# Summary

This is a large architectural change to the Hyperlinker.

  * extract link (and now also type) information from `.hie` instead
    of doing ad-hoc SYB traversals of the `RenamedSource`. Also
    adds a superb type-on-hover feature (#715).

 * re-engineer the lexer to avoid needless string conversions. By going
    directly through GHC's `P` monad and taking bytestring slices, we
    avoid a ton of allocation and have better handling of position
    pragmas and CPP.

In terms of performance, the Haddock side of things has gotten _much_
more efficient. Unfortunately, much of this is cancelled out by the
increased GHC workload for generating `.hie` files. For the full set of
boot libs (including `ghc`-the-library)

  * the sum of total time went down by 9-10% overall
  * the sum of total allocations went down by 6-7%

# Motivation

Haddock is moving towards working entirely over `.hi` and `.hie` files.
This change means we no longer need the `RenamedSource` from
`TypecheckedModule` (something which is _not_ in `.hi` files).

# Details

Along the way a bunch of things were fixed:

 * Cross package (and other) links are now more reliable (#496)
 * The lexer tries to recover from errors on every line (instead of at CPP
    boundaries)
 * `LINE`/`COLUMN` pragmas are taken into account
 * filter out zero length tokens before rendering
 * avoid recomputing the `ModuleName`-based `SrcMap`
 * remove the last use of `Documentation.Haddock.Utf8` (see  #998)
 * restructure temporary folder logic for `.hi`/`.hie` model

Since 53874834 in GHC, "GHC.Maybe"
is marked as `not-home`. That changes around some test output.

Fixes #885.

The functionality is easily inlined into one short function: `gmapEverywhere`.
This doesn't warrant pulling in another package.

* Synify and render properly promoted type variables

Fixes #923.

* Accept output

This commit should not introduce any change in functionality!

  * consistently use `getOccString` to convert `Name`s to strings
  * compare names directly when possible (instead of comparing strings)
  * get rid of unused utility functions

Zejun Wu authored 6 years ago and Alec Theriault committed 6 years ago

This will make investigation of #979 easier

* remove redundant imports (only brought to light due to recent work for
  improving redundant import detection)
* fix a bug that was casuing exports to appear in reverse order
* fix something in haddock-library that prevented compilation on old GHC's

Trac Issues #15495

This patch removes the ping-pong style from HsPat (only, for now), using the plan laid out at https://ghc.haskell.org/trac/ghc/wiki/ImplementingTreesThatGrow/HandlingSourceLocations (solution A).
- the class `HasSrcSpan`, and its functions (e.g., `cL` and `dL`), are introduced
- some instances of `HasSrcSpan` are introduced
- some constructors `L` are replaced with `cL`
- some patterns `L` are replaced with `dL->L` view pattern
- some type annotation are necessarily updated (e.g., `Pat p` --> `Pat (GhcPass p)`)

Follow GHC HEAD's HsTypes.Promoted -> BasicTypes.PromotionFlag change

It got introduced in ghc/ghc@ae2c9b40.

Fangyi Zhou authored 6 years ago and Alec Theriault committed 6 years ago

Summary:
For links in subpackages as well.
https://phabricator.haskell.org/D5257

Test Plan: Manually verify links

Reviewers: mpickering, bgamari, osa1

Reviewed By: osa1

GHC Trac Issues: #15733

Differential Revision: https://phabricator.haskell.org/D5262

Introduce NewOcean theme.

Also, functions and data decls now have the same space before and after
them.

In the unfortunate event that the "Contents" summary doesn't fit
vertically (like in the "Prelude"), it will be scrollable.

  * swap the minimize unicode to something more intuitive
  * use new unicode expander/collapser for instance lists
  * address some alignment issues in the "index" page

Inline markup in markdown-style links and images

Inline markup is supported in image links but, as per the [commonmark
recommendation][0], it is stripped back to a plain text representation.

  [0]: https://spec.commonmark.org/0.28/#example-547

The parser for pictures hasn't been properly adjusted yet.

Perf only change:

  * use 'getParserState'/'setParserState' to make 'Text'-optimized
    parser combinators
  * minimize uses of 'Data.Text.{pack,unpack,cons,snoc}'

Perf only change:

  * don't look up type variable names (they're never in the environment)
  * use a difference list for accumulating missing names
  * more efficient 'Functor'/'Applicative' instances for 'RnM'

Perf only change:

  * Add a 'SPECIALIZE' pragma to help GHC optimize a 'Data a =>' constraint
  * Manually specialize the needlessly general type of 'specializeTyVarBndrs'

Perf only change:

  * avoid needlessly union-ing maps
  * avoid synify-ing instances twice

Took this opportunity to add some docs too

Correspondingly, we wrap all inline/diplay math in

    <span class="mathjax"> ... the math .... </span>

This fixes #959.

* Fix misplaced Haddocks in Haddock itself

Haddock should be able to generate documentation for 'haddock-api'
again.

* Make CI check that documentation can be built.

* Add back a doc that is OK

AFAICT this wasn't causing any crashes, but that's mostly because
we happen not to be forcing `pkgStr` when it would diverge. We come
dangerously close to doing that in `ppHtmlIndex`.

Fixes #569.