Edward Z. Yang ezyang

Keybase proof

I hereby claim:

I am ezyang on github.
I am ezyang (https://keybase.io/ezyang) on keybase.
I have a public key whose fingerprint is 4BC5 AC12 3110 82F3 B06F 01B0 96C0 0CE8 C9B8 55B2

To claim this, I am signing this object:

How `ghc --make` works

In abstract, the job of ghc --make is very simple: compute a dependency graph between modules, and rebuild the ones that have changed. Unfortunately, the code in GhcMake is quite a bit more complicated than that, and some of this complexity is essential to the design of GHC:

Interaction with GHCi involves mutating process-global state.

	/home/ezyang/Dev/rust-sandbox/test.rs:13:20: 13:27 error: cannot borrow `*z` as mutable more than once at a time
	/home/ezyang/Dev/rust-sandbox/test.rs:13 let x = &mut *z;
	^~~~~~~
	/home/ezyang/Dev/rust-sandbox/test.rs:12:24: 12:25 note: second borrow of `*z` as mutable occurs here
	/home/ezyang/Dev/rust-sandbox/test.rs:12 let r = foo(z);
	^
	/home/ezyang/Dev/rust-sandbox/test.rs:12:24: 12:25 note: old loan gen'd here
	/home/ezyang/Dev/rust-sandbox/test.rs:12 let r = foo(z);
	^
	/home/ezyang/Dev/rust-sandbox/test.rs:7:4: 16:5 note: old loan kill'd here

	{-# LANGUAGE Rank2Types #-}
	{-# LANGUAGE ExistentialQuantification #-}
	{-# LANGUAGE ScopedTypeVariables #-}
	{-# LANGUAGE KindSignatures #-}
	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE MultiParamTypeClasses #-}
	{-# LANGUAGE InstanceSigs #-}
	module Productive where

	-- \| Productive coprogramming in the Par monad. Based off of

	module GhcSort where

	import GHC
	import GhcPlugins
	import DriverPhases

	import Control.Monad
	import Data.List
	import Data.Maybe
	import System.FilePath

	Please add the following two keys to my GHC committer account:

	ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDADGfn5WgodBZjJoA1KEKSCsFzxeKwiCFNLm4UuL32XCOtJtaEeJrSXwCqnkNtTm7RCknwL5A1xc7Qx2Tkde+XtlD6wEKSMqE6I6xYPtDRJ4yo9n25ujJBwi7GmAqp9SPEGfs98IFaySAmUN5bt/OXXuNHtc9SFqhwXajKA9d0ks6akugAEgeOpCd9KBe/SzDVp9cPVFg5wgncbFcxwlhJYh7AwnxlblR3IIxULPWR//n6Jy+4aPseyL11ViD+aoELBgypwPYa1exPPr6GaHWm8zwC0735zrPmn3WzU3slC5TVTuuvhyLlEw3J6qwrN6Gehn7PMTHsJbPOfLQfB8ZP ezyang@market.scs.stanford.edu

	ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCz/VWtZwUOWtyfOBRfCm22Xswemri3n9ekpLHiHwR14CFmjuxGTjVQLCavSmmRw9395Nyr8Nel2bcduTx4Y0wuEwLWcn2K0kD322JaRUXOzmmJZBgwneh8H/HltLTETOivcLzPOwZ/Oylftt9O7j/EyIrho4rPBSh8/56Vn36CU9z9W3SgC+IOLl+ql9LdC7iyN6gthmx/MOpXePYvqbZQstdham6XkX9oPKi4y38aswrPpcyLK0w78j7WS+P+7D/96yxDV0KFIupjmbssqIX66CLRme7ZwtUvDY8XTIn1m6MYLgyPC5jFsleGlHOQhaH9U8TkW+mJYkz/alAHwnr7 ezyang@sabre

Edward Z. Yang ezyang

Keybase proof

How ghc --make works

How `ghc --make` works