update

desugar.js

@@ -9,3 +9,59 @@ var typ = require("./representation.js");
 // Lists get desugared to nested function calls
 // i.e. (cons (cons (cons ...)))
 function desugarList(lst) {
+  if (lst.xs.length <= 0) {
+    return new typ.Nil();
+  }
+  else {
+    var x = desugar(lst.xs[0]);
+    var rest = lst.xs.slice(1);
+    return new typ.App(new typ.App(new typ.Name("(:)"), x), desugarList(new typ.ListT(rest)));
+  }
+}
+
+function desugarDefFunc(def) {
+  return new typ.Def(def.ident, new typ.FuncT(desugar(def.params), desugar(def.body)));
+}
+
+//function desugarString(str) {
+
+
+function desugar(stx) {
+  switch (stx.exprType) {
+    case "If":
+      if (stx.elseexp)
+        return new typ.If(desugar(stx.condition), desugar(stx.thenexp), desugar(stx.elseexp));
+      return new typ.If(desugar(stx.condition), desugar(stx.thenexp));
+    case "FunctionDefinition":
+      return desugarDefFunc(stx);
+    case "Definition":
+      return new typ.Def(stx.ident, desugar(stx.val));
+    case "Name":
+      return stx;
+    case "Application":
+      if (stx.p)
+        return new typ.App(stx.func, desugar(stx.p));
+      return new typ.App(stx.func);
+    case "Function":
+      return new typ.FuncT(stx.p, desugar(stx.body));
+    case "List":
+      return desugarList(stx);
+    case "Bool":
+      return stx;
+    case "String":
+      return stx;
+    case "Float":
+      return stx;
+    case "Integer":
+      return stx;
+    default:
+      return stx;
+  }
+}
+
+module.exports = { desugar : desugar };
+//var test = typ.ListT([1,2,3]);
+
+//console.log(desugarList(test));
+
+

parse.js

@@ -3,6 +3,7 @@
 var typ = require("./representation.js");
 var tool = require("./tools.js");
 var tokenizer = require("./tokenize.js");
+var desugarer = require("./desugar.js");
 var fs = require("fs");
 
 function fst(ts) {
@@ -322,7 +323,7 @@ function pprintFunc(func) {
 
 function pprintApp(app) {
   if (!app.p || app.p === undefined)
-    return "(" + pprint(app.func) + ")";
+    return pprint(app.func);
   return "((" + pprint(app.func) + ") " + pprint(app.p) + ")";
 }
 
@@ -361,13 +362,15 @@ function pprint(expr) {
     return pprintIf(expr);
   else if (expr.exprType === "Function")
     return pprintFunc(expr);
+  else if (expr.exprType === "Nil")
+    return "[]";
 }
 
 var input = fs.readFileSync('/dev/stdin').toString();
 var tokenized = tokenizer.tokenize(input).reverse().filter(function(x) { return x[0] !== "whitespace";});
 //console.log(tokenized);
 while (tokenized !== []) {
-  console.log(parse(tokenized));
+  console.log(pprint(desugarer.desugar(parse(tokenized))));
   if (!tokenized)
     break;
 }

representation.js

@@ -62,6 +62,12 @@ function ListT(xs) {
 	return this;
 }
 
+function Nil() {
+  this.exprType = "Nil";
+  return this;
+}
+Nil.prototype = Expression;
+
 ListT.prototype = Expression;
 
 function FuncT(p, body) {
@@ -120,7 +126,7 @@ function DefFunc(ident, params, body) {
 function If(condition, thenexp, elseexp) {
 	this.condition = condition;
 	this.thenexp = thenexp;
-if (elseexp)
+  if (elseexp)
 		this.elseexp = elseexp;
 	this.exprType = "If";
 	return this;
@@ -156,6 +162,7 @@ OPInfo = {"+" : [3, "Left"],
       "==" : [2, "Left"],
       ">" : [2, "Left"],
       "<" : [2, "Left"],
+      ":" : [2, "Left"],
       "$" : [1, "Left"]}
 
 module.exports =
@@ -172,4 +179,5 @@ module.exports =
 	 OPInfo : OPInfo,
 	 makeApp : makeApp,
 	 If      : If,
-   DefFunc : DefFunc}
+   DefFunc : DefFunc,
+   Nil : Nil}

test.jl

@@ -1,31 +1,24 @@
-def square
-  (lambda a -> (a * a))
+def (f a b)
+  (a ++ b)
 
-def pow
-  (lambda base exp ->
-    (base ^ exp))
+def (add a b)
+  (a + b)
 
-def powed (pow (2 + 3 * 5) 2)
+def (catstrs strs)
+  (foldr f (head strs) (tail strs))
 
-def squared (square powed)
+def strs ["aa", "bb"]
 
-def fact
-  (lambda n ->
-    if (n == 0)
-      then 1
-    else
-      (n * (fact (n - 1))))
+def (mymap f xs)
+  if ((length xs) == 0)
+    then
+      xs
+  else
+    (: (f (head xs))
+     (mymap f (tail xs)))
 
-def fib
-  (lambda n ->
-    if (n == 0)
-      then 0
-    else
-      if (n == 1)
-        then 1
-    else
-      (+
-        (fib (n - 1))
-        (fib (n - 2))))
-
-def main (print (fib 15))
+def main
+  if (2 < 3)
+    then
+    (print (mymap add [1,2,3,4 , 5]))
+    else (print "")

tokenize.js

@@ -67,7 +67,7 @@ function tokenizeNum(tokstream) {
 function tokenizeIdent(tokstream) {
   var identifier = [];
   var n = 0;
-  while ((!isWhitespace(tokstream[0])) && (!isDigit(tokstream[0])) && isIdentifier(tokstream[0])) {
+  while ((!isWhitespace(tokstream[0])) && isIdentifier(tokstream[0])) {
     identifier.push(tokstream[0]);
     tokstream = tokstream.substr(1);
     n++;