forked from mirrors/nixpkgs
152c63c9ff
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 )
103 lines
2.5 KiB
Nix
103 lines
2.5 KiB
Nix
{ lib }:
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rec {
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/* The identity function
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For when you need a function that does “nothing”.
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Type: id :: a -> a
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*/
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id = x: x;
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/* The constant function
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Ignores the second argument.
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Or: Construct a function that always returns a static value.
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Type: const :: a -> b -> a
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Example:
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let f = const 5; in f 10
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=> 5
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*/
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const = x: y: x;
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## Named versions corresponding to some builtin operators.
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/* Concat two strings */
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concat = x: y: x ++ y;
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/* boolean “or” */
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or = x: y: x || y;
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/* boolean “and” */
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and = x: y: x && y;
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/* Convert a boolean to a string.
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Note that toString on a bool returns "1" and "".
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*/
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boolToString = b: if b then "true" else "false";
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/* Merge two attribute sets shallowly, right side trumps left
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Example:
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mergeAttrs { a = 1; b = 2; } { b = 3; c = 4; }
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=> { a = 1; b = 3; c = 4; }
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*/
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mergeAttrs = x: y: x // y;
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# Flip the order of the arguments of a binary function.
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flip = f: a: b: f b a;
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# Apply function if argument is non-null
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mapNullable = f: a: if isNull a then a else f a;
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# Pull in some builtins not included elsewhere.
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inherit (builtins)
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pathExists readFile isBool isFunction
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isInt add sub lessThan
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seq deepSeq genericClosure;
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inherit (lib.strings) fileContents;
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# Return the Nixpkgs version number.
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nixpkgsVersion =
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let suffixFile = ../.version-suffix; in
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fileContents ../.version
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+ (if pathExists suffixFile then fileContents suffixFile else "pre-git");
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# Whether we're being called by nix-shell.
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inNixShell = builtins.getEnv "IN_NIX_SHELL" != "";
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# Return minimum/maximum of two numbers.
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min = x: y: if x < y then x else y;
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max = x: y: if x > y then x else y;
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/* Integer modulus
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Example:
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mod 11 10
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=> 1
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mod 1 10
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=> 1
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*/
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mod = base: int: base - (int * (builtins.div base int));
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/* Reads a JSON file. */
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importJSON = path:
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builtins.fromJSON (builtins.readFile path);
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/* See https://github.com/NixOS/nix/issues/749. Eventually we'd like these
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to expand to Nix builtins that carry metadata so that Nix can filter out
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the INFO messages without parsing the message string.
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Usage:
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{
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foo = lib.warn "foo is deprecated" oldFoo;
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}
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TODO: figure out a clever way to integrate location information from
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something like __unsafeGetAttrPos.
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*/
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warn = msg: builtins.trace "WARNING: ${msg}";
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info = msg: builtins.trace "INFO: ${msg}";
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}
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