From 739afb8dc69653d7b7d31b99724aa28e76a7df79 Mon Sep 17 00:00:00 2001
From: itsumura-h <39766805+itsumura-h@users.noreply.github.com>
Date: Sun, 5 Sep 2021 01:03:05 +0900
Subject: [PATCH] empty interface (#3)

---
 interface_implements.nimble  |  2 +-
 src/interface_implements.nim | 10 +++++++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/interface_implements.nimble b/interface_implements.nimble
index 6c3742f..824fb75 100644
--- a/interface_implements.nimble
+++ b/interface_implements.nimble
@@ -1,6 +1,6 @@
 # Package
 
-version       = "0.2.1"
+version       = "0.2.2"
 author        = "dumblepy"
 description   = "Creating toInterface macro."
 license       = "MIT"
diff --git a/src/interface_implements.nim b/src/interface_implements.nim
index b2408b7..2bc474c 100644
--- a/src/interface_implements.nim
+++ b/src/interface_implements.nim
@@ -4,6 +4,8 @@ macro implements*(implName, interfaceName, procs:untyped):untyped =
   let procsStr = procs.repr
   var tuples = ""
   for i, aProc in procs:
+    if aProc.repr == "discard":
+      break
     var args: seq[string]
     var anonimousProcArgs: seq[string]
     let procName = aProc[0]
@@ -21,7 +23,13 @@ macro implements*(implName, interfaceName, procs:untyped):untyped =
     var tupleRow = fmt"    {procName.repr}: proc({anonimousProcArgsStr}){returnType} = self.{procName.repr}({argPart})"
     if i != 0: tuples.add(",\n")
     tuples.add(tupleRow)
-  let resultStr = fmt"""proc toInterface*(self:{implName.repr}):{interfaceName.repr} =
+  let resultStr =
+    if tuples.len == 0:
+     fmt"""proc toInterface*(self:{implName.repr}):{interfaceName.repr} =
+  return ()
+"""
+    else:
+      fmt"""proc toInterface*(self:{implName.repr}):{interfaceName.repr} =
   return (
 {tuples}
   )