lean4-htt/tests/lean/interactive/docstringLinksExamples.lean
David Thrane Christiansen eb58f46ce7
feat: language reference links and examples in docstrings (#7240)
This PR adds a canonical syntax for linking to sections in the language
reference along with formatting of examples in docstrings according to
the docstring style guide.


Docstrings are now pre-processed as follows:

* Output included as part of examples is shown with leading line comment
indicators in hovers

* URLs of the form `lean-manual://section/section-id` are rewritten to
links that point at the corresponding section in the Lean reference
manual. The reference manual's base URL is configured when Lean is built
and can be overridden with the `LEAN_MANUAL_ROOT` environment variable.
This way, releases can point documentation links to the correct
snapshot, and users can use their own, e.g. for offline reading.

Manual URLs in docstrings are validated when the docstring is added. The
presence of a URL starting with `lean-manual://` that is not a
syntactically valid section link causes the docstring to be rejected.
This allows for future extensibility to the set of allowed links. There
is no validation that the linked-to section actually exists. To provide
the best possible error messages in case of validation failures,
`Lean.addDocString` now takes a `TSyntax ``docComment` instead of a
string; clients should adapt by removing the step that extracts the
string, or by calling the lower-level `addDocStringCore` in cases where
the docstring in question is obtained from the environment and has thus
already had its links validated.

A stage0 update is required to make the documentation site configurable
at build time and for releases. A local commit on top of a stage0 update
that will be sent in a followup PR includes the configurable reference
manual root and updates to the release checklist.

---------

Co-authored-by: Marc Huisinga <mhuisi@protonmail.com>
2025-03-12 09:17:27 +00:00

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1.8 KiB
Text

import Lean
/-!
This file tests that the convention for Lean block examples is correctly displayed in hovers.
Blocks that are indicated as output should be distinguished from blocks that are indicated as code
when hovers are shown. This is done by prefixing them with line comment markers.
This occurs only in hovers, so that other clients of this information can apply their own
conventions.
-/
/-!
# Ordinary Formatting
-/
/--
Does something complicated with IO that involves output.
```lean example
#eval complicatedIOProgram
```
```output
Hello!
More output
```
-/
def complicatedIOProgram : IO Unit := do
--^ textDocument/hover
IO.println "Hello!"
IO.println "More output"
/-!
# Indentation
These tests check the handling of indentation for output blocks
-/
/--
Does something complicated with IO that involves output.
```lean example
#eval anotherComplicatedIOProgram
```
```output
Hello!
More output
```
-/
def anotherComplicatedIOProgram : IO Unit := do
--^ textDocument/hover
IO.println "Hello!"
IO.println " More output"
/--
Does something complicated with IO that involves output.
```lean example
#eval yetAnotherComplicatedIOProgram
```
```output
Hello!
More output
```
-/
def yetAnotherComplicatedIOProgram : IO Unit := do
--^ textDocument/hover
IO.println "Hello!"
IO.println " More output"
/-!
# Programmatic Access
This test ensures that when looking up the docstring programmatically, the output blocks are not rewritten.
-/
/--
info: Does something complicated with IO that involves output.
```lean example
#eval complicatedIOProgram
```
```output
Hello!
More output
```
-/
#guard_msgs in
open Lean Elab Command in
#eval show CommandElabM Unit from do
let str ← Lean.findDocString? (← getEnv) ``complicatedIOProgram
str.forM (IO.println ·)