Re: [Groff] Heirloom TBL problem

[Tadziu Hoffmann]

> A.  MM has no clear way to set ll

You can use ll in MM, but the effect will remain local.

It is common practice among macro packages to reset the line length
to some "master value" on every paragraph / section header / etc.
In MM that master value is taken from register W while defining
the macros.  In MS the master value resides in register LL.
ME renames ll to xl, and creates a wrapper macro ll around xl
(so that when you use ll you will not get the raw troff request,
but instead something with (possibly unwanted) side effects).
Caveat emptor.


> B.  Tbl clearly understands ll with MM in groff, and it makes sense.

Tbl uses the value in register .l, however that was set.

And let's not forget, GNU MM is only interface-compatible with
AT&T MM, not secret-internals-compatible.  The raw troff request
ll was apparently not intended to be part of that interface.

Of course it's possible to rewrite AT&T MM to behave differently,
but this might cause incompatibilities elsewhere.