release: the macro

haxelib.json

@@ -7,9 +7,9 @@
     "externs"
   ],
   "description": "Create neovim plugins using Haxe",
-  "version": "0.2.2",
+  "version": "0.2.3",
   "classPath": "src/",
-  "releasenote": "better user arguments support",
+  "releasenote": "macro for easier plugin integration",
   "contributors": [
     "danielo515"
   ],

src/vim/plugin/Plugin.hx

@@ -1,12 +1,12 @@
 package vim.plugin;
 
-import lua.Lua;
-
-inline function load< T >(pluginName:String):Option< T > {
-  final requireResult = Lua.pcall(Lua.require, pluginName);
-  if (requireResult.status) {
-    return Some(requireResult.value);
-  } else {
-    return None;
-  }
+@:autoBuild(vim.plugin.PluginMacro.pluginInterface())
+interface VimPlugin {
+  /*
+    This is an empty interface that is used to attach the @:autoBuild
+    to classes that implement it.  The @:autoBuild macro will generate
+    the required require code to load the plugin safely.
+    The implementing class must have a field named libName, which will be used 
+    in the generated require function.
+   */
 }

src/vim/plugin/PluginMacro.hx

@@ -0,0 +1,38 @@
+package vim.plugin;
+
+using haxe.macro.TypeTools;
+
+import haxe.macro.Context;
+import haxe.macro.Expr;
+
+class PluginMacro {
+  macro static public function pluginInterface():Array< Field > {
+    final fields = Context.getBuildFields();
+    final localType = Context.getLocalType().toComplexType();
+    final returnType = macro :$localType;
+    final newFields = [for (field in fields) {
+      switch field {
+        case {name: "libName", kind: FVar(_, {expr: EConst(CString(val, _))})}:
+          final built = macro class X {
+            inline static public function require():Null< $returnType > {
+              final module = lua.Lua.pcall(lua.Lua.require, $v{val});
+              final value = if (module.status) {
+                module.value;
+              } else {
+                null;
+              };
+              return value;
+            }
+          };
+          built.fields[0];
+
+        case _:
+          continue;
+      }
+    }];
+    if (newFields.length == 0) {
+      Context.error("No libName field found in plugin interface", Context.currentPos());
+    }
+    return fields.concat(newFields);
+  }
+}