bool is_known(ast_t* type)
{
if(type == NULL)
return false;
switch(ast_id(type))
{
case TK_UNIONTYPE:
case TK_TUPLETYPE:
return false;
case TK_ISECTTYPE:
{
ast_t* child = ast_child(type);
while(child != NULL)
{
if(is_known(child))
return true;
child = ast_sibling(child);
}
return false;
}
case TK_NOMINAL:
{
ast_t* def = (ast_t*)ast_data(type);
switch(ast_id(def))
{
case TK_INTERFACE:
case TK_TRAIT:
return false;
case TK_PRIMITIVE:
case TK_STRUCT:
case TK_CLASS:
case TK_ACTOR:
return true;
default: {}
}
break;
}
case TK_ARROW:
return is_known(ast_childidx(type, 1));
case TK_TYPEPARAMREF:
return is_known(typeparam_constraint(type));
default: {}
}
assert(0);
return false;
}
bool is_entity(ast_t* type, token_id entity)
{
if(type == NULL)
return false;
switch(ast_id(type))
{
case TK_TUPLETYPE:
return false;
case TK_UNIONTYPE:
{
ast_t* child = ast_child(type);
while(child != NULL)
{
if(!is_entity(child, entity))
return false;
child = ast_sibling(child);
}
return true;
}
case TK_ISECTTYPE:
{
ast_t* child = ast_child(type);
while(child != NULL)
{
if(is_entity(child, entity))
return true;
child = ast_sibling(child);
}
return false;
}
case TK_NOMINAL:
{
ast_t* def = (ast_t*)ast_data(type);
return ast_id(def) == entity;
}
case TK_ARROW:
return is_entity(ast_childidx(type, 1), entity);
case TK_TYPEPARAMREF:
return is_entity(typeparam_constraint(type), entity);
default: {}
}
assert(0);
return false;
}
ast_result_t flatten_typeparamref(pass_opt_t* opt, ast_t* ast)
{
ast_t* cap_ast = cap_fetch(ast);
token_id cap = ast_id(cap_ast);
typeparam_set_cap(ast);
token_id set_cap = ast_id(cap_ast);
if((cap != TK_NONE) && (cap != set_cap))
{
ast_t* def = (ast_t*)ast_data(ast);
ast_t* constraint = typeparam_constraint(ast);
if(constraint != NULL)
{
ast_error(opt->check.errors, cap_ast, "can't specify a capability on a "
"type parameter that differs from the constraint");
ast_error_continue(opt->check.errors, constraint,
"constraint definition is here");
if(ast_parent(constraint) != def)
{
ast_error_continue(opt->check.errors, def,
"type parameter definition is here");
}
} else {
ast_error(opt->check.errors, cap_ast, "a type parameter with no "
"constraint can only have #any as its capability");
ast_error_continue(opt->check.errors, def,
"type parameter definition is here");
}
return AST_ERROR;
}
return AST_OK;
}