static bool reify_typeparamref(ast_t** astp, ast_t* typeparam, ast_t* typearg)
{
ast_t* ast = *astp;
assert(ast_id(ast) == TK_TYPEPARAMREF);
ast_t* ref_name = ast_child(ast);
ast_t* param_name = ast_child(typeparam);
if(ast_name(ref_name) != ast_name(param_name))
return false;
// Keep ephemerality.
switch(ast_id(ast_childidx(ast, 2)))
{
case TK_EPHEMERAL:
typearg = consume_type(typearg, TK_NONE);
break;
case TK_NONE:
break;
case TK_BORROWED:
typearg = alias(typearg);
break;
default:
assert(0);
return false;
}
ast_replace(astp, typearg);
return true;
}
static void reify_typeparamref(ast_t** astp, ast_t* typeparam, ast_t* typearg)
{
ast_t* ast = *astp;
assert(ast_id(ast) == TK_TYPEPARAMREF);
ast_t* ref_def = (ast_t*)ast_data(ast);
ast_t* param_def = (ast_t*)ast_data(typeparam);
assert(ref_def != NULL);
assert(param_def != NULL);
if(ref_def != param_def)
return;
// Keep ephemerality.
switch(ast_id(ast_childidx(ast, 2)))
{
case TK_EPHEMERAL:
typearg = consume_type(typearg, TK_NONE);
break;
case TK_NONE:
break;
case TK_BORROWED:
typearg = alias(typearg);
break;
default:
assert(0);
}
ast_replace(astp, typearg);
}
bool expr_consume(pass_opt_t* opt, ast_t* ast)
{
AST_GET_CHILDREN(ast, cap, term);
ast_t* type = ast_type(term);
if(is_typecheck_error(type))
return false;
const char* name = NULL;
switch(ast_id(term))
{
case TK_VARREF:
case TK_LETREF:
case TK_PARAMREF:
{
ast_t* id = ast_child(term);
name = ast_name(id);
break;
}
case TK_THIS:
{
name = stringtab("this");
break;
}
default:
ast_error(opt->check.errors, ast,
"consume must take 'this', a local, or a parameter");
return false;
}
// Can't consume from an outer scope while in a loop condition.
if((opt->check.frame->loop_cond != NULL) &&
!ast_within_scope(opt->check.frame->loop_cond, ast, name))
{
ast_error(opt->check.errors, ast,
"can't consume from an outer scope in a loop condition");
return false;
}
ast_setstatus(ast, name, SYM_CONSUMED);
token_id tcap = ast_id(cap);
ast_t* c_type = consume_type(type, tcap);
if(c_type == NULL)
{
ast_error(opt->check.errors, ast, "can't consume to this capability");
ast_error_continue(opt->check.errors, term, "expression type is %s",
ast_print_type(type));
return false;
}
ast_settype(ast, c_type);
return true;
}
static void reify_typeparamref(ast_t** astp, ast_t* typeparam, ast_t* typearg)
{
ast_t* ast = *astp;
pony_assert(ast_id(ast) == TK_TYPEPARAMREF);
pony_assert(ast_id(typeparam) == TK_TYPEPARAM);
ast_t* ref_def = (ast_t*)ast_data(ast);
// We can't compare ref_def and typeparam, as they could be a copy or
// a iftype shadowing. However, their data points back to the original
// typeparam definition, which can be compared.
ref_def = (ast_t*)ast_data(ref_def);
typeparam = (ast_t*)ast_data(typeparam);
pony_assert(ref_def != NULL);
pony_assert(typeparam != NULL);
if(ref_def != typeparam)
return;
// Keep ephemerality.
switch(ast_id(ast_childidx(ast, 2)))
{
case TK_EPHEMERAL:
typearg = consume_type(typearg, TK_NONE);
break;
case TK_NONE:
break;
case TK_ALIASED:
typearg = alias(typearg);
break;
default:
pony_assert(0);
}
ast_replace(astp, typearg);
}
bool expr_reference(pass_opt_t* opt, ast_t** astp)
{
typecheck_t* t = &opt->check;
ast_t* ast = *astp;
// Everything we reference must be in scope.
const char* name = ast_name(ast_child(ast));
sym_status_t status;
ast_t* def = ast_get(ast, name, &status);
if(def == NULL)
{
const char* alt_name = suggest_alt_name(ast, name);
if(alt_name == NULL)
ast_error(ast, "can't find declaration of '%s'", name);
else
ast_error(ast, "can't find declaration of '%s', did you mean '%s'?",
name, alt_name);
return false;
}
switch(ast_id(def))
{
case TK_PACKAGE:
{
// Only allowed if in a TK_DOT with a type.
if(ast_id(ast_parent(ast)) != TK_DOT)
{
ast_error(ast, "a package can only appear as a prefix to a type");
return false;
}
ast_setid(ast, TK_PACKAGEREF);
return true;
}
case TK_INTERFACE:
case TK_TRAIT:
case TK_TYPE:
case TK_TYPEPARAM:
case TK_PRIMITIVE:
case TK_STRUCT:
case TK_CLASS:
case TK_ACTOR:
{
// It's a type name. This may not be a valid type, since it may need
// type arguments.
ast_t* id = ast_child(def);
const char* name = ast_name(id);
ast_t* type = type_sugar(ast, NULL, name);
ast_settype(ast, type);
ast_setid(ast, TK_TYPEREF);
return expr_typeref(opt, astp);
}
case TK_FVAR:
case TK_FLET:
case TK_EMBED:
{
// Transform to "this.f".
if(!def_before_use(def, ast, name))
return false;
ast_t* dot = ast_from(ast, TK_DOT);
ast_add(dot, ast_child(ast));
ast_t* self = ast_from(ast, TK_THIS);
ast_add(dot, self);
ast_replace(astp, dot);
if(!expr_this(opt, self))
return false;
return expr_dot(opt, astp);
}
case TK_PARAM:
{
if(t->frame->def_arg != NULL)
{
ast_error(ast, "can't reference a parameter in a default argument");
return false;
}
if(!def_before_use(def, ast, name))
return false;
ast_t* type = ast_type(def);
if(is_typecheck_error(type))
return false;
if(!valid_reference(opt, ast, type, status))
return false;
if(!sendable(type) && (t->frame->recover != NULL))
{
ast_error(ast,
"can't access a non-sendable parameter from inside a recover "
"expression");
return false;
}
// Get the type of the parameter and attach it to our reference.
// Automatically consume a parameter if the function is done.
ast_t* r_type = type;
if(is_method_return(t, ast))
r_type = consume_type(type, TK_NONE);
ast_settype(ast, r_type);
ast_setid(ast, TK_PARAMREF);
return true;
}
case TK_NEW:
case TK_BE:
case TK_FUN:
{
// Transform to "this.f".
ast_t* dot = ast_from(ast, TK_DOT);
ast_add(dot, ast_child(ast));
ast_t* self = ast_from(ast, TK_THIS);
ast_add(dot, self);
ast_replace(astp, dot);
if(!expr_this(opt, self))
return false;
return expr_dot(opt, astp);
}
case TK_ID:
{
if(!def_before_use(def, ast, name))
return false;
ast_t* type = ast_type(def);
if(type != NULL && ast_id(type) == TK_INFERTYPE)
{
ast_error(ast, "cannot infer type of %s\n", ast_nice_name(def));
ast_settype(def, ast_from(def, TK_ERRORTYPE));
ast_settype(ast, ast_from(ast, TK_ERRORTYPE));
return false;
}
if(is_typecheck_error(type))
return false;
if(!valid_reference(opt, ast, type, status))
return false;
ast_t* var = ast_parent(def);
switch(ast_id(var))
{
case TK_VAR:
ast_setid(ast, TK_VARREF);
break;
case TK_LET:
case TK_MATCH_CAPTURE:
ast_setid(ast, TK_LETREF);
break;
default:
assert(0);
return false;
}
if(!sendable(type))
{
if(t->frame->recover != NULL)
{
ast_t* def_recover = ast_nearest(def, TK_RECOVER);
if(t->frame->recover != def_recover)
{
ast_error(ast, "can't access a non-sendable local defined outside "
"of a recover expression from within that recover expression");
return false;
}
}
}
// Get the type of the local and attach it to our reference.
// Automatically consume a local if the function is done.
ast_t* r_type = type;
if(is_method_return(t, ast))
r_type = consume_type(type, TK_NONE);
ast_settype(ast, r_type);
return true;
}
default: {}
}
assert(0);
return false;
}
bool expr_assign(pass_opt_t* opt, ast_t* ast)
{
// Left and right are swapped in the AST to make sure we type check the
// right side before the left. Fetch them in the opposite order.
assert(ast != NULL);
AST_GET_CHILDREN(ast, right, left);
ast_t* l_type = ast_type(left);
if(!is_lvalue(&opt->check, left, is_result_needed(ast)))
{
ast_error(ast, "left side must be something that can be assigned to");
return false;
}
assert(l_type != NULL);
if(!coerce_literals(&right, l_type, opt))
return false;
ast_t* r_type = ast_type(right);
if(is_typecheck_error(r_type))
return false;
if(!infer_locals(left, r_type))
return false;
// Inferring locals may have changed the left type.
l_type = ast_type(left);
// Assignment is based on the alias of the right hand side.
ast_t* a_type = alias(r_type);
if(!is_subtype(a_type, l_type))
{
ast_error(ast, "right side must be a subtype of left side");
ast_error(a_type, "right side type: %s", ast_print_type(a_type));
ast_error(l_type, "left side type: %s", ast_print_type(l_type));
ast_free_unattached(a_type);
return false;
}
if((ast_id(left) == TK_TUPLE) && (ast_id(a_type) != TK_TUPLETYPE))
{
switch(ast_id(a_type))
{
case TK_UNIONTYPE:
ast_error(ast,
"can't destructure a union using assignment, use pattern matching "
"instead");
break;
case TK_ISECTTYPE:
ast_error(ast,
"can't destructure an intersection using assignment, use pattern "
"matching instead");
break;
default:
assert(0);
break;
}
ast_error(a_type, "right side type: %s", ast_print_type(a_type));
ast_free_unattached(a_type);
return false;
}
bool ok_safe = safe_to_write(left, a_type);
if(!ok_safe)
{
if(ast_id(left) == TK_FVARREF && ast_child(left) != NULL &&
ast_id(ast_child(left)) == TK_THIS)
{
// We are writing to a field in this
ast_t* fn = ast_nearest(left, TK_FUN);
if(fn != NULL)
{
ast_t* iso = ast_child(fn);
assert(iso != NULL);
token_id iso_id = ast_id(iso);
if(iso_id == TK_BOX || iso_id == TK_VAL || iso_id == TK_TAG)
{
ast_error(ast, "cannot write to a field in a %s function",
lexer_print(iso_id));
ast_free_unattached(a_type);
return false;
}
}
}
ast_error(ast, "not safe to write right side to left side");
ast_error(a_type, "right side type: %s", ast_print_type(a_type));
ast_free_unattached(a_type);
return false;
}
ast_free_unattached(a_type);
// If it's an embedded field, check for a constructor result.
if(ast_id(left) == TK_EMBEDREF)
{
if((ast_id(right) != TK_CALL) ||
(ast_id(ast_childidx(right, 2)) != TK_NEWREF))
{
ast_error(ast, "an embedded field must be assigned using a constructor");
return false;
}
}
ast_settype(ast, consume_type(l_type, TK_NONE));
ast_inheritflags(ast);
return true;
}
bool expr_assign(pass_opt_t* opt, ast_t* ast)
{
// Left and right are swapped in the AST to make sure we type check the
// right side before the left. Fetch them in the opposite order.
assert(ast != NULL);
AST_GET_CHILDREN(ast, right, left);
ast_t* l_type = ast_type(left);
if(l_type == NULL || !is_lvalue(opt, left, is_result_needed(ast)))
{
ast_error(opt->check.errors, ast,
"left side must be something that can be assigned to");
return false;
}
if(!coerce_literals(&right, l_type, opt))
return false;
ast_t* r_type = ast_type(right);
if(is_typecheck_error(r_type))
return false;
if(is_control_type(r_type))
{
ast_error(opt->check.errors, ast,
"the right hand side does not return a value");
return false;
}
if(!infer_locals(opt, left, r_type))
return false;
// Inferring locals may have changed the left type.
l_type = ast_type(left);
// Assignment is based on the alias of the right hand side.
ast_t* a_type = alias(r_type);
errorframe_t info = NULL;
if(!is_subtype(a_type, l_type, &info, opt))
{
errorframe_t frame = NULL;
ast_error_frame(&frame, ast, "right side must be a subtype of left side");
errorframe_append(&frame, &info);
errorframe_report(&frame, opt->check.errors);
ast_free_unattached(a_type);
return false;
}
if((ast_id(left) == TK_TUPLE) && (ast_id(a_type) != TK_TUPLETYPE))
{
switch(ast_id(a_type))
{
case TK_UNIONTYPE:
ast_error(opt->check.errors, ast,
"can't destructure a union using assignment, use pattern matching "
"instead");
break;
case TK_ISECTTYPE:
ast_error(opt->check.errors, ast,
"can't destructure an intersection using assignment, use pattern "
"matching instead");
break;
default:
assert(0);
break;
}
ast_free_unattached(a_type);
return false;
}
bool ok_safe = safe_to_write(left, a_type);
if(!ok_safe)
{
if(ast_id(left) == TK_FVARREF && ast_child(left) != NULL &&
ast_id(ast_child(left)) == TK_THIS)
{
// We are writing to a field in this
ast_t* fn = ast_nearest(left, TK_FUN);
if(fn != NULL)
{
ast_t* iso = ast_child(fn);
assert(iso != NULL);
token_id iso_id = ast_id(iso);
if(iso_id == TK_BOX || iso_id == TK_VAL || iso_id == TK_TAG)
{
ast_error(opt->check.errors, ast,
"cannot write to a field in a %s function. If you are trying to "
"change state in a function use fun ref",
lexer_print(iso_id));
ast_free_unattached(a_type);
return false;
}
}
}
ast_error(opt->check.errors, ast,
"not safe to write right side to left side");
ast_error_continue(opt->check.errors, a_type, "right side type: %s",
ast_print_type(a_type));
ast_free_unattached(a_type);
return false;
}
ast_free_unattached(a_type);
if(!check_embed_construction(opt, left, right))
return false;
ast_settype(ast, consume_type(l_type, TK_NONE));
return true;
}
static void replace_type(ast_t** astp, ast_t* target, ast_t* with)
{
ast_t* ast = *astp;
ast_t* child = ast_child(ast);
while(child != NULL)
{
replace_type(&child, target, with);
child = ast_sibling(child);
}
ast_t* node_type = ast_type(ast);
if(node_type != NULL)
replace_type(&node_type, target, with);
if(ast_id(ast) == ast_id(target))
{
switch(ast_id(target))
{
case TK_THISTYPE:
// Replace `this`.
ast_replace(astp, ast_dup(with));
break;
case TK_TYPEPARAMREF:
{
// Replace a typeparamref with a reification.
ast_t* target_def = (ast_t*)ast_data(target);
ast_t* left_def = (ast_t*)ast_data(ast);
if(target_def == left_def)
{
AST_GET_CHILDREN(ast, id, cap, eph);
ast_t* a_with = with;
switch(ast_id(eph))
{
case TK_EPHEMERAL:
a_with = consume_type(with, TK_NONE);
break;
case TK_BORROWED:
a_with = alias(with);
break;
default: {}
}
if(a_with == with)
a_with = ast_dup(with);
ast_replace(astp, a_with);
}
break;
}
default:
assert(0);
}
} else if(ast_id(ast) == TK_ARROW) {
// Recalculate all arrow types.
AST_GET_CHILDREN(ast, left, right);
ast_t* r_type = viewpoint_type(left, right);
ast_replace(astp, r_type);
}
}
