[developers] Regular Expressions in Transfer Rules

Stephan Oepen oe at ifi.uio.no
Wed Mar 1 22:02:24 CET 2017

dear all,

> Incidentally, how do you feel about "~mark$" matching "_mark_rel"?  To me,
> it would seem hard to justify ignoring quotes without also ignoring the _rel
> suffix.  I would be curious to know the current LOGON implementation’s
> stance on this.

from memory, i have long operated on the assumption that the ‘_rel’
suffix is a convention in the TFS descriptions of MRSs and should be
stripped when reading out an MRS from a feature structure.  most
likely, that stripping happens both in the construction of transfer
rules and when reading an MRS as input to the transfer component.

until the 2016 move towards greater predicate normalization, in the
sense of ignoring the distinction between TDL type names vs. TDL
strings in all MRS manipulation, the LOGON transfer code used to not
generally match a(n unquoted) type name against a (quoted) string, but
the regular expression operator has always been an exception, i.e. it
would match /_mark$/ successfully against either foo_mark or
"foo_mark".  these subtleties fortunately become irrelevant with the
introduction of MRS predicate normalization.

best wishes, oe

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