crystal-lang · Sep 16, 2016 · Sep 16, 2016 · Sep 16, 2016
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,18 @@
+## 0.19.2  (16-09-2016)
+
+* Generic type variables no longer need to be single-letter names (for example `class Gen(Foo)` is now possible)
+* Added syntax to denote free variables: `def foo(x : T) forall T`. The old rule of single-letter name still applies but will be removed in the future.
+* Removed the restriction that top-level types and constants can't have single-letter names
+* Added `@[Extern]` attribute to mark regular Crystal structs as being able to be used in C bindings
+* Faster `Char#to_s` when it's ASCII: this improves the performance of JSON and CSV parsing
+* `crystal spec`: allow passing `--release` and other options
+* `crystal spec`: allow running all specs in a given directory
+* `crystal playground`: support custom workbook resources (thanks @bcardiff)
+* `crystal playground`: standard output now understands ANSI colors (thanks @bcardiff)
+* Added many more macro methods to traverse AST nodes (thanks @BlaXpirit)
+* Error messages no longer include a type trace by default, pass `--error-trace` to show the full trace (the trace is often useless and makes it harder to understand error messages)
+* [Several bug fixes](https://github.com/crystal-lang/crystal/issues?q=is%3Aclosed+milestone%3A0.19.2)
+
 ## 0.19.1  (09-09-2016)
 
 * Types (class, module, etc.) can now be marked as `private`.

diff --git a/spec/compiler/semantic/def_overload_spec.cr b/spec/compiler/semantic/def_overload_spec.cr
@@ -921,4 +921,27 @@ describe "Semantic: def overload" do
       {foo(1), foo(nil)}
       )) { tuple_of([char, bool]) }
   end
+
+  it "errors when binding free variable to different types" do
+    assert_error %(
+      def foo(x : T, y : T) forall T
+      end
+
+      foo(1, 'a')
+      ),
+      "no overload matches"
+  end
+
+  it "errors when binding free variable to different types (2)" do
+    assert_error %(
+      class Gen(T)
+      end
+
+      def foo(x : T, y : Gen(T)) forall T
+      end
+
+      foo(1, Gen(Char).new)
+      ),
+      "no overload matches"
+  end
 end
diff --git a/spec/compiler/semantic/macro_spec.cr b/spec/compiler/semantic/macro_spec.cr
@@ -908,4 +908,14 @@ describe "Semantic: macro" do
       ->{ foo }.call
       )) { int32 }
   end
+
+  it "finds var in proc for macros" do
+    assert_type(%(
+      macro foo(x)
+        {{x}}
+      end
+
+      ->(x : Int32) { foo(x) }.call(1)
+      )) { int32 }
+  end
 end
diff --git a/src/compiler/crystal/semantic/match.cr b/src/compiler/crystal/semantic/match.cr
@@ -63,6 +63,11 @@ module Crystal
       free_vars[name] = type
     end
 
+    def has_def_free_var?(name)
+      return false if get_free_var(name)
+      !!(@def_free_vars.try &.includes?(name))
+    end
+
     # Returns the type that corresponds to using `self` when looking
     # a type relative to this context.
     #

diff --git a/src/compiler/crystal/semantic/restrictions.cr b/src/compiler/crystal/semantic/restrictions.cr
@@ -347,7 +347,7 @@ module Crystal
       single_name = other.names.size == 1
       if single_name
         first_name = other.names.first
-        if context.def_free_vars.try(&.includes?(first_name))
+        if context.has_def_free_var?(first_name)
           return context.set_free_var(first_name, self)
         end
       end
@@ -835,7 +835,7 @@ module Crystal
       single_name = other.names.size == 1
       if single_name
         first_name = other.names.first
-        if context.def_free_vars.try(&.includes?(first_name))
+        if context.has_def_free_var?(first_name)
           return context.set_free_var(first_name, self)
         end
       end

diff --git a/src/compiler/crystal/semantic/top_level_visitor.cr b/src/compiler/crystal/semantic/top_level_visitor.cr
@@ -642,7 +642,19 @@ class Crystal::TopLevelVisitor < Crystal::SemanticVisitor
   end
 
   def visit(node : ProcLiteral)
+    old_vars_keys = @vars.keys
+
+    node.def.args.each do |arg|
+      @vars[arg.name] = MetaVar.new(arg.name)
+    end
+
     node.def.body.accept self
+
+    # Now remove these vars, but only if they weren't vars before
+    node.def.args.each do |arg|
+      @vars.delete(arg.name) unless old_vars_keys.includes?(arg.name)
+    end
+
     false
   end