Problem compiling program

I'm having a hard time writing a program that fades in and out a led, this is what i'm trying:

module Blink
open(Prelude, Io, Time)

let boardLed = 11

let tState = Time:state()
let ledState = ref (0u16, high())

fun loop() = (
    fadeLed(boardLed, tState, ledState)    
)   

fun folder(_ : uint32, lastState: (uint16 * pinState)) = (
    case (lastState) of
    | (0, low()) => (1, high())
    | (x, low()) => (x - 1, low())
    | (100, high()) => (99, low())
    | (x, high()) => (x + 1, high())
    end
)

fun fadeLed(boardLed, tState, ledState) = (
    let timeSignal = Time:every(10, tState);
    let fader = Signal:foldP(folder, ledState, timeSignal);
    let pinSignal = Signal:map(fst, fader);
    Io:anaOut(boardLed, pinSignal)
)

fun setup() =
    Io:setPinMode(boardLed, Io:output())

However, i'm getting this message when i try to uptade the cpp to a arduino uno using platformIO:

> Executing task in folder Juniper: pio run --target upload <

Processing uno (platform: atmelavr; board: uno; framework: arduino)
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Verbose mode can be enabled via `-v, --verbose` option
CONFIGURATION: https://docs.platformio.org/page/boards/atmelavr/uno.html
PLATFORM: Atmel AVR (3.0.0) > Arduino Uno
HARDWARE: ATMEGA328P 16MHz, 2KB RAM, 31.50KB Flash
DEBUG: Current (avr-stub) On-board (avr-stub, simavr)
PACKAGES: 
 - framework-arduino-avr 5.1.0 
 - tool-avrdude 1.60300.200527 (6.3.0) 
 - toolchain-atmelavr 1.50400.190710 (5.4.0)
LDF: Library Dependency Finder -> http://bit.ly/configure-pio-ldf
LDF Modes: Finder ~ chain, Compatibility ~ soft
Found 5 compatible libraries
Scanning dependencies...
No dependencies
Building in release mode
Compiling .pio/build/uno/src/main.cpp.o
src/main.cpp: In instantiation of 'Result juniper::concrete_function<Func, Result, Args>::operator()(Args ...) [with Func = Prelude::tuple2<long int, Io::pinState> (*)(long unsigned int, Prelude::tuple2<unsigned int, Io::pinState>); Result = Prelude::tuple2<unsigned int, Io::pinState>; Args = {long unsigned int, Prelude::tuple2<unsigned int, Io::pinState>}]':
src/main.cpp:4504:1:   required from here
src/main.cpp:130:29: error: could not convert '((juniper::concrete_function<Prelude::tuple2<long int, Io::pinState> (*)(long unsigned int, Prelude::tuple2<unsigned int, Io::pinState>), Prelude::tuple2<unsigned int, Io::pinState>, long unsigned int, Prelude::tuple2<unsigned int, Io::pinState> >*)this)->juniper::concrete_function<Prelude::tuple2<long int, Io::pinState> (*)(long unsigned int, Prelude::tuple2<unsigned int, Io::pinState>), Prelude::tuple2<unsigned int, Io::pinState>, long unsigned int, Prelude::tuple2<unsigned int, Io::pinState> >::f(args#0, args#1)' from 'Prelude::tuple2<long int, Io::pinState>' to 'Prelude::tuple2<unsigned int, Io::pinState>'
             return f(args...);
                             ^
*** [.pio/build/uno/src/main.cpp.o] Error 1
================================================================================================= [FAILED] Took 0.56 seconds =================================================================================================
The terminal process "pio 'run', '--target', 'upload'" terminated with exit code: 1.

It there something i'm doing wrong?

calebh / Juniper

Problem compiling program #6