reorganize directory and file structure

lib/util/pretty.js

@@ -0,0 +1,49 @@
+import { inspect } from 'node:util';
+import { symbolDict, symbolFunction, symbolList, symbolProduct, symbolSum } from '../structures/type_constructors.js';
+import { symbolSet } from "../structures/type_constructors.js";
+import { mapRecursiveStructure } from './util.js';
+import { getHumanReadableName } from '../primitives/symbol.js';
+
+export function pretty(obj) {
+  return inspect(obj, { colors: true, depth: null, breakLength: 120 });
+}
+
+// Pretty print Type
+export const prettyT = type => {
+  return mapRecursiveStructure(([type, m, seen], map) => {
+    if (typeof type === "symbol") {
+      // type variable
+      return type.description;
+    }
+    // if (type.params === undefined) {
+    //   throw new Error("parameter is not a Type ... did you mean to call prettyGenT instead?")
+    // }
+    if (!m.has(type)) {
+      m.add(type); // next time we encounter this type, we'll only render a placeholder
+      const params = type.params.map(p => map([p(type), m, seen])());
+      // if while visiting the children, we encountered ourselves, add annotation:
+      const annot = seen.has(type) ? seen.get(type) : ``;
+      return renderType(type.symbol, annot, params);
+    }
+    if (!seen.has(type)) {
+      seen.set(type, `#${seen.size}`);
+    }
+    return seen.get(type);
+  })([type, new Set(), new Map()])();
+};
+
+const renderType = (symbol, annot, params) => {
+  return {
+    [symbolList]    : `${annot}[${params[0]}]`,
+    [symbolSet]     : `${annot}{${params[0]}}`,
+    [symbolFunction]: `${annot}(${params[0]} -> ${params[1]})`,
+    [symbolSum]     : `${annot}(${params[0]} + ${params[1]})`,
+    [symbolProduct] : `${annot}(${params[0]} ⨯ ${params[1]})`,
+    [symbolDict]    : `${annot}(${params[0]} => ${params[1]})`,
+  }[symbol] || getHumanReadableName(symbol);
+};
+
+// Pretty print GenericType
+export const prettyGenT = genericType => {
+  return `∀${[...genericType.typeVars].map(prettyT).sort((a, b) => a.localeCompare(b)).join(",")}: ${prettyT(genericType.type)}`;
+};