[csubbdev]

Summary

Adds optional C-style types to Ascend, a batch of language upgrades and new builtins, VS Code syntax highlighting, and a GitHub Actions build.

C-style types

u8 age = 30
f32 ratio = 0.5
char grade = 'A'
string? nickname          // ? allows null; starts as null
i32 count                 // starts at 0
const f64 RATE = 0.07

i32 add(i32 a, i32 b = 1) {
    return a + b
}

void log(string message) {
    print("log:", message)
}

• Types: i8 i16 i32 i64 u8 u16 u32 u64 byte int f32 f64 float bool char string list map func any, void for return types, and nullable T?.
• Every number carries its type. Arithmetic stays in that type, literals adapt to the other operand, mixed types widen to a type that holds both, and overflow is an error instead of a silent wrap.
• Typed variables, parameters and return values are checked. Literal mismatches like u8 x = 300 are reported before the program runs.
• Untyped code still works (x := 5, func f(a, b) { }). The name: type form is rejected with a hint showing the C-style spelling.

Language

• const, match, f-strings with format specs (f"{price:>8.2f}"), a char type, Unicode-aware strings
• Hex/binary/octal literals, type suffixes (255u8), bitwise operators & | ^ ~ << >>
• Modules via import("file"); errors inside a module point at that module's file

Tools

• 124 builtins, including file I/O, JSON, format, string/list/map helpers, math, time and system functions
• ascend --check file.asc finds errors without running
• VS Code syntax highlighting in editors/vscode, checked with VS Code's TextMate engine

CI

.github/workflows/build.yml builds and tests on Linux (GCC and Clang), macOS and Windows (MSVC), runs the tests under ASan and UBSan, and uploads the built interpreters as artifacts.

Behavior changes

These are listed in CHANGELOG.md:

• Single quotes now make a char, so strings need double quotes.
• & and | are now bitwise operators; use and/or for logic.
• Indexing a string gives a char. s[0] == "a" still works.
• String lengths and indexes count characters, not bytes.

Windows fix found by CI

The first Windows run crashed in the deep-recursion test. Two commits fix it:

• The stack guard now measures the real stack on every platform (GetCurrentThreadStackLimits on Windows) and also protects the parser.
• Errors no longer get caught and rethrown at every evaluation level to attach their location. With MSVC, each rethrow runs on top of the frames still being unwound, so thousands of them overflowed the stack. The location is now recorded in a destructor and applied once. Error messages and locations are unchanged.

The test runner now prints each test's name before running it, so a future crash shows which test caused it.

Testing

• CI passes on all five jobs: Linux (GCC), Linux (Clang), macOS, Windows (MSVC), and the ASan + UBSan run.
• 114 unit tests plus all 13 example programs run through ctest, with no compiler warnings on GCC or Clang.

🤖 Generated with Claude Code

https://claude.ai/code/session_014xWEy3pVr7ofMaomGRbiuo