Flags diacritics

Introduction

The use of flag diacritics is documented in chapter 8 of the Xerox book. The present page documents the flag diacritics format, and the use of them in the parser.

Flag diacritics are used in the Saami morphological parser in order to remove illegal compounds, and in order to handle automatic downcasing of proper names when they are converted to e.g. adjectives. See the documentation for each language for an overview.

Flag diacritics format

There are four types of flag diacritics, all of them with the format @operator.feature.value@ or @operator.feature@:

U or Unification flags, @U.feature.value@

U is the unification operator, and the form is accepted if, for the relevant feature, the two flags in the derivation string have the same value.

P or Positive (Re)Setting, @P.feature.value@

Sets or resets the feature to the given value.

N or Negative (Re)Setting, @N.feature.value@

Sets or resets the feature to the negation of the given value.

R or Require Test, @R.feature.value@

For this diacritic, a test is performed, and it succeeds iff feature is currently set to value, otherwise the path is blocked.

D or Disallow Test, @D.feature.value@

A test is performed that succeds if feature is neutral or set to a value that is incompatible with value.

C or Clear Feature, @C.feature@

For this flag, the value of feature is reset to neutral.

U or Unification Test, @U.feature.value@

If feature is currently neutra, this diacritic causes feature to be set to value. Else if feature is currently set, then the test succeeds iff value is compatible with the current value of feature.