ast_t* control_type_add_branch(ast_t* control_type, ast_t* branch)
{
assert(branch != NULL);
ast_t* branch_type = ast_type(branch);
if(is_typecheck_error(branch_type))
return branch_type;
if(is_type_literal(branch_type))
{
// The new branch is a literal
if(control_type == NULL)
control_type = ast_from(branch, TK_LITERAL);
if(ast_id(control_type) != TK_LITERAL)
{
// The current control type is not a literal, fix that
ast_t* old_control = control_type;
control_type = ast_from(branch, TK_LITERAL);
ast_settype(control_type, old_control);
}
assert(ast_id(control_type) == TK_LITERAL);
// Add a literal branch reference to the new branch
ast_t* member = ast_from(branch, TK_LITERALBRANCH);
ast_setdata(member, (void*)branch);
ast_append(control_type, member);
ast_t* branch_non_lit = ast_type(branch_type);
if(branch_non_lit != NULL)
{
// The branch's literal type has a non-literal component
ast_t* non_literal_type = ast_type(control_type);
ast_settype(control_type, type_union(non_literal_type, branch_non_lit));
}
return control_type;
}
if(control_type != NULL && ast_id(control_type) == TK_LITERAL)
{
// New branch is not literal, but the control structure is
// Add new branch type to the control structure's non-literal aspect
ast_t* non_literal_type = ast_type(control_type);
non_literal_type = type_union(non_literal_type, branch_type);
ast_settype(control_type, non_literal_type);
return control_type;
}
// No literals here, just union the types
return type_union(control_type, branch_type);
}
void collect_type_params(ast_t* ast, ast_t** out_params, ast_t** out_args)
{
assert(ast != NULL);
// Create params and args as TK_NONE, we'll change them if we find any type
// params
ast_t* params = out_params ? ast_from(ast, TK_NONE) : NULL;
ast_t* args = out_args ? ast_from(ast, TK_NONE) : NULL;
// Find enclosing entity, or NULL if not within an entity
ast_t* entity = ast;
while(entity != NULL && ast_id(entity) != TK_INTERFACE &&
ast_id(entity) != TK_TRAIT && ast_id(entity) != TK_PRIMITIVE &&
ast_id(entity) != TK_STRUCT && ast_id(entity) != TK_CLASS &&
ast_id(entity) != TK_ACTOR)
{
entity = ast_parent(entity);
}
// Find enclosing method, or NULL if not within a method
ast_t* method = ast;
while(method != NULL && ast_id(method) != TK_FUN &&
ast_id(method) != TK_NEW && ast_id(method) != TK_BE)
{
method = ast_parent(method);
}
// Collect type parameters defined on the entity (if within an entity)
if(entity != NULL)
{
ast_t* entity_t_params = ast_childidx(entity, 1);
for(ast_t* p = ast_child(entity_t_params); p != NULL; p = ast_sibling(p))
collect_type_param(p, params, args);
}
// Collect type parameters defined on the method (if within a method)
if(method != NULL)
{
ast_t* method_t_params = ast_childidx(method, 2);
for(ast_t* p = ast_child(method_t_params); p != NULL; p = ast_sibling(p))
collect_type_param(p, params, args);
}
if(out_params != NULL)
*out_params = params;
if(out_args != NULL)
*out_args = args;
}
ast_t* viewpoint_replacethis(ast_t* ast, ast_t* with)
{
ast_t* thistype = ast_from(ast, TK_THISTYPE);
ast_t* r_ast = viewpoint_replace(ast, thistype, with);
ast_free_unattached(thistype);
return r_ast;
}
bool expr_compiler_intrinsic(typecheck_t* t, ast_t* ast)
{
if(t->frame->method_body == NULL)
{
ast_error(ast, "a compiler intrinsic must be a method body");
return false;
}
ast_t* child = ast_child(t->frame->method_body);
// Allow a docstring before the compiler_instrinsic.
if(ast_id(child) == TK_STRING)
child = ast_sibling(child);
if((child != ast) || (ast_sibling(child) != NULL))
{
ast_error(ast, "a compiler intrinsic must be the entire body");
return false;
}
// Disable debuglocs on calls to this method.
ast_setdebug(t->frame->method, false);
ast_settype(ast, ast_from(ast, TK_COMPILER_INTRINSIC));
return true;
}
static bool check_type_params(ast_t** astp)
{
ast_t* lhs = *astp;
ast_t* type = ast_type(lhs);
if(is_typecheck_error(type))
return false;
ast_t* typeparams = ast_childidx(type, 1);
assert(ast_id(type) == TK_FUNTYPE);
if(ast_id(typeparams) == TK_NONE)
return true;
BUILD(typeargs, typeparams, NODE(TK_TYPEARGS));
if(!check_constraints(typeparams, typeargs, true))
{
ast_free_unattached(typeargs);
return false;
}
type = reify(type, typeparams, typeargs);
typeparams = ast_childidx(type, 1);
ast_replace(&typeparams, ast_from(typeparams, TK_NONE));
REPLACE(astp, NODE(ast_id(lhs), TREE(lhs) TREE(typeargs)));
ast_settype(*astp, type);
return true;
}
static void add_field_to_object(pass_opt_t* opt, ast_t* field,
ast_t* class_members, ast_t* create_params, ast_t* create_body,
ast_t* call_args)
{
AST_GET_CHILDREN(field, id, type, init);
ast_t* p_id = ast_from_string(id, package_hygienic_id(&opt->check));
// The param is: $0: type
BUILD(param, field,
NODE(TK_PARAM,
TREE(p_id)
TREE(type)
NONE));
// The arg is: $seq init
BUILD(arg, init,
NODE(TK_SEQ,
TREE(init)));
// The body of create contains: id = consume $0
BUILD(assign, init,
NODE(TK_ASSIGN,
NODE(TK_CONSUME, NODE(TK_NONE) NODE(TK_REFERENCE, TREE(p_id)))
NODE(TK_REFERENCE, TREE(id))));
// Remove the initialiser from the field
ast_replace(&init, ast_from(init, TK_NONE));
ast_add(class_members, field);
ast_append(create_params, param);
ast_append(create_body, assign);
ast_append(call_args, arg);
}
bool expr_break(typecheck_t* t, ast_t* ast)
{
if(t->frame->loop_body == NULL)
{
ast_error(ast, "must be in a loop");
return false;
}
if(!ast_all_consumes_in_scope(t->frame->loop_body, ast))
return false;
// break is always the last expression in a sequence
assert(ast_sibling(ast) == NULL);
ast_settype(ast, ast_from(ast, TK_BREAK));
ast_inheritflags(ast);
// Add type to loop.
ast_t* body = ast_child(ast);
if(is_control_type(ast_type(body)))
{
ast_error(body, "break value cannot be a control statement");
return false;
}
ast_t* loop_type = ast_type(t->frame->loop);
loop_type = control_type_add_branch(loop_type, body);
ast_settype(t->frame->loop, loop_type);
return true;
}
static bool push_assume(ast_t* sub, ast_t* super)
{
// Returns true if we have already assumed sub is a subtype of super.
if(subtype_assume != NULL)
{
ast_t* assumption = ast_child(subtype_assume);
while(assumption != NULL)
{
AST_GET_CHILDREN(assumption, assume_sub, assume_super);
if(exact_nominal(sub, assume_sub) &&
exact_nominal(super, assume_super))
return true;
assumption = ast_sibling(assumption);
}
} else {
subtype_assume = ast_from(sub, TK_NONE);
}
BUILD(assume, sub, NODE(TK_NONE, TREE(ast_dup(sub)) TREE(ast_dup(super))));
ast_add(subtype_assume, assume);
return false;
}
static ast_result_t sugar_binop(ast_t** astp, const char* fn_name)
{
AST_GET_CHILDREN(*astp, left, right);
ast_t* positional = ast_from(right, TK_POSITIONALARGS);
if(ast_id(right) == TK_TUPLE)
{
ast_t* value = ast_child(right);
while(value != NULL)
{
BUILD(arg, right, NODE(TK_SEQ, TREE(value)));
ast_append(positional, arg);
value = ast_sibling(value);
}
} else {
BUILD(arg, right, NODE(TK_SEQ, TREE(right)));
ast_add(positional, arg);
}
REPLACE(astp,
NODE(TK_CALL,
TREE(positional)
NONE
NODE(TK_DOT, TREE(left) ID(fn_name))
));
return AST_OK;
}
bool expr_lambda(pass_opt_t* opt, ast_t** astp)
{
assert(astp != NULL);
ast_t* ast = *astp;
assert(ast != NULL);
AST_GET_CHILDREN(ast, cap, t_params, params, captures, ret_type, raises,
body);
ast_t* members = ast_from(ast, TK_MEMBERS);
ast_t* last_member = NULL;
bool failed = false;
// Process captures
for(ast_t* p = ast_child(captures); p != NULL; p = ast_sibling(p))
{
ast_t* field = make_capture_field(p);
if(field != NULL)
ast_list_append(members, &last_member, field);
else // 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);
// Make the apply function
BUILD(apply, ast,
NODE(TK_FUN, AST_SCOPE
NONE // Capability
ID("apply")
TREE(t_params)
TREE(params)
TREE(ret_type)
TREE(raises)
TREE(body)
NONE)); // Doc string
ast_list_append(members, &last_member, apply);
// Replace lambda with object literal
REPLACE(astp,
NODE(TK_OBJECT,
TREE(cap);
NONE // Provides list
TREE(members)));
// Catch up passes
return ast_passes_subtree(astp, opt, PASS_EXPR);
}
static ast_t* make_single_arrow(ast_t* left, ast_t* right)
{
switch(ast_id(left))
{
case TK_ARROW:
{
ast_t* arrow = ast_dup(left);
ast_t* child = ast_childidx(arrow, 1);
// Arrow is right associative.
while(ast_id(child) == TK_ARROW)
child = ast_childidx(child, 1);
ast_t* view = viewpoint_type(child, right);
if(view == NULL)
{
ast_free_unattached(arrow);
return NULL;
}
ast_replace(&child, view);
return arrow;
}
default: {}
}
ast_t* arrow = ast_from(left, TK_ARROW);
ast_add(arrow, right);
ast_add(arrow, left);
return arrow;
}
bool expr_compile_error(ast_t* ast)
{
// compile_error is always the last expression in a sequence
assert(ast_sibling(ast) == NULL);
ast_settype(ast, ast_from(ast, TK_COMPILE_ERROR));
return true;
}
bool expr_error(pass_opt_t* opt, ast_t* ast)
{
(void)opt;
// error is always the last expression in a sequence
assert(ast_sibling(ast) == NULL);
ast_settype(ast, ast_from(ast, TK_ERROR));
return true;
}
// Sugar any case methods in the given entity.
ast_result_t sugar_case_methods(typecheck_t* t, ast_t* entity)
{
assert(entity != NULL);
ast_result_t result = AST_OK;
ast_t* members = ast_childidx(entity, 4);
bool cases_found = false;
// Check each method to see if its name is repeated, which indicates a case
// method.
for(ast_t* p = ast_child(members); p != NULL; p = ast_sibling(p))
{
if(ast_id(p) == TK_FUN || ast_id(p) == TK_BE)
{
const char* p_name = ast_name(ast_childidx(p, 1));
// Check if any subsequent methods share p's name.
for(ast_t* q = ast_sibling(p); q != NULL; q = ast_sibling(q))
{
if(ast_id(q) == TK_FUN || ast_id(q) == TK_BE)
{
const char* q_name = ast_name(ast_childidx(q, 1));
if(q_name == p_name)
{
// p's name is repeated, it's a case method, get a match method.
if(!sugar_case_method(p, members, p_name, t))
result = AST_ERROR;
cases_found = true;
break;
}
}
}
}
}
if(cases_found)
{
// Remove nodes marked during processing.
ast_t* filtered_members = ast_from(members, TK_MEMBERS);
ast_t* list = NULL;
ast_t* member;
while((member = ast_pop(members)) != NULL)
{
if(ast_id(member) == TK_NONE) // Marked for removal.
ast_free(member);
else // Put back in filtered list.
ast_list_append(filtered_members, &list, member);
}
ast_replace(&members, filtered_members);
}
return result;
}
// Handle the given case method parameter list.
// Combine and check the case parameters against the existing match parameters
// and generate the match pattern to go in the worker method.
// Returns: match pattern, NULL on error.
static ast_t* process_params(ast_t* match_params, ast_t* case_params)
{
assert(match_params != NULL);
assert(case_params != NULL);
bool ok = true;
size_t count = 0;
ast_t* pattern = ast_from(case_params, TK_TUPLE);
ast_t* case_param = ast_child(case_params);
ast_t* match_param = ast_child(match_params);
while(case_param != NULL && match_param != NULL)
{
AST_GET_CHILDREN(case_param, id, type, def_arg);
if(ast_id(type) != TK_NONE)
{
// We have a parameter.
if(!param_with_type(case_param, match_param, pattern))
ok = false;
}
else
{
// We have a value to match.
if(!param_without_type(case_param, pattern))
ok = false;
}
case_param = ast_sibling(case_param);
match_param = ast_sibling(match_param);
count++;
}
if(case_param != NULL || match_param != NULL)
{
ast_error(case_params, "differing number of parameters to case methods");
ast_error(match_params, "clashing parameter count here");
ok = false;
}
if(!ok)
{
ast_free(pattern);
return NULL;
}
assert(count > 0);
if(count == 1)
{
// Only one parameter, don't need a tuple pattern.
ast_t* tmp = ast_pop(ast_child(pattern));
ast_free(pattern);
pattern = tmp;
}
return pattern;
}
ast_t* viewpoint_reifythis(ast_t* type)
{
ast_t* tuple = ast_from(type, TK_TUPLETYPE);
ast_t* this_ref = ast_from(type, TK_REF);
ast_append(tuple, viewpoint_replacethis(type, this_ref));
ast_free_unattached(this_ref);
ast_t* this_val = ast_from(type, TK_VAL);
ast_append(tuple, viewpoint_replacethis(type, this_val));
ast_free_unattached(this_val);
ast_t* this_box = ast_from(type, TK_BOX);
ast_append(tuple, viewpoint_replacethis(type, this_box));
ast_free_unattached(this_box);
return tuple;
}
static token_id partial_application_cap(pass_opt_t* opt, ast_t* ftype,
ast_t* receiver, ast_t* positional)
{
// Check if the apply method in the generated object literal can accept a box
// receiver. If not, it must be a ref receiver. It can accept a box receiver
// if box->receiver <: lhs->receiver and box->arg <: lhs->param.
AST_GET_CHILDREN(ftype, cap, typeparams, params, result);
ast_t* type = ast_type(receiver);
ast_t* view_type = viewpoint_type(ast_from(type, TK_BOX), type);
ast_t* need_type = set_cap_and_ephemeral(type, ast_id(cap), TK_NONE);
bool ok = is_subtype(view_type, need_type, NULL, opt);
ast_free_unattached(view_type);
ast_free_unattached(need_type);
if(!ok)
return TK_REF;
ast_t* param = ast_child(params);
ast_t* arg = ast_child(positional);
while(arg != NULL)
{
if(ast_id(arg) != TK_NONE)
{
type = ast_type(arg);
view_type = viewpoint_type(ast_from(type, TK_BOX), type);
need_type = ast_childidx(param, 1);
ok = is_subtype(view_type, need_type, NULL, opt);
ast_free_unattached(view_type);
ast_free_unattached(need_type);
if(!ok)
return TK_REF;
}
arg = ast_sibling(arg);
param = ast_sibling(param);
}
return TK_BOX;
}
bool expr_repeat(pass_opt_t* opt, ast_t* ast)
{
AST_GET_CHILDREN(ast, body, cond, else_clause);
ast_t* body_type = ast_type(body);
ast_t* cond_type = ast_type(cond);
ast_t* else_type = ast_type(else_clause);
if(is_typecheck_error(cond_type))
return false;
if(!is_bool(cond_type))
{
ast_error(opt->check.errors, cond, "condition must be a Bool");
return false;
}
if(is_typecheck_error(body_type) || is_typecheck_error(else_type))
return false;
// All consumes have to be in scope when the loop body finishes.
errorframe_t errorf = NULL;
if(!ast_all_consumes_in_scope(body, body, &errorf))
{
errorframe_report(&errorf, opt->check.errors);
return false;
}
// Union with any existing type due to a break expression.
ast_t* type = ast_type(ast);
// No symbol status is inherited from the loop body or condition. Nothing
// from outside can be consumed, and definitions inside may not occur.
if(!is_control_type(body_type))
type = control_type_add_branch(opt, type, body);
if(!is_control_type(else_type))
{
type = control_type_add_branch(opt, type, else_clause);
ast_inheritbranch(ast, else_clause);
// Use a branch count of two instead of one. This means we will pick up any
// consumes, but not any definitions, since definitions may not occur.
ast_consolidate_branches(ast, 2);
}
if(type == NULL)
type = ast_from(ast, TK_REPEAT);
ast_settype(ast, type);
literal_unify_control(ast, opt);
// Push our symbol status to our parent scope.
ast_inheritstatus(ast_parent(ast), ast);
return true;
}
bool expr_if(pass_opt_t* opt, ast_t* ast)
{
ast_t* cond = ast_child(ast);
ast_t* left = ast_sibling(cond);
ast_t* right = ast_sibling(left);
ast_t* cond_type = ast_type(cond);
if(is_typecheck_error(cond_type))
return false;
if(!is_bool(cond_type))
{
ast_error(cond, "condition must be a Bool");
return false;
}
ast_t* l_type = ast_type(left);
ast_t* r_type = ast_type(right);
ast_t* type = NULL;
size_t branch_count = 0;
if(!is_control_type(l_type))
{
type = control_type_add_branch(type, left);
ast_inheritbranch(ast, left);
branch_count++;
}
if(!is_control_type(r_type))
{
type = control_type_add_branch(type, right);
ast_inheritbranch(ast, right);
branch_count++;
}
if(type == NULL)
{
if(ast_sibling(ast) != NULL)
{
ast_error(ast_sibling(ast), "unreachable code");
return false;
}
type = ast_from(ast, TK_IF);
}
ast_settype(ast, type);
ast_inheritflags(ast);
ast_consolidate_branches(ast, branch_count);
literal_unify_control(ast, opt);
// Push our symbol status to our parent scope.
ast_inheritstatus(ast_parent(ast), ast);
return true;
}
bool expr_try(pass_opt_t* opt, ast_t* ast)
{
AST_GET_CHILDREN(ast, body, else_clause, then_clause);
ast_t* body_type = ast_type(body);
ast_t* else_type = ast_type(else_clause);
ast_t* then_type = ast_type(then_clause);
if(is_typecheck_error(body_type) ||
is_typecheck_error(else_type) ||
is_typecheck_error(then_type))
return false;
ast_t* type = NULL;
if(!is_control_type(body_type))
type = control_type_add_branch(opt, type, body);
if(!is_control_type(else_type))
type = control_type_add_branch(opt, type, else_clause);
if(type == NULL)
{
if(ast_sibling(ast) != NULL)
{
ast_error(opt->check.errors, ast_sibling(ast), "unreachable code");
return false;
}
type = ast_from(ast, TK_TRY);
}
// The then clause does not affect the type of the expression.
if(is_control_type(then_type))
{
ast_error(opt->check.errors, then_clause,
"then clause always terminates the function");
return false;
}
if(is_type_literal(then_type))
{
ast_error(opt->check.errors, then_clause,
"Cannot infer type of unused literal");
return false;
}
ast_settype(ast, type);
literal_unify_control(ast, opt);
// Push the symbol status from the then clause to our parent scope.
ast_inheritstatus(ast_parent(ast), then_clause);
return true;
}
ast_t* set_cap_and_ephemeral(ast_t* type, token_id cap, token_id ephemeral)
{
switch(ast_id(type))
{
case TK_UNIONTYPE:
case TK_ISECTTYPE:
case TK_TUPLETYPE:
{
ast_t* child = ast_child(type);
type = ast_from(type, ast_id(type));
while(child != NULL)
{
ast_append(type, set_cap_and_ephemeral(child, cap, ephemeral));
child = ast_sibling(child);
}
return type;
}
case TK_NOMINAL:
{
type = ast_dup(type);
AST_GET_CHILDREN(type, package, id, typeargs, tcap, eph);
if(cap != TK_NONE)
ast_setid(tcap, cap);
ast_setid(eph, ephemeral);
return type;
}
case TK_TYPEPARAMREF:
{
type = ast_dup(type);
AST_GET_CHILDREN(type, id, tcap, eph);
if(cap != TK_NONE)
ast_setid(tcap, cap);
ast_setid(eph, ephemeral);
return type;
}
case TK_ARROW:
// Just use the lhs of the viewpoint type.
return set_cap_and_ephemeral(ast_childidx(type, 1), cap, ephemeral);
default: {}
}
assert(0);
return NULL;
}
// Convert the given method into a delegation indirection to the specified
// field.
static void make_delegation(ast_t* method, ast_t* field, ast_t* delegate_ref,
ast_t* body_donor)
{
assert(method != NULL);
assert(field != NULL);
assert(delegate_ref != NULL);
// Make a redirection method body.
ast_t* args = ast_from(delegate_ref, TK_NONE);
ast_t* last_arg = NULL;
AST_GET_CHILDREN(method, cap, id, t_params, params, result, error, old_body);
for(ast_t* p = ast_child(params); p != NULL; p = ast_sibling(p))
{
const char* param_name = ast_name(ast_child(p));
BUILD(arg, delegate_ref,
NODE(TK_SEQ,
NODE(TK_CONSUME,
NONE
NODE(TK_REFERENCE, ID(param_name)))));
ast_list_append(args, &last_arg, arg);
ast_setid(args, TK_POSITIONALARGS);
}
BUILD(body, delegate_ref,
NODE(TK_SEQ,
NODE(TK_CALL,
TREE(args) // Positional args.
NODE(TK_NONE) // Named args.
NODE(TK_DOT, // Receiver.
NODE(TK_REFERENCE, ID(ast_name(ast_child(field))))
ID(ast_name(ast_childidx(method, 1)))))));
if(is_none(result))
{
// Add None to end of body. Whilst the call generated above will return
// None anyway in this case, without this extra None testing is very hard
// since a directly written version of this body will have the None.
BUILD(none, delegate_ref, NODE(TK_REFERENCE, ID("None")));
ast_append(body, none);
}
ast_replace(&old_body, body);
// Setup method info.
method_t* info = (method_t*)ast_data(method);
assert(info != NULL);
info->body_donor = body_donor;
info->delegated_field = field;
}
ast_t* ast_from_string(ast_t* ast, const char* name)
{
if(name == NULL)
return ast_from(ast, TK_NONE);
token_t* t = token_dup(ast->t);
token_set_id(t, TK_ID);
token_set_string(t, name, 0);
ast_t* new_ast = ast_token(t);
set_scope_no_parent(new_ast, ast->parent);
return new_ast;
}
void collect_type_params(ast_t* ast, ast_t** out_params, ast_t** out_args)
{
assert(ast != NULL);
assert(out_params != NULL);
assert(out_args != NULL);
// Create params and args as TK_NONE, we'll change them if we find any type
// params
ast_t* params = ast_from(ast, TK_NONE);
ast_t* args = ast_from(ast, TK_NONE);
ast_t* method = ast;
// Find enclosing method
while(ast_id(method) != TK_FUN && ast_id(method) != TK_NEW &&
ast_id(method) != TK_BE)
{
method = ast_parent(method);
assert(method != NULL);
}
// Find enclosing entity
ast_t* entity = ast_parent(ast_parent(method));
ast_t* entity_t_params = ast_childidx(entity, 1);
// Collect type parameters defined on the entity
for(ast_t* p = ast_child(entity_t_params); p != NULL; p = ast_sibling(p))
collect_type_param(p, params, args);
ast_t* method_t_params = ast_childidx(method, 1);
// Collect type parameters defined on the method
for(ast_t* p = ast_child(method_t_params); p != NULL; p = ast_sibling(p))
collect_type_param(p, params, args);
*out_params = params;
*out_args = args;
}
static ast_result_t sugar_as(pass_opt_t* opt, ast_t** astp)
{
typecheck_t* t = &opt->check;
ast_t* ast = *astp;
AST_GET_CHILDREN(ast, expr, type);
ast_t* pattern_root = ast_from(type, TK_LEX_ERROR);
ast_t* body_root = ast_from(type, TK_LEX_ERROR);
add_as_type(t, type, pattern_root, body_root);
ast_t* body = ast_pop(body_root);
ast_free(body_root);
if(body == NULL)
{
// No body implies all types are "don't care"
ast_error(ast, "Cannot treat value as \"don't care\"");
ast_free(pattern_root);
return AST_ERROR;
}
// Don't need top sequence in pattern
assert(ast_id(ast_child(pattern_root)) == TK_SEQ);
ast_t* pattern = ast_pop(ast_child(pattern_root));
ast_free(pattern_root);
REPLACE(astp,
NODE(TK_MATCH, AST_SCOPE
NODE(TK_SEQ, TREE(expr))
NODE(TK_CASES, AST_SCOPE
NODE(TK_CASE, AST_SCOPE
TREE(pattern)
NONE
TREE(body)))
NODE(TK_SEQ, AST_SCOPE NODE(TK_ERROR, NONE))));
return ast_visit(astp, pass_sugar, NULL, opt, PASS_SUGAR);
}
// Setup the type, or lack thereof, for local variable declarations.
// This is not really anything to do with traits, but must be done before the
// expr pass (to allow initialisation references to the variable type) but
// after the name pass (to get temporal capabilities).
static void local_types(ast_t* ast)
{
assert(ast != NULL);
// Setup type or mark as inferred now to allow calling create on a
// non-inferred local to initialise itself
AST_GET_CHILDREN(ast, id, type);
assert(type != NULL);
if(ast_id(type) == TK_NONE)
type = ast_from(id, TK_INFERTYPE);
ast_settype(id, type);
ast_settype(ast, type);
}
static void reify_reference(ast_t** astp, ast_t* typeparam, ast_t* typearg)
{
ast_t* ast = *astp;
pony_assert(ast_id(ast) == TK_REFERENCE);
const char* name = ast_name(ast_child(ast));
sym_status_t status;
ast_t* ref_def = ast_get(ast, name, &status);
if(ref_def == NULL)
return;
ast_t* param_def = (ast_t*)ast_data(typeparam);
pony_assert(param_def != NULL);
if(ref_def != param_def)
return;
ast_setid(ast, TK_TYPEREF);
ast_add(ast, ast_from(ast, TK_NONE)); // 1st child: package reference
ast_append(ast, ast_from(ast, TK_NONE)); // 3rd child: type args
ast_settype(ast, typearg);
}
ast_t* viewpoint_cap(token_id cap, token_id eph, ast_t* type)
{
if(cap == TK_TAG)
return NULL;
switch(ast_id(type))
{
case TK_UNIONTYPE:
case TK_ISECTTYPE:
case TK_TUPLETYPE:
{
// Adapt all elements.
ast_t* r_type = ast_from(type, ast_id(type));
ast_t* child = ast_child(type);
while(child != NULL)
{
ast_append(r_type, viewpoint_cap(cap, eph, child));
child = ast_sibling(child);
}
return r_type;
}
case TK_NOMINAL:
return viewpoint_for_type(cap, eph, type, 3);
case TK_TYPEPARAMREF:
return viewpoint_for_type(cap, eph, type, 1);
case TK_ARROW:
{
// Adapt the lower bounds.
ast_t* lower = viewpoint_lower(type);
ast_t* r_type = viewpoint_cap(cap, eph, lower);
if(r_type != lower)
ast_free_unattached(lower);
return r_type;
}
default: {}
}
assert(0);
return NULL;
}
static bool insert_apply(pass_opt_t* opt, ast_t** astp)
{
// Sugar .apply()
ast_t* ast = *astp;
AST_GET_CHILDREN(ast, positional, namedargs, lhs);
ast_t* dot = ast_from(ast, TK_DOT);
ast_add(dot, ast_from_string(ast, "apply"));
ast_swap(lhs, dot);
ast_add(dot, lhs);
if(!expr_dot(opt, &dot))
return false;
return expr_call(opt, astp);
}
bool expr_continue(typecheck_t* t, ast_t* ast)
{
if(t->frame->loop_body == NULL)
{
ast_error(ast, "must be in a loop");
return false;
}
if(!ast_all_consumes_in_scope(t->frame->loop_body, ast))
return false;
// continue is always the last expression in a sequence
assert(ast_sibling(ast) == NULL);
ast_settype(ast, ast_from(ast, TK_CONTINUE));
return true;
}