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doc: improve docstrings for repeat* tactics (#4338)

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Kyle Miller 2024-06-03 18:47:40 -07:00 • committed by GitHub
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src/Init/Tactics.lean
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@ -833,14 +833,41 @@ syntax (name := cases) "cases " casesTarget,+ (" using " term)? (inductionAlts)?
syntax (name := renameI) "rename_i" (ppSpace colGt binderIdent)+ : tactic
/--
`repeat tac` repeatedly applies `tac` to the main goal until it fails.
That is, if `tac` produces multiple subgoals, only subgoals up to the first failure will be visited.
The `Batteries` library provides `repeat'` which repeats separately in each subgoal.
`repeat tac` repeatedly applies `tac` so long as it succeeds.
The tactic `tac` may be a tactic sequence, and if `tac` fails at any point in its execution,
`repeat` will revert any partial changes that `tac` made to the tactic state.
The tactic `tac` should eventually fail, otherwise `repeat tac` will run indefinitely.
See also:
* `try tac` is like `repeat tac` but will apply `tac` at most once.
* `repeat' tac` recursively applies `tac` to each goal.
* `first | tac1 | tac2` implements the backtracking used by `repeat`
-/
syntax "repeat " tacticSeq : tactic
macro_rules
| `(tactic| repeat $seq) => `(tactic| first | ($seq); repeat $seq | skip)
/--
`repeat' tac` recursively applies `tac` on all of the goals so long as it succeeds.
That is to say, if `tac` produces multiple subgoals, then `repeat' tac` is applied to each of them.
See also:
* `repeat tac` simply repeatedly applies `tac`.
* `repeat1' tac` is `repeat' tac` but requires that `tac` succeed for some goal at least once.
-/
syntax (name := repeat') "repeat' " tacticSeq : tactic
/--
`repeat1' tac` recursively applies to `tac` on all of the goals so long as it succeeds,
but `repeat1' tac` fails if `tac` succeeds on none of the initial goals.
See also:
* `repeat tac` simply applies `tac` repeatedly.
* `repeat' tac` is like `repeat1' tac` but it does not require that `tac` succeed at least once.
-/
syntax (name := repeat1') "repeat1' " tacticSeq : tactic
/--
`trivial` tries different simple tactics (e.g., `rfl`, `contradiction`, ...)
to close the current goal.
@ -1041,18 +1068,6 @@ This can be used to simulate the `specialize` and `apply at` tactics of Coq.
-/
syntax (name := replace) "replace" haveDecl : tactic
/--
`repeat' tac` runs `tac` on all of the goals to produce a new list of goals,
then runs `tac` again on all of those goals, and repeats until `tac` fails on all remaining goals.
-/
syntax (name := repeat') "repeat' " tacticSeq : tactic
/--
`repeat1' tac` applies `tac` to main goal at least once. If the application succeeds,
the tactic is applied recursively to the generated subgoals until it eventually fails.
-/
syntax (name := repeat1') "repeat1' " tacticSeq : tactic
/-- `and_intros` applies `And.intro` until it does not make progress. -/
syntax "and_intros" : tactic
macro_rules | `(tactic| and_intros) => `(tactic| repeat' refine And.intro ?_ ?_)