Inform 7 open-source release
Thursday, April 28, 2022
Comments: 4 (latest September 5)
Tagged: inweb, inform 7, literate programming, it looks alive to me
Today is the traditional Inform 7 birthday. Okay, April 30 may be more traditional, but close enough. The point is, today Graham posted the full source code for a new release of Inform 7. Here is his announcement forum post.
This is tagged as a beta release, and the IDEs have not yet incorporated the new compiler. So it's not fully ready for use. But I have successfully downloaded it, compiled it, and run some tests.
In other good news, the Inform bug tracker is back, now in Jira form.
Do you like NeXT-style release numbers, named releases, datestamps, or semantic versioning? Inform has you covered every which way! This release is formally "Inform 7, v10.1.0-beta+6U93 'Krypton' (28 April 2022)".
Some older versions of I7 now have semantic version numbers as well, and will be available as options in the IDE:
- 6L02 (May 2014): Inform 9.1
- 6L38 (August 2014): Inform 9.2
- 6M62 (December 2015): Inform 9.3
This is good news for existing users, as upgrading a large game across Inform versions has always been a moderate headache. It's even possible that users will contribute bug fixes to the 9.x branches.
All three are written in inweb, a "literate programming" meta-dialect of C. Read the forum post or the inweb manual for a full explanation of this. The micro-summary is that it's C code annotated with documentation such that it can generate either an executable or a manual.
The fact that inweb is written in inweb means that the whole mess requires a certain amount of bootstrapping, in the original sense. But it's just a few commands, and they go smoothly on Mac/Win/Linux. See the READMEs for details.
Reading source code in this style is somewhat unnerving to us old coders. You can look at a source file, or the equivalent web page -- they're blatantly the same thing; just nicer formatting on the web version. It reads like a manual with bits of sample code. But of course this is the code. You're looking at it. If you want to fix a bug, you fix this file; the change applies to executable and manual alike.
The effect is somehow like one of those night-in-the-museum fantasies where the buffalo and the Transparent Woman start walking around and talking to you. In the manual (or source), Graham quotes Christopher Wyk (CACM 33.3, 1990): "...no one has yet volunteered to write a program using another's system for literate programming." This may yet remain true.
This I7 release doesn't change the language much from the last (2015) release. The big changes are under the hood. The classic two-stage compiler (I7→I6→Glulx) is now three stages (I7→Inter→I6→Glulx). But the new Inter stage can also be compiled to C source and then a native executable. More formats like JS or C# could be added in the future. This is still experimental, but it opens the possibility of using Inform as middleware in other game frameworks. (This has always been possible with enough layers of hackery, but now it's more sensible.)
Plenty more could be said, but I think that'll do for tonight. Have fun poking around.