nixpkgs/lib/strings-with-deps.nix

85 lines
2.5 KiB
Nix
Raw Normal View History

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 )
2017-07-29 02:05:35 +02:00
{ 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 (?)
*/
let
inherit (lib)
concatStringsSep
head
isAttrs
listToAttrs
tail
;
in
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; };
}