From 9cb5319bc68e364dfbc288542d3630e38c6cd0d8 Mon Sep 17 00:00:00 2001
From: Jim Pryor <profjim@jimpryor.net>
Date: Thu, 23 Sep 2010 04:01:56 -0400
Subject: [PATCH] tweak lambda evaluator

Signed-off-by: Jim Pryor <profjim@jimpryor.net>
---
 code/parse.js | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 54 insertions(+), 8 deletions(-)

diff --git a/code/parse.js b/code/parse.js
index 4fbab09e..d9f76ec2 100644
--- a/code/parse.js
+++ b/code/parse.js
@@ -75,7 +75,6 @@ var make_parse = function () {
         return s;
     };
 
-
 //     try {
 //         if (console && console.debug) {
 //             function print() {
@@ -84,13 +83,8 @@ var make_parse = function () {
 //         }
 //     } catch (e) {}
 
-
-    var itself = function () {
-        return this;
-    };
-
-    var var_table = {};
-    var name_table = {};
+    var var_table;
+    var name_table;
 
     var name_handler = function () {
         var n = name_table[this.value];
@@ -132,6 +126,12 @@ var make_parse = function () {
         return body;
     };
 
+
+
+    var itself = function () {
+        return this;
+    };
+
     symbol("(end)");
     symbol("(name)").handler = name_handler;
     symbol("(literal)").handler = itself;
@@ -144,6 +144,52 @@ var make_parse = function () {
     symbol("lambda").handler = lambda_handler;
     symbol(".");
 
+	function make_constants() {
+
+		var constant = function (s, v) {
+			var x = symbol(s);
+			x.handler = function () {
+				this.value = symbol_table[this.id].value;
+				this.arity = "literal";
+				return this;
+			};
+			x.value = v;
+			return x;
+		};
+
+		function make_lam2(a, b, aa) {
+			return make_lam(a, make_lam(b, aa));
+		}
+		function make_lam3(a, b, c, aa) {
+			return make_lam(a, make_lam(b, make_lam(c, aa)));
+		}
+		}
+		function make_app3(aa, bb, cc) {
+			return make_app(make_app(aa, bb), cc);
+		}
+		var u = make_var("u");
+		var v = make_var("v");
+		var x = make_var("x");
+		var s = make_var("s");
+		var z = make_var("z");
+		var uu = new Lambda_var(u);
+		var vv = new Lambda_var(v);
+		var xx = new Lambda_var(x);
+		var ss = new Lambda_var(s);
+		var zz = new Lambda_var(z);
+		var_table = { u: u, v: v, x: x, s: s, z: z};
+		name_table = {u: uu, v: vv, x: xx, s: ss, z: zz};
+
+		constant("S", make_lam3(u, v, x, make_app3(uu, xx, make_app(vv, xx))) );
+		constant("K", make_lam2(u, v, uu) );
+		constant("I", make_lam(x, xx) );
+		constant("B", make_lam3(u, v, x, make_app(uu, make_app(vv, xx))) );
+		constant("C", make_lam3(u, v, x, make_app3(uu, xx, vv)) );
+		constant("W", make_lam2(u, v, make_app3(uu, vv, vv)) );
+		constant("T", make_lam2(u, v, make_app(vv, uu)) );
+	}
+	make_constants();
+
     var expression = function (in_let) {
         var t, n;
         if (token.id === "\\" || token.id === "lambda") {
-- 
2.11.0