translation: avoid unnecessary lookups

[benoit-pierre]

Summary of changes

With the following dictionary stacks:

• user:

{
  "EUPB/EBGS/PEPBS/EUF": "inexpensive",
}

• commands:

{
  "PHROLG": "{PLOVER:TOGGLE}"
}

• main:

{
  "A*/KR*/*E/T*/O*/P*/H*/*EU/HR*/*EU/KR*": "acidophilic",
  "OBLG": "okay",
  "-RBGS": "{,}",
  "HRET": "let",
  "AES": "{^'s}",
  "SAOE": "see",
  "HOU": "how",
  "PHAEPB": "many",
  "HRAOUP": "lookup",
  "TP-R": "for",
  "SUFBGS": "suffix",
  "-G": "{^ing}",
  "-S": "{^s}",
  "-D": "{^ed}",
  "-Z": "{^s}",
}

Writing OBLG -RBGS HRET AES SAOE HOU PHAEPB HRAOUP -S TP-R SUFBGSZ, the last stroke results in the following dictionary collection lookups:

# Macros:
/SUFBGSZ in user, main
SUFBGSZ in user, cmds, main
# No suffix:
/-RBGS/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBGSZ
-RBGS/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBGSZ in main
/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBGSZ in main
HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBGSZ in main
[…]
/SUFBGSZ/SUFBGSZ in user, main
SUFBGSZ/SUFBGSZ in user, main
/SUFBGSZ in user, main
SUFBGSZ in user, cmds, main
# With suffix:
/-RBGS/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBGSZ
-Z in user, cmds, main
/-RBGS/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBGS
-S in user, cmds, main
/-RBGS/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBGZ
-G in user, cmds, main
/-RBGS/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBSZ
-RBGS/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBGSZ in main
-Z in user, cmds, main
-RBGS/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBGS in main
-S in user, cmds, main
-RBGS/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBGZ in main
-G in user, cmds, main
-RBGS/HRET/AES/SAOE/HOU/PHAEPB/HRAOUP/-S/TP-R/SUFBGSZ/SUFBSZ in main
[…]
/SUFBGSZ/SUFBSZ in user, main
SUFBGSZ/SUFBGSZ in user, main
-Z in user, cmds, main
SUFBGSZ/SUFBGS in user, main
-S in user, cmds, main
SUFBGSZ/SUFBGZ in user, main
-G in user, cmds, main
SUFBGSZ/SUFBSZ in user, main
/SUFBGSZ in user, main
-Z in user, cmds, main
/SUFBGS in user, main
-S in user, cmds, main
/SUFBGZ in user, main
-G in user, cmds, main
/SUFBSZ in user, main
SUFBGSZ in user, cmds, main
-Z in user, cmds, main
SUFBGS in user, cmds, main

Stats:

• dictionary collection: 174
• duplicates : 85 (-Z [21], -G [20], -S [20], …)
• user : 99
• commands : 68
• main : 169
• dictionaries : 336

This PR cut down on unnecessary / duplicate lookups:

• Avoid lookups over the longest key limit (prefix stroke).
• When calling _find_longest_match a second time to account for a possible implicit suffix in the last stroke, don't duplicate lookups for a non-suffix match.
• Only lookup each possible implicit suffix once (before looking for a longest match).
• Reuse the results of the initial (macro check) lookups of the last stroke if needed, instead of re-doing them.

Stats with this PR:

• dictionary collection: 85
• user : 29
• commands : 5
• main : 85
• dictionaries : 119

Pull Request Checklist

• Changes have tests
• News fragment added in news.d. See documentation for details