static matchtype_t is_isect_match_x(ast_t* operand, ast_t* pattern,
errorframe_t* errorf, bool report_reject, pass_opt_t* opt)
{
matchtype_t ok = MATCHTYPE_ACCEPT;
for(ast_t* child = ast_child(operand);
child != NULL;
child = ast_sibling(child))
{
switch(is_x_match_x(child, pattern, NULL, false, opt))
{
case MATCHTYPE_ACCEPT:
break;
case MATCHTYPE_REJECT:
// If any type in the operand isect rejects a match, then the entire
// operand isect rejects match.
ok = MATCHTYPE_REJECT;
break;
case MATCHTYPE_DENY:
// If any type in the operand isect denies a match, then the entire
// operand isect is denied a match.
ok = MATCHTYPE_DENY;
break;
}
if(ok == MATCHTYPE_DENY)
break;
}
if((ok != MATCHTYPE_ACCEPT) && (errorf != NULL))
{
if(ok == MATCHTYPE_DENY)
report_reject = false;
for(ast_t* child = ast_child(operand);
child != NULL;
child = ast_sibling(child))
{
is_x_match_x(child, pattern, errorf, report_reject, opt);
}
if(ok == MATCHTYPE_DENY)
{
ast_error_frame(errorf, pattern,
"matching %s with %s could violate capabilities",
ast_print_type(operand), ast_print_type(pattern));
} else if(report_reject) {
ast_error_frame(errorf, pattern, "not every element of %s can match %s",
ast_print_type(operand), ast_print_type(pattern));
}
}
return ok;
}
static matchtype_t is_x_match_union(ast_t* operand, ast_t* pattern,
pass_opt_t* opt)
{
matchtype_t ok = MATCHTYPE_REJECT;
for(ast_t* child = ast_child(pattern);
child != NULL;
child = ast_sibling(child))
{
switch(is_x_match_x(operand, child, opt))
{
case MATCHTYPE_ACCEPT:
// If any type in the pattern union accepts a match, the entire pattern
// union accepts a match.
ok = MATCHTYPE_ACCEPT;
break;
case MATCHTYPE_REJECT:
break;
case MATCHTYPE_DENY:
// If any type in the pattern union denies a match, the entire pattern
// union denies a match.
return MATCHTYPE_DENY;
}
}
return ok;
}
static matchtype_t is_isect_match_x(ast_t* operand, ast_t* pattern,
pass_opt_t* opt)
{
matchtype_t ok = MATCHTYPE_ACCEPT;
for(ast_t* child = ast_child(operand);
child != NULL;
child = ast_sibling(child))
{
switch(is_x_match_x(child, pattern, opt))
{
case MATCHTYPE_ACCEPT:
break;
case MATCHTYPE_REJECT:
// If any type in the operand isect rejects a match, then the entire
// operand isect rejects match.
ok = MATCHTYPE_REJECT;
break;
case MATCHTYPE_DENY:
// If any type in the operand isect denies a match, then the entire
// operand isect is denied a match.
return MATCHTYPE_DENY;
}
}
return ok;
}
static matchtype_t is_arrow_match_x(ast_t* operand, ast_t* pattern,
pass_opt_t* opt)
{
// upperbound(this->T1) match T2
// ---
// (this->T1) match T2
// lowerbound(T1->T2) match T3
// ---
// (T1->T2) match T3
ast_t* operand_view;
AST_GET_CHILDREN(operand, left, right);
if(ast_id(left) == TK_THISTYPE)
operand_view = viewpoint_upper(operand);
else
operand_view = viewpoint_lower(operand);
if(operand_view == NULL)
return MATCHTYPE_DENY;
matchtype_t ok = is_x_match_x(operand_view, pattern, opt);
ast_free_unattached(operand_view);
return ok;
}
static matchtype_t is_tuple_match_tuple(ast_t* operand, ast_t* pattern,
pass_opt_t* opt)
{
// Must be a pairwise match.
if(ast_childcount(operand) != ast_childcount(pattern))
return MATCHTYPE_REJECT;
ast_t* operand_child = ast_child(operand);
ast_t* pattern_child = ast_child(pattern);
matchtype_t ok = MATCHTYPE_ACCEPT;
while(operand_child != NULL)
{
switch(is_x_match_x(operand_child, pattern_child, opt))
{
case MATCHTYPE_ACCEPT:
break;
case MATCHTYPE_REJECT:
ok = MATCHTYPE_REJECT;
break;
case MATCHTYPE_DENY:
return MATCHTYPE_DENY;
}
operand_child = ast_sibling(operand_child);
pattern_child = ast_sibling(pattern_child);
}
return ok;
}
static matchtype_t is_x_match_arrow(ast_t* operand, ast_t* pattern,
errorframe_t* errorf, bool report_reject, pass_opt_t* opt)
{
// T1 match upperbound(T2->T3)
// ---
// T1 match T2->T3
ast_t* pattern_upper = viewpoint_upper(pattern);
if(pattern_upper == NULL)
{
if((errorf != NULL) && report_reject)
{
ast_error_frame(errorf, pattern,
"%s cannot match %s: the pattern type has no upper bounds",
ast_print_type(operand), ast_print_type(pattern));
}
return MATCHTYPE_REJECT;
}
matchtype_t ok = is_x_match_x(operand, pattern_upper, errorf, report_reject,
opt);
ast_free_unattached(pattern_upper);
return ok;
}
static matchtype_t is_x_match_typeparam(ast_t* operand, ast_t* pattern,
pass_opt_t* opt)
{
ast_t* pattern_upper = typeparam_upper(pattern);
// An unconstrained typeparam can match anything.
if(pattern_upper == NULL)
return MATCHTYPE_ACCEPT;
// Otherwise, match the constraint.
matchtype_t ok = is_x_match_x(operand, pattern_upper, opt);
ast_free_unattached(pattern_upper);
return ok;
}
static matchtype_t is_typeparam_match_x(ast_t* operand, ast_t* pattern,
pass_opt_t* opt)
{
ast_t* operand_upper = typeparam_upper(operand);
// An unconstrained typeparam could match anything.
if(operand_upper == NULL)
return MATCHTYPE_ACCEPT;
// Check if the constraint can match the pattern.
matchtype_t ok = is_x_match_x(operand_upper, pattern, opt);
ast_free_unattached(operand_upper);
return ok;
}
static matchtype_t is_x_match_arrow(ast_t* operand, ast_t* pattern,
pass_opt_t* opt)
{
// T1 match upperbound(T2->T3)
// ---
// T1 match T2->T3
ast_t* pattern_upper = viewpoint_upper(pattern);
if(pattern_upper == NULL)
return MATCHTYPE_REJECT;
matchtype_t ok = is_x_match_x(operand, pattern_upper, opt);
ast_free_unattached(pattern_upper);
return ok;
}
static matchtype_t is_nominal_match_tuple(ast_t* operand, ast_t* pattern,
errorframe_t* errorf, bool report_reject, pass_opt_t* opt)
{
if(!is_top_type(operand, true))
{
if((errorf != NULL) && report_reject)
{
ast_t* operand_def = (ast_t*)ast_data(operand);
ast_error_frame(errorf, pattern,
"%s cannot match %s: the pattern type is a tuple",
ast_print_type(operand), ast_print_type(pattern));
ast_error_frame(errorf, operand_def, "this might be possible if the "
"match type were an empty interface, such as the Any type");
}
return MATCHTYPE_REJECT;
}
ast_t* child = ast_child(pattern);
while(child != NULL)
{
matchtype_t r = is_x_match_x(operand, child, errorf, false, opt);
pony_assert(r != MATCHTYPE_REJECT);
if(r == MATCHTYPE_DENY)
{
if(errorf != NULL)
{
ast_error_frame(errorf, pattern,
"matching %s with %s could violate capabilities",
ast_print_type(operand), ast_print_type(pattern));
}
return r;
}
child = ast_sibling(child);
}
return MATCHTYPE_ACCEPT;
}
static matchtype_t is_arrow_match_x(ast_t* operand, ast_t* pattern,
errorframe_t* errorf, bool report_reject, pass_opt_t* opt)
{
// upperbound(this->T1) match T2
// ---
// (this->T1) match T2
// lowerbound(T1->T2) match T3
// ---
// (T1->T2) match T3
ast_t* operand_view;
AST_GET_CHILDREN(operand, left, right);
if(ast_id(left) == TK_THISTYPE)
operand_view = viewpoint_upper(operand);
else
operand_view = viewpoint_lower(operand);
if(operand_view == NULL)
{
if(errorf != NULL)
{
// this->X always has an upper bound.
pony_assert(ast_id(left) != TK_THISTYPE);
ast_error_frame(errorf, pattern,
"matching %s with %s could violate capabilities: "
"the match type has no lower bounds",
ast_print_type(operand), ast_print_type(pattern));
}
return MATCHTYPE_DENY;
}
matchtype_t ok = is_x_match_x(operand_view, pattern, errorf, report_reject,
opt);
ast_free_unattached(operand_view);
return ok;
}
matchtype_t is_matchtype(ast_t* operand, ast_t* pattern, pass_opt_t* opt)
{
return is_x_match_x(operand, pattern, opt);
}
matchtype_t is_matchtype(ast_t* operand, ast_t* pattern, errorframe_t* errorf,
pass_opt_t* opt)
{
return is_x_match_x(operand, pattern, errorf, true, opt);
}
static matchtype_t is_tuple_match_tuple(ast_t* operand, ast_t* pattern,
errorframe_t* errorf, bool report_reject, pass_opt_t* opt)
{
// Must be a pairwise match.
if(ast_childcount(operand) != ast_childcount(pattern))
{
if((errorf != NULL) && report_reject)
{
ast_error_frame(errorf, pattern,
"%s cannot match %s: they have a different number of elements",
ast_print_type(operand), ast_print_type(pattern));
}
return MATCHTYPE_REJECT;
}
ast_t* operand_child = ast_child(operand);
ast_t* pattern_child = ast_child(pattern);
matchtype_t ok = MATCHTYPE_ACCEPT;
while(operand_child != NULL)
{
switch(is_x_match_x(operand_child, pattern_child, NULL, false, opt))
{
case MATCHTYPE_ACCEPT:
break;
case MATCHTYPE_REJECT:
ok = MATCHTYPE_REJECT;
break;
case MATCHTYPE_DENY:
ok = MATCHTYPE_DENY;
break;
}
if(ok != MATCHTYPE_ACCEPT)
break;
operand_child = ast_sibling(operand_child);
pattern_child = ast_sibling(pattern_child);
}
if((ok != MATCHTYPE_ACCEPT) && (errorf != NULL))
{
if(ok == MATCHTYPE_DENY)
report_reject = false;
operand_child = ast_child(operand);
pattern_child = ast_child(pattern);
while(operand_child != NULL)
{
is_x_match_x(operand_child, pattern_child, errorf, report_reject, opt);
operand_child = ast_sibling(operand_child);
pattern_child = ast_sibling(pattern_child);
}
if(ok == MATCHTYPE_DENY)
{
ast_error_frame(errorf, pattern,
"matching %s with %s could violate capabilities",
ast_print_type(operand), ast_print_type(pattern));
} else if(report_reject) {
ast_error_frame(errorf, pattern, "%s cannot pairwise match %s",
ast_print_type(operand), ast_print_type(pattern));
}
}
return ok;
}