Dice rollers!

frontend/app/services/widgets/DiceParser.js

@@ -1,4 +1,4 @@
-// dice-parser.js
+// DiceParser.js
 
 function roll(sides) {
   return Math.floor(Math.random() * sides) + 1;
@@ -27,10 +27,9 @@ export function parse(expr) {
   const tokens = tokenize(expr);
   if (!tokens.length) throw new Error('Empty expression');
   let pos = 0;
-  const rolls = [];
 
-  function peek() { return tokens[pos]; }
-  function consume() { return tokens[pos++]; }
+  const peek = () => tokens[pos];
+  const consume = () => tokens[pos++];
 
   function parseExpr() { return parseAddSub(); }
 
@@ -41,7 +40,7 @@ export function parse(expr) {
       const right = parseMulDiv();
       left = {
         value: op === '+' ? left.value + right.value : left.value - right.value,
-        rolls: [...left.rolls, ...right.rolls],
+        steps: [...left.steps, { type: 'op', op }, ...right.steps],
       };
     }
     return left;
@@ -55,7 +54,7 @@ export function parse(expr) {
       if (op === '/' && right.value === 0) throw new Error('Division by zero');
       left = {
         value: op === '*' ? left.value * right.value : Math.floor(left.value / right.value),
-        rolls: [...left.rolls, ...right.rolls],
+        steps: [...left.steps, { type: 'op', op }, ...right.steps],
       };
     }
     return left;
@@ -65,7 +64,7 @@ export function parse(expr) {
     if (peek() === '-') {
       consume();
       const r = parsePrimary();
-      return { value: -r.value, rolls: r.rolls };
+      return { value: -r.value, steps: [{ type: 'op', op: '-' }, ...r.steps] };
     }
     return parsePrimary();
   }
@@ -79,7 +78,10 @@ export function parse(expr) {
       const inner = parseExpr();
       if (peek() !== ')') throw new Error('Missing closing )');
       consume();
-      return inner;
+      return {
+        value: inner.value,
+        steps: [{ type: 'op', op: '(' }, ...inner.steps, { type: 'op', op: ')' }],
+      };
     }
 
     const diceInfo = parseDiceToken(tok);
@@ -90,7 +92,8 @@ export function parse(expr) {
 
     if (/^\d+$/.test(tok)) {
       consume();
-      return { value: parseInt(tok), rolls: [] };
+      const v = parseInt(tok);
+      return { value: v, steps: [{ type: 'const', value: v }] };
     }
 
     throw new Error(`Unexpected token: ${tok}`);
@@ -119,12 +122,13 @@ export function parse(expr) {
     }
 
     const entry = { sides, rawRolls, kept, mod, value: kept.reduce((a, b) => a + b, 0) };
-    rolls.push(entry);
-    return { value: entry.value, rolls: [entry] };
+    return {
+      value: entry.value,
+      steps: [{ type: 'dice', entry }],
+    };
   }
 
   const result = parseExpr();
   if (pos < tokens.length) throw new Error(`Unexpected token: ${tokens[pos]}`);
-
-  return { total: result.value, rolls: result.rolls };
+  return { total: result.value, steps: result.steps };
 }