add dict comparison function

lib/compare/registry.js

@@ -1,10 +1,8 @@
 import { getInst, getType } from "../primitives/dynamic.js";
 import { SymbolBool, SymbolChar, SymbolDouble, SymbolInt, SymbolType, SymbolUnit } from "../primitives/primitive_types.js";
-import { getHumanReadableName } from "../primitives/symbol.js";
 import { symbolDict, symbolList, symbolProduct, symbolSet, symbolSum } from "../structures/type_constructors.js";
-import { capitalizeFirstLetter } from "../util/util.js";
 import { compareBools, compareNumbers, compareStrings, compareUnits } from "./primitives.js";
-import { compareLists, compareProducts, compareSets, compareSums } from "./structures.js";
+import { compareDicts, compareLists, compareProducts, compareSets, compareSums } from "./structures.js";
 import { compareTypes } from "./type.js";
 
 const typeSymbolToCmp = new Map([
@@ -20,7 +18,7 @@ const typeSymbolToCmp = new Map([
   [symbolProduct , compareProducts],
   [symbolSum     , compareSums],
   [symbolSet     , compareSets],
-  // [symbolDict    , compareDicts], TODO
+  [symbolDict    , compareDicts],
 ]);
 
 export const makeCompareFn = type => {

lib/compare/structures.js

@@ -2,11 +2,11 @@
 
 import { compareNumbers } from "./primitives.js"
 import { get, length as lengthLs } from "../structures/list.js";
-import { read, length as lengthSet } from "../structures/set.js";
-import { newProduct, getLeft, getRight } from "../structures/product.js";
+import { read as readSet, length as lengthSet, first as firstSet } from "../structures/set.js";
+import { read as readDict, length as lengthDict, first as firstDict } from "../structures/dict.js";
+import { getLeft, getRight } from "../structures/product.js";
 import { match } from "../structures/sum.js";
 
-// (a -> a -> Int) -> [a] -> [a] -> Int
 export const compareLists = compareElems => x => y => {
   return compareNumbers(lengthLs(x))(lengthLs(y))
     || (() => {
@@ -20,13 +20,11 @@ export const compareLists = compareElems => x => y => {
     })();
 };
 
-// (a -> a -> Int) -> (b -> b -> Int) -> (a, b) -> (a, b) -> Int
 export const compareProducts = compareLeft => compareRight => x => y => {
   return compareLeft (getLeft (x))(getLeft (y))
       || compareRight(getRight(x))(getRight(y));
 };
 
-// (a -> a -> Int) -> (b -> b -> Int) -> (a | b) -> (a | b) -> Int
 export const compareSums = compareLeft => compareRight => x => y => {
   // console.log("compareSums...", x, y)
   return match(x)
@@ -46,21 +44,47 @@ export const compareSums = compareLeft => compareRight => x => y => {
     );
 };
 
-// (a -> a -> Int) -> {a} -> {a} -> Int
 export const compareSets = compareElems => x => y => {
   return compareNumbers(lengthSet(x))(lengthSet(y))
     || (() => {
       // sets have same size -> iterate over both sets and compare their elements pairwise
       // because of the underlying red-black tree, iteration happens in ordered fashion
-      const iterate = iterX => iterY =>
-        read(iterX)
-          (keyX => nextX =>
-            read(iterY)
-              // we could also use the comparison function that is embedded in the set object,
-              // but to be consistent with the other comparison-functions, we don't.
-              (keyY => nextY => compareElems(keyX)(keyY) || iterate(nextX)(nextY))
-              (0)) // end of set y (we'll never get here because sets are same size)
-          (0); // end of set x
-      return iterate(first(x))(first(y));
+      const iterate = iterX => entryY =>
+        match(readSet(iterX))
+          (entryX =>
+            match(readSet(entryY))
+              (resultY => compareElems
+                            (getLeft(entryX))
+                            (getLeft(resultY))
+                       || iterate
+                            (getRight(entryX))
+                            (getRight(resultY)))
+              (_ => 0))
+          (_ => 0); // we made it, sets are equal
+      return iterate(firstSet(x))(firstSet(y));
+    })();
+};
+
+export const compareDicts = compareKeys => compareValues => x => y => {
+  return compareNumbers(lengthDict(x))(lengthDict(y))
+    || (() => {
+      // dicts have same size -> iterate over both and compare their entries pairwise
+      // because of the underlying red-black tree, iteration happens in ordered fashion
+      const iterate = iterX => iterY =>
+        match(readDict(iterX))
+          (entryX =>
+            match(readDict(iterY))
+              (entryY => compareKeys
+                            (getLeft(getLeft(entryX)))
+                            (getLeft(getLeft(entryY)))
+                       || compareValues
+                            (getRight(getLeft(entryX)))
+                            (getRight(getLeft(entryY)))
+                       || iterate
+                            (getRight(entryX))
+                            (getRight(entryY)))
+              (_ => 0))
+          (_ => 0); // we made it, dicts are equal
+      return iterate(firstDict(x))(firstDict(y));
     })();
 };

lib/compare/structures.types.js

@@ -1,5 +1,5 @@
 import { getDefaultTypeParser } from "../parser/type_parser.js";
-import { compareLists, compareProducts, compareSets, compareSums } from "./structures.js";
+import { compareDicts, compareLists, compareProducts, compareSets, compareSums } from "./structures.js";
 
 const mkType = getDefaultTypeParser();
 
@@ -11,4 +11,6 @@ export const ModuleCompareStructures = [
   {i: compareSums, t: mkType("∀a,b: (a -> a -> Int) -> (b -> b -> Int) -> (a+b) -> (a+b) -> Int")},
 
   {i: compareSets, t: mkType("∀a: (a -> a -> Int) -> {a} -> {a} -> Int")},
-];
+
+  {i: compareDicts, t: mkType("∀a,b: (a -> a -> Int) -> (b -> b-> Int) -> (a => b) -> (a => b) -> Int")}
+];

lib/structures/dict.js

@@ -14,7 +14,12 @@ export const last  = dict => dict.tree.end;
 
 export const read = iter => {
   if (iter !== undefined && iter.valid) {
-    return newRight(newProduct(newProduct(iter.key)(iter.value))(iter.clone().next()));
+    return newRight(
+      newProduct(
+        newProduct(iter.key)(iter.value)
+        (iter.clone().next())
+      )
+    );
   }
   else {
     return newLeft(unit);

lib/structures/set.js

@@ -17,7 +17,11 @@ export const last  = set => set.tree.end;
 // test if iterator is 'done', and if not, get element and advance iterator.
 export const read = iter => {
   if (iter !== undefined && iter.valid) {
-    return newRight(newProduct(iter.key)(iter.clone().next()));
+    return newRight(
+      newProduct
+        (iter.key)
+        (iter.clone().next())
+    );
   }
   else {
     return newLeft(unit);