Host

:= {
    frame_count : U64,
    timestamp_nanos : U64,
    frame_time : F32,
    keys : List(U8),
    keys_pressed : List(U8),
    keys_released : List(U8),
    mouse : {
        buttons : List(U8),
        buttons_pressed : List(U8),
        buttons_released : List(U8),
        left : Bool,
        middle : Bool,
        right : Bool,
        wheel : F32,
        x : F32,
        y : F32,
    },
}

Host module - provides platform state and system effects

exit! : I32 => {  }

Exit the application with the given exit code. The exit happens after the current frame completes to allow proper cleanup.

get_screen_size! : () => ScreenSize

Get the current screen/window dimensions.

read_env_raw! : Host, Str => Try(Str, [NotFound])

Read an environment variable by key. Returns Ok with the value if found, or Err NotFound if not set.

read_env! : Host, Str => Try(Str, [NotFound])

Read an environment variable by key. Returns Ok with the value if found, or Err NotFound if not set.

read_file_raw! : Str => ReadFileRawResult

Raw hosted file read. Prefer read_file!.

read_file! : Str => Try(Str, [NotFound, ReadFailed])

Read a UTF-8 text file from disk.

random_i32! : I32, I32 => I32

Get a random integer in the range [min, max] (both endpoints included). The generator is seeded once at startup, so sequences differ between runs. Derive other ranges/floats from this, e.g. a random direction with if Host.random_i32!(0, 1) == 0 -1 else 1.

set_screen_size_raw! : { width : F32, height : F32 } => Try({  }, [NotSupported])

Set the window/screen size. Returns Err NotSupported on platforms that don't support window resizing (e.g., web).

set_screen_size! : { width : F32, height : F32 } => Try({  }, [NotSupported])

Set the window/screen size. Returns Err NotSupported on platforms that don't support window resizing (e.g., web).

set_target_fps! : I32 => {  }

Set the target frames per second for the render loop. Note: On web/WASM, this has no effect as the browser controls frame timing.

ScreenSize : { width : I32, height : I32 }

ReadFileRawResult : {
    ok : Bool,
    err : U8,
    contents : Str,
}