v1.1.1 - Memoization Bug Fix

🐛 Bug Fix Release

This patch release fixes a critical bug in the memoization system where assignment rules (:=) were unintentionally sharing cache state across multiple rules.

What's Fixed

Memoization Cache Bug - Assignment rules that called the same non-terminal would generate identical values instead of different ones:

Before Fix:
S ::= first A and second B;
A := pick X;
B := pick X;
X ::= a | b | c;

Output: "first a and second a" (both same) ❌

After Fix:
Output: "first a and second b" (different values) ✅

Root Cause

All assignment closures were unintentionally capturing a reference to the same $cache variable due to PHP's loop variable scope behavior. This was fixed by creating a factory method that ensures each assignment gets its own isolated cache variable.

Changes

• Fixed: Cache variable isolation in Generator.php
• Added: createAssignmentClosure() factory method
• Added: Comprehensive test suite in MemoizationTest.php
• Added: Reference test grammar demonstrating the fix
• Tested: All 160 existing tests pass with no regressions

Test Results

✅ All 160 tests passing
✅ 2 new memoization tests confirm proper behavior
✅ Counter-based weighted selection works correctly

Installation

composer require procionegobbo/polygen-php:^1.1.1

Files Changed

• src/Generator/Generator.php - Fixed closure cache sharing
• tests/Feature/MemoizationTest.php - New comprehensive tests
• grm/other/memoization_test.grm - Reference grammar
• MEMOIZATION_FIX_PLAN.md - Detailed analysis

Impact

This fix ensures that any grammar using multiple assignment rules with shared dependencies will now generate the expected diverse values instead of predictable identical output.

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