lix/doc/manual/src
John Ericson 44c8d83831 Create outputOf primop.
In the Nix language, given a drv path, we should be able to construct
another string referencing to one of its output. We can do this today
with `(import drvPath).output`, but this only works for derivations we
already have.

With dynamic derivations, however, that doesn't work well because the
`drvPath` isn't yet built: importing it like would need to trigger IFD,
when the whole point of this feature is to do "dynamic build graph"
without IFD!

Instead, what we want to do is create a placeholder value with the right
string context to refer to the output of the as-yet unbuilt derivation.
A new primop in the language, analogous to `builtins.placeholder` can be
used to create one. This will achieve all the right properties. The
placeholder machinery also will match out the `outPath` attribute for CA
derivations works.

In 60b7121d2c we added that type of
placeholder, and the derived path and string holder changes necessary to
support it. Then in the previous commit we cleaned up the code
(inspiration finally hit me!) to deduplicate the code and expose exactly
what we need. Now, we can wire up the primop trivally!

Part of RFC 92: dynamic derivations (tracking issue #6316)

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-08-14 09:37:37 -04:00
..
advanced-topics rewrap lines to use one line per sentence 2023-05-31 01:32:03 +02:00
architecture Add description for file system objects (#8500) 2023-06-18 23:45:08 -04:00
command-ref list moving parts of channels 2023-07-19 10:26:25 +02:00
contributing fix broken links (#8722) 2023-07-20 17:58:14 +02:00
figures Move figures 2020-07-24 12:58:31 +02:00
installation nix actually needs c++20 now 2023-06-10 13:56:05 +02:00
language Stabilize discard-references 2023-08-07 16:53:37 +02:00
package-management remove the Channels section 2023-07-19 09:39:04 +02:00
protocols Apply suggestions from code review 2023-06-16 16:48:37 +02:00
release-notes Create outputOf primop. 2023-08-14 09:37:37 -04:00
glossary.md Add description for file system objects (#8500) 2023-06-18 23:45:08 -04:00
introduction.md Convert short nix options to long ones 2023-05-17 08:10:30 +01:00
quick-start.md Update doc/manual/src/quick-start.md 2023-02-19 20:00:02 -05:00
SUMMARY.md.in Release notes 2023-07-24 17:19:31 +02:00