#defcomp -math-

if [[ "$PREFIX" = *[^a-zA-Z0-9_]* ]]; then
  IPREFIX="$IPREFIX${PREFIX%%[a-zA-Z0-9_]#}"
  PREFIX="${PREFIX##*[^a-zA-Z0-9_]}"
fi
if [[ "$SUFFIX" = *[^a-zA-Z0-9_]* ]]; then
  ISUFFIX="${SUFFIX##[a-zA-Z0-9_]#}$ISUFFIX"
  SUFFIX="${SUFFIX%%[^a-zA-Z0-9_]*}"
fi

compgen -v
#defcomp -math-

IPREFIX="$IPREFIX${PREFIX%[a-zA-Z0-9_]*}"
PREFIX="${PREFIX##*[^a-zA-Z0-9_]}"

compgen -v