Merge remote-tracking branch 'origin/cancall_new' into develop

codon/parser/visitors/typecheck/call.cpp

@@ -1033,25 +1033,15 @@ std::pair<bool, ExprPtr> TypecheckVisitor::transformInternalStaticFn(CallExpr *e
       callArgs.back().value->setType(a.second);
     }
 
-    auto fn = expr->args[0].value->type->getFunc();
+    if (auto fn = expr->args[0].value->type->getFunc()) {
-    if (!fn) {
-      bool canCompile = true;
-      // Special case: not a function, just try compiling it!
-      auto ocache = *(ctx->cache);
-      auto octx = *ctx;
-      try {
-        transform(N<CallExpr>(clone(expr->args[0].value),
-                              N<StarExpr>(clone(expr->args[1].value)),
-                              N<KeywordStarExpr>(clone(expr->args[2].value))));
-      } catch (const exc::ParserException &e) {
-        // LOG("{}", e.what());
-        canCompile = false;
-        *ctx = octx;
-        *(ctx->cache) = ocache;
-      }
-      return {true, transform(N<BoolExpr>(canCompile))};
-    }
       return {true, transform(N<BoolExpr>(canCall(fn, callArgs) >= 0))};
+    } else if (auto pt = expr->args[0].value->type->getPartial()) {
+      return {true, transform(N<BoolExpr>(canCall(pt->func, callArgs, pt) >= 0))};
+    } else {
+      compilationWarning("cannot use fn_can_call on non-functions", getSrcInfo().file,
+                         getSrcInfo().line, getSrcInfo().col);
+      return {true, transform(N<BoolExpr>(false))};
+    }
   } else if (expr->expr->isId("std.internal.static.fn_arg_has_type")) {
     expr->staticValue.type = StaticValue::INT;
     auto fn = ctx->extractFunction(expr->args[0].value->type);

codon/parser/visitors/typecheck/typecheck.cpp

@@ -26,6 +26,7 @@ StmtPtr TypecheckVisitor::apply(Cache *cache, const StmtPtr &stmts) {
   auto so = clone(stmts);
   auto s = v.inferTypes(so, true);
   if (!s) {
+    // LOG("{}", so->toString(2));
     v.error("cannot typecheck the program");
   }
   if (s->getSuite())
@@ -251,13 +252,21 @@ public:
 /// Check if a function can be called with the given arguments.
 /// See @c reorderNamedArgs for details.
 int TypecheckVisitor::canCall(const types::FuncTypePtr &fn,
-                              const std::vector<CallExpr::Arg> &args) {
+                              const std::vector<CallExpr::Arg> &args,
+                              std::shared_ptr<types::PartialType> part) {
+  auto getPartialArg = [&](size_t pi) -> types::TypePtr {
+    if (pi < part->args.size())
+      return part->args[pi];
+    else
+      return nullptr;
+  };
+
   std::vector<std::pair<types::TypePtr, size_t>> reordered;
   auto niGenerics = fn->ast->getNonInferrableGenerics();
   auto score = ctx->reorderNamedArgs(
       fn.get(), args,
       [&](int s, int k, const std::vector<std::vector<int>> &slots, bool _) {
-        for (int si = 0, gi = 0; si < slots.size(); si++) {
+        for (int si = 0, gi = 0, pi = 0; si < slots.size(); si++) {
           if (fn->ast->args[si].status == Param::Generic) {
             if (slots[si].empty()) {
               // is this "real" type?
@@ -275,15 +284,21 @@ int TypecheckVisitor::canCall(const types::FuncTypePtr &fn,
             }
             gi++;
           } else if (si == s || si == k || slots[si].size() != 1) {
+            // Partials
+            if (slots[si].empty() && part && part->known[si]) {
+              reordered.emplace_back(getPartialArg(pi++), 0);
+            } else {
               // Ignore *args, *kwargs and default arguments
               reordered.emplace_back(nullptr, 0);
+            }
           } else {
             reordered.emplace_back(args[slots[si][0]].value->type, slots[si][0]);
           }
         }
         return 0;
       },
-      [](error::Error, const SrcInfo &, const std::string &) { return -1; });
+      [](error::Error, const SrcInfo &, const std::string &) { return -1; },
+      part ? part->known : std::vector<char>{});
   int ai = 0, mai = 0, gi = 0, real_gi = 0;
   for (; score != -1 && ai < reordered.size(); ai++) {
     auto expectTyp = fn->ast->args[ai].status == Param::Normal
@@ -341,6 +356,8 @@ TypecheckVisitor::findMatchingMethods(const types::ClassTypePtr &typ,
       continue; // avoid overloads that have not been seen yet
     auto method = ctx->instantiate(mi, typ)->getFunc();
     int score = canCall(method, args);
+    // LOG("{}: {} {} :: {} :: {}", getSrcInfo(), method->debugString(2), args, score,
+    //     method->ast->getSrcInfo());
     if (score != -1) {
       results.push_back(mi);
     }

codon/parser/visitors/typecheck/typecheck.h

@@ -220,7 +220,8 @@ private:
   types::FuncTypePtr
   findBestMethod(const types::ClassTypePtr &typ, const std::string &member,
                  const std::vector<std::pair<std::string, types::TypePtr>> &args);
-  int canCall(const types::FuncTypePtr &, const std::vector<CallExpr::Arg> &);
+  int canCall(const types::FuncTypePtr &, const std::vector<CallExpr::Arg> &,
+              std::shared_ptr<types::PartialType> = nullptr);
   std::vector<types::FuncTypePtr>
   findMatchingMethods(const types::ClassTypePtr &typ,
                       const std::vector<types::FuncTypePtr> &methods,

stdlib/internal/internal.codon

@@ -208,11 +208,14 @@ class __internal__:
 
     def _union_call_helper(union, args, kwargs) -> Union:
         for tag, T in vars_types(union, with_index=1):
-            if hasattr(T, '__call__'):
+            if fn_can_call(T, *args, **kwargs):
-                if fn_can_call(__internal__.union_get_data(union, T), *args, **kwargs):
+                if __internal__.union_get_tag(union) == tag:
+                    return __internal__.union_get_data(union, T)(*args, **kwargs)
+            elif hasattr(T, '__call__'):
+                if fn_can_call(T.__call__, *args, **kwargs):
                     if __internal__.union_get_tag(union) == tag:
                         return __internal__.union_get_data(union, T).__call__(*args, **kwargs)
-        raise TypeError("cannot call union")
+        raise TypeError("cannot call union " + union.__class__.__name__)
 
     def union_call(union, args, kwargs):
         t = __internal__._union_call_helper(union, args, kwargs)

stdlib/internal/static.codon

@@ -15,6 +15,8 @@ def fn_arg_has_type(F, i: Static[int]):
 def fn_arg_get_type(F, i: Static[int]):
     pass
 
+@no_type_wrap
+@no_argument_wrap
 def fn_can_call(F, *args, **kwargs):
     pass
 
@@ -28,6 +30,7 @@ def fn_get_default(F, i: Static[int]):
     pass
 
 @no_type_wrap
+@no_argument_wrap
 def static_print(*args):
     pass