On this page:
2.1.1 Initial Environment
2.1.2 Details Pane of Language Dialog

2.1 Language Declared in Source🔗

The The Racket Language mode in DrRacket is a kind of meta-language, where the program itself specifies its language, usually through a #lang line.

More generally, when using this mode, the definitions window must contain a module in some form. Besides #lang, a Racket module can be written as (module ...); aside from comments, the definitions window must contain exactly one module.

2.1.1 Initial Environment🔗

DrRacket initializes the environment before it starts running the program in ways slightly different than the racket command-line binary does to reflect the extra GUI capabilities that it provides. Using the default settings in the language dialog, it initializes the parameters described in this subsection. Changing the defaults can result in additional parameters changing, as described in the next subsection.

DrRacket initializes the pretty-print-size-hook and pretty-print-print-hook to specially recognize

It also initializes the global-port-print-handler to use pretty-print instead of just print.

DrRacket initializes the error-display-handler to specially highlight the source locations of the errors and to include icons that provide access to the stacktrace.

2.1.2 Details Pane of Language Dialog🔗

In the details pane of the language dialog, some of the configuration options correspond to using various libraries and thus can be used without DrRacket. Here’s how, for the ones that are straightforward (the ones not mentioned here require more sophisticated configuration of various libraries).