Technology of IF: Text Parsers and Interpreters
Most Interactive Fiction games are programmed with text parsers, but when you’re first getting into the culture this can be a bit confusing to navigate. Our major concern as newbies is to see what programs we need just to play the games. To explain this I’ll go into a little bit of background.
Put broadly a text parser is a program that simplifies user input. As far as games are concerned, text parsers interpret user commands such as “go east” or “take sword” or “attack monster.” This allows programmers to write games that respond to complex player direction.
Text parser games are the most common format in Interactive Fiction. It’s what most people think of when they think of IF, with notable examples ranging from Photopia to Zork to the iconic Adventure. These text-based games present players with a setting and allow them to control the characters with typed commands.
Historically there have been tons of different ways to use text parser programs and write these games, which means a number of different file formats that have to be translated into something a computer can read. In the past most games were published as executable programs and written to disks, but independently developed Interactive Fiction games were shared more informally.
Luckily, the IF community has made this easy by relying on just two primary file formats: z-machine and glulx. Z-machine is the older of the two, designed in the late 70s and still being used regularly today. Glulx was designed in the late 90s to be an updated version of z-machine – it has more data space, allowing for more complicated game designs and visual elements.
There are other formats designed for the modern text parser - notably TADS, which has been gaining traction in the last decade - but almost every game you decide you want to play will be saved in one of those two formats.
For my game-playing, I’ve downloaded Glulxe and Windows Frotz. They’re both simple executable files designed to display the game files without any bells and whistles. You can download them both at the links provided.
I’ve recently learned about Gargoyle, however, a program created from a library of different text parser interpreters. With Gargoyle, you can play any text parser game without having to worry about finding the write interpreter to use. It really streamlines the process, something I feel the IF community’s been needing. You can read more about Gargoyle and download it at the link provided.
Last but not least, Parchment is a browser-based text parser interpreter which requires no download at all. You can find a list of games that have been uploaded onto Parchment here