Brassica.SoundChange.Apply.Internal

Warning: This module is internal, and does not follow the Package Versioning Policy. It may be useful for extending Brassica, but be prepared to track development closely if you import this module.

This module contains the lower-level functions used by Brassica to match and apply sound changes. The overall algorithm is similar to that described by Howard (1973).

Some essential points:

• Words are represented as MultiZippers, with a cursor index and zero or more tagged indices. A sound change can then be applied (applyRuleMZ) by advancing through the word from left to right. (Right-to-left application is achieved by reversing both word and rule.)
• For each potential application site, applyOnce checks the target, environments and exceptions. If they are all satisfied, it then replaces the target graphemes with the replacement graphemes. After running applyOnce, setupForNextApplication can be used to advance to the next application site.
• The lowest-level function for matching is match, which matches an individual Lexeme at some point in a word. The lowest-level function for replacement is mkReplacement, which constructs replacement graphemes.

Lexeme matching

data RuleTag

Defines the tags used when applying a Rule.

Constructors

AppStart

The start of a rule application

TargetStart

The start of the target

TargetEnd

The end of the target

PrevEnd

The end of the replacement from the last rule application (used to avoid infinite loops from iterative rules)

Instances

Show RuleTag

Defined in Brassica.SoundChange.Apply.Internal

Methods

showsPrec :: Int -> RuleTag -> ShowS

show :: RuleTag -> String

showList :: [RuleTag] -> ShowS

Eq RuleTag

Defined in Brassica.SoundChange.Apply.Internal

Methods

(==) :: RuleTag -> RuleTag -> Bool

(/=) :: RuleTag -> RuleTag -> Bool

Ord RuleTag

Defined in Brassica.SoundChange.Apply.Internal

Methods

compare :: RuleTag -> RuleTag -> Ordering

(<) :: RuleTag -> RuleTag -> Bool

(<=) :: RuleTag -> RuleTag -> Bool

(>) :: RuleTag -> RuleTag -> Bool

(>=) :: RuleTag -> RuleTag -> Bool

max :: RuleTag -> RuleTag -> RuleTag

min :: RuleTag -> RuleTag -> RuleTag

data RuleStatus

Status of a rule application at a single location.

Constructors

SuccessNormal

Rule was successful, with no need for special handling

SuccessEpenthesis

Rule was successful, but cursor was not advanced (need to avoid infinite loop)

Failure

Rule failed

Instances

Show RuleStatus

Defined in Brassica.SoundChange.Apply.Internal

Methods

showsPrec :: Int -> RuleStatus -> ShowS

show :: RuleStatus -> String

showList :: [RuleStatus] -> ShowS

Eq RuleStatus

Defined in Brassica.SoundChange.Apply.Internal

Methods

(==) :: RuleStatus -> RuleStatus -> Bool

(/=) :: RuleStatus -> RuleStatus -> Bool

data MatchOutput

Describes the output of a match operation.

Constructors

MatchOutput

Fields

• matchedCatIxs :: [Int]

  For each non-backreferenced category matched: the index of the matched grapheme in that category.

• matchedOptionals :: [Bool]

  For each optional group: whether it matched or not

• matchedWildcards :: [[Grapheme]]

  For each wildcard: the graphemes which it matched

• matchedKleenes :: [Int]

  For each Kleene star: how many repetitions it matched

• matchedGraphemes :: [Grapheme]

  The actual graphemes which were matched

• matchedFeatures :: Map String [FeatureState]

  The features which were matched, by name

• matchedBackrefIds :: Map String Int

  Backreferenced categories which were matched, by ID

• matchedFeatureIds :: Map String FeatureState

  Backreferenced features which were matched, by ID

Instances

Show MatchOutput

Defined in Brassica.SoundChange.Apply.Internal

Methods

showsPrec :: Int -> MatchOutput -> ShowS

show :: MatchOutput -> String

showList :: [MatchOutput] -> ShowS

data FeatureState

The result of matching a Feature or Autosegment: either a specific index in the Feature, or an indeterminate result (when no indices matched)

Constructors

Index Int

Indeterminate

Instances

Show FeatureState

Defined in Brassica.SoundChange.Apply.Internal

Methods

showsPrec :: Int -> FeatureState -> ShowS

show :: FeatureState -> String

showList :: [FeatureState] -> ShowS

Eq FeatureState

Defined in Brassica.SoundChange.Apply.Internal

Methods

(==) :: FeatureState -> FeatureState -> Bool

(/=) :: FeatureState -> FeatureState -> Bool

newOutput :: MatchOutput -> MatchOutput

Create MatchOutput for next section of rule given last output (preserving backreferences but emptying all other fields)

initialOutput :: MatchOutput

The empty MatchOutput

match

Arguments

:: MatchOutput

The previous MatchOutput

-> Maybe Grapheme

The previously-matched grapheme, if any. (Used to match a Geminate.)

-> Lexeme Expanded 'Matched

The lexeme to match.

-> MultiZipper t Grapheme

The MultiZipper to match against.

-> [(MatchOutput, MultiZipper t Grapheme)]

The output: a tuple (g, mz) as described below.

Match a single Lexeme against a MultiZipper, and advance the MultiZipper past the match. For each match found, returns the updated MatchOutput tupled with the updated MultiZipper.

matchMany :: MatchOutput -> Maybe Grapheme -> [Lexeme Expanded 'Matched] -> MultiZipper t Grapheme -> [(MatchOutput, MultiZipper t Grapheme)]

Match a list of several Lexemes against a MultiZipper. Arguments and output are as with match.

mkReplacement

Arguments

:: MatchOutput

The result of matching against the target

-> [Lexeme Expanded 'Replacement]

The Lexemes specifying the replacement.

-> MultiZipper t Grapheme

-> [MultiZipper t Grapheme]

Given a list of Lexemes specifying a replacement, generate all possible replacements and apply them to the given input.

exceptionAppliesAtPoint

Arguments

:: [Lexeme Expanded 'Matched]

Target

-> Environment Expanded

Exceptional environment

-> MultiZipper RuleTag Grapheme

-> [Int]

Given a Rule and a MultiZipper, determines whether the exception of that rule (if any) applies starting at the current position of the MultiZipper; if it does, returns the index at which each matching target begins.

matchRuleAtPoint

Arguments

:: [Lexeme Expanded 'Matched]

Target

-> Environment Expanded

Environment

-> MultiZipper RuleTag Grapheme

-> [(MatchOutput, MultiZipper RuleTag Grapheme)]

Given a target and environment, determine if the rule matches at the current position of the MultiZipper. If so, for each match, return the MatchOutput and the output MultiZipper. The output MultiZipper is advanced past the matched environment, and has its RuleTags set as appropriate.

Sound change application

applyOnce :: Rule Expanded -> StateT (MultiZipper RuleTag Grapheme) List RuleStatus

Given a Rule, determine if the rule matches at the current point; if so, apply the rule, adding appropriate tags.

setupForNextApplication :: RuleStatus -> Rule Expanded -> MultiZipper RuleTag Grapheme -> Maybe (MultiZipper RuleTag Grapheme)

Remove tags and advance the current index to the next Grapheme after the rule application.

applyRuleMZ :: Rule Expanded -> MultiZipper RuleTag Grapheme -> [MultiZipper RuleTag Grapheme]

Apply a Rule to a MultiZipper. The application will start at the beginning of the MultiZipper, and will be repeated as many times as possible. Returns all valid results.

Note: unlike applyRuleStr, this can produce duplicate outputs.

checkGraphemes :: [Grapheme] -> MultiZipper RuleTag Grapheme -> MultiZipper RuleTag Grapheme

Check that the MultiZipper contains only graphemes listed in the given list, replacing all unlisted graphemes other than "#" with U+FFFD.

applyStatementMZ :: Statement Expanded GraphemeList -> MultiZipper RuleTag Grapheme -> [MultiZipper RuleTag Grapheme]

Apply a Statement to a MultiZipper, returning zero, one or more results.

applyRuleStr :: Rule Expanded -> PWord -> [PWord]

Apply a single sound change Rule to a word.

applyStatementStr :: Statement Expanded GraphemeList -> PWord -> [PWord]

Apply a single Statement to a word. The statement can be a sound change, a filter, or any other element which remains in a sound change file after expansion.

Logging

data LogItem r

A log item representing a single action r (usually a Statement), and the result from that action.

Constructors

ActionApplied r (Maybe PWord)

The word was modified: gives the output word, or Nothing if the wordwas deleted

ReportWord PWord

Corresponds to ReportS, giving the intermediate form to report

Instances

Functor LogItem

Defined in Brassica.SoundChange.Apply.Internal

Methods

fmap :: (a -> b) -> LogItem a -> LogItem b

(<$) :: a -> LogItem b -> LogItem a

Generic (LogItem r)

Defined in Brassica.SoundChange.Apply.Internal

Associated Types

type Rep (LogItem r) :: Type -> Type

Methods

from :: LogItem r -> Rep (LogItem r) x

to :: Rep (LogItem r) x -> LogItem r

Show r => Show (LogItem r)

Defined in Brassica.SoundChange.Apply.Internal

Methods

showsPrec :: Int -> LogItem r -> ShowS

show :: LogItem r -> String

showList :: [LogItem r] -> ShowS

NFData r => NFData (LogItem r)

Defined in Brassica.SoundChange.Apply.Internal

Methods

rnf :: LogItem r -> ()

type Rep (LogItem r)

Defined in Brassica.SoundChange.Apply.Internal

type Rep (LogItem r) = D1 ('MetaData "LogItem" "Brassica.SoundChange.Apply.Internal" "brassica-1.0.0-23v7eBGV3gz5i0Q0Z9IDsG" 'False) (C1 ('MetaCons "ActionApplied" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 r) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (Maybe PWord))) :+: C1 ('MetaCons "ReportWord" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 PWord)))

data Log r

Logs the evolution of a word as it undergoes sound changes and other actions.

Constructors

Log

Fields

• inputWord :: PWord

  The input word, before any actions have been applied

• derivations :: [LogItem r]

  All actions which were applied, with the state of the word at each point

Instances

Functor Log

Defined in Brassica.SoundChange.Apply.Internal

Methods

fmap :: (a -> b) -> Log a -> Log b

(<$) :: a -> Log b -> Log a

Generic (Log r)

Defined in Brassica.SoundChange.Apply.Internal

Associated Types

type Rep (Log r) :: Type -> Type

Methods

from :: Log r -> Rep (Log r) x

to :: Rep (Log r) x -> Log r

Show r => Show (Log r)

Defined in Brassica.SoundChange.Apply.Internal

Methods

showsPrec :: Int -> Log r -> ShowS

show :: Log r -> String

showList :: [Log r] -> ShowS

NFData r => NFData (Log r)

Defined in Brassica.SoundChange.Apply.Internal

Methods

rnf :: Log r -> ()

type Rep (Log r)

Defined in Brassica.SoundChange.Apply.Internal

type Rep (Log r) = D1 ('MetaData "Log" "Brassica.SoundChange.Apply.Internal" "brassica-1.0.0-23v7eBGV3gz5i0Q0Z9IDsG" 'False) (C1 ('MetaCons "Log" 'PrefixI 'True) (S1 ('MetaSel ('Just "inputWord") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 PWord) :*: S1 ('MetaSel ('Just "derivations") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [LogItem r])))

reportAsHtmlRows

Arguments

:: (r -> String)

Specifies how to pretty-print actions as text

-> Log r

-> String

Pretty-print a single Log as rows of an HTML table. For instance, the example log given in the documentation for reportAsText would be converted to the following HTML:

<tr><td>tara</td><td>&rarr;</td><td>tazha</td><td>(r / zh)</td></tr><tr><td></td><td>&rarr;</td><td>tazh</td><td>(V / / _ #)</td></tr>

Which might be displayed in a browser as follows:

tara	→	tazha	(r / zh)
	→	tazh	(V _ #)

reportAsText

Arguments

:: (r -> String)

Specifies how to pretty-print actions as text

-> Log r

-> String

Pretty-print a Log as plain text. For instance, this log:

Log
  { inputWord = ["t", "a", "r", "a"]
  , derivations =
    [ (Just ["t", "a", "zh", "a"], "r / zh")
    , (Just ["t", "a", "zh"], "V / / _ #")
    ]
  }

Would be pretty-printed by reportAsText id as:

tara
  -> tazha  (r / zh)
  -> tazh   (V / / _ #)

applyStatement :: Statement Expanded GraphemeList -> PWord -> [LogItem (Statement Expanded GraphemeList)]

Apply a single Statement to a word. Returns a LogItem for each possible result, or [] if the rule does not apply and the input is returned unmodified.

applyChanges :: SoundChanges Expanded GraphemeList -> PWord -> [Log (Statement Expanded GraphemeList)]

Apply a set of SoundChanges to a word, returning a log of which sound changes applied to produce each output word.

getOutput :: Log r -> Maybe PWord

Returns the final output from a sound change log.

getReports :: Log r -> [PWord]

Returns, in order: the input word, any intermediate results from ReportS, and then the final output.

getChangedOutputs :: Log (Statement c d) -> Maybe (PWord, Bool)

Returns the final output from a sound change log, as well as an indication of whether any sound changes have applied to it (accounting for highlightChanges flags).

getChangedReports :: Log (Statement c d) -> [(PWord, Bool)]

A combination of getOutput and getChangedOutputs: returns all intermediate results, as well as whether each has undergone any sound changes.