nixpkgs/lib/systems/doubles.nix
Graham Christensen 152c63c9ff
Convert libs to a fixed-point
This does break the API of being able to import any lib file and get
its libs, however I'm not sure people did this.

I made this while exploring being able to swap out docFn with a stub
in #2305, to avoid functor performance problems. I don't know if that
is going to move forward (or if it is a problem or not,) but after
doing all this work figured I'd put it up anyway :)

Two notable advantages to this approach:

1. when a lib inherits another lib's functions, it doesn't
   automatically get put in to the scope of lib
2. when a lib implements a new obscure functions, it doesn't
   automatically get put in to the scope of lib

Using the test script (later in this commit) I got the following diff
on the API:

  + diff master fixed-lib
  11764a11765,11766
  > .types.defaultFunctor
  > .types.defaultTypeMerge
  11774a11777,11778
  > .types.isOptionType
  > .types.isType
  11781a11786
  > .types.mkOptionType
  11788a11794
  > .types.setType
  11795a11802
  > .types.types

This means that this commit _adds_ to the API, however I can't find a
way to fix these last remaining discrepancies. At least none are
_removed_.

Test script (run with nix-repl in the PATH):

  #!/bin/sh

  set -eux

  repl() {
      suff=${1:-}
      echo "(import ./lib)$suff" \
          | nix-repl 2>&1
  }

  attrs_to_check() {
      repl "${1:-}" \
          | tr ';'  $'\n' \
          | grep "\.\.\." \
          | cut -d' ' -f2 \
          | sed -e "s/^/${1:-}./" \
          | sort
  }

  summ() {
      repl "${1:-}" \
          | tr ' ' $'\n' \
          | sort \
          | uniq
  }

  deep_summ() {
      suff="${1:-}"
      depth="${2:-4}"
      depth=$((depth - 1))
      summ "$suff"

      for attr in $(attrs_to_check "$suff" | grep -v "types.types"); do
          if [ $depth -eq 0 ]; then
              summ "$attr" | sed -e "s/^/$attr./"
          else
              deep_summ "$attr" "$depth" | sed -e "s/^/$attr./"
          fi
      done
  }

  (
      cd nixpkgs

      #git add .
      #git commit -m "Auto-commit, sorry" || true
      git checkout fixed-lib
      deep_summ > ../fixed-lib
      git checkout master
      deep_summ > ../master
  )

  if diff master fixed-lib; then
      echo "SHALLOW MATCH!"
  fi

  (
      cd nixpkgs
      git checkout fixed-lib
      repl .types
  )
2017-09-16 21:36:43 -04:00

48 lines
1.5 KiB
Nix

{ lib }:
let
inherit (lib) lists;
parse = import ./parse.nix { inherit lib; };
inherit (import ./inspect.nix { inherit lib; }) predicates;
inherit (lib.attrsets) matchAttrs;
all = [
"aarch64-linux"
"armv5tel-linux" "armv6l-linux" "armv7l-linux"
"mips64el-linux"
"i686-cygwin" "i686-freebsd" "i686-linux" "i686-netbsd" "i686-openbsd"
"x86_64-cygwin" "x86_64-darwin" "x86_64-freebsd" "x86_64-linux"
"x86_64-netbsd" "x86_64-openbsd" "x86_64-solaris"
];
allParsed = map parse.mkSystemFromString all;
filterDoubles = f: map parse.doubleFromSystem (lists.filter f allParsed);
in rec {
inherit all;
allBut = platforms: lists.filter (x: !(builtins.elem x platforms)) all;
none = [];
arm = filterDoubles predicates.isArm;
i686 = filterDoubles predicates.isi686;
mips = filterDoubles predicates.isMips;
x86_64 = filterDoubles predicates.isx86_64;
cygwin = filterDoubles predicates.isCygwin;
darwin = filterDoubles predicates.isDarwin;
freebsd = filterDoubles predicates.isFreeBSD;
# Should be better, but MinGW is unclear, and HURD is bit-rotted.
gnu = filterDoubles (matchAttrs { kernel = parse.kernels.linux; abi = parse.abis.gnu; });
illumos = filterDoubles predicates.isSunOS;
linux = filterDoubles predicates.isLinux;
netbsd = filterDoubles predicates.isNetBSD;
openbsd = filterDoubles predicates.isOpenBSD;
unix = filterDoubles predicates.isUnix;
mesaPlatforms = ["i686-linux" "x86_64-linux" "x86_64-darwin" "armv5tel-linux" "armv6l-linux" "armv7l-linux" "aarch64-linux"];
}