidx(*astp, 2), AST_FLAG_PRESERVE); // Type params.
ast_setflag(ast_childidx(*astp, 3), AST_FLAG_PRESERVE); // Parameters.
ast_setflag(ast_childidx(*astp, 5), AST_FLAG_PRESERVE); // Return type.
ast_setflag(ast_childidx(*astp, 7), AST_FLAG_PRESERVE); // Body.
// Catch up to this pass.
return ast_passes_subtree(astp, opt, PASS_EXPR);
}
static bool partial_application(pass_opt_t* opt, ast_t** astp)
{
ast_t* ast = *astp;
typecheck_t* t = &opt->check;
if(!method_application(opt, ast, true))
return false;
AST_GET_CHILDREN(ast, positional, namedargs, lhs);
// LHS must be a TK_TILDE, possibly contained in a TK_QUALIFY.
AST_GET_CHILDREN(lhs, receiver, method);
switch(ast_id(receiver))
{
case TK_NEWAPP:
case TK_BEAPP:
case TK_FUNAPP:
AST_GET_CHILDREN_NO_DECL(receiver, receiver, method);
break;
default: {}
}
// The TK_FUNTYPE of the LHS.
ast_t* type = ast_type(lhs);
if(is_typecheck_error(type))
return false;
token_id apply_cap = partial_application_cap(type, receiver, positional);
AST_GET_CHILDREN(type, cap, typeparams, params, result);
// Create a new anonymous type.
ast_t* c_id = ast_from_string(ast, package_hygienic_id(t));
BUILD(def, ast,
NODE(TK_CLASS, AST_SCOPE
TREE(c_id)
NONE
NONE
NONE
NODE(TK_MEMBERS)
NONE
NONE));
// We will have a create method in the type.
BUILD(create, ast,
NODE(TK_NEW, AST_SCOPE
NONE
ID("create")
NONE
NODE(TK_PARAMS)
NONE
NONE
NODE(TK_SEQ)
NONE));
// We will have an apply method in the type.
token_id can_error = ast_canerror(lhs) ? TK_QUESTION : TK_NONE;
BUILD(apply, ast,
NODE(TK_FUN, AST_SCOPE
NODE(apply_cap)
ID("apply")
NONE
NODE(TK_PARAMS)
TREE(result)
NODE(can_error)
NODE(TK_SEQ)
NONE));
// We will replace partial application with $0.create(...)
BUILD(call_receiver, ast, NODE(TK_REFERENCE, TREE(c_id)));
BUILD(call_dot, ast, NODE(TK_DOT, TREE(call_receiver) ID("create")));
BUILD(call, ast,
NODE(TK_CALL,
NONE
NODE(TK_NAMEDARGS)
TREE(call_dot)));
ast_t* class_members = ast_childidx(def, 4);
ast_t* create_params = ast_childidx(create, 3);
ast_t* create_body = ast_childidx(create, 6);
ast_t* apply_params = ast_childidx(apply, 3);
ast_t* apply_body = ast_childidx(apply, 6);
ast_t* call_namedargs = ast_childidx(call, 1);
// Add the receiver to the anonymous type.
ast_t* r_id = ast_from_string(receiver, package_hygienic_id(t));
ast_t* r_field_id = ast_from_string(receiver, package_hygienic_id(t));
ast_t* r_type = ast_type(receiver);
if(is_typecheck_error(r_type))
return false;
// A field in the type.
BUILD(r_field, receiver, NODE(TK_FLET, TREE(r_field_id) TREE(r_type) NONE));
// A parameter of the constructor.
BUILD(r_ctor_param, receiver, NODE(TK_PARAM, TREE(r_id) TREE(r_type) NONE));
// An assignment in the constructor body.
BUILD(r_assign, receiver,
NODE(TK_ASSIGN,
NODE(TK_CONSUME, NODE(TK_NONE) NODE(TK_REFERENCE, TREE(r_id)))
NODE(TK_REFERENCE, TREE(r_field_id))));
// A named argument at the call site.
BUILD(r_call_seq, receiver, NODE(TK_SEQ, TREE(receiver)));
BUILD(r_call_arg, receiver, NODE(TK_NAMEDARG, TREE(r_id) TREE(r_call_seq)));
ast_settype(r_call_seq, r_type);
ast_append(class_members, r_field);
ast_append(create_params, r_ctor_param);
ast_append(create_body, r_assign);
ast_append(call_namedargs, r_call_arg);
// Add a call to the original method to the apply body.
BUILD(apply_call, ast,
NODE(TK_CALL,
NODE(TK_POSITIONALARGS)
NONE
NODE(TK_DOT, NODE(TK_REFERENCE, TREE(r_field_id)) TREE(method))));
ast_append(apply_body, apply_call);
ast_t* apply_args = ast_child(apply_call);
// Add the arguments to the anonymous type.
ast_t* arg = ast_child(positional);
ast_t* param = ast_child(params);
while(arg != NULL)
{
AST_GET_CHILDREN(param, id, p_type);
if(ast_id(arg) == TK_NONE)
{
// A parameter of the apply method, using the same name, type and default
// argument.
ast_append(apply_params, param);
// An arg in the call to the original method.
BUILD(apply_arg, param,
NODE(TK_SEQ,
NODE(TK_CONSUME,
NODE(TK_NONE)
NODE(TK_REFERENCE, TREE(id)))));
ast_append(apply_args, apply_arg);
} else {
ast_t* p_id = ast_from_string(id, package_hygienic_id(t));
// A field in the type.
BUILD(field, arg, NODE(TK_FLET, TREE(id) TREE(p_type) NONE));
// A parameter of the constructor.
BUILD(ctor_param, arg, NODE(TK_PARAM, TREE(p_id) TREE(p_type) NONE));
// An assignment in the constructor body.
BUILD(assign, arg,
NODE(TK_ASSIGN,
NODE(TK_CONSUME, NODE(TK_NONE) NODE(TK_REFERENCE, TREE(p_id)))
NODE(TK_REFERENCE, TREE(id))));
// A named argument at the call site.
BUILD(call_arg, arg, NODE(TK_NAMEDARG, TREE(p_id) TREE(arg)));
// An arg in the call to the original method.
BUILD(apply_arg, arg, NODE(TK_SEQ, NODE(TK_REFERENCE, TREE(id))));
ast_append(class_members, field);
ast_append(create_params, ctor_param);
ast_append(create_body, assign);
ast_append(call_namedargs, call_arg);
ast_append(apply_args, apply_arg);
}
arg = ast_sibling(arg);
param = ast_sibling(param);
}
// Add create and apply to the anonymous type.
ast_append(class_members, create);
ast_append(class_members, apply);
// Typecheck the anonymous type.
ast_add(t->frame->module, def);
if(!type_passes(def, opt))
return false;
// Typecheck the create call.
if(!expr_reference(opt, &call_receiver))
return false;
if(!expr_dot(opt, &call_dot))
return false;
if(!expr_call(opt, &call))
return false;
// Replace the partial application with the create call.
ast_replace(astp, call);
return true;
}
