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Credo quia incredible est. |
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Our motto for this section is supplied by a noted medieval Christian theologian. Roughly translated, it means, ''I believe in that which is unbelievable." Thus fortified, I may proceed to investigate the behavior of the SCDTL functions with a fair expectation of success. |
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All functions in the SCDTL system are exercised by one or more test programs, in a series called the Date/Time Library Test series, or DTLT. Each program illustrates the use of one or more SCDTL functions. |
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You may wonder why more frequent use is not made in later test programs of functions tested in earlier ones. The reason is again primarily pedagogical. The staple utility functions are exercised many times, but an overall depth limit has been observed in the writing of the test programs. Later programs in the series are not constructed as a pyramid of calls to other SCDTL functions tested in earlier programs, because this situation would make an independent study and understanding of the later programs much more difficult. It has been a goal throughout to make each test program an independent unit for the purpose of study, as much as possible, even when (especially when) the use of SCDTL functions would have simplified the task. |
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You should know that the numbering system for DTLT programs is essentially chronological. As functions were designed and written, test programs were designed and written to exercise and test them. Most test programs were then modified or rewritten to demonstrate the use of the functions, to reveal their limitations and to generate test output. The balance between the test and demonstration value of a given program thus depends a bit upon the nature of the individual program. |
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