TODO.txt

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                        HYPERCODE COURSE IMPROVEMENT TODO
                              88 courses, ~415+ lessons
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  SECTION 1: CRITICAL / INFRASTRUCTURE ISSUES  (ALL DONE)
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[x] MISSING TEST RUNNERS - Created algorithms + distributed-systems + three.js runners
[x] C COURSE INDEX BUG - Renamed file, fixed import
[x] ELIXIR LESSON 13 TRUNCATED - Fixed text and numbering
[x] RAY TRACER COURSE MISSING - Already exists


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  SECTION 2: TEST COVERAGE GAPS  (ALL DONE)
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[x] Java - 62 tests    [x] C++ - 67 tests     [x] Elixir - 48 tests
[x] HolyC - 54 tests   [x] SQL - 75 tests     [x] C - 130 tests
[x] ARM64 - 54 tests   [x] Ruby - 45 tests    [x] Chaos Theory - 60 tests
[x] Kotlin - 51 tests  [x] Linux - 51 tests   [x] Coreutils - 92 tests
[x] Kernel - 89 tests  [x] DS - 54 tests      [x] Rust - 110 tests
[x] Algorithms - 79 tests  [x] Three.js - 54 tests
[x] All other courses already had good coverage


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  SECTION 3: MISSING CONCEPTS BY COURSE
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---------- Programming Languages ----------

[x] Go - Added variadic functions lesson + copy()/nil-vs-empty slice content
    + init() explanation + embedded interfaces (67/67 pass)

[x] Zig - Added tagged unions exercise, @divTrunc, comptime generics lesson,
    recursive data structures (linked list), safety & build modes (65/65 pass)

[x] Rust - Added capture semantics + scan() vs fold() (110/110 pass)

[x] C++ - Added smart pointers, STL algorithms, destructors, copy/move semantics (70/70)

[x] C - Added unions, const correctness, heap vs stack, valgrind notes (130/130)

[x] Java - Added exception handling, enums, static/final, lambda expressions,
    access modifiers (65/65 pass)

[x] Python - Added decorator, set operation explanations

[x] JavaScript - Added immutability notes to map/filter

[x] TypeScript - Added optional/rest params + as const content (49/49 pass)

[x] Ruby - Added :: scope resolution and ? suffix convention

[x] Haskell - Added module system lesson + factorial explanation

[x] Gleam - Added recursion lesson before FizzBuzz

[x] Kotlin - Added null-safety + scope functions/extension functions (51/51)

[x] HolyC - Added structs + recursion lessons (54 tests)

[x] Lean - Added dependent types, inductive types, proof tactics content

[x] Elixir - Added comprehensions & streams lesson (48/48 pass)

---------- Databases ----------

[x] SQL/PostgreSQL - Added Transactions + Views lessons (75/75 pass)
[x] SQLite - Added Transactions & Savepoints + PRAGMA & CTEs lessons (40/40 pass)
[ ] MySQL - Uses SQLite as emulator; MySQL-specific features can't be tested
[x] Redis - Added Streams + Geospatial lessons (42/42 pass)

---------- CS / Systems ----------

[x] Algorithms - Added hash table, min heap, trie, union-find, topological
    sort lessons (79/79 pass)
[x] Distributed Systems - Added CAP theorem + time synchronization lessons (57/57)
[x] Trees - Added BST deletion + AVL tree lessons (56/56 pass)
[x] Linked Lists - Added doubly linked list + Floyd's cycle detection (54/54)
[x] Kernel - Added all 5 state transitions + dup/dup2 (89/89 pass)

---------- Finance ----------

[x] Algorithmic Trading - Added drawdown limits + volatility targeting (64/64)
[x] Options Pricing - Added volatility smile/skew content (62/62)
[x] Portfolio Theory - Added N-asset optimization + risk parity (63/63)

---------- ML / AI ----------

[x] Machine Learning - Added cross-validation, evaluation metrics (72/72)
[x] Neural Networks - Added GELU/SiLU, He init, batch processing (56/56)
[x] MicroGPT - Added log-sum-exp, BPE tokenization, positional encoding (21/21)

---------- Web ----------

[x] HTML - Added DOCTYPE, ARIA, script defer/async explanations
[x] CSS - Added specificity, CSS variables, inheritance explanations
[x] Tailwind - Added configuration/customization lesson (63/63 pass)
[x] Three.js - Added shadows lesson + test runner (54/54 pass)

---------- Science ----------

[x] Fluid Mechanics - 16 lessons confirmed intentional


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  SECTION 4: CONTENT QUALITY ISSUES  (ALL DONE)
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[x] All confusing/misleading explanations fixed (10 items)
[x] All difficulty progression issues fixed (7 items)
[x] Star Trek Theme Consistency - Added transporter/viewscreen references to lessons 23-24


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  SECTION 5: PEDAGOGICAL IMPROVEMENTS  (ALL DONE)
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[x] All task/exercise design issues fixed (5 items)
[x] All "why" explanations added (6 items)
[x] Test count standardized, naming improved, notation disambiguated
[x] String handling consistency - Standardized .trim() on all 80 test runners


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  SECTION 6: NEW COURSES / LESSONS TO CONSIDER
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---------- High Value Additions (ALL DONE) ----------

[x] Java Exception Handling + Enums + Static/Final + Lambdas (62/62)
[x] SQL Transactions + Views (75/75)
[x] SQLite Transactions (40/40)
[x] Haskell Module System
[x] Gleam Recursion
[x] C++ Smart Pointers + STL Algorithms + Destructors (67/67)
[x] Kotlin Null Safety + Scope Functions (51/51)
[x] HolyC Structs + Recursion (54 tests)
[x] Algorithms Hash Table + Min Heap + Trie + Union-Find + Topo Sort (79/79)
[x] Trees BST Deletion (52/52)
[x] Linked Lists Doubly Linked List + Cycle Detection (54/54)
[x] Go Variadic Functions (64/64)
[x] C Unions (130/130)
[x] Elixir Comprehensions & Streams (48/48)
[x] Zig Comptime Generics + Recursive Data Structures + Safety Modes (65/65)
[x] Redis Streams + Geospatial (42/42)
[x] Distributed Systems CAP Theorem (54/54)
[x] MicroGPT BPE + Positional Encoding (21/21)
[x] Tailwind Configuration (63/63)
[x] Three.js Shadows (54/54)

---------- Course Gaps (requires entirely new courses - very large scope) ----------

[x] No Lua course - Created (15 lessons, 29 tests, Lua→JS transpiler)
[x] No Perl course - Created (15 lessons, 50 tests, Perl→JS transpiler)
[x] No OCaml course - Created (15 lessons, 37 tests, OCaml→JS transpiler)
[x] No Assembly x86_64 course - Created (15 lessons, 15 tests, x86 assembler+interpreter)
[x] No networking course - Created (15 lessons, 58 tests, JS runner)
[x] No compiler/interpreter course - Created (15 lessons, 45 tests, JS runner)
[x] No real analysis course - Created (15 lessons, 52 tests, Python runner)
[x] No abstract algebra course - Created (15 lessons, 51 tests, Python runner)
[x] No graph theory dedicated course - Already exists (15 lessons, "Graphs in Python")


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  SECTION 7: TEST INFRASTRUCTURE IMPROVEMENTS  (ALL DONE except MySQL limitation)
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[x] SQL/SQLite/MySQL - Improved from row counts to actual data checks
[x] Three.js - Created test runner (was missing entirely)

[x] HTML/CSS/Tailwind tests only check tag/property presence via regex - by design, acceptable
[x] Music tests - confirmed NOT brittle, .toFixed() precision is appropriate
[x] R tests - fixed whitespace normalization in test runner
[x] Property-based testing - added sorting invariant tests (commutativity, length preservation)
[x] Numerical stability tests: BS edge cases (63/63), softmax large logits (22/22), sigmoid overflow fix (73/73)
[x] Gradient validation tests - added central-difference gradient checking for neural networks
[x] Performance/efficiency tests for algorithms - added scaling tests (100-10000 elements)
[ ] MySQL uses SQLite as emulator; MySQL-specific features untestable - platform limitation


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  SECTION 8: MINOR POLISH  (ALL DONE)
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[x] All 7 items completed


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  REMAINING ITEMS
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PLATFORM LIMITATION (not fixable):
   - MySQL uses SQLite emulator (can't test MySQL-specific features)

ALL other items across all 8 sections have been completed, including:
   - All 8 new courses (Lua, Perl, OCaml, x86_64, networking, compiler,
     real analysis, abstract algebra) created with full test coverage
   - Fixed extractPythonFunctions to properly handle uppercase variable
     assignments that contain function calls (was breaking AdvLA + Crypto tests)
   - Added dotnet skip check to C# test runner (matches other CLI-dependent runners)
   - Full test suite: 5313/5313 passing (6 courses skipped: no CLI installed)

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  END OF TODO
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