Environment Notes

This page discusses how Gwydion Dylan interacts with an operating system.

Summary
Environment Notes
This page discusses how Gwydion Dylan interacts with an operating system.
Debugger customizations
A note on terminology: We use the term “debugger” here in the loose, Dylan sense of anything that handles an uncaught error.

Debugger customizations

A note on terminology: We use the term “debugger” here in the loose, Dylan sense of anything that handles an uncaught error.  In Mindy, this debugger is indeed a full fledged debugger, but in other Gwydion compilers it may not be.

The debugger uses the function report-condition to print conditions as error messages to users; for example, this is the function that implements the %S format-string directive for conditions.  The debugger also uses the format function exported from Module format to process format strings, and it prints directly to the Unix STDOUT.

You can extend how the debugger prints conditions, change what formatting function it uses, and direct where debugger output goes with the following:

Writes a condition to a stream.
Format a string and write it to a stream.
The Format module provides a way to control output to a stream.
This function serves as a firewall between the condition system and the Streams and Format modules.
Flushes the condition output stream.
default-handler for <warning> uses *warning-output* to print warning messages.