Compatibility

Planning to move a live game? Compatibility findings are inputs to a rehearsal, not proof that an import is ready for players. Use the PennMUSH migration runbook to test your own identities, data, softcode, connection paths, portal, and integrations.

SharpMUSH does away with some of the more unique aspects of PennMUSH parser curiosities.

Unbalanced Parenthesis

In PennMUSH, the following is legal, while is not in SharpMUSH:

PennMUSH

think add(1,2
> 3

Instead, complete the parenthesis.

SharpMUSH

think add(1,2)
> 3

Forgiving Parenthesis

In PennMUSH, the following is legal, while is not in SharpMUSH:

PennMUSH

lsearch(all,eval,\[strmatch(##,%#)\])
> #1

Instead, escape all the contents. This is also needed for #lambda evaluation.

SharpMUSH

lsearch(all,eval,\[strmatch\(##\,%#\)\])
> #1

Full Recursion Parsing

In PennMUSH, TinyMUX, etc, you can do the following:

PennMUSH

&fn me=ucstr; think [v(fn)](foo)
> FOO

Instead, use callfn() to call the intended function.

SharpMUSH

&fn me=ucstr; think callfn(v(fn),foo)
> FOO

This is an awesome feature of MUSH-likes, but we explicitly do not support this, as it makes the parser non-deterministic, ambiguous and harder to maintain. Most existing Softcode does not rely on this behavior however.

Note

SharpMUSH introduces callfn() and @callcmd to replace this loss, which ensures most scenarios have a way to build the compatibility back in.

## Double-Evaluation

In PennMUSH, ## inside iter() performs double-evaluation, meaning the substitution result is evaluated again as MUSHcode:

PennMUSH

iter(\[if(true\,red\,white)\],##,)
> red

In SharpMUSH, ## is substituted as %iL (a literal reference), so the result is returned as-is without further evaluation:

SharpMUSH

iter(\[if(true\,red\,white)\],##,)
> [if(true,red,white)]

If double-evaluation is needed, use s() or objeval() to explicitly evaluate the result.