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nixpkgs/lib/strings-with-deps.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

80 lines
2.4 KiB
Nix

{ lib }:
/*
Usage:
You define you custom builder script by adding all build steps to a list.
for example:
builder = writeScript "fsg-4.4-builder"
(textClosure [doUnpack addInputs preBuild doMake installPhase doForceShare]);
a step is defined by noDepEntry, fullDepEntry or packEntry.
To ensure that prerequisite are met those are added before the task itself by
textClosureDupList. Duplicated items are removed again.
See trace/nixpkgs/trunk/pkgs/top-level/builder-defs.nix for some predefined build steps
Attention:
let
pkgs = (import <nixpkgs>) {};
in let
inherit (pkgs.stringsWithDeps) fullDepEntry packEntry noDepEntry textClosureMap;
inherit (pkgs.lib) id;
nameA = noDepEntry "Text a";
nameB = fullDepEntry "Text b" ["nameA"];
nameC = fullDepEntry "Text c" ["nameA"];
stages = {
nameHeader = noDepEntry "#! /bin/sh \n";
inherit nameA nameB nameC;
};
in
textClosureMap id stages
[ "nameHeader" "nameA" "nameB" "nameC"
nameC # <- added twice. add a dep entry if you know that it will be added once only [1]
"nameB" # <- this will not be added again because the attr name (reference) is used
]
# result: Str("#! /bin/sh \n\nText a\nText b\nText c\nText c",[])
[1] maybe this behaviour should be removed to keep things simple (?)
*/
with lib.lists;
with lib.attrsets;
with lib.strings;
rec {
/* !!! The interface of this function is kind of messed up, since
it's way too overloaded and almost but not quite computes a
topological sort of the depstrings. */
textClosureList = predefined: arg:
let
f = done: todo:
if todo == [] then {result = []; inherit done;}
else
let entry = head todo; in
if isAttrs entry then
let x = f done entry.deps;
y = f x.done (tail todo);
in { result = x.result ++ [entry.text] ++ y.result;
done = y.done;
}
else if done ? ${entry} then f done (tail todo)
else f (done // listToAttrs [{name = entry; value = 1;}]) ([predefined.${entry}] ++ tail todo);
in (f {} arg).result;
textClosureMap = f: predefined: names:
concatStringsSep "\n" (map f (textClosureList predefined names));
noDepEntry = text: {inherit text; deps = [];};
fullDepEntry = text: deps: {inherit text deps;};
packEntry = deps: {inherit deps; text="";};
stringAfter = deps: text: { inherit text deps; };
}