See the short comment on the topic in section 3.9 of "J for the APL Programmer". http://www.jsoftware.com/jwiki/Doc/J4APL
Some other observations: 0. Tacit is shorter than explicit. This is especially pronounced in short expressions. For example, the monad +/\ is more preferrable than the equivalent 3 : '+/y'\ 1. Tacit is more amenable to formal manipulations than explicit. For example, the interpreter "recognizes" +/\ and implements it with special code. To do the same for 3 : '+/y'\ would be more difficult. Likewise for many of the entries in http://www.jsoftware.com/help/dictionary/special.htm Formal manipulations also come into play in things like f^:_1 and f&.g . http://www.jsoftware.com/jwiki/Essays/Under 2. Explicit is clearer if more than 2 names are involved. For example, a tacit version of cnv in http://www.jsoftware.com/jwiki/Essays/Collatz_Conjecture is possible but it would not be as reable. 3. Tacit encourages building up a more complex function from components. The same can be done with explicit but it tends not to be done; instead, the components end up being temporary local names that are not as readily accessible. For example: http://www.jsoftware.com/jwiki/Essays/Matrix_Inverse ----- Original Message ----- From: Tracy Harms <[EMAIL PROTECTED]> Date: Monday, February 19, 2007 11:19 am Subject: [Jprogramming] tacit vs explicit definition > I've learned how to use adverb 13 : to produce tacit > phrasing of an explicit definition. I have some sense > as to when tacit verbs are stylistically easier to > read. I also have learned that there is some degree > of speed increase that occurs with tacit definitions, > because they somehow involve less work from the > interpreter during execution. > > What I have not been able to find, so far, is a > definitive overview of the advantages to using tacit > verb definition. Is there such a section in the > existing texts? > > (It seem that the advantage of explicit definition is > straightforward: It is necessary when the coder > wishes to write the verb in more than one line, and it > is convenient for increased readability esp. when the > code is more complex. But please, correct me if I'm > in error.) ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
