Commit Graph

22 Commits

Author SHA1 Message Date
Profpatsch 41e13149f7 lib/debug: add traceFnSeqN
Immensely helpful when you want to see the changes a function makes to
its value as it passes through.

Example:

```
$ nix-instantiate --strict --eval -E '(with import ./lib; traceFnSeqN 2 "id" (x: x) { a.b.c = 3; })'
trace: {
  fn = "id";
  from = {
    a = {
      b = {…};
    };
  };
  to = {
    a = {
      b = {…};
    };
  };
}
{ a = { b = { c = 3; }; }; }
```
2021-01-25 19:25:50 +01:00
Robert Hensing afa6c51f27 lib: Use Nix's static scope checking, fix error message, optimize
Nix can perform static scope checking, but whenever code is inside
a `with` expression, the analysis breaks down, because it can't
know statically what's in the attribute set whose attributes were
brought into scope. In those cases, Nix has to assume that
everything works out.

Except it doesnt. Removing `with` from lib/ revealed an undefined
variable in an error message.

If that doesn't convince you that we're better off without `with`,
I can tell you that this PR results in a 3% evaluation performance
improvement because Nix can look up local variables by index.
This adds up with applications like the module system.

Furthermore, removing `with` makes the binding site of each
variable obvious, which helps with comprehension.
2020-10-22 13:46:47 +02:00
Vincent Ambo da18b92635 lib/debug: Update documentation comments for docs generation
Documents functions in `lib.debug` for docs generation with nixdoc.

Note that type signatures and clearer descriptions are still missing
on some of these functions, but this is good enough for a first run.
2018-10-29 10:45:25 +01:00
Matthieu Coudron 5a9ba174bd lib.debug: fix traceValSeqFn
was calling the wrong parent version.
2018-07-15 09:36:08 +09:00
Profpatsch 900cec79a0 lib/debug: add replacement instructions & release notes
for every deprecated function.
2018-04-27 18:59:39 +02:00
Profpatsch 5012c49fc0 lib/debug: document module & functions, prune imports 2018-04-27 18:59:39 +02:00
Profpatsch e49f40e1ca lib/debug: deprecate `traceCallXml`
Incompletely documented, and a FIXME/bug that has been there for years.
2018-04-27 18:59:39 +02:00
Profpatsch fd54a946ca lib/debug: deprecate `addErrorContextToAttrs`
The function isn’t used anywhere and `addErrorContext` is an undocumented
builtin.
The builtin is explicitely qualified at its two uses in the module system.
2018-04-27 18:59:39 +02:00
Profpatsch 562286aa56 lib/debug: deprecate `traceValIfNot`
The function is only used in exactly one module and overly specific (`c` must be
a true predicate for `x`, if not, a specific trace is called).
2018-04-27 18:59:39 +02:00
Profpatsch 7365671fb2 lib/debug: deprecate attrNamesToStr, traceXMLVal(Marked)
`attrNamesToStr` is very specific (and pretty trivial), so it doesn’t make sense
to have it in the library.
`traceXMLVal(Marked)` are just a builtin and `trace` and not very useful in
general (trace output should not be parsed anyway).
2018-04-27 18:59:39 +02:00
Profpatsch a7fdd10bf3 lib/debug: deprecate & modernize showVal
The code is re-implemented in terms of `generators.toPretty`, but is strictly
less general than `traceValSeqN`, so we deprecate it.
2018-04-27 18:59:39 +02:00
Profpatsch a455637d28 lib/debug: remove the deprecated strict function
The grace period was long enough.
2018-04-27 18:59:39 +02:00
Profpatsch a5f6cdfd7e lib/debug: add traceValFn, traceValSeqFn, traceValSeqNFn
Being able to modify the value on-the-fly before printing is very useful in
practice.
2018-04-27 18:59:39 +02:00
Shea Levy 943592f698
Add setFunctionArgs lib function.
Among other things, this will allow *2nix tools to output plain data
while still being composable with the traditional
callPackage/.override interfaces.
2018-01-31 14:02:19 -05:00
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
Profpatsch feb8cbdc38 lib/debug: traceSeqN & traceSeqValN
Strict trace functions that only go down to a specified depth.
Handy to get a better picture and prevent infinite recursions.
2017-06-22 00:58:59 +02:00
Benjamin Staffin d9123a2329 lib: fix mixed tab/space indents, trailing whitespace, etc
Nix style seems to have settled on not using spaces between bound
variable names and the lambda : so I also tried to make those somewhat
more consistent throughout.
2017-03-11 17:48:43 -05:00
Profpatsch 93bbe13f98 debug.nix: deprecate strict
Replace the implementation by seq and add a deprecation warning.
The semantics seems a little bit off, but the function should only be
used for debugging.
2016-06-26 02:05:45 +02:00
Profpatsch 6889f53397 debug.nix: add traceSeq & traceValSeq
Debugging functions that strictly deep-evaluate the argument that should
be traced.
2016-06-26 02:04:58 +02:00
Jan Malakhovski 5990cce95f lib: cleanup a little bit, add traceIf 2015-03-26 12:43:42 +00:00
Eelco Dolstra eeac1e70aa Remove obsolete checks for missing primops 2014-10-05 01:10:37 +02:00
Eelco Dolstra 5fef92c4a0 Move pkgs/lib/ to lib/ 2013-10-10 13:28:21 +02:00
Renamed from pkgs/lib/debug.nix (Browse further)