From a4a525b84a20dcd64d71ab6a746ab11bd97c0194 Mon Sep 17 00:00:00 2001
From: "Alex A. Naanou" <alex.nanou@gmail.com>
Date: Wed, 5 Sep 2018 02:58:15 +0300
Subject: [PATCH] lots of fixes and tweaks...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
---
 diff.js   | 43 ++++++++++++++++++++++++++++++++++++++++---
 format.js | 18 +++++++++---------
 2 files changed, 49 insertions(+), 12 deletions(-)

diff --git a/diff.js b/diff.js
index 70a13df..01ba54f 100644
--- a/diff.js
+++ b/diff.js
@@ -297,20 +297,37 @@ var LogicTypePrototype = {
 
 	__cmp__: function(obj, cmp, context){
 		return false },
+	//
+	// 	Deep compare this to obj (use Diff.cmp(..))...
+	// 	.cmp(obj)
+	// 		-> bool
+	//
+	// 	Deep compare this to obj in context (use Diff.cmp(..))...
+	// 	.cmp(obj, context)
+	// 		-> bool
+	//
+	// 	Compare this to obj using comparator cmp and an optional context context...
+	// 	.cmp(obj, cmp)
+	// 	.cmp(obj, cmp, context)
+	// 		-> bool
+	//
 	// XXX need to track loops...
+	// XXX HACK???: this uses Diff.cmp(..) in simple cases...
 	cmp: function(obj, cmp, context){
 		// XXX HACK???
-		if(arguments.length < 3){
+		if(arguments.length < 3 || !(cmp instanceof Function)){
 			return Diff.cmp(
 				cmp instanceof Function ? this : this.context(cmp),
 				obj)
 		}
 
+		/*
 		cmp = cmp || function(a, b){
 			return a === b 
 				//|| a == b 
 				|| (a.__cmp__ && a.__cmp__(b, cmp, context))
 				|| (b.__cmp__ && b.__cmp__(a, cmp, context)) }
+		//*/
 		context = context || this.context().__context__
 
 		// cache...
@@ -365,6 +382,22 @@ module.ANY =
 		function(){ return true })()
 
 
+// Null type pattern...
+//
+// 	NULL
+// 		-> pattern
+//
+// This matches null and undefined.
+//
+// NOTE: this will not match NaN (XXX revise)
+var NULL = 
+module.NULL = 
+	makeCIPattern('NULL', 
+		function(obj){ 
+			return obj === null 
+				|| obj === undefined })()
+
+
 // Bool pattern...
 //
 //	BOOL
@@ -547,6 +580,7 @@ object.makeConstructor('AND', Object.assign(new LogicType(), {
 	},
 }))
 
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
 // XXX BUG: 
 // 		CONTEXT([ANY, ANY, ANY]).cmp([1, 2, 3]) 
@@ -602,6 +636,7 @@ object.makeConstructor('LIKE', Object.assign(new VAR(), {
 				obj) },
 }))
 
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
 // TEST(func) == L iff func(L) is true.
 var TEST = 
@@ -614,6 +649,7 @@ object.makeConstructor('TEST', Object.assign(new VAR(), {
 	}
 }))
 
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
 // IN(A) == L iff A in L
 //
@@ -1266,8 +1302,9 @@ module.Types = {
 		// basic compare...
 		// XXX do we need to differentiate things like: new Number(123) vs. 123???
 		var bcmp = function(a, b, cmp){
+			// NOTE: we can't use a == b directly because of things like
+			// 		[2] == 2 -> true...
 			return a === b 
-				//|| a == b 
 				// basic patters...
 				|| a === that.ANY 
 				|| b === that.ANY 
@@ -1677,7 +1714,7 @@ Types.set('Basic', {
 	no_attributes: true,
 
 	compatible: function(obj, options){
-		return typeof(obj) != 'object' },
+		return obj === null || typeof(obj) != 'object' },
 	handle: function(obj, diff, A, B, options){
 		;(!options.keep_none && A === NONE)
 			|| (obj.A = A)
diff --git a/format.js b/format.js
index d7c3811..fb7456d 100644
--- a/format.js
+++ b/format.js
@@ -13,7 +13,7 @@
 var diff = require('./diff')
 var {
 	ANY,
-	BOOL, NUMBER, STRING, ARRAY, FUNCTION,
+	NULL, BOOL, NUMBER, STRING, ARRAY, FUNCTION,
 	OR, AND, NOT,
 	AT, OF, IN,
 	VAR, LIKE, TEST,
@@ -144,14 +144,14 @@ module.DIFF_OBJECT = AND(
 
 	// instance metadata...
 	AT('options', AND(
- 		AT('tree_diff', OR(BOOL, null)),
- 		AT('keep_none', OR(BOOL, null)),
- 		AT('min_text_length', OR(NUMBER, null)),
-		AT('no_attributes', OR(BOOL, null)),
- 		AT('NONE', OR(ANY, null)),
- 		AT('EMPTY', OR(ANY, null)),
- 		AT('no_length', OR(BOOL, null)),
- 		AT('cmp', OR(FUNCTION, null)) )),
+ 		AT('tree_diff', OR(BOOL, NULL)),
+ 		AT('keep_none', OR(BOOL, NULL)),
+ 		AT('min_text_length', OR(NUMBER, NULL)),
+		AT('no_attributes', OR(BOOL, NULL)),
+ 		AT('NONE', OR(ANY, NULL)),
+ 		AT('EMPTY', OR(ANY, NULL)),
+ 		AT('no_length', OR(BOOL, NULL)),
+ 		AT('cmp', OR(FUNCTION, NULL)) )),
 	AT('placeholders', AND(
 		// XXX would be nice to store these and to use them to test 
 		// 		deeper stuff (i.e. VALUE)...