SLAG: A Z-Machine Hint System

In a nutshell, SLAG is a Perl script that takes a command file describing hints to be built, then converts the command file to Inform source code. Once built and executed, the program will run the invisiclues in the standard menu-oriented manner. The z-code binaries are fairly lean since they reasonably do not build in Graham's parser and all that.

John Kean's similar project which I had hoped to help on (but completely failed to for a variety of reasons) has other intentions: convert the Invisiclues directly from human-readable to Inform. This was a loftier goal than I wanted to achieve, and besides I wanted a straightforward "mark up language" to make new invisiclues-style programs.

So this SLAG hack was born.

Note that I intended for the Inform output of SLAG to be stand-alone, but there's nothing stopping you from taking it and working it into your own code. (Except, of course, the fact that other menuing systems might be better.)

Features

Well, there are actually a number of these:

1. Ability to show an intro "splash" screen.
2. Ability to nest menus.
3. Ability to show just plain text (fixed or proportional fonts) in addition to clues.

The SLAG input files, below, demonstrate pretty much everything.

"Features"

1. To link from a menu to another item requires typing the title of that item twice to identify the link.
2. Syntax errors are often ignored by SLAG, leaving you to attempt to figure out what you did wrong at the Inform-compile stage.
3. To convert from the human-readable Invisiclues you download, you must manually tidy it up into the SLAG input format. vi macros really help out here, but it is easy to accidentally eyeball the clues if you haven't played the game. Check John Kean's stuff if this is what you're after.
4. I'm a real novice when it comes to this low-level screen manipulation. It works fine under Frotz for Unix, and acceptably under xzip. I'll bet there are other interpreters that have a fit.
5. Some parts of the code are still virgin.
6. Clues, hints, and menu items must be typed onto a single line.
7. User must remember to keep the number of menu items less than 22 or so, or screen output will suffer on small terminals.
8. Doesn't handle small screens well at all.
9. Written in Perl.
10. Etc.

Downloads

slag--The Perl script itself (Release 8)

The following two files are not required, but might prove interesting to some:

Makefile--A Makefile to build the invisiclues
vimac--Some vi macros to help convert Invisiclue files to SLAG files (contains escape characters)

	SLAG input	Z-Machine output
Zork I	zork1inv.slg	zork1inv.z5
Zork II	zork2inv.slg	zork2inv.z5
Zork III	zork3inv.slg	zork3inv.z5
Zork: The Undiscovered Underground	ztuuinv.slg	ztuuinv.z5
Enchanter	enchaninv.slg	enchaninv.z5
Sorcerer	sorcinv.slg	sorcinv.z5
Spellbreaker	spellbinv.slg	spellbinv.z5
Trinity	trininv.slg	trininv.z5
Planetfall	planetinv.slg	planetinv.z5
Stationfall	stationinv.slg	stationinv.z5
Lurking Horror	lurkinginv.slg	lurkinginv.z5
Leather Goddesses	lgopinv.slg	lgopinv.z5
Hitchhikers Guide	hhgginv.slg	hhgginv.z5

I have released the SLAG source code into the public domain. So there. If you want me to make changes or fixes, feel free to request them and I'll accommodate you, time permitting.

I'm not doing any more .z5 files for now, but if you mail me your requests, I'll queue them up.

Change Log

Release 8:

• Doh! Still missed some functions when unpolluting namespace in release 7. Fixed that, and added a "generated by" comment block at the top of the Inform output.

Release 7:

• Unpolluted namespace by prepending "SLAG_" to a bunch of internal functions and classes that I missed last time. That should be all of it.

Release 6:

• Fixed the output with "-s" so you only need to call one function to get to the menus from your code (in R5 you had to add several ugly lines.)
• Unpolluted namespace by prepending "SLAG_" to a bunch of internal functions and classes.

Release 5:

• Added "-s" flag to strip unnecessary code from output. Useful if you're embedding SLAG output in your own source. Prints instructions to standard output.
• Added "-q" flag to quiet SLAG when "-s" is specified. Useful in Makefiles when you don't want to read that stuff again and again.
• Added dummy call to Center() so that Inform won't complain about it not being used if you don't ".CENTER" anything.

Release 4:

• Allow multiple links and hints to have the same name. In the SLAG input add a "n:" before the string, where "n" is a number (single or multiple digit) that uniquely identifies the hint. The number will be stripped before printing. See the Hitchhikers input file for a demo.

Release 3:

• Added key help to the menu titlebar at John Holder's suggestion. This reduces the menu title length (not the hint length, though) to about 46 characters on an 80 column screen. This doesn't seem to be a problem.
• Added the "WordStar diamond" of keys for controlling the cursor.

Release 2:

• Removed a restriction that required all link names to be unique to the first 32 characters.
• That same change reduced z-code file sizes by about 5%-10%.

Why "SLAG"?

Since I had just been watching Red Dwarf, I credit Dave Lister for inspiring me.