ExpectPreconditionWithReason

Typestatement
DictionaryLCB
LibraryLiveCode Builder
Syntax
expect [that] <Condition> because <Reason>
Associationscom.livecode.assert
Summary

Check a precondition, with a reason

Parameters
NameTypeDescription
Condition

Expression that must be true for code to work

Reason

Description of the precondition

Example
-- Draw a random variate from the Bernoulli distribution with
-- parameter pParam.  A Bernoulli variate may be 0 or 1; the
-- parameter pParam is the probability that the result is 1.
handler BernoulliVariate(in pParam as Number) returns Number
	expect (pParam >= 0 and pParam <= 1) \
		 because "Bernoulli parameter must be a probability in [0,1]"
	if (any number <= pParam) then
		return 1
	else
		return 0
	end if
end handler
RelatedStatement: ExpectPrecondition
Description

Use this statement at the start of a handler to check that necessary preconditions for the handler are satisfied. For example, the handler may require that its parameters have a particular structure or fall within a particular range, or may need the system to be in a specific state.

If the Condition is false, an error will be thrown including the Reason for the check.

Tagsassertions