ast_t* viewpoint_type(ast_t* l_type, ast_t* r_type)
{
switch(ast_id(l_type))
{
case TK_TUPLETYPE:
case TK_UNIONTYPE:
case TK_ISECTTYPE:
{
// Only occurs in codegen.
return r_type;
}
case TK_NOMINAL:
{
if(ast_id(r_type) == TK_ARROW)
return make_arrow_type(l_type, r_type);
AST_GET_CHILDREN(l_type, pkg, id, typeargs, cap, eph);
token_id tcap = ast_id(cap);
if(tcap == TK_CAP_READ)
return make_arrow_type(l_type, r_type);
return viewpoint_cap(tcap, ast_id(eph), r_type);
}
case TK_TYPEPARAMREF:
{
if(ast_id(r_type) == TK_ARROW)
return make_arrow_type(l_type, r_type);
AST_GET_CHILDREN(l_type, id, cap, eph);
token_id tcap = ast_id(cap);
if(tcap == TK_CAP_READ)
return make_arrow_type(l_type, r_type);
return viewpoint_cap(tcap, ast_id(eph), r_type);
}
case TK_ARROW:
case TK_BOXTYPE:
case TK_THISTYPE:
return make_arrow_type(l_type, r_type);
default: {}
}
return NULL;
}
ast_t* viewpoint_type(ast_t* l_type, ast_t* r_type)
{
switch(ast_id(l_type))
{
case TK_TUPLETYPE:
case TK_UNIONTYPE:
case TK_ISECTTYPE:
{
// Only occurs in codegen.
return r_type;
}
case TK_NOMINAL:
{
if(ast_id(r_type) == TK_ARROW)
return make_arrow_type(l_type, r_type);
AST_GET_CHILDREN(l_type, pkg, id, typeargs, cap, eph);
return viewpoint_cap(ast_id(cap), ast_id(eph), r_type);
}
case TK_TYPEPARAMREF:
{
if(ast_id(r_type) == TK_ARROW)
return make_arrow_type(l_type, r_type);
// If the left side is a type parameter, return an arrow type if the
// capability is box, otherwise adapt the type.
AST_GET_CHILDREN(l_type, id, cap, eph);
token_id tcap = ast_id(cap);
if(tcap == TK_BOX_GENERIC)
return make_arrow_type(l_type, r_type);
return viewpoint_cap(tcap, ast_id(eph), r_type);
}
case TK_ARROW:
case TK_BOXTYPE:
case TK_THISTYPE:
return make_arrow_type(l_type, r_type);
default: {}
}
return NULL;
}
static ast_t* make_arrow_type(ast_t* left, ast_t* right)
{
switch(ast_id(right))
{
case TK_UNIONTYPE:
case TK_ISECTTYPE:
case TK_TUPLETYPE:
{
ast_t* type = ast_from(right, ast_id(right));
ast_t* child = ast_child(right);
while(child != NULL)
{
ast_append(type, make_arrow_type(left, child));
child = ast_sibling(child);
}
return type;
}
case TK_NOMINAL:
case TK_TYPEPARAMREF:
{
switch(cap_single(right))
{
case TK_VAL:
case TK_TAG:
return right;
default: {}
}
return make_single_arrow(left, right);
}
case TK_ARROW:
return make_single_arrow(left, right);
default: {}
}
assert(0);
return NULL;
}
