assert

Signals an error if assumption is incorrect.

This macro signals an error if value is #f.  Otherwise, it does nothing.  It may or may not evaluate its argument exactly once.  So, it goes to follow that users of assert should not have side-effects in the expression that is passed to assert because if we ever turn assertions off, that would mean the program runs differently in debug mode than it does in release mode.

Exported from

Macro call

assert ( (expr), (message), (values) )

Arguments

exprAn expression which should be true.
messageA format string to display if expr is false.  Optional.
valuesValues to insert into message.  Optional.
Signals an error if assumption is incorrect.
Ultimately, there will be several, more logically separate libraries that extend Dylan or provide an application framework for users.
The common-dylan module.
Miscellaneous extensions to the Dylan language.