split 'environment' example up into library and interactive prompt

lib/environment/env.js

@@ -0,0 +1,60 @@
+import { makeCompareFn } from "../compare/dynamic.js";
+import { compareTypes } from "../compare/type.js";
+import { getInst, getType, newDynamic } from "../primitives/dynamic.js";
+import { Dynamic, Type } from "../primitives/primitive_types.js";
+import { getSymbol } from "../primitives/type.js";
+import { emptyDict, get, get as getDict, set as setDict } from "../structures/dict.js";
+import { fold as foldList } from "../structures/list.js";
+import { add, emptySet, fold as foldSet } from "../structures/set.js";
+import { symbolFunction } from "../structures/type_constructors.js";
+
+const addEntry = env => i => t => {
+  const setOfInstances = getInstances(env)(t);
+  return setDict(env)(t)(add(setOfInstances)(i));
+};
+
+export const growEnv = env => dynamic => {
+  const t = getType(dynamic);
+  const typeDictWithEntry   = addEntry(env              )(getInst(dynamic))(t      );
+  const typeDictWithType    = addEntry(typeDictWithEntry)(t               )(Type   );
+  const typeDictWithDynamic = addEntry(typeDictWithType )(dynamic         )(Dynamic);
+  return typeDictWithDynamic
+};
+
+export const module2Env = module => {
+  return foldList(typeDict => dynamic => {
+    try {
+      return growEnv(typeDict)(dynamic);
+    } catch (e) {
+      console.log('warning:', e.message);
+      return typeDict;
+    }
+  })(emptyDict(compareTypes))(module);
+};
+
+export const getInstances = env => type => {
+  return getDict(env)(type) || emptySet(makeCompareFn(type));
+};
+
+export const getTypes = env => {
+  return getDict(env)(Type) || emptySet(compareTypes);
+};
+
+export const getFunctions = env => {
+  const types = getTypes(env);
+  return foldSet(types => type => {
+    if (getSymbol(type) === symbolFunction) {
+      return [
+        ...types,
+        ...foldSet
+          (functions => fn => [
+            ...functions,
+            newDynamic(fn)(type),
+          ])
+          ([])
+          (getInstances(env)(type)),
+      ];
+    }
+    return types;
+  })([])(types);
+};