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    proton_ffi

    MoonBit Foreign Function Interface.

    ffi
    bindings
    abi
    utils
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    Version
    0.2.5
    License
    Apache-2.0
    Repository
    Last updated
    10 days ago
    Downloads
    7K

    Dependencies

    #moonbit-community/proton_ffi

    Helpers for converting MoonBit String values to and from null-terminated UTF-8 and UTF-16LE buffers at FFI boundaries.

    Originally developed at justjavac/moonbit-ffi; now maintained inside the Proton repository and licensed under Apache-2.0.

    #Usage

    ///|
    test {
      let c_name = @proton_ffi.to_cstr("ffi")
      assert_eq(c_name, b"ffi\x00")
      assert_eq(@proton_ffi.from_cstr(c_name), "ffi")

      let wide_name = @proton_ffi.to_wstr("世界")
      assert_eq(@proton_ffi.from_wstr_lossy(wide_name), "世界")
    }

    EventWakeup

    source
    #external
    pub type EventWakeup

    An opaque native callback that wakes an embedding host event loop.

    MoonBit code may only pass this token back to a native event producer. It cannot invoke or wrap the callback, which keeps foreign threads out of the MoonBit runtime.

    from_cstr

    source
    fn from_cstr(b : Bytes) -> String

    Decode a null-terminated UTF-8 buffer into a MoonBit String.

    from_cstr requires a trailing \x00, removes that terminator, and then decodes the remaining bytes as UTF-8. Invalid byte sequences are replaced with the Unicode replacement character so callers can safely inspect or log malformed input that came from native code.

    Parameters

    • b: A C-style byte buffer that must end with \x00

    Returns

    The decoded string without the trailing null byte.

    Panics

    Aborts if b is empty or does not end with \x00.

    Example

    let raw = @proton_ffi.to_cstr("hello")
    inspect(@proton_ffi.from_cstr(raw), content="hello")

    from_wstr_lossy

    source
    fn from_wstr_lossy(b : Bytes) -> String

    Decode a null-terminated UTF-16LE buffer into a MoonBit String.

    The trailing wide null (\x00\x00) is required and removed before decoding. Invalid UTF-16 sequences are replaced with the Unicode replacement character, which keeps the function safe for lossy logging and interop code.

    Parameters

    • b: A UTF-16LE byte buffer that must end with \x00\x00

    Returns

    The decoded string without the trailing wide null.

    Panics

    Aborts if b is shorter than two bytes or is missing the trailing wide null terminator.

    Example

    let raw = @proton_ffi.to_wstr("Hello")
    inspect(@proton_ffi.from_wstr_lossy(raw), content="Hello")

    to_cstr

    source
    fn to_cstr(s : String) -> Bytes

    Encode a MoonBit String as a null-terminated UTF-8 buffer.

    This is the companion to from_cstr. The returned Bytes value is suitable for passing to C APIs that expect UTF-8 char* input terminated by a single zero byte.

    Parameters

    • s: The MoonBit string to encode

    Returns

    UTF-8 bytes for s followed by a trailing \x00.

    Example

    inspect(@proton_ffi.to_cstr("ffi"), content=b"ffi\x00")

    to_wstr

    source
    fn to_wstr(s : String) -> Bytes

    Encode a MoonBit String as a null-terminated UTF-16LE buffer.

    Use this when calling Windows APIs that accept wchar_t* or LPCWSTR values. The returned bytes always end with a wide null terminator.

    Parameters

    • s: The MoonBit string to encode

    Returns

    UTF-16LE bytes for s followed by \x00\x00.

    Example

    inspect(@proton_ffi.to_wstr("Hi"), content=b"\x48\x00\x69\x00\x00\x00")

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