X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=code%2Fparse.js;h=9712809b40c5d7d608b48543eb4c5270cc4e6712;hp=8a4761b50be13482cdf30a8be23527b9198aae9d;hb=c51047cd5851147777c81822d00b1dd6e35988d5;hpb=847feba6f0cf9ca175f3786dbcefacdc3f1cac5a;ds=sidebyside

diff --git a/code/parse.js b/code/parse.js
index 8a4761b5..9712809b 100644
--- a/code/parse.js
+++ b/code/parse.js
@@ -4,6 +4,9 @@
 //      http://javascript.crockford.com/tdop/index.html
 //      Douglas Crockford 2010-06-26
 
+//      See also http://effbot.org/zone/simple-top-down-parsing.htm
+
+
 /*jslint onevar: false
  */
 
@@ -65,6 +68,7 @@ var make_parse = function () {
         }
     };
 
+	/*
 	try {
 		if (console && console.debug) {
 			function print() {
@@ -72,6 +76,7 @@ var make_parse = function () {
 			}
 		}
 	} catch (e) {}
+	*/
 
     var symbol = function (id) {
         var s = symbol_table[id];
@@ -126,13 +131,8 @@ var make_parse = function () {
         return body;
     };
 
-    var number_handler = function () {
-
-    };
-
     symbol("(end)");
     symbol("(name)").handler = name_handler;
-    symbol("(number)").handler = number_handler;
     symbol("let").handler = lambda_handler;
     symbol("=").handler = branch_handler;
     symbol("in");
@@ -140,27 +140,13 @@ var make_parse = function () {
     symbol("(");
     symbol("\\").handler = lambda_handler;
     symbol("lambda").handler = lambda_handler;
+    symbol("\u03bb").handler = lambda_handler;
+    // symbol("\u2203").handler = exists_handler;
+    // symbol("\u2200").handler = forall_handler;
     symbol(".");
 
 	function make_constants() {
 
-		var constant = function (s, v) {
-			var x = symbol(s);
-			x.handler = function () {
-				this.value = symbol_table[this.id].value;
-				if (this.first) {
-					return make_app(this.first.handler(), this.value);
-				} else {
-					return this.value;
-				}
-			};
-			// constants have their own id and arity = literal
-			// numbers have id = "(number)" and arity = literal
-			x.arity = "literal";
-			x.value = v;
-			return x;
-		};
-
 		function make_lam2(a, b, aa) {
 			return make_lam(a, make_lam(b, aa));
 		}
@@ -182,14 +168,62 @@ var make_parse = function () {
 		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};
+		number_table = {};
+
+		// constants have their own id and arity = literal
+		// numbers have id = "(number)" and arity = literal
+		symbol("(number)").handler = function () {
+			var n = this.value;
+			var res = number_table[n];
+			if (!res) {
+				res = zz;
+				while (n > 0) {
+					n -= 1;
+					res = make_app(ss, res);
+				}
+				res = make_lam2(s, z, res);
+				number_table[this.value] = res;
+			}
+			if (this.first) {
+				return make_app(this.first.handler(), res);
+			} else {
+				return res;
+			}
+		}
+
+		var constant = function (s, v) {
+			var x = symbol(s);
+			x.handler = function () {
+				this.value = symbol_table[this.id].value;
+				if (this.first) {
+					return make_app(this.first.handler(), this.value);
+				} else {
+					return this.value;
+				}
+			};
+			x.arity = "literal";
+			x.value = v;
+			return x;
+		};
 
 		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)));
+
+		// trush \uv.vu = CI = box
 		constant("T", make_lam2(u, v, make_app(vv, uu)));
+		// vireo \uvw.wuv = pair
+		constant("V", make_lam3(u, v, x, make_app3(xx, uu, vv)));
+		// warbler \uv.uvv = C(BM(BBT) = C(BS(C(BBI)I))I
+		constant("W", make_lam2(u, v, make_app3(uu, vv, vv)));
+		// mockingbird \u.uu = SII = omega
+		constant("M", make_lam(u, make_app(uu, uu)));
+		// lark \uv.u(vv) = CBM = BWB
+		constant("L", make_lam2(u, v, make_app(uu, make_app(vv, vv))));
+		// Y is SLL
+
 	}
 	make_constants();
 
@@ -212,9 +246,11 @@ var make_parse = function () {
                 return t;
             } else {
                 t.first = [];
-                while (token.arity === "name") {
-                    t.first.push(n);
-                    n = token;
+                while (token.arity === "name" || token.id === "\\") {
+		    if (token.id !== "\\") {
+                      t.first.push(n);
+                      n = token;
+		    }
                     advance();
                 }
 				if (token.arity === "literal" && t.first.length === 0) {
@@ -272,7 +308,7 @@ var make_parse = function () {
         tokens = source.tokens();
         token_nr = 0;
         advance();
-        
+
         // let n = c in b
         // (\n. b) c
 
@@ -302,7 +338,7 @@ var make_parse = function () {
             target = t;
             advance("in");
         }
-    
+
         target.second = expression(false);
 
         advance("(end)");