[Bug other/69968] RFC: Use Damerau-Levenshtein within spellcheck.c, rather than Levenshtein

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69968

--- Comment #5 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Author: dmalcolm
Date: Tue Jun 12 18:28:37 2018
New Revision: 261521

URL: https://gcc.gnu.org/viewcvs?rev=261521&root=gcc&view=rev
Log:
spellcheck: support transpositions aka Damerau-Levenshtein (PR other/69968)

gcc/fortran/ChangeLog:
        PR other/69968
        * misc.c (gfc_closest_fuzzy_match): Update for renaming of
        levenshtein_distance to get_edit_distance.

gcc/ChangeLog:
        PR other/69968
        * spellcheck-tree.c (levenshtein_distance): Rename to...
        (get_edit_distance): ...this, and update for underlying renaming.
        * spellcheck-tree.h (levenshtein_distance): Rename to...
        (get_edit_distance): ...this.
        * spellcheck.c (levenshtein_distance): Rename to...
        (get_edit_distance): ...this.  Convert from Levenshtein distance
        to Damerau-Levenshtein distance by supporting transpositions of
        adjacent characters.  Rename "v1" to "v_next" and "v0" to
        "v_one_ago".
        (selftest::levenshtein_distance_unit_test_oneway): Rename to...
        (selftest::test_edit_distance_unit_test_oneway): ...this, and
        update for underlying renaming.
        (selftest::levenshtein_distance_unit_test): Rename to...
        (selftest::test_get_edit_distance_unit): ...this, and update for
        underlying renaming.
        (selftest::test_find_closest_string): Add example from PR 69968
        where transposition helps
        (selftest::test_metric_conditions): Update for renaming.
        (selftest::test_metric_conditions): Likewise.
        (selftest::spellcheck_c_tests): Likewise.
        * spellcheck.h (levenshtein_distance): Rename both overloads to...
        (get_edit_distance): ...this.
        (best_match::consider): Update for renaming.

gcc/testsuite/ChangeLog:
        PR other/69968
        * gcc.dg/spellcheck-transposition.c: New test.


Added:
    trunk/gcc/testsuite/gcc.dg/spellcheck-transposition.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/misc.c
    trunk/gcc/spellcheck-tree.c
    trunk/gcc/spellcheck-tree.h
    trunk/gcc/spellcheck.c
    trunk/gcc/spellcheck.h
    trunk/gcc/testsuite/ChangeLog