It seems the regex implementation is not complete.
value =~ '[A-Za-z0-9][A-Za-z0-9]*'
worked for matching a term "com", but
value =~ '[A-Za-z0-9]+'
does not work.
In general not all constructions you can see in man
lex
are working. There are as well some small differences
between
the definitions in the tokens of a Montages project,
and the
use of a regex in Xasm (for instance, \' cannot be used
in the Xasm
case, but in the Montages case)