[Scummvm-tracker] [ScummVM] #10404: SCI: LSL7: parser behavior improvement (Italian version)

[MIKZER0]

#10404: SCI: LSL7: parser behavior improvement (Italian version)
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Reporter:  MIKZER0      |      Owner:  (none)
    Type:  enhancement  |     Status:  new
Priority:  normal       |  Component:  Engine: SCI
Keywords:  sci32        |       Game:  Leisure Suit Larry 7
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 First, this is not an issue with the current implementation as the scummvm
 version behave the same as the original game.

 The italian version of Larry 7 has a couple of issue. The game is
 completable but one of this issue prevent the player from getting one of
 the easter eggs and reach the complete ending.

 The verb "unzip" in italian was translated as "Aprire la cerniera" but is
 never recognized by the parser. The verb "Aprire" is recognized instead
 but it's related to the verb "Open" in the english version.
 At first I thought the reason was that the verb was composed by more than
 one word, but the english version has multiple words verb recognized (turn
 on, turn off) and works fine.
 I checked the parsing code in ScummVm and it seem it stops at the first
 complete match in every version of the SCI engine.
 In the end I think I find the reason the Italian version has this issue.
 The parser stops at the first complete match of the game verbs on the
 input, but doesn't check if there is a verb that completely match the
 input, in other words it checks if the game verb match the start of the
 input (it is contained in it) but not if the input has characters left
 that could better match another verb. It also checks each entry in order
 (verb number and maybe sequence). I believe that the list of verbs was
 carefully crafted to works with this system (the order in which each verb
 is numbered is important) so that in case of verbs with the initial part
 in common the parser would pick the right one.

 One example is this list of verbs:
 -turn off
 -turn on
 -turn
 in this order.
 If the player input "turn on" the parser would:
 -check "turn off" and fail
 -check "turn on" and match
 -stop
 -verb "turn on" is recognized
 If the order was different (turn, turn on, turn off) this would happen:
 -check "turn" and match (turn is contained in turn on)
 -stop
 -verb "turn" is recognized

 In the english version there are in fact other cases of verbs that cannot
 be matched using the parser due to the matching argorithm but luckily they
 are not needed to complete the game.
 "Lay" and "Lay down", lay down is never matched. "Lay cable" however get
 recognized as it is placed before the others.
 "Look over" and "Look down" are never recognized as "Look" comes before
 them. They have a different number associated that "look", I don't know if
 there are events related to those verbs that never happens in the game due
 to this issue.
 In the Italian version however, translating some of those verbs messed up
 the matching order and some (one in particular) of those verbs are needed
 to have a complete ending.

 The behavior is the same on both the original game (DOS and Windows
 client) and is correctly replicated in ScummVm.
 For the italian version an easy fix is to change the problematic verb with
 another one. We (a group of fan) already did that and it works.
 However it would be good to also have the parser improved to correctly
 match the words the player input. It would also allow owners of the
 original Italian retail version to complete the game without the need of a
 fanmade patch (that we can provide to you if you wish to make it
 available).
 I don't know if this could create new issues with other languages
 (including english) as those version have been tested with the original
 parser. I have a limited understanding of scummvm code but if you need
 further assistance on the issue I'm willing to help as well as providing
 better reproducible examples.

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Ticket URL: <https://bugs.scummvm.org/ticket/10404>
ScummVM <https://bugs.scummvm.org>
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