Fixed symbol evaluation to actually lookup variables. Updated README.

README

@@ -14,10 +14,9 @@ Latest version available on github:
 (or "You must be kidding")
 ==========================
 
-I'm not 100% sure why I think this might be useful to somebody.  The
-idea of editing code directly on github or bitbucket in a web browser
-is pretty cool though, and if you're going to do such a thing why not
-use the best tools available.  IMO those tools are written in Emacs
+The idea of editing code directly on github or bitbucket in a web
+browser is pretty cool, and if you're going to do such a thing why not
+use the best tools available?  IMO those tools are written in Emacs
 Lisp so I would like to use them in the browser.  Maybe with some
 HTML5 offline goodness thrown in.
 
@@ -25,84 +24,77 @@ Seeing Ymacs[1] in action[2] was also an inspiration to start this
 project as I've had it on my TODO list for several months now.  Emacs
 in the browser could be a reality; Ymacs is proof.
 
+With Palm's release of "Project Ares"[3] the need for such tools is
+beginning to be a reality.  I'm no longer that uncertain why such a
+beast would be useful.  The question now is whether using something
+like Google's Native Client and original C version of Emacs is the way
+to go, or if a slower implementation in JavaScript is feasible for
+real use.
+
 [1] http://www.ymacs.org/
 [2] http://www.ymacs.org/demo/
+[3] http://pdnblog.palm.com/2009/12/project-ares-open-beta/
+[4] http://code.google.com/p/nativeclient/
 
 
 Getting Started
 ===============
 
-Command line
-------------
+I'm currently using CommonJS via Narwhal[1] with the JavaScriptCore
+engine.  I've run the tests under v8 as well and they all pass, but
+not everything is tested by any means.
 
-If you have rlwrap and js then just run el.sh.  If not install a
-JavaScript shell of your choice, and I recommend you install rlwrap
-(readline wrap).  Edit el.sh to reflect whether or not you use rlwrap
-and your shell's name or path.  Then run el.sh.  I've only run this
-under SpiderMonkey so I have no idea if it works under any other
-implementations.  Glad to accept info and/or patches.
+[1] http://narwhaljs.org/
+
+If you have rlwrap and narwhal then just run elisp.sh.  If not install
+a JavaScript shell of your choice, and I recommend you install rlwrap
+(readline wrap).  Edit elisp.sh to reflect whether or not you use
+rlwrap and your shell's name or path, and then run elisp.sh.
 
 Type a 'Q' or 'q' to quit the repl.  Or anything that starts with Q,
 like 'quickly quit lisp!'.  (If lisp freaks out because you entered ^D
 or something ^C or ^Z should still get you out.)
 
-
-Emacs
------
-
-I use Emacs and js-comint.el[3] with inferior-js set to
-/opt/local/bin/js, which is SpiderMonkey[4] from MacPorts[5] on Snow
-Leopard.
-
-[3] http://js-comint-el.sourceforge.net/
-[4] http://www.mozilla.org/js/spidermonkey/
-[5] http://www.macports.org/
-
-For loading code C-c b sends the buffer to the JS repl.  I also use
-the EL.rep (read-eval-print), EL.parse, EL.eval, and EL.print
-functions defined in el/repl.js
-
 Here's an example:
 
 % cd Projects/elisp.js
-% rlwrap js
-js> load('el.js')
-elisp> 
+% ./elisp.sh
+elisp>
 (defvar *directory* "/Users/sjs" "My home directory")
+nil
 elisp>
 *directory*
-["string", "/Users/sjs"]
+"/Users/sjs"
 elisp> 
 (setq foo 1 bar 2 baz 3)
-["number", 3]
+3
 elisp> 
 (/ (+ foo bar baz) 3)
-["number", 2]
+2
 elisp> 
 (string-match "[a-z]lurgh" (symbol-name 'foo-blurgh))
-["number", 4]
+4
 elisp> 
 q
-js> 
+% 
 
-(If you know how to print without a trailing newline in SpiderMonkey
+(If you know how to print without a trailing newline in JavaScript
  please let me know.)
 
 There are other interfaces into the parser and evaluator besides the
-shortcuts.  new EL.Parser([input]) returns a parser object and likewise
-new EL.Evaluator([exprs]) returns an evaluator object.
+shortcuts.  new elisp.parser.Parser([input]) returns a parser object
+and likewise new elisp.evaluator.Evaluator([exprs]) returns an
+evaluator object.
 
 Mainly toy functions that do extremely simple operations on numbers
 and strings can be implemented right now.  Stay tuned, or better yet
-hack away and submit a pull request on github[6].
-
-[6] http://github.com/samsonjs/elisp.js
+hack away and submit a pull request on github.
 
 
 What's here?
 ============
 
-Not much compared to the real thing but it's a decent start for < 1000
+Not much compared to the real thing but it's a decent start for 1500
 lines.
 
  * parser/reader. there's no lexing to tokens we go straight to tagged
@@ -115,7 +107,7 @@ lines.
 
  * expression evaluator
 
- * simple tagged primitive types
+ * primitive types
    (string, symbol, lambda, number, cons)
 
  * special forms for defvar, defun, set, setq, if, and quote
@@ -124,6 +116,3 @@ lines.
 
  * a few primitive math ops
    (thanks to JS' overloading + works on strings too)
-
- * 2 horrible print functions
-   (JS "pretty" printer & a half-assed Lisp print)

elisp/evaluator.js

@@ -58,7 +58,6 @@ Evaluator.prototype.evalExpressions = function(expressions) {
 	    }
 	}
     }
-//     Utils.pp(result);
     return result;
 };
 
@@ -84,13 +83,10 @@ Evaluator.prototype.apply = function(func, args) {
 	this.functions.pushScope();
 	this.variables.pushScope(func.params.map(function(e, i){
 		var name = e.symbolName(),
-		    value = {
-			type: 'variable',
-			value: this.eval(args[i])
-		    };
-                return [name, value];
-	    }));
-	result = func.body.map(function(e) {return this.eval(e); }).last();
+		    value = this.eval(args[i]);
+                return [name, {type:'variable', value:value}];
+	    }).unlist());
+	result = this.evalExpressions(func.body);
 	this.functions.popScope();
 	this.variables.popScope();
     }
@@ -102,7 +98,7 @@ Evaluator.prototype.eval = function(expr) {
     //utils.pp(expr);
     var result, x,
 	tag = expr.tag();
-    if (expr.isAtom()) {
+    if (expr.isString() || expr.isNumber()) {
 	result = expr;
     }
     else if (expr.isSymbol()) {
@@ -121,9 +117,9 @@ Evaluator.prototype.eval = function(expr) {
 	result = expr.cdr();
     }
     else if (expr.isDefvar()) {
-	var name = expr.cadr().symbolName(),   // 2nd param
-	    value = this.eval(expr.caddr()),   // 3rd param
-	    docstring = expr.cadddr();         // 4th param
+	var name = expr.nth(1).symbolName(),
+	    value = this.eval(expr.nth(2)),
+	    docstring = expr.nth(3);
 	// TODO check for re-definitions
 	this.defineVar(name, value, docstring);
 	result = type.NIL;
@@ -138,8 +134,8 @@ Evaluator.prototype.eval = function(expr) {
 	result = type.NIL;
     }
     else if (expr.isSet()) {
-	var name = expr.car().symbolName(),
-	    value = this.eval(expr.cdr());
+	var name = expr.nth(1).symbolName(),
+	    value = this.eval(expr.nth(2));
 	this.setVar(name, value);
 	result = value;
     }
@@ -188,10 +184,12 @@ Evaluator.prototype.eval = function(expr) {
 	    result = this.apply(func, args);
 	}
 	else {
+	    result = type.NIL;
 	    this.error('undefined-func', name);
 	}
     }
     else {
+	result = type.NIL;
 	this.error('not-expr', expr);
     }
 //     print('RESULT: ' + result);

elisp/list.js

@@ -30,15 +30,15 @@ LispCons.prototype.cdr = function() {
 };
 
 LispCons.prototype.cadr = function() {
-    return this.cdr().car();
+    return this.nth(1);
 };
 
 LispCons.prototype.caddr = function() {
-    return this.cdr().cdr().car();
+    return this.nth(2);
 };
 
 LispCons.prototype.cadddr = function() {
-    return this.cdr().cdr().cdr().car();
+    return this.nth(3);
 };
 
 LispCons.prototype.length = function() {
@@ -60,7 +60,6 @@ LispCons.prototype.map = function(fn) {
     var list = [],
 	i = 0,
 	cons = this;
-//    print('[LispCons.map] calling cons.isNil - cons: ' + cons + ' - _car: ' + cons._car + ' _cdr: ' + this._cdr);
     while (!cons.isNil()) {
 	list.push(fn(cons.car(), i));
 	cons = cons.cdr();
@@ -79,7 +78,7 @@ LispCons.prototype.reduce = function(accum, fn) {
 };
 
 LispCons.prototype.unlist = function() {
-    return this.reduce([], function(x){return x;});
+    return this.reduce([], function(acc, x){acc.push(x); return acc;});
 };
 
 LispCons.prototype.nth = function(n) {
@@ -92,7 +91,7 @@ LispCons.prototype.nth = function(n) {
 	cons = cons.cdr();
 	++i;
     }
-    return n > --i ? type.NIL : e;
+    return n > (i-1) ? type.NIL : e;
 };
 
 LispCons.prototype.nthcdr = function(n) {

elisp/repl.js

@@ -60,7 +60,6 @@ var repl = function() {
 	} catch (x) {
 	    if (x.evalError) {
 		print('[error] ' + x.message + ': ' + x.expression);
-		utils.pp(x);		
 	    }
 	    else throw(x);
 	}

elisp/symtab.js

@@ -39,6 +39,7 @@ SymbolTable.prototype.lookup = function(name) {
 // store the given symbol/value pair in the symbol table at the current level.
 SymbolTable.prototype.define = function(name, value) {
 //    print('###### REAL DEFINE: ' + name + ' = ' + value);
+//    print('           (TYPES): ' + utils.typeOf(name) + ' = ' + utils.typeOf(value));
     if (value === undefined && utils.typeOf(name) == 'array') {	
 	var bindings = name,
 	    i = 0,

elisp/types.js

@@ -218,7 +218,7 @@ var inferType = function(exprs) {
     var type_name = 'number',
         initial = 0,
         i = exprs.length-1;
-    while(i >= 0) {
+    while (i >= 0) {
 	if (!exprs[i--].isNumber()) {
 	    type_name = 'string';
 	    initial = '';

elisp/utils.js

@@ -69,7 +69,11 @@ var pp = function(x, toString) {
 	s = '';
     }
     else if (!x.repr) {
-	s = '[UNKNOWN VALUE: ' + x + ']'; // what are you?!
+	s = '[UNKNOWN VALUE: ' + x + ' = {\n'; // what are you?!
+	for (var y in x) {
+	    s += '    ' + y + ': ' + x[y] + "\n";
+	}
+	s += '}';
     }
     else {
 	s = x.repr();