Successful conversion to lists. Yay.

Makefile

@@ -1,7 +1,4 @@
-lib/lisp_parser.js: lib/lisp_parser.peg
-	node_modules/.bin/pegjs $< $@
-
-tests: lib/lisp_parser.js
+tests: 
 	node_modules/.bin/coffee bin/lisp test.scm
 
 

lib/eval.coffee

@@ -1,17 +1,16 @@
 lookup = require './lookup'
-{car, cdr} = require './lists'
+{car, cdr, cadr, caadr, cdadr} = require './lists'
 
 lispeval = (element, scope) ->
 
-  switch element.type
-    when 'number' then parseInt(element.value, 10)
-    when 'symbol'
-      lookup(scope, element.value)
+  switch (car element)
+    when 'number' then parseInt (cadr element), 10
+    when 'symbol' then lookup scope, (cadr element)
     when 'list'
-      proc = lispeval((car element.value), scope)
-      args = (cdr element.value)
+      proc = lispeval (caadr element), scope
+      args = cdadr element
       proc args, scope
-    else throw new Error ("Unrecognized type in parse: #{element.type}")
+    else throw new Error ("Unrecognized type in parse: #{(car element)}")
 
 module.exports = lispeval
 

lib/fn.coffee

@@ -4,19 +4,33 @@ lispeval = require './eval'
 module.exports = 
   create_vm_expression_evaluator: (defining_scope, params, body) ->
     (cells, scope) ->
-      args = listToVector(cells).map (i) -> lispeval i, scope
+      args = (amap = (cells, accum) ->
+        return accum if nilp cells
+        amap((cdr cells), accum.concat(lispeval (car cells), scope)))(cells, [])
       body.apply null, args
 
   create_lisp_expression_evaluator: (defining_scope, params, body) ->
     (cells, scope) ->
+
+      # Takes the current scope, which has been passed in during the
+      # execution phase, and evaluate the contents of the parameters
+      # in the context in which this call is made (i.e. when the
+      # function is *called*, rather than defined.
+
       new_scope = (cmap = (cells, params, nscope) ->
         return nscope if (nilp cells) or (nilp params)
         nscope[(car params)] = lispeval (car cells), scope
         cmap((cdr cells), (cdr params), nscope))(cells, params, {})
-      inner = cons(new_scope, defining_scope)
+
+      # Execute and evaluate the body, creating an inner scope that
+      # consists of all the bound variables (the parameters) evaluated
+      # in the context of the function call, and all of free variables
+      # evaluated in the context of the defining scope.
+
+      inner_scope = cons(new_scope, defining_scope)
       (nval = (body, memo) ->
         return memo if nilp body
-        nval((cdr body), lispeval((car body), inner)))(body)
+        nval((cdr body), lispeval((car body), inner_scope)))(body)
 
   create_special_form_evaluator: (defining_scope, params, body) ->
     (cells, scope) -> body(cells, scope)

lib/lisp.coffee

@@ -2,16 +2,15 @@ fs = require 'fs'
 {readForms} = require './reader'
 lispeval = require './eval'
 scope = require './scope'
-{car, cdr, nilp} = require './lists'
+{car, cdr, nilp, cadr} = require './lists'
 
 module.exports =
   run: (pathname) ->
     text = fs.readFileSync(pathname, 'utf8')
-    root = scope
     ast = readForms(text)
     (nval = (body, memo) ->
       return memo if nilp body
-      nval((cdr body), lispeval((car body), root)))(ast.value)
+      nval((cdr body), lispeval((car body), scope)))(cadr ast)
 
 
     

lib/lisp_parser.peg

@@ -1,34 +0,0 @@
-lisp
-    = cell*
-
-cell
-    = _* datum:datum _*
-    { return datum }
-
-datum
-    = list / boolean / number / symbol
-
-list
-    = "(" items:cell* ")"
-    { return { type: "list", value: items } }
-
-boolean
-    = b:("#t" / "#f")
-    { return { type: 'boolean', value: b } }
-
-delim
-    = paren / _
-
-number
-    = b:( [0-9]+ )
-    { return { type: 'number', value: b.join("") } }
-
-symbol
-    = b:(!delim c:. { return c })+
-    { return { type: 'symbol', value: b.join("") } }
-
-paren
-    = "(" / ")"
-
-_
-    = w:[ \t\n\r]+ 

lib/lists.coffee

@@ -1,6 +1,8 @@
 vectorp = (a) -> toString.call(a) == '[object Array]'
 
-listp = (a) -> vectorp(a) and a.__list == true
+pairp = (a) -> vectorp(a) and a.__list == true
+
+listp = (a) -> (pairp a) and (pairp cdr a)
 
 recordp = (a) -> Object.prototype.toString.call(a) == '[object Object]'
 
@@ -16,7 +18,7 @@ car = (a) -> a[0]
 
 cdr = (a) -> a[1]
 
-nilp = (a) -> listp(a) and a.length == 0
+nilp = (a) -> pairp(a) and a.length == 0
 
 vectorToList = (v, p) ->
   p = if p? then p else 0
@@ -25,14 +27,17 @@ vectorToList = (v, p) ->
   # have to be intercepted first.  The use of duck-typing here is
   # frustrating, but I suppose the eventual runtime will be doing
   # something like this anyway for base types.
-  item = if listp(v[p]) then v[p] else if vectorp(v[p]) then vectorToList(v[p]) else v[p]
+  item = if pairp(v[p]) then v[p] else if vectorp(v[p]) then vectorToList(v[p]) else v[p]
   cons(item, vectorToList(v, p + 1))
 
-list = (v...) -> vectorToList v
+list = (v...) ->
+  ln = v.length;
+  (nl = (a) ->
+    cons(v[a], if (a < ln) then (nl(a + 1)) else nil))(0)
 
 listToVector = (l, v = []) ->
   return v if nilp l
-  v.push if listp (car l) then listToVector(car l) else (car l)
+  v.push if pairp (car l) then listToVector(car l) else (car l)
   listToVector (cdr l), v
 
 # This is the simplified version. It can't be used stock with reader,
@@ -41,7 +46,7 @@ listToVector = (l, v = []) ->
 
 listToString = (l) ->
   return "" if nilp l
-  if listp (car l)
+  if pairp (car l)
     "(" + (listToString(car l)).replace(/\ *$/, "") + ") " + listToString(cdr l)
   else
     p = if typeof (car l) == 'string' then '"' else ''
@@ -54,7 +59,7 @@ module.exports =
   cdr: cdr
   list: list
   nilp: nilp
-  listp: listp
+  pairp: pairp
   vectorp: vectorp
   recordp: recordp
   vectorToList: vectorToList

lib/reader.coffee

@@ -1,4 +1,4 @@
-{car, cdr, cons, nil, nilp, listp} = require './lists'
+{car, cdr, cons, nil, nilp, pairp, vectorToList} = require './lists'
 
 NEWLINES   = ["\n", "\r", "\x0B", "\x0C"]
 WHITESPACE = [" ", "\t"].concat(NEWLINES)
@@ -32,10 +32,7 @@ skipWS = (inStream) ->
 
 # (type, value, line, column) -> (node {type, value, line, column)}
 makeObj = (type, value, line, column) ->
-  'type': type
-  'value': value
-  'line': line
-  'column': column
+  vectorToList([type, value, line, column])  
 
 # msg -> (IO -> Node => Error)
 handleError = (message) ->

lib/reduce.coffee

@@ -1,4 +1,4 @@
-{car, cdr, cons, listp, nilp, nil, list, listToString} = require './lists'
+{car, cdr, cons, pairp, nilp, nil, list, listToString} = require './lists'
 
 reduce = (lst, iteratee, memo, context) ->
   count = 0

lib/scope.coffee

@@ -1,5 +1,5 @@
 lispeval = require './eval'
-{cons, car, cdr, nilp, nil} = require './lists'
+{cons, car, cdr, nilp, nil, cadar, cadr, caddr} = require './lists'
 {create_lisp_expression_evaluator, create_vm_expression_evaluator, create_special_form_evaluator} = require './fn'
 
 scope = cons
@@ -13,20 +13,19 @@ scope = cons
 
   'define': create_special_form_evaluator scope, [], (nodes, scope) ->
     current = (car scope)
-    current[(car nodes).value] = lispeval((car cdr nodes), scope)
+    current[(cadar nodes)] = lispeval((cadr nodes), scope)
 
   'lambda': create_special_form_evaluator scope, [], (nodes, scope) ->
-    param_nodes = (car nodes).value
+    param_nodes = cadar nodes
     reducer = (l) ->
-      if (nilp l) then nil else cons((car l).value, reducer(cdr l))
+      if (nilp l) then nil else cons (cadar l), reducer(cdr l)
     param_names = reducer(param_nodes)
-
-    create_lisp_expression_evaluator(scope, param_names, (cdr nodes))
+    create_lisp_expression_evaluator scope, param_names, (cdr nodes)
         
   'if': create_special_form_evaluator scope, [], (nodes, scope) ->
-    if lispeval((car nodes), scope)
-      lispeval((car cdr nodes), scope)
+    if lispeval (car nodes), scope
+      lispeval (cadr nodes), scope
     else
-      lispeval((car cdr cdr nodes), scope)
+      lispeval (caddr nodes), scope
 
 module.exports = scope