From 39403648ecca7c2d827f6c0d42005b500add8485 Mon Sep 17 00:00:00 2001
From: nisstyre56 <wjak56@gmail.com>
Date: Sun, 18 May 2014 03:36:43 -0400
Subject: [PATCH] fix a few bugs, functionality for aliasing type operators now
 works

---
 parse.js          |  7 ++++++-
 pprint.js         |  7 +++++++
 representation.js | 11 +++++++----
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/parse.js b/parse.js
index b3e8607..5e53364 100755
--- a/parse.js
+++ b/parse.js
@@ -374,7 +374,7 @@ function parseDefType(tokens, linenum, charnum) {
     return parseDataType(tokens, linenum, charnum);
   }
 
-  if (notFollowedBy(tokens, ["constructor"]. linenum, charnum)) {
+  if (notFollowedBy(tokens, ["constructor"], linenum, charnum)) {
     throw error.JSyntaxError(linenum,
                              charnum,
                              "deftype must be followed by a single constructor" +
@@ -400,6 +400,8 @@ function parseDefType(tokens, linenum, charnum) {
                                rhs.charnum,
                                "was expecting an application or type operator on the right-hand side of a type definition");
     }
+    result = new typ.DefType(lhs, rhs);
+    return result;
   }
 }
 
@@ -737,6 +739,9 @@ function parse(tokens) {
            toktype === "let") {
     return parseDef(tokens, linenum, charnum);
   }
+  else if (toktype === "deftype") {
+    return parseDefType(tokens, linenum, charnum);
+  }
   else if (toktype === "defop") {
     return parseDefOp(tokens, linenum, charnum);
   }
diff --git a/pprint.js b/pprint.js
index 305ea8c..da57019 100644
--- a/pprint.js
+++ b/pprint.js
@@ -26,6 +26,10 @@ function pprintIf(ifexp) {
          " else " + pprint(ifexp.elseexp) + ")");
 }
 
+function pprintDefType(stx) {
+  return pprint(stx.lhs) + " = " + pprint(stx.rhs);
+}
+
 function pprint(expr) {
   if (expr.exprType === "Name") {
     return expr.val;
@@ -56,6 +60,9 @@ function pprint(expr) {
   else if (expr.exprType === "Definition") {
     return pprintDef(expr);
   }
+  else if (expr.exprType === "TypeDefinition") {
+    return pprintDefType(expr);
+  }
   else if (expr.exprType === "If") {
     return pprintIf(expr);
   }
diff --git a/representation.js b/representation.js
index c45e237..e0734f9 100644
--- a/representation.js
+++ b/representation.js
@@ -295,9 +295,9 @@ function DefType(rhs, lhs) {
   /* Both rhs and lhs are expected
    * to be fully desugared already
    */
-  if (!isExprType(rhs) ||
-      !isExprType(lhs)) {
-        throw erros.JSyntaxError(
+  if (!isTypeExpr(rhs) ||
+      !isTypeExpr(lhs)) {
+        throw errors.JSyntaxError(
           rhs.linenum,
           rhs.charnum,
           "Illegal type definition, both sides must be valid type expressions");
@@ -308,6 +308,8 @@ function DefType(rhs, lhs) {
   return this;
 }
 
+DefType.prototype = Expression;
+
 
 //Applies the function ``name'' to the list of parameters
 function makeApp(name, parameters) {
@@ -381,5 +383,6 @@ module.exports =
      TypeOp : TypeOp,
      TypeApp: TypeApp,
      Closure : Closure,
-     isTypeExpr : isTypeExprRec
+     isTypeExpr : isTypeExprRec,
+     DefType : DefType
    };