qpliu

Half-baked proposal: Error-return statement for Go (golang)

Code in Go that propagates errors can get pretty verbose. For example:

    a, err := ...
    if err != nil {
            return nil, err
    }

b, err := ...

qpliu

-- Implementation of version 1.1 of http://0x10c.com/doc/dcpu-16.txt.
-- This work is public domain.
module DCPU16 where

import Control.Monad(foldM)
import Data.Array.IO(IOArray)
import Data.Array.MArray(newListArray,readArray,writeArray)
import Data.Bits((.&.),(.|.),shiftL,shiftR,xor)
import Data.Ix(Ix)
import Data.Word(Word16,Word32)

qpliu

> import Control.Monad(MonadPlus(mzero),liftM,unless)

The regular filter can be implemented recursively:

> f1 _ [] = []
> f1 test (a:as) | test a = a : f1 test as | otherwise = f1 test as

Or the recursion can be abstracted:

> f2 test list = foldr (\ a rest -> if test a then a : rest else rest) [] list