Inform Syntax Highlighting in Vim

The syntax highlighting file for Inform, inform.vim is always available here. There are three versions:

• The stable inform.vim, currently dated 2004 May 16 is always the most recent version currently included in standard Vim distributions. Vim 6.3 has this version. It has the following changes against the previous stable version (dated 2003 Apr 06 in Vim 6.2):
  • Feature: Support for Inform Compiler 6.30/Library 6.11. This is enabled by default, but can be disabled.

  • Bugfix: predicate keywords hasnt, in, notin, ofclase, provides and or were not being highlighted.

  • Bugfix: comment synchronization was not working properly.

• The pending inform.vim is always the version that has been most recently forwarded to Bram Moolenaar (Vim's creator) for inclusion in the next standard Vim distribution. With the release of Vim 6.3, there is no current pending version.

• The development inform.vim contains experimental features and/or bug fixes that I would like people to try out before sending them onto Bram. Currently, there is no development version.

Obviously the life-cycle goes something like this: New features appear in development versions, and get tested (hopefully by others besides me). Once we are happy, a file with the development features is sent to Bram, which then becomes the pending version. Finally, once a new version of Vim is released, the most recent pending version sent to him becomes the stable version.

To install a new copy of inform.vim, follow the instructions relating to installing a syntax file in Vim's online help.

Vim's Inform syntax highlighting support can be customized in a few ways:

• A complete Inform system is actually composed of two parts. Firstly there is the Inform compiler, which translates Inform programs into target executable code. Secondly there is the Inform Library, which contains a large selection of facilities which greatly ease the task of authoring interactive fiction.

  The vast majority of Inform users will be using it for its primary purpose - writing interactive fiction. By default, Vim's Inform syntax highlighting comes configured for such users. As well as highlighting basic Inform language features, various symbols defined by the Library are also emphasized.

  However, there are users who use the Inform language but not the Library - effectively they are using Inform as a more general programming language (something which, frankly, it is not that well adapted for). As these users may well be using identifiers normally defined by the Library for completely different purposes, highlighting Library symbols may be confusing. To suppress Library symbol highlighting, put the command:

  :let inform_highlight_simple=1

  in your vimrc file.

• The Inform compiler normally generates code targeted for the Z-Machine, a virtual machine originally devised by Infocom for their range of interactive fiction games back in the late 1970's and early-to-mid 1980's. However, Inform 6.30/6.11 also supports the more modern Glulx virtual machine, developed by Andrew Plotkin. Earlier Inform releases did not officially support Glulx, but it was possible to obtain modified releases.

  Most Inform programs need not be aware of which kind of machine they are going to run on, but some programs may need to make use of, for example, in-line assembly language which is very different for the two targets. Additionally, there are slight differences in the Library symbols provided by Glulx and Z-Machine Inform implementations.

  By default, Vim's Inform syntax highlighting assumes you are writing programs targeted for the Z-Machine. To make the highlighting Glulx-orientated, put the command:

  :let inform_highlight_glulx=1

  in your vimrc file.

  [This is not adequate in some ways. Inform code intended to be usable on both the Z-Machine and Glulx will contain blocks of code for both, using conditional compilation to select whichever is appropriate. However, when editing such code the user will probably want both Z-Machine and Glulx highlighting features active at the same time, and at the moment you get to choose one. This will be improved in future versions of inform.vim.]

• Normally, obsolete constructs are highlighted as errors. This can be annoying so there are two ways of preventing this. Firstly, you could put the command:

  :let inform_suppress_obsolete=1

  in your vimrc. This will simply stop obsolete constructs being highlighted as errors.

  The second, more preferable, way to prevent obsoletes highlighting as errors is to modernize your source code, of course.

• By default the features highlighted conform to Compiler version 6.30 and Library version 6.11, the most recent stable releases. However, if you are coding against the previous releases, Compiler 6.21 and Library 6.10, you might wish to disable highlighting of newer features by adding:

  :let inform_highlight_old=1

  to your vimrc file.

When running Vim, you can get Inform-specific help (such as it is) by using the command ":help inform".

Updated: 11th September 2004