lean4-htt/tests/lean/run/diff.lean
David Thrane Christiansen b6d77be6a5
feat: show diffs when #guard_msgs fails (#3912)
Adds the ability to show a diff when `guard_msgs` fails, using the
histogram diff algorithm pioneered in jgit. This algorithm tends to
produce more user-friendly diffs, but it can be quadratic in the worst
case. Empirically, the quadratic case of this implementation doesn't
seem to be slow enough to matter for messages smaller than hundreds of
megabytes, but if it's ever a problem, we can mitigate it the same way
jgit does by falling back to Myers diff.

See lean/run/guard_msgs.lean in the tests directory for some examples of
its output.
2024-04-18 15:09:44 +00:00

97 lines
2.7 KiB
Text
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

import Lean.Util.Diff
open Lean.Diff
/-!
# Tests for diff
Tests for various parts of the diffing system
-/
/-!
## Prefix and Suffix Matching
These tests check that the prefix and suffix matching operations on subarrays used by diff perform
as expected.
-/
def Ex.abc' := #['a', 'b', 'c']
def Ex.abc := abc'.toSubarray
def Ex.abcde : Subarray Char := #['a','b','c','d','e'].toSubarray
def Ex.bcde : Subarray Char := #['b','c','d','e'].toSubarray
/-- info: (#['a', 'b', 'c'], #[].toSubarray, #['d', 'e'].toSubarray) -/
#guard_msgs in
#eval matchPrefix Ex.abc Ex.abcde
/-- info: (#['a', 'b', 'c'], #['d', 'e'].toSubarray, #[].toSubarray) -/
#guard_msgs in
#eval matchPrefix Ex.abcde Ex.abc
/-- info: (#[], #['a', 'b', 'c'].toSubarray, #['b', 'c', 'd', 'e'].toSubarray) -/
#guard_msgs in
#eval matchPrefix Ex.abc Ex.bcde
/-- info: (#[], #["A"].toSubarray, #["B"].toSubarray) -/
#guard_msgs in
#eval matchPrefix #["A"].toSubarray #["B"].toSubarray
/-- info: (#["D", "E", "F"], #["G"].toSubarray, #[].toSubarray) -/
#guard_msgs in
#eval matchPrefix #["D", "E", "F", "G"].toSubarray #["D", "E", "F"].toSubarray
/-- info: (#["A", "A"], #["B"].toSubarray, #["X"].toSubarray) -/
#guard_msgs in
#eval matchPrefix #["A", "A", "B"].toSubarray #["A", "A", "X"].toSubarray
def Ex.xyzabc : Subarray Char := #['x', 'y', 'z', 'a', 'b', 'c'].toSubarray
def Ex.xyzab : Subarray Char := #['x', 'y', 'z', 'a', 'b'].toSubarray
/-- info: (#[].toSubarray, #['x', 'y', 'z'].toSubarray, #['a', 'b', 'c']) -/
#guard_msgs in
#eval matchSuffix Ex.abc Ex.xyzabc
/-- info: (#['a', 'b', 'c'].toSubarray, #['x', 'y', 'z', 'a', 'b'].toSubarray, #[]) -/
#guard_msgs in
#eval matchSuffix Ex.abc Ex.xyzab
/-- info: (#['a'].toSubarray, #[].toSubarray, #['b']) -/
#guard_msgs in
#eval matchSuffix #['a', 'b'].toSubarray #['b'].toSubarray
/-!
## Least Common Subsequence
These tests find least common subsequences.
-/
/-- info: #[] -/
#guard_msgs in
#eval lcs (α := Nat) (#[].toSubarray) (#[].toSubarray)
/-- info: #[] -/
#guard_msgs in
#eval lcs (#[1].toSubarray) (#[].toSubarray)
/-- info: #[1] -/
#guard_msgs in
#eval lcs (#[1].toSubarray) (#[1].toSubarray)
/-- info: #[1, 3] -/
#guard_msgs in
#eval lcs (#[1,3].toSubarray) (#[1,2,3].toSubarray)
/-- info: #["A", "A"] -/
#guard_msgs in
#eval lcs ("A,A,B".split (·==',') |>.toArray).toSubarray ("A,A,X".split (·==',') |>.toArray).toSubarray
/-- info: #["A", "D", "E", "F"] -/
#guard_msgs in
#eval lcs ("A,C,D,E,F,G".split (·==',') |>.toArray).toSubarray ("A,Y,Z,D,E,F".split (·==',') |>.toArray).toSubarray
/-- info: #["A", "A", "D", "E", "F"] -/
#guard_msgs in
#eval lcs ("A,A,B,C,D,E,F,G".split (·==',') |>.toArray).toSubarray ("A,A,X,Y,Z,D,E,F".split (·==',') |>.toArray).toSubarray