code cleanup

Signed-off-by: Jim Pryor <profjim@jimpryor.net>

diff --git a/code/lambda.js b/code/lambda.js
index 0eea4c9..89bd21b 100644 (file)
--- a/code/lambda.js
+++ b/code/lambda.js
@@ -453,178 +453,181 @@ try {
 
 
 
 
 
 

-// Chris's original
-
-// // Basic data structure, essentially a LISP/Scheme-like cons
-// // pre-terminal nodes are expected to be of the form new cons(null, "string")
-// function cons(car, cdr) {
-//   this.car = car;
-//   this.cdr = cdr;
-// }
-
-// // takes a stack of symbols, returns a pair: a tree and the remaining symbols
-// function parse(split) {
-//   if (split == null) return (new cons (null, null));
-//   if (split.length == 0) return (new cons (null, null));
-//   var token = split.shift();
-//   if (token == ")") return (new cons (null, split));
-//   var next = parse(split);
-//   if (token == "(") {
-//     var nextnext = parse(next.cdr);
-//     return (new cons ((new cons (next.car, nextnext.car)),
-//                       nextnext.cdr));
-//   }
-//   return (new cons ((new cons ((new cons (null, token)),
-//                                next.car)),
-//                     next.cdr))
-// }
-
-// // substitute arg in for v in tree
-// function sub(tree, v, arg) {
-//   if (tree == null) return (null);
-//   if (tree.car == null) if (tree.cdr == v) return (arg);
-//   if (tree.car == null) return (tree);
-
-//   // perform alpha reduction to prevent variable collision
-//   if (isBindingForm(tree)) 
-//     return (new cons (tree.car, 
-//                       sub(sub(tree.cdr,         // inner sub = alpha reduc.
-//                               tree.cdr.car.cdr, 
-//                               fresh(tree.cdr.car.cdr)),
-//                           v,
-//                           arg)));
-
-//   return (new cons ((sub (tree.car, v, arg)),
-//                     (sub (tree.cdr, v, arg))))
-// }
-
-// // Guaranteed unique for each call as long as string is not empty.
-// var i = 0;
-// function fresh(string) {
-//   i = i+1;
-//   if (typeof(string) != "string") return (string);
-//   return (new cons (null,  
-//                     string.substring(0,1) + (i).toString()));
-// }
-
-// // Keep reducing until there is no more change
-// function fixedPoint (tree) {
-//   var t2 = reduce(tree);
-//   if (treeToString(tree) == treeToString(t2)) return (tree);
-//   return (fixedPoint (t2));
-// }
-
-// // Reduce all the arguments, then try to do beta conversion on the whole
-// function reduce(tree) {
-//   if (tree == null) return (tree);
-//   if (typeof(tree) == "string") return (tree);
-//   return (convert (new cons (reduce (tree.car), mapReduce (tree.cdr))));
-// }
-
-// // Reduce all the arguments in a list
-// function mapReduce(tree) {
-//   if (tree == null) return (tree);
-//   if (tree.car == null) return (tree);
-//   return (new cons (reduce (tree.car), mapReduce(tree.cdr )));
-// }
-
-// // If the list is of the form ((lambda var body) arg), do beta reduc.
-// function convert(tree) {
-//     if (isLet(tree)) {
-//       return (sub(tree.cdr.car, tree.car.cdr.car.cdr, tree.car.cdr.cdr.car));}
-//     else 
-//       if (isConvertable(tree)) {
-//         return (sub(tree.car.cdr.cdr.car, tree.car.cdr.car.cdr, tree.cdr.car));}
-//       else return(tree);
-// } 
-
-// // Is of form ((let var arg) body)?
-// function isLet(tree) {
-//   if (tree == null) return (false);
-//   if (!(isBindingForm(tree.car))) return (false);
-//   if (tree.car.car.cdr != "let") return (false);
-//   if (tree.cdr == null) return (false);
-//   if (tree.cdr.car == null) return (false);
-//   return(true);
-// }  
-
-// // Is of form ((lambda var body) arg)?
-// function isConvertable(tree) {
-//   if (tree == null) return (false);
-//   if (!(isBindingForm(tree.car))) return (false);
-//   if (tree.car.car.cdr != "lambda") return (false);
-//   if (tree.cdr == null) return (false);
-//   if (tree.cdr.car == null) return (false);
-//   return(true);
-// }  
-
-// // Is of form (lambda var body)?
-// function isBindingForm(tree) {
-//   if (tree == null) return (false);
-//   if (tree.car == null) return (false);
-//   if (tree.car.car != null) return (false);
-//   if ((tree.car.cdr != "lambda") 
-//       && (tree.car.cdr != "let")
-//       && (tree.car.cdr != "exists")
-//       && (tree.car.cdr != "forall")
-//       && (tree.car.cdr != "\u03BB")
-//       && (tree.car.cdr != "\u2200")
-//       && (tree.car.cdr != "\u2203")
-//      )
-//     return (false);
-//   if (tree.car.cdr == null) return (false);
-//   if (tree.cdr.car == null) return (false);
-//   if (tree.cdr.car.car != null) return (false);
-//   if (tree.cdr.cdr == null) return (false);
-//   return (true);
-// }
-
-// function treeToString(tree) {
-//   if (tree == null) return ("")
-//   if (tree.car == null) return (tree.cdr)
-//   if ((tree.car).car == null) 
-//     return (treeToString(tree.car) + " " + treeToString(tree.cdr))
-//   return ("(" + treeToString(tree.car) + ")" + treeToString(tree.cdr))
-// }
-
-// // use this instead of treeToString if you want to see the full structure
-// function treeToStringRaw(tree) {
-//   if (tree == null) return ("@")
-//   if (typeof(tree) == "string") return (tree);
-//   return ("(" + treeToStringRaw(tree.car) + "." + 
-//                 treeToStringRaw(tree.cdr) + ")")
-// }
-
-// // Make sure each paren will count as a separate token
-// function stringToTree(input) {
-//   input = input.replace(/let/g, " ( ( let ");
-//   input = input.replace(/=/g, " ");
-//   input = input.replace(/in/g, " ) ");
-//   input = input.replace(/\(/g, " ( ");
-//   input = input.replace(/\)/g, " ) ");
-//   input = input.replace(/;.*\n/g," ");
-//   input = input.replace(/\^/g, " ^ ");
-//   input = input.replace(/[\\]/g, " lambda ");
-//   input = input.replace(/\u03BB/g, " lambda ");
-//   return ((parse(input.split(/[ \f\n\r\t\v]+/))).car)
-// }
-
-// // Adjust spaces to print pretty
-// function formatTree(tree) {
-//   output = treeToStringRaw (tree);
-//   output = output.replace(/^[ \f\n\r\t\v]+/, "");
-//   output = output.replace(/[ \f\n\r\t\v]+$/, "");
-//   output = output.replace(/[ \f\n\r\t\v]+\)/g, ")");
-//   output = output.replace(/\)([^)(])/g, ") $1");
-//   output = output.replace(/lambda/g, "\\");
-// //  output = output.replace(/lambda/g, "\u03BB");
-// //  output = output.replace(/exists/g, "\u2203");
-// //  output = output.replace(/forall/g, "\u2200");
-//   return (output)
-// }
-
-// function mytry(form) { 
-//   i = 0;
-//   form.result.value = formatTree((stringToTree(form.input.value)));
-//   // form.result.value = formatTree(fixedPoint(stringToTree(form.input.value)));
-// }
+/* Chris's original
+
+// Basic data structure, essentially a LISP/Scheme-like cons
+// pre-terminal nodes are expected to be of the form new cons(null, "string")
+function cons(car, cdr) {
+  this.car = car;
+  this.cdr = cdr;
+}
+
+// takes a stack of symbols, returns a pair: a tree and the remaining symbols
+function parse(split) {
+  if (split == null) return (new cons (null, null));
+  if (split.length == 0) return (new cons (null, null));
+  var token = split.shift();
+  if (token == ")") return (new cons (null, split));
+  var next = parse(split);
+  if (token == "(") {
+       var nextnext = parse(next.cdr);
+       return (new cons ((new cons (next.car, nextnext.car)),
+                                         nextnext.cdr));
+  }
+  return (new cons ((new cons ((new cons (null, token)),
+                                                          next.car)),
+                                       next.cdr))
+}
+
+// substitute arg in for v in tree
+function sub(tree, v, arg) {
+  if (tree == null) return (null);
+  if (tree.car == null) if (tree.cdr == v) return (arg);
+  if (tree.car == null) return (tree);
+
+  // perform alpha reduction to prevent variable collision
+  if (isBindingForm(tree)) 
+       return (new cons (tree.car, 
+                                         sub(sub(tree.cdr,         // inner sub = alpha reduc.
+                                                         tree.cdr.car.cdr, 
+                                                         fresh(tree.cdr.car.cdr)),
+                                                 v,
+                                                 arg)));
+
+  return (new cons ((sub (tree.car, v, arg)),
+                                       (sub (tree.cdr, v, arg))))
+}
+
+// Guaranteed unique for each call as long as string is not empty.
+var i = 0;
+function fresh(string) {
+  i = i+1;
+  if (typeof(string) != "string") return (string);
+  return (new cons (null,  
+                                       string.substring(0,1) + (i).toString()));
+}
+
+// Keep reducing until there is no more change
+function fixedPoint (tree) {
+  var t2 = reduce(tree);
+  if (treeToString(tree) == treeToString(t2)) return (tree);
+  return (fixedPoint (t2));
+}
+
+// Reduce all the arguments, then try to do beta conversion on the whole
+function reduce(tree) {
+  if (tree == null) return (tree);
+  if (typeof(tree) == "string") return (tree);
+  return (convert (new cons (reduce (tree.car), mapReduce (tree.cdr))));
+}
+
+// Reduce all the arguments in a list
+function mapReduce(tree) {
+  if (tree == null) return (tree);
+  if (tree.car == null) return (tree);
+  return (new cons (reduce (tree.car), mapReduce(tree.cdr )));
+}
+
+// If the list is of the form ((lambda var body) arg), do beta reduc.
+function convert(tree) {
+       if (isLet(tree)) {
+         return (sub(tree.cdr.car, tree.car.cdr.car.cdr, tree.car.cdr.cdr.car));}
+       else 
+         if (isConvertable(tree)) {
+               return (sub(tree.car.cdr.cdr.car, tree.car.cdr.car.cdr, tree.cdr.car));}
+         else return(tree);
+} 
+
+// Is of form ((let var arg) body)?
+function isLet(tree) {
+  if (tree == null) return (false);
+  if (!(isBindingForm(tree.car))) return (false);
+  if (tree.car.car.cdr != "let") return (false);
+  if (tree.cdr == null) return (false);
+  if (tree.cdr.car == null) return (false);
+  return(true);
+}  
+
+// Is of form ((lambda var body) arg)?
+function isConvertable(tree) {
+  if (tree == null) return (false);
+  if (!(isBindingForm(tree.car))) return (false);
+  if (tree.car.car.cdr != "lambda") return (false);
+  if (tree.cdr == null) return (false);
+  if (tree.cdr.car == null) return (false);
+  return(true);
+}  
+
+// Is of form (lambda var body)?
+function isBindingForm(tree) {
+  if (tree == null) return (false);
+  if (tree.car == null) return (false);
+  if (tree.car.car != null) return (false);
+  if ((tree.car.cdr != "lambda") 
+         && (tree.car.cdr != "let")
+         && (tree.car.cdr != "exists")
+         && (tree.car.cdr != "forall")
+         && (tree.car.cdr != "\u03BB")
+         && (tree.car.cdr != "\u2200")
+         && (tree.car.cdr != "\u2203")
+        )
+       return (false);
+  if (tree.car.cdr == null) return (false);
+  if (tree.cdr.car == null) return (false);
+  if (tree.cdr.car.car != null) return (false);
+  if (tree.cdr.cdr == null) return (false);
+  return (true);
+}
+
+function treeToString(tree) {
+  if (tree == null) return ("")
+  if (tree.car == null) return (tree.cdr)
+  if ((tree.car).car == null) 
+       return (treeToString(tree.car) + " " + treeToString(tree.cdr))
+  return ("(" + treeToString(tree.car) + ")" + treeToString(tree.cdr))
+}
+
+// use this instead of treeToString if you want to see the full structure
+function treeToStringRaw(tree) {
+  if (tree == null) return ("@")
+  if (typeof(tree) == "string") return (tree);
+  return ("(" + treeToStringRaw(tree.car) + "." + 
+                               treeToStringRaw(tree.cdr) + ")")
+}
+
+// Make sure each paren will count as a separate token
+function stringToTree(input) {
+  input = input.replace(/let/g, " ( ( let ");
+  input = input.replace(/=/g, " ");
+  input = input.replace(/in/g, " ) ");
+  input = input.replace(/\(/g, " ( ");
+  input = input.replace(/\)/g, " ) ");
+  input = input.replace(/;.*\n/g," ");
+  input = input.replace(/\^/g, " ^ ");
+  input = input.replace(/[\\]/g, " lambda ");
+  input = input.replace(/\u03BB/g, " lambda ");
+  return ((parse(input.split(/[ \f\n\r\t\v]+/))).car)
+}
+
+// Adjust spaces to print pretty
+function formatTree(tree) {
+  output = treeToStringRaw (tree);
+  output = output.replace(/^[ \f\n\r\t\v]+/, "");
+  output = output.replace(/[ \f\n\r\t\v]+$/, "");
+  output = output.replace(/[ \f\n\r\t\v]+\)/g, ")");
+  output = output.replace(/\)([^)(])/g, ") $1");
+  output = output.replace(/lambda/g, "\\");
+//  output = output.replace(/lambda/g, "\u03BB");
+//  output = output.replace(/exists/g, "\u2203");
+//  output = output.replace(/forall/g, "\u2200");
+  return (output)
+}
+
+function mytry(form) { 
+  i = 0;
+  form.result.value = formatTree((stringToTree(form.input.value)));
+  // form.result.value = formatTree(fixedPoint(stringToTree(form.input.value)));
+}
+
+*/
+

diff --git a/code/parse.js b/code/parse.js
index 08ac5f0..5cdeb40 100644 (file)
--- a/code/parse.js
+++ b/code/parse.js
@@ -140,6 +140,9 @@ var make_parse = function () {
     symbol("(");
     symbol("\\").handler = lambda_handler;
     symbol("lambda").handler = lambda_handler;
     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() {
     symbol(".");
 
        function make_constants() {

diff --git a/code/tokens.js b/code/tokens.js
index 921040d..c6630fa 100644 (file)
--- a/code/tokens.js
+++ b/code/tokens.js
@@ -12,8 +12,8 @@
 //      Comments of the ; type are ignored.
 
 //      Operators are by default single characters. Multicharacter
 //      Comments of the ; type are ignored.
 
 //      Operators are by default single characters. Multicharacter

-//      operators can be made by supplying a string of prefix and
-//      suffix characters.
+//      operators can be made by supplying a string of multi_start and
+//      multi_continue characters.

 //      characters. For example,
 //           '<>+-&', '=>&:'
 //      will match any of these:
 //      characters. For example,
 //           '<>+-&', '=>&:'
 //      will match any of these:


@@ -22,7 +22,7 @@
 /*jslint onevar: false
  */
 
 /*jslint onevar: false
  */
 

-String.prototype.tokens = function (prefix, suffix) {
+String.prototype.tokens = function (multi_start, multi_continue) {

     var c;                      // The current character.
     var from;                   // The index of the start of the token.
     var i = 0;                  // The index of the current character.
     var c;                      // The current character.
     var from;                   // The index of the start of the token.
     var i = 0;                  // The index of the current character.


@@ -51,13 +51,13 @@ String.prototype.tokens = function (prefix, suffix) {
         return;
     }
 
         return;
     }
 

-// If prefix and suffix strings are not provided, supply defaults.
+// If multi_start and multi_continue strings are not provided, supply defaults.

 
 

-    if (typeof prefix !== 'string') {
-        prefix = '';
+    if (typeof multi_start !== 'string') {
+        multi_start = '';

     }
     }

-    if (typeof suffix !== 'string') {
-        suffix = '';
+    if (typeof multi_continue !== 'string') {
+        multi_continue = '';

     }
 
 
     }
 
 


@@ -153,12 +153,12 @@ String.prototype.tokens = function (prefix, suffix) {
 
 // multi-char operator.
 
 
 // multi-char operator.
 

-        } else if (prefix.indexOf(c) >= 0) {
+        } else if (multi_start.indexOf(c) >= 0) {

             str = c;
             i += 1;
             while (i < length) {
                 c = this.charAt(i);
             str = c;
             i += 1;
             while (i < length) {
                 c = this.charAt(i);

-                if (suffix.indexOf(c) < 0) {
+                if (multi_continue.indexOf(c) < 0) {

                     break;
                 }
                 str += c;
                     break;
                 }
                 str += c;