Merge pull request #2723 from crystal-lang/feature/macro_flag

Macros: add `flag?` method. Part of #2710
crystal-lang · Jun 2, 2016 · 5fcfdd7 · 5fcfdd7
2 parents 36ab7e8 + bf1d25f
commit 5fcfdd7
Showing 3 changed files with 26 additions and 3 deletions.
diff --git a/spec/compiler/macro/macro_methods_spec.cr b/spec/compiler/macro/macro_methods_spec.cr
@@ -989,4 +989,14 @@ describe "macro methods" do
       assert_macro "", %({{env("FOO")}}), [] of ASTNode, %(nil)
     end
   end
+
+  describe "flag?" do
+    it "has flag" do
+      assert_macro "", %({{flag?(:foo)}}), [] of ASTNode, %(true), flags: "foo"
+    end
+
+    it "doesn't have flag" do
+      assert_macro "", %({{flag?(:foo)}}), [] of ASTNode, %(false)
+    end
+  end
 end
diff --git a/spec/spec_helper.cr b/spec/spec_helper.cr
@@ -231,12 +231,13 @@ def assert_error(str, message, inject_primitives = true)
   end
 end
 
-def assert_macro(macro_args, macro_body, call_args, expected)
-  assert_macro(macro_args, macro_body, expected) { call_args }
+def assert_macro(macro_args, macro_body, call_args, expected, flags = nil)
+  assert_macro(macro_args, macro_body, expected, flags) { call_args }
 end
 
-def assert_macro(macro_args, macro_body, expected)
+def assert_macro(macro_args, macro_body, expected, flags = nil)
   program = Program.new
+  program.flags = flags if flags
   sub_node = yield program
   assert_macro_internal program, sub_node, macro_args, macro_body, expected
 end

diff --git a/src/compiler/crystal/macros/methods.cr b/src/compiler/crystal/macros/methods.cr
@@ -9,6 +9,8 @@ module Crystal
         interpret_debug
       when "env"
         interpret_env(node)
+      when "flag?"
+        interpret_flag?(node)
       when "puts", "p"
         interpret_puts(node)
       when "pp"
@@ -40,6 +42,16 @@ module Crystal
       end
     end
 
+    def interpret_flag?(node)
+      if node.args.size == 1
+        node.args[0].accept self
+        flag = @last.to_macro_id
+        @last = BoolLiteral.new(@mod.has_flag?(flag))
+      else
+        node.wrong_number_of_arguments "macro call 'flag?'", node.args.size, 1
+      end
+    end
+
     def interpret_puts(node)
       node.args.each do |arg|
         arg.accept self