lean4-htt/tests/lean/run/simpTrace.lean
Marc Huisinga f180eee7bf
feat: use widget message for "try this" (#9966)
This PR adjusts the "try this" widget to be rendered as a widget message
under 'Messages', not a separate widget under a 'Suggestions' section.
The main benefit of this is that the message of the widget is not
duplicated between 'Messages' and 'Suggestions'.

Since widget message suggestions were already implemented by @jrr6 for
the new hint infrastructure, this PR replaces the old "try this"
implementation with the new hint infrastructure. In doing so, the
`style?` field of suggestions is deprecated, since the hint
infrastructure highlights hints using diff colors, and `style?` also
never saw much use downstream. Additionally, since the message and the
suggestion are now the same component, the `messageData?` field of
suggestions is deprecated as well. Notably, the "Try this:" message
string now also contains a newline and indentation to separate the
suggestion from the rest of the message more clearly and the `postInfo?`
field of the suggestion is now part of the message.

Finally, this PR changes the diff colors used by the hint infrastructure
to be more color-blindness-friendly (insertions are now blue, not green,
and text that remains unchanged is now using the editor foreground color
instead of blue).

### Breaking changes
Tests that use `#guard_msgs` to test the "Try this:" message may need to
be adjusted for the new formatting of the message.
2025-08-26 12:15:32 +00:00

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2.6 KiB
Text

import Lean.Meta.Tactic.Simp.Simproc
/-!
# Behavior of `simp?`
-/
/-!
`simp?` lists the lemmas in order of being applied and not in the order of being declared.
Note: This is not always desirable, see #4615
-/
def x1 := 1
def x2 := 1
def x3 := 1
def x4 := 1
@[simp] theorem x2_eq_x3 : x2 = x3 := rfl
@[simp] theorem x3_eq_x4 : x3 = x4 := rfl
@[simp] theorem x1_eq_x2 : x1 = x2 := rfl
/--
info: Try this:
simp only [x1_eq_x2, x2_eq_x3, x3_eq_x4]
-/
#guard_msgs in
example : x1 = x4 := by
simp?
/-!
`simp?` lists every theorem being used only once.
-/
/--
info: Try this:
simp only [x1_eq_x2, x2_eq_x3, x3_eq_x4]
-/
#guard_msgs in
example : x1 * x1 = x4 * x4 := by
simp?
@[simp]
def test : Nat → Nat
| 0 => 3
| 1 => 5
| 2 => 9
| 3 => 4
| 4 => 16
| _ => 0
/-!
`simp?` mentions the name of the definition instead of the names of the equation lemmas.
-/
/--
info: Try this:
simp only [test]
-/
#guard_msgs in
example : [test 3, test 2, test 4, test 5, test 0] = [4, 9, 16, 0, 3] := by
simp?
/-!
`simp?` records names of `let` declarations being unfolded.
-/
/--
info: Try this:
simp only [a]
-/
#guard_msgs in
example : let a := 5; a = 5 := by
intro a
simp? [a]
/-!
`simp?` shouldn't mention matcher equations.
-/
/--
info: Try this:
simp only [h]
---
error: unsolved goals
a b : Nat
h : a = 3
⊢ 9 = b
-/
#guard_msgs in
example (h : a = 3) : (match (generalizing := false) a with | 0 => 7 | _ + 1 => 9) = b := by
simp? [h]
/-!
`simp?` also mentions simprocs (builtin and non-builtin) but only if they succeeded.
-/
def y1 := 1
def y2 := 1
simproc rewriteY1 (y1) := fun _ => do
return .done { expr := Lean.mkConst ``y2 }
simproc dontRewriteY2 (y2) := fun _ => do
Lean.logInfo "was run"
return .continue
/--
info: was run
---
info: Try this:
simp only [rewriteY1]
-/
#guard_msgs in
example : y1 = y2 := by
simp? -- rewriteY1 succeeds, dontRewriteY2 doesn't
/--
info: Try this:
simp only [Nat.reduceAdd]
-/
#guard_msgs in
example : 1 + 1 = 2 := by
simp?
/-!
The left arrow (`←`) should be grouped together with the lemma name.
-/
def z1 := 1
def z2 := 1
def z3 := 1
theorem very_long_lemma_oh_no_can_you_please_stop_we're_getting_to_the_limit : z1 = z2 := rfl
theorem wait_this_is_rewritten_backwards_and_wow_it's_very_clear_and_obvious : z3 = z2 := rfl
/--
info: Try this:
simp only [very_long_lemma_oh_no_can_you_please_stop_we're_getting_to_the_limit,
← wait_this_is_rewritten_backwards_and_wow_it's_very_clear_and_obvious]
-/
#guard_msgs in
example : z1 = z3 := by
simp? [very_long_lemma_oh_no_can_you_please_stop_we're_getting_to_the_limit,
← wait_this_is_rewritten_backwards_and_wow_it's_very_clear_and_obvious]