create 'Ordering' type

lib/compare/primitives.js

@@ -1,18 +1,25 @@
 // Total ordering of primitive types
 
-export const compareNumbers = x => y => {
+export const compareInts = x => y => {
+  if (typeof(x) !== 'bigint' || typeof(y) !== 'bigint') {
+    throw new Error(`was only meant to compare bigints! got ${x} and ${y}`);
+  }
+  return (x < y) ? -1 : (x > y) ? 1 : 0;
+};
+
+export const compareDoubles = x => y => {
   if (typeof(x) !== 'number' || typeof(y) !== 'number') {
     throw new Error(`was only meant to compare numbers! got ${x} and ${y}`);
   }
   return (x < y) ? -1 : (x > y) ? 1 : 0;
-}
+};
 
 export const compareStrings = x => y => {
   if (typeof(x) !== 'string' || typeof(y) !== 'string') {
     throw new Error(`was only meant to compare strings! got ${x} and ${y}`);
   }
   return (x < y) ? -1 : (x > y) ? 1 : 0;
-}
+};
 
 export const compareBools = x => y => {
   if (typeof(x) !== 'boolean' || typeof(y) !== 'boolean') {
@@ -26,3 +33,5 @@ export const compareUnits = _ => _ => 0;
 
 // Symbols are encoded as strings
 export const compareSymbols = a => b => compareStrings(a)(b);
+
+export const compareOrderings = a => b => compareDoubles(a)(b);