From e838f9a4b18a381e861a78be642737a1e8385c5f Mon Sep 17 00:00:00 2001
From: hyper <hx.hyper@qq.com>
Date: Sat, 12 Sep 2026 23:44:24 +0800
Subject: [PATCH] fix(journal): tokenize bare dice notation

The tokenizer only recognized dice when the pattern started with a count (3d6), so a bare d20 fell through to the identifier branch and failed as an unknown identifier. Add a dedicated branch for the bare d-form; DICE_RE already accepted it.
---
 src/cli/completions/variable-system.test.ts   | 14 ++++++++++++++
 src/components/journal/variable-expression.ts | 18 +++++++++++++++++-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/cli/completions/variable-system.test.ts b/src/cli/completions/variable-system.test.ts
index 7989084..97bcfbf 100644
--- a/src/cli/completions/variable-system.test.ts
+++ b/src/cli/completions/variable-system.test.ts
@@ -379,6 +379,20 @@ describe("evaluateExpression", () => {
     expect(result.value.value).toBeLessThanOrEqual(23);
   });
 
+  test("evaluates bare dice notation", () => {
+    const result = evaluateExpression("d20", { lookup: () => undefined });
+    expect(result.value.kind).toBe("number");
+    expect(result.value.value).toBeGreaterThanOrEqual(1);
+    expect(result.value.value).toBeLessThanOrEqual(20);
+  });
+
+  test("evaluates bare dice alongside modifiers", () => {
+    const result = evaluateExpression("d6 + 5", { lookup: () => undefined });
+    expect(result.value.kind).toBe("number");
+    expect(result.value.value).toBeGreaterThanOrEqual(6);
+    expect(result.value.value).toBeLessThanOrEqual(11);
+  });
+
   test("throws on division by zero", () => {
     expect(() =>
       evaluateExpression("10 / 0", { lookup: () => undefined }),
diff --git a/src/components/journal/variable-expression.ts b/src/components/journal/variable-expression.ts
index 0cb21d4..9ad2362 100644
--- a/src/components/journal/variable-expression.ts
+++ b/src/components/journal/variable-expression.ts
@@ -6,7 +6,7 @@
  *   - Number literals (integer or decimal)
  *   - Tagmap literals: #warrior:1;#druid:2 (bare #warrior → #warrior:1)
  *   - $var references (resolved via lookup; auto-detects number vs tagmap)
- *   - Dice patterns: 3d6, 2d8kh1, etc. (delegates to rollFormula)
+ *   - Dice patterns: 3d6, 2d8kh1, d20, etc. (delegates to rollFormula)
  *   - Arithmetic: + - * / (type-checked via registry)
  *   - Functions: floor(x), ceil(x), round(x) (numbers only)
  *   - Parentheses for grouping
@@ -225,6 +225,22 @@ function tokenize(input: string): Token[] {
       continue;
     }
 
+    // Dice pattern without a leading count: e.g. "d20", "d6kh1". The number
+    // branch above only catches dice that start with a digit ("3d6"), so bare
+    // forms need their own branch before the generic identifier branch.
+    if (/[dD]/.test(ch) && i + 1 < input.length && /[0-9]/.test(input[i + 1])) {
+      let dice = "";
+      while (i < input.length && /[a-zA-Z0-9]/.test(input[i])) {
+        dice += input[i];
+        i++;
+      }
+      if (!DICE_RE.test(dice)) {
+        throw new Error(`Invalid dice notation: "${dice}"`);
+      }
+      tokens.push({ kind: "number", value: String(rollDice(dice)), raw: dice });
+      continue;
+    }
+
     // Tagmap literal: #warrior:1;#druid:2 or bare #warrior
     if (ch === "#") {
       let raw = "";