Commit graph

6 commits

Author SHA1 Message Date
Yueh-Shun Li
e026f3e1ae treewide: Reference HashFormat members with scope
Base* -> HashFormat::Base*
2023-10-19 00:56:41 +08:00
John Ericson
2f5d3da806 Introduce OutputName and OutputNameView type aliases
Hopefully they make the code easier to understand!
2023-08-25 09:55:07 -04:00
John Ericson
e7c39ff00b Rework evaluator SingleDerivedPath infra
`EvalState::mkSingleDerivedPathString` previously contained its own
inverse (printing, rather than parsing) in order to validate what was
parsed. Now that is pulled out into its own separate function:
`EvalState::coerceToSingleDerivedPath`.

In additional that pulled out logic is deduplicated with
`EvalState::mkOutputString` via `EvalState::mkOutputStringRaw`, which is
itself deduplicated (and generalized) with
`DownstreamPlaceholder::mkOutputStringRaw`.

All these changes make the unit tests simpler.

(We would ideally write more unit tests for `mkSingleDerivedPathString`
`coerceToSingleDerivedPath` directly, but we cannot yet do that because
the IO in reading the store path won't work when the dummy store cannot
hold anything. Someday we'll have a proper in-memory store which will
work for this.)

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-08-14 08:44:50 -04:00
John Ericson
60b7121d2c Make the Derived Path family of types inductive for dynamic derivations
We want to be able to write down `foo.drv^bar.drv^baz`:
`foo.drv^bar.drv` is the dynamic derivation (since it is itself a
derivation output, `bar.drv` from `foo.drv`).

To that end, we create `Single{Derivation,BuiltPath}` types, that are
very similar except instead of having multiple outputs (in a set or
map), they have a single one. This is for everything to the left of the
rightmost `^`.

`NixStringContextElem` has an analogous change, and now can reuse
`SingleDerivedPath` at the top level. In fact, if we ever get rid of
`DrvDeep`, `NixStringContextElem` could be replaced with
`SingleDerivedPath` entirely!

Important note: some JSON formats have changed.

We already can *produce* dynamic derivations, but we can't refer to them
directly. Today, we can merely express building or example at the top
imperatively over time by building `foo.drv^bar.drv`, and then with a
second nix invocation doing `<result-from-first>^baz`, but this is not
declarative. The ethos of Nix of being able to write down the full plan
everything you want to do, and then execute than plan with a single
command, and for that we need the new inductive form of these types.

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2023-08-10 00:08:32 -04:00
John Ericson
caabc4f648 Feature gate DownstreamPlaceholder::unknownCaOutput
This is a part of CA derivations that we forgot to put behind the
experimental feature.

This was caught by @fricklerhandwerk in
https://github.com/NixOS/nix/pull/8369#discussion_r1258133719
2023-07-13 07:56:33 -04:00
John Ericson
b9e5ce4a27 Upgrade downstreamPlaceholder to a type with methods
This gets us ready for dynamic derivation dependencies (part of RFC 92).
2023-05-17 17:41:16 -04:00