Revise term output function

src/termoutput.test.ts

@@ -0,0 +1,16 @@
+import { test, expect } from 'vitest';
+import { dataToTerm, termToData, termToString } from './termoutput.js';
+
+test('termToString', () => {
+  expect(termToString(dataToTerm(termToData(null)))).toBe('()');
+  expect(termToString(dataToTerm(termToData(-12)))).toBe('-12');
+  expect(termToString(dataToTerm(termToData(12n)))).toBe('12');
+  expect(termToString(dataToTerm(termToData(false)))).toBe('bool#false');
+  expect(termToString(dataToTerm(termToData('hello world')))).toBe('"hello world"');
+  expect(
+    termToString(
+      dataToTerm(termToData({ name: 's', args: [{ name: 's', args: [{ name: 'z' }] }] })),
+    ),
+  ).toBe('s (s z)');
+  expect(termToString(dataToTerm(termToData({ name: 'const', args: [] })))).toBe('const');
+});

src/termoutput.ts

@@ -1,4 +1,4 @@
-import { Data, TRIVIAL, expose, hide } from './datastructures/data.js';
+import { Data, TRIVIAL, escapeString, expose, hide } from './datastructures/data.js';
 
 export type Term =
   | null // Trivial type ()
@@ -52,19 +52,14 @@ export function termToData(tm: InputTerm): Data {
   return hide({ type: 'int', value: BigInt(tm) });
 }
 
-export function termToString(t: Term) {
-  let s = '';
-  if (t.name) {
-    s += t.name;
-  }
-  if (t.args) {
-    s = '(' + s;
-    for (const t2 of t.args) s += ' ' + termToString(t2);
-    s += ')';
-  }
-  if (!t.name && !t.args) {
-    // it's a base type like int or string that js already knows how to print
-    return t;
-  }
-  return s;
+export function termToString(tm: Term, parens = false): String {
+  if (tm === null) return '()';
+  if (typeof tm === 'boolean') return `bool#${tm}`;
+  if (typeof tm === 'string') return `"${escapeString(tm)}"`;
+  if (typeof tm === 'bigint') return `${tm}`;
+  if (tm.name === null) return `ref#${tm.value}`;
+  if (!tm.args) return tm.name;
+  const tmStr = `${tm.name} ${tm.args.map((arg) => termToString(arg, true)).join('')}`;
+  if (!parens) return tmStr;
+  return `(${tmStr})`;
 }