it is working

lib/set.zion

@@ -44,14 +44,12 @@ instance HasLength (Set a) {
 
 instance Iterable (Set a) a {
     fn iter(set Set a) fn () Maybe a {
-        let Set(inner_map) = set
-        return iter(
-            map(
-                fn (pair) {
-                    let (a, _) = pair
-                    return a
-                },
-                inner_map)) as fn () Maybe a
+      let Set(inner_map) = set
+      return iter(
+        inner_map.map(|pair| {
+          let (a, _) = pair
+          return a
+        }))
     }
 }
 

lib/std.zion

@@ -746,15 +746,15 @@ instance Iterable (Range a) a {
 
 fn compose(f, g) => fn (x) => f(g(x))
 
-fn map(f fn (a) b, iterable) fn () Maybe b {
+fn map(iterable, f fn (a) b) fn () Maybe b {
     let iterator = iter(iterable)
     return fn () => match iterator() {
         Just(x) => Just(f(x))
         Nothing => Nothing
     }
 }
 
-fn filter(f fn (a) Bool, xs_input) fn () Maybe a {
+fn filter(xs_input, f fn (a) Bool) fn () Maybe a {
     let xs = iter(xs_input)
     return fn() {
         while match xs() {

src/compiler.cpp

@@ -15,6 +15,7 @@
 #include "parse_state.h"
 #include "parser.h"
 #include "prefix.h"
+#include "tld.h"
 #include "utils.h"
 #include "zion.h"
 
@@ -252,12 +253,18 @@ std::shared_ptr<Compilation> merge_compilation(
   /* next, merge the entire set of modules into one program */
   for (const Module *module : modules) {
     /* get a list of all top-level decls */
-    std::set<std::string> bindings = get_top_level_decls(
+    std::set<std::string> maybe_not_tld_bindings = get_top_level_decls(
         module->decls, module->type_decls, module->type_classes,
         module->imports);
 
+    std::set<std::string> bindings;
+    for (auto binding: maybe_not_tld_bindings) {
+      bindings.insert(binding);
+      bindings.insert(tld::tld(binding));
+    }
     const Module *module_rebound = prefix(bindings, module);
 
+
     /* now all locally referring vars are fully qualified */
     for (const Decl *decl : module_rebound->decls) {
       program_decls.push_back(decl);

src/main.cpp

@@ -1301,6 +1301,7 @@ int run_job(const Job &job) {
     ship_assert(!zion::tld::is_tld_type("copy"));
     ship_assert(zion::tld::is_tld_type("::copy::Copy"));
     ship_assert(!zion::tld::is_tld_type("::copy::copy"));
+    ship_assert(tld::split_fqn("::inc").size() == 1);
 
     return EXIT_SUCCESS;
   };

src/parser.cpp

@@ -538,15 +538,21 @@ const Expr *parse_var_ref(ParseState &ps) {
     return var_ref;
   } else {
     /* we know that this was declared as a "var", so let's just automatically
-     * load it for the user. if they want to treat is as a ref, then they need
-     * to preface it with & */
-    return new Application(new Var(Identifier{tld::mktld("std", "load_value"), id.location}),
-                           {var_ref});
+     * load it for the user. */
+    return new Application(
+        new Var(Identifier{tld::mktld("std", "load_value"), id.location}),
+        {var_ref});
   }
 }
 
 const Expr *parse_base_expr(ParseState &ps) {
-  if (ps.token.tk == tk_lparen) {
+  if (ps.token.tk == tk_dot) {
+    auto iid = gensym(ps.token.location);
+    return new Lambda(
+        {iid}, {type_variable(ps.token.location)},
+        type_variable(ps.token.location),
+        new ReturnStatement(parse_postfix_chain(ps, new Var(iid))));
+  } else if (ps.token.tk == tk_lparen) {
     return parse_tuple_expr(ps);
   } else if (ps.token.is_ident(K(new))) {
     return parse_new_expr(ps);
@@ -1099,51 +1105,57 @@ const Expr *parse_literal(ParseState &ps) {
   }
 }
 
-const Expr *parse_postfix_expr(ParseState &ps) {
-  const Expr *expr = parse_base_expr(ps);
+const Expr *parse_application(ParseState &ps,
+                              const Expr *expr,
+                              std::vector<const Expr *> args) {
+  /* function call or implicit partial application (implicit lambda) */
+  auto location = ps.token.location;
+  ps.advance();
+  if (ps.token.tk == tk_rparen) {
+    ps.advance();
+    if (args.size() == 0) {
+      args.push_back(unit_expr(ps.token.location));
+    }
+    return new Application(expr, args);
+  } else {
+    while (ps.token.tk != tk_rparen) {
+      args.push_back(parse_expr(ps, true /*allow_for_comprehensions*/));
+      if (ps.token.tk == tk_comma) {
+        ps.advance();
+      } else {
+        expect_token(tk_rparen);
+      }
+    }
+    expr = new Application(expr, args);
 
-  while (!ps.line_broke() &&
-         (ps.token.tk == tk_lsquare || ps.token.tk == tk_lparen ||
-          ps.token.tk == tk_dot || ps.token.tk == tk_bang)) {
+    chomp_token(tk_rparen);
+  }
+  return expr;
+}
+
+const Expr *parse_postfix_chain(ParseState &ps, const Expr *expr) {
+  while (ps.token.tk == tk_dot ||
+         (!ps.line_broke() &&
+          (ps.token.tk == tk_lsquare || ps.token.tk == tk_lparen ||
+           ps.token.tk == tk_bang))) {
     switch (ps.token.tk) {
     case tk_bang:
       expr = new As(expr, type_unit(ps.token_and_advance().location),
                     true /*force_cast*/);
       break;
     case tk_lparen: {
-      /* function call or implicit partial application (implicit lambda) */
-      auto location = ps.token.location;
-      ps.advance();
-      if (ps.token.tk == tk_rparen) {
-        ps.advance();
-        expr = new Application(expr, {unit_expr(ps.token.location)});
-      } else {
-        std::vector<const Expr *> callsite_refs;
-        for (int index = 0; ps.token.tk != tk_rparen; ++index) {
-          callsite_refs.push_back(
-              parse_expr(ps, true /*allow_for_comprehensions*/));
-          if (ps.token.tk == tk_comma) {
-            ps.advance();
-          } else {
-            expect_token(tk_rparen);
-          }
-        }
-        expr = new Application(expr, {callsite_refs});
-
-        chomp_token(tk_rparen);
-      }
+      expr = parse_application(ps, expr, {});
       break;
     }
     case tk_dot: {
       ps.advance();
       expect_token(tk_identifier);
-      if (!islower(ps.token.text[0])) {
-        throw user_error(
-            ps.token.location,
-            "property accessors must start with lowercase letters");
+      auto iid = tld::tld(ps.identifier_and_advance());
+      if (!ps.line_broke() && ps.token.tk == tk_lparen) {
+        expr = parse_application(ps, new Var(iid), {expr});
+      } else {
+        expr = new Application(new Var(iid), {expr});
       }
-      auto iid = ps.identifier_and_advance();
-      expr = new Application(new Var(iid), {expr});
       break;
     }
     case tk_lsquare: {
@@ -1169,13 +1181,15 @@ const Expr *parse_postfix_expr(ParseState &ps) {
           auto location = ps.token_and_advance().location;
           auto rhs = parse_expr(ps, false /*allow_for_comprehensions*/);
           expr = new Application(
-              new Var(Identifier{tld::mktld("std", "set_indexed_item"), location}),
+              new Var(
+                  Identifier{tld::mktld("std", "set_indexed_item"), location}),
               {expr, start, rhs});
         } else {
           expr = new Application(
-              new Var(Identifier{tld::mktld("std", is_slice ? "get_slice_from"
-                                                       : "get_indexed_item"),
-                                 ps.token.location}),
+              new Var(
+                  Identifier{tld::mktld("std", is_slice ? "get_slice_from"
+                                                        : "get_indexed_item"),
+                             ps.token.location}),
               {expr, start});
         }
       } else {
@@ -1184,8 +1198,8 @@ const Expr *parse_postfix_expr(ParseState &ps) {
 
         assert(is_slice);
         expr = new Application(
-            new Var(ps.id_mapped(
-                Identifier{tld::mktld("std", "get_slice_from_to"), ps.token.location})),
+            new Var(ps.id_mapped(Identifier{
+                tld::mktld("std", "get_slice_from_to"), ps.token.location})),
             {expr, start, stop});
       }
       break;
@@ -1198,6 +1212,12 @@ const Expr *parse_postfix_expr(ParseState &ps) {
   return expr;
 }
 
+const Expr *parse_postfix_expr(ParseState &ps) {
+  const Expr *expr = parse_base_expr(ps);
+
+  return parse_postfix_chain(ps, expr);
+}
+
 const Expr *parse_cast_expr(ParseState &ps) {
   const Expr *expr = parse_postfix_expr(ps);
   while (!ps.line_broke() && ps.token.is_ident(K(as))) {

src/parser.h

@@ -76,6 +76,7 @@ const ast::Predicate *parse_predicate(ParseState &ps,
                                       bool allow_else,
                                       maybe<Identifier> name_assignment,
                                       bool allow_var_refs = true);
+const ast::Expr *parse_postfix_chain(ParseState &ps, const ast::Expr *expr);
 const ast::Predicate *unfold_application_into_predicate(
     const ast::Application *application);
 const ast::Predicate *convert_expr_to_predicate(const ast::Expr *expr);

src/prefix.cpp

@@ -11,7 +11,8 @@ using namespace ast;
 std::string prefix(const std::set<std::string> &bindings,
                    std::string pre,
                    std::string name) {
-  if (tld::split_fqn(name).size() > 1) {
+  auto names = tld::split_fqn(name);
+  if (names.size() > 1) {
     return name;
   }
 

src/tld.cpp

@@ -24,7 +24,11 @@ std::string mktld(std::string module, std::string name) {
   } else if (starts_with(name, PTR_TYPE_OPERATOR)) {
     return name;
   } else {
-    return tld(module + SCOPE_SEP + name);
+    if (starts_with(name, SCOPE_SEP)) {
+      return tld(module + name);
+    } else {
+      return tld(module + SCOPE_SEP + name);
+    }
   }
 }
 

tests/test_bad_instance.zion

@@ -1,5 +1,5 @@
 # test: fail
-# expect: type error. Int != string.String
+# expect: type error. Int != ::string::String
 
 class Foo a {
   fn foo(a) Int

tests/test_chaining_function_calls.zion

@@ -0,0 +1,11 @@
+# test: pass, noprelude
+# expect: 12
+
+fn multiply(x, y) {
+  return __builtin_multiply_int(x, y)
+}
+
+fn main() {
+  let multiply = 3
+  __builtin_print_int(multiply.multiply(4))
+}

tests/test_chaining_multiple.zion

@@ -0,0 +1,6 @@
+# test: pass
+# expect: 4:5:6:7
+
+fn main() {
+  ":".join([4, 5, 6, 7]).print
+}

tests/test_eq_ptrs.zion

@@ -1,6 +1,6 @@
 # test: fail
 # expect: could not find a definition for
-# expect: std.==
+# expect: ::std::==
 
 data NonComparable {
     Monkey

tests/test_euler_02.zion

@@ -10,25 +10,25 @@ struct FibonacciIterator {
 }
 
 fn fibonacci_sequence() {
-    let fs = FibonacciIterator(Ref(0), Ref(1), Ref(1))
-    return fn () {
-        fs.index += 1
-        if !fs.index > 2 {
-            let next = !fs.prior + !fs.cur
-            fs.prior = !fs.cur
-            fs.cur = next
-        }
-        return Just(!fs.cur)
+  let fs = FibonacciIterator(Ref(0), Ref(1), Ref(1))
+  return fn () {
+    fs.index += 1
+    if !fs.index > 2 {
+      let next = !fs.prior + !fs.cur
+      fs.prior = !fs.cur
+      fs.cur = next
     }
+    return Just(!fs.cur)
+  }
 }
 
 fn main() {
-    var total = 0
-    for n in filter(even, fibonacci_sequence()) {
-        if n > 4000000 {
-            break
-        }
-        total += n
+  var total = 0
+  for n in fibonacci_sequence().filter(even) {
+    if n > 4000000 {
+      break
     }
-    print(total)
+    total += n
+  }
+  print(total)
 }

tests/test_illegal_imports.zion

@@ -1,5 +1,5 @@
 # test: fail
-# expect: map.needs_to_grow is not exported or does not exist
+# expect: ::map::needs_to_grow is not exported or does not exist
 
 import map {needs_to_grow}
 

tests/test_import_unexported_class.zion

@@ -1,5 +1,5 @@
 # test: fail
-# expect: error. test_utils.UnexportedClass is not exported or does not exist
+# expect: error. ::test_utils::UnexportedClass is not exported or does not exist
 
 import test_utils {UnexportedClass}
 

tests/test_iter_filter.zion

@@ -4,7 +4,7 @@
 import math {sum}
 
 fn main() {
-    let filtered_sum = |xs| => sum(filter(|x| => x > 2, xs))
+    let filtered_sum = .filter(|x| => x > 2).sum
     let a = filtered_sum([1, 2, 3, 4])
     let b = sum(x for x in [1..4] if x > 2)
     assert(a == b)

tests/test_iter_map.zion

@@ -4,5 +4,8 @@
 import math {sum}
 
 fn main() {
-    print(sum(map(fn (x Int) Float { return from_int(x + 1) }, [1, 2, 3])))
+  [1, 2, 3]
+    .map(|x| Float => from_int(x + 1))
+    .sum
+    .print
 }

tests/test_let_destructuring_var.zion

@@ -1,6 +1,6 @@
 # test: pass
 # expect: 2
-# expect: the type is std.Ref Int
+# expect: the type is ::std::Ref Int
 
 newtype N = N(var Int)
 

tests/test_ord_int_compare.zion

@@ -1,5 +1,5 @@
 # test: pass
-# expect: the type is std.Ordering
+# expect: the type is ::std::Ordering
 # expect: PASS
 
 fn main() {