repl: add mode detection, cli persistent history

this creates a new internal module responsible for providing
the repl created via "iojs" or "iojs -i," and adds the following
options to the readline and repl subsystems:

* "repl mode" - determine whether a repl is strict mode, sloppy mode,
  or auto-detect mode.
* historySize - determine the maximum number of lines a repl will store
  as history.

The built-in repl gains persistent history support when the
NODE_REPL_HISTORY_FILE environment variable is set. This functionality
is not exposed to userland repl instances.

PR-URL: https://github.com/iojs/io.js/pull/1513
Reviewed-By: Fedor Indutny <fedor@indutny.com>

1 files changed, 12 insertions, 9 deletions

diff --git a/lib/module.js b/lib/module.js
index eba3de8171..515ab6789c 100644
--- a/lib/module.js
+++ b/lib/module.js
@@ -273,6 +273,17 @@ Module._load = function(request, parent, isMain) {
     debug('Module._load REQUEST  ' + (request) + ' parent: ' + parent.id);
   }
 
+  // REPL is a special case, because it needs the real require.
+  if (request === 'internal/repl' || request === 'repl') {
+    if (Module._cache[request]) {
+      return Module._cache[request];
+    }
+    var replModule = new Module(request);
+    replModule._compile(NativeModule.getSource(request), `${request}.js`);
+    NativeModule._cache[request] = replModule;
+    return replModule.exports;
+  }
+
   var filename = Module._resolveFilename(request, parent);
 
   var cachedModule = Module._cache[filename];
@@ -281,14 +292,6 @@ Module._load = function(request, parent, isMain) {
   }
 
   if (NativeModule.nonInternalExists(filename)) {
-    // REPL is a special case, because it needs the real require.
-    if (filename == 'repl') {
-      var replModule = new Module('repl');
-      replModule._compile(NativeModule.getSource('repl'), 'repl.js');
-      NativeModule._cache.repl = replModule;
-      return replModule.exports;
-    }
-
     debug('load native module ' + request);
     return NativeModule.require(filename);
   }
@@ -502,7 +505,7 @@ Module._initPaths = function() {
 
 // bootstrap repl
 Module.requireRepl = function() {
-  return Module._load('repl', '.');
+  return Module._load('internal/repl', '.');
 };
 
 Module._initPaths();