chore(labrat): Convert to TS

Author: pdubroy

packages/labrat/index.test.js renamed to packages/labrat/index.test.ts

@@ -1,17 +1,17 @@
 import assert from 'node:assert/strict';
 import test from 'node:test';
 
-import {Matcher, RuleApplication, Sequence, Choice, Terminal, Repetition} from './index.js';
+import {Matcher, RuleApplication, Sequence, Choice, Terminal, Repetition} from './index.ts';
 
 test('basic matcher', () => {
   const m = new Matcher({
     start: new RuleApplication('exp'),
     exp: new Sequence([
       new RuleApplication('var'),
-      new Repetition(new Sequence([new RuleApplication('op'), new RuleApplication('var')])),
+      new Repetition(new Sequence([new RuleApplication('op'), new RuleApplication('var')]))
     ]),
     op: new Choice([new Terminal('+'), new Terminal('-')]),
-    var: new Choice([new Terminal('x'), new Terminal('y'), new Terminal('z')]),
+    var: new Choice([new Terminal('x'), new Terminal('y'), new Terminal('z')])
   });
 
   assert.ok(m.match('x'));
@@ -27,11 +27,11 @@ test('left recursion', () => {
       new Sequence([
         new RuleApplication('mulExp'),
         new Terminal('+'),
-        new RuleApplication('priExp'),
+        new RuleApplication('priExp')
       ]),
-      new RuleApplication('priExp'),
+      new RuleApplication('priExp')
     ]),
-    priExp: new Choice([new Terminal('pi'), new Terminal('x')]),
+    priExp: new Choice([new Terminal('pi'), new Terminal('x')])
   });
   assert.ok(g.match('pi+pi+x'));
 });

packages/labrat/index.js renamed to packages/labrat/index.ts

@@ -1,9 +1,32 @@
+interface PExpr {
+  eval(matcher: Matcher): CstNode;
+}
+
+type RuleDict = {
+  [name: string]: PExpr;
+};
+
+type CstNode = string | true | null | CstNode[];
+
+interface MemoRec {
+  cst: CstNode;
+  nextPos: number;
+  used?: boolean;
+}
+
+type MemoCol = {[key: string]: MemoRec};
+
 class Matcher {
-  constructor(rules) {
+  rules: RuleDict;
+  input: string = '';
+  pos: number = 0;
+  memoTable: MemoCol[] = [];
+
+  constructor(rules: RuleDict) {
     this.rules = rules;
   }
 
-  match(input) {
+  match(input: string): CstNode {
     this.input = input;
     this.pos = 0;
     this.memoTable = [];
@@ -14,7 +37,7 @@ class Matcher {
     return null;
   }
 
-  memoTableAt(pos) {
+  memoTableAt(pos: number): MemoCol {
     let memo = this.memoTable[pos];
     if (!memo) {
       // Lazily initialize the memo column.
@@ -23,17 +46,17 @@ class Matcher {
     return memo;
   }
 
-  hasMemoizedResult(ruleName) {
+  hasMemoizedResult(ruleName: string) {
     return !!this.memoTableAt(this.pos)[ruleName];
   }
 
-  memoizeResult(ruleName, pos, cst) {
+  memoizeResult(ruleName: string, pos: number, cst: CstNode): MemoRec {
     const result = {cst, nextPos: this.pos};
     this.memoTableAt(pos)[ruleName] = result;
     return result;
   }
 
-  useMemoizedResult(ruleName) {
+  useMemoizedResult(ruleName: string) {
     const result = this.memoTableAt(this.pos)[ruleName];
     // Unconditionally set the position. If it was a failure, `result.cst`
     // is `null` and the assignment to `this.pos` is a noop.
@@ -44,13 +67,13 @@ class Matcher {
     return result.cst;
   }
 
-  memoizeLRFailureAtCurrPos(ruleName) {
+  memoizeLRFailureAtCurrPos(ruleName: string) {
     const lrFailure = {cst: null, nextPos: -1, used: false};
     this.memoTableAt(this.pos)[ruleName] = lrFailure;
     return lrFailure;
   }
 
-  consume(c) {
+  consume(c: string) {
     if (this.input[this.pos] === c) {
       this.pos++;
       return true;
@@ -59,12 +82,14 @@ class Matcher {
   }
 }
 
-class RuleApplication {
-  constructor(ruleName) {
+class RuleApplication implements PExpr {
+  ruleName: string;
+
+  constructor(ruleName: string) {
     this.ruleName = ruleName;
   }
 
-  eval(matcher) {
+  eval(matcher: Matcher) {
     if (matcher.hasMemoizedResult(this.ruleName)) {
       return matcher.useMemoizedResult(this.ruleName);
     }
@@ -85,12 +110,14 @@ class RuleApplication {
   }
 }
 
-class Terminal {
-  constructor(str) {
+class Terminal implements PExpr {
+  str: string;
+
+  constructor(str: string) {
     this.str = str;
   }
 
-  eval(matcher) {
+  eval(matcher: Matcher) {
     for (let i = 0; i < this.str.length; i++) {
       if (!matcher.consume(this.str[i])) {
         return null;
@@ -100,12 +127,14 @@ class Terminal {
   }
 }
 
-class Choice {
-  constructor(exps) {
+class Choice implements PExpr {
+  exps: PExpr[];
+
+  constructor(exps: PExpr[]) {
     this.exps = exps;
   }
 
-  eval(matcher) {
+  eval(matcher: Matcher) {
     const origPos = matcher.pos;
     for (let i = 0; i < this.exps.length; i++) {
       matcher.pos = origPos;
@@ -118,13 +147,15 @@ class Choice {
   }
 }
 
-class Sequence {
-  constructor(exps) {
+class Sequence implements PExpr {
+  exps: PExpr[];
+
+  constructor(exps: PExpr[]) {
     this.exps = exps;
   }
 
-  eval(matcher) {
-    const ans = [];
+  eval(matcher: Matcher) {
+    const ans: CstNode = [];
     for (let i = 0; i < this.exps.length; i++) {
       const exp = this.exps[i];
       const cst = exp.eval(matcher);
@@ -139,12 +170,14 @@ class Sequence {
   }
 }
 
-class Not {
-  constructor(exp) {
+class Not implements PExpr {
+  exp: PExpr;
+
+  constructor(exp: PExpr) {
     this.exp = exp;
   }
 
-  eval(matcher) {
+  eval(matcher: Matcher) {
     const origPos = matcher.pos;
     if (this.exp.eval(matcher) === null) {
       matcher.pos = origPos;
@@ -154,13 +187,15 @@ class Not {
   }
 }
 
-class Repetition {
-  constructor(exp) {
+class Repetition implements PExpr {
+  exp: PExpr;
+
+  constructor(exp: PExpr) {
     this.exp = exp;
   }
 
-  eval(matcher) {
-    const ans = [];
+  eval(matcher: Matcher) {
+    const ans: CstNode = [];
     while (true) {
       const origPos = matcher.pos;
       const cst = this.exp.eval(matcher);

packages/labrat/package.json

@@ -2,6 +2,11 @@
   "private": true,
   "type": "module",
   "scripts": {
-    "test": "node --test"
+    "test": "node --test",
+    "build": "tsc --noEmit"
+  },
+  "devDependencies": {
+    "@types/node": "^16.18.126",
+    "typescript": "^5.8.3"
   }
 }

packages/labrat/tsconfig.json

@@ -0,0 +1,20 @@
+{
+  "files": ["index.ts", "index.test.ts"],
+
+  // Based on the following:
+  // https://www.npmjs.com/package/@tsconfig/recommended
+  // https://www.npmjs.com/package/@tsconfig/node-ts
+  // https://www.npmjs.com/package/@tsconfig/node24
+  "compilerOptions": {
+    "erasableSyntaxOnly": true,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "module": "nodenext",
+    "moduleResolution": "nodenext",
+    "rewriteRelativeImportExtensions": true,
+    "skipLibCheck": true,
+    "strict": true,
+    "verbatimModuleSyntax": true
+  },
+  "$schema": "https://json.schemastore.org/tsconfig"
+}