[DISCOVERY] 6 Critical Stdlib Function Bugs Found

🛑 Toyota Way Jidoka: STOP THE LINE - Critical stdlib bugs discovered

Bugs Discovered (DEPYLER-0190 through DEPYLER-0195):
1. DEPYLER-0190: sorted() function missing implementation
2. DEPYLER-0191: reversed() function missing implementation
3. DEPYLER-0192: sum() function missing implementation
4. DEPYLER-0193: max() for iterables missing (std::cmp::max only works for 2 args)
5. DEPYLER-0194: min() for iterables missing (std::cmp::min only works for 2 args)
6. DEPYLER-0195: enumerate() type inference incorrect (usize vs i32, &str vs String)

Discovery Method:
- Systematic stdlib verification post-v3.19.5
- Transpiled /tmp/test_stdlib_itertools_builtins.py
- Compilation revealed 6 missing function errors

Impact Analysis:
- Functions broken: 6 fundamental Python builtins
- Severity: CRITICAL - ~15% of common builtins tested don't work
- User impact: Any code using sorted/reversed/sum/max/min fails to compile

Root Cause:
- Python builtin functions not mapped to Rust stdlib equivalents
- Need runtime helper functions or proper iterator method mapping

Documentation:
- All bugs documented in roadmap.yaml with:
  - Problem description & error messages
  - Root cause analysis
  - Expected output/solution approach
  - Priority & severity assessment

Next Steps:
- Decide: Fix immediately OR continue verification
- Create comprehensive test suite for ALL stdlib functions
- Implement runtime library with helper functions

🎯 Validation-Driven Development: We WANT to find bugs!

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: Claude

docs/execution/roadmap.yaml

@@ -12,18 +12,19 @@ metadata:
   next_version: v3.19.6
 
 session_context:
-  achievement: "✅ v3.19.5 PUBLISHED - DEPYLER-0189 Fixed"
-  latest_work: "Successfully published v3.19.5 to crates.io with critical test generation panic fix. All 9 crates published: depyler, depyler-core, depyler-analyzer, depyler-verify, depyler-mcp, depyler-quality, depyler-ruchy, depyler-wasm, depyler-annotations. GitHub release created. Ready to continue stdlib verification."
+  achievement: "🛑 STDLIB VERIFICATION - 6 CRITICAL BUGS FOUND"
+  latest_work: "Discovered 6 critical stdlib function bugs during systematic verification: sorted(), reversed(), sum(), max(), min() all missing implementations, plus enumerate() type inference error. Applied Toyota Way Jidoka - STOP THE LINE to document bugs. All bugs documented in roadmap (DEPYLER-0190 through DEPYLER-0195). Impact: ~15% of common Python builtins don't work. Ready to fix or continue discovery."
   recent_completions:
     - "✅ PUBLISHED: v3.19.5 to crates.io (all 9 crates)"
-    - "✅ FIXED: DEPYLER-0189 (Test generation panic - array bounds)"
-    - "✅ Added 5 defensive bounds checks in test_generation.rs"
-    - "✅ 443/443 tests passing (100%)"
-    - "✅ Zero regressions maintained"
-    - "✅ Extreme TDD & Toyota Way Jidoka applied"
-    - "✅ Defense-in-depth strategy implemented"
-  next_focus: "Continue stdlib verification to discover more bugs"
-  current_status: "READY_FOR_VERIFICATION"
+    - "✅ DISCOVERED: DEPYLER-0190 (sorted() missing)"
+    - "✅ DISCOVERED: DEPYLER-0191 (reversed() missing)"
+    - "✅ DISCOVERED: DEPYLER-0192 (sum() missing)"
+    - "✅ DISCOVERED: DEPYLER-0193 (max() for iterables missing)"
+    - "✅ DISCOVERED: DEPYLER-0194 (min() for iterables missing)"
+    - "✅ DISCOVERED: DEPYLER-0195 (enumerate() type inference error)"
+    - "✅ Documented all 6 bugs in roadmap with root cause analysis"
+  next_focus: "Decide: Fix stdlib bugs immediately OR continue verification to find more bugs"
+  current_status: "BUGS_DISCOVERED_DOCUMENTED"
 
 # ============================================================================
 # v3.18.0 MODULARIZATION PROJECT
@@ -2675,3 +2676,140 @@ metrics_history:
       total: 393
     coverage:
       status: TIMEOUT
+# ============================================================================
+# v3.19.6 STDLIB VERIFICATION SPRINT - 6 CRITICAL BUGS FOUND
+# ============================================================================
+
+v3_19_6_stdlib_verification:
+  name: "Stdlib Function Verification Sprint"
+  status: IN_PROGRESS
+  priority: P0
+  start_date: 2025-10-14
+  target_completion: 2025-10-15
+  
+  trigger:
+    event: "Post-v3.19.5 Stdlib Verification"
+    method: "Systematic testing of Python stdlib functions"
+    severity: CRITICAL
+    action_taken: "HALT - Fix stdlib function generation bugs"
+  
+  discovery_method: "Toyota Way Jidoka - Validation-Driven Development"
+  philosophy: "We WANT to find bugs to improve transpiler quality"
+  
+  bugs_discovered: 6
+  
+  tickets:
+    - ticket_id: DEPYLER-0190
+      name: "Missing sorted() function implementation"
+      priority: P0
+      severity: BLOCKING
+      status: DISCOVERED
+      
+      problem:
+        code: "let result = sorted(numbers);"
+        error: "cannot find function `sorted` in this scope"
+        impact: "sorted() is fundamental Python builtin - must work"
+      
+      root_cause:
+        issue: "sorted() not mapped to Rust stdlib equivalent"
+        missing: "Need to generate helper function or use .sort() method"
+        expected_output: |
+          fn sorted<T: Ord + Clone>(mut items: Vec<T>) -> Vec<T> {
+              items.sort();
+              items
+          }
+    
+    - ticket_id: DEPYLER-0191
+      name: "Missing reversed() function implementation"
+      priority: P0
+      severity: BLOCKING
+      status: DISCOVERED
+      
+      problem:
+        code: "let result = reversed(numbers).into_iter().collect::<Vec<_>>();"
+        error: "cannot find function `reversed` in this scope"
+        impact: "reversed() is fundamental Python builtin"
+      
+      root_cause:
+        issue: "reversed() not mapped to Rust stdlib equivalent"
+        expected_output: |
+          fn reversed<T>(mut items: Vec<T>) -> Vec<T> {
+              items.reverse();
+              items
+          }
+    
+    - ticket_id: DEPYLER-0192
+      name: "Missing sum() function implementation"
+      priority: P0
+      severity: BLOCKING
+      status: DISCOVERED
+      
+      problem:
+        code: "let _cse_temp_0 = sum(numbers);"
+        error: "cannot find function `sum` in this scope"
+        impact: "sum() is fundamental Python builtin"
+      
+      root_cause:
+        issue: "sum() not mapped to Rust iterator method"
+        expected_output: "numbers.iter().sum()"
+    
+    - ticket_id: DEPYLER-0193
+      name: "Missing max() function for iterables"
+      priority: P0
+      severity: BLOCKING
+      status: DISCOVERED
+      
+      problem:
+        code: "let _cse_temp_0 = max(numbers);"
+        error: "cannot find function `max` in this scope"
+        impact: "max() is fundamental Python builtin"
+      
+      root_cause:
+        issue: "max() not mapped correctly for Vec<T>"
+        note: "std::cmp::max works for 2 args, not iterables"
+        expected_output: "numbers.into_iter().max().unwrap()"
+    
+    - ticket_id: DEPYLER-0194
+      name: "Missing min() function for iterables"
+      priority: P0
+      severity: BLOCKING
+      status: DISCOVERED
+      
+      problem:
+        code: "let _cse_temp_0 = min(numbers);"
+        error: "cannot find function `min` in this scope"
+        impact: "min() is fundamental Python builtin"
+      
+      root_cause:
+        issue: "min() not mapped correctly for Vec<T>"
+        note: "std::cmp::min works for 2 args, not iterables"
+        expected_output: "numbers.into_iter().min().unwrap()"
+    
+    - ticket_id: DEPYLER-0195
+      name: "enumerate() type inference incorrect"
+      priority: P1
+      severity: MAJOR
+      status: DISCOVERED
+      
+      problem:
+        code: "pub fn test_enumerate_simple() -> Vec<(i32, String)>"
+        error: "expected `Vec<(i32, String)>`, found `Vec<(usize, &str)>`"
+        impact: "Type signatures don't match Python annotations"
+      
+      root_cause:
+        issue: "enumerate() generates usize (correct) but type annotation says i32"
+        note: "Also &str vs String mismatch"
+        fix_needed: "Better type inference or explicit casting"
+  
+  impact_analysis:
+    functions_broken: 6
+    percentage_stdlib: "~15% of common builtins tested"
+    severity: "CRITICAL - Core Python builtins don't work"
+    user_impact: "Any code using sorted/reversed/sum/max/min fails"
+  
+  next_steps:
+    - "Create failing test cases for all 6 bugs"
+    - "Implement stdlib function helpers in runtime library"
+    - "Update code generator to emit proper stdlib calls"
+    - "Add CI validation for stdlib functions"
+    - "Document all stdlib function mappings"