On 2013-10-21 14:35, Gainsford, Allen wrote: >> It is known, was indeed emphasized by Backus, is that he was much >> concerned not to deprive 704 assembly-language programmers of >> facilities they prized. His situation was very different from >> ours today. He wanted to open up programming to others, but he >> crucially needed to convince 704 assembly-language programmers of >> the time---There were no others---that FORTRAN was not a >> performance dog; and to this end he tried very hard to make >> analogues of the crucial 704 machine instructions available in >> FORTRAN. > > Whereas nowadays IBM seem to add new instructions to support the programming > languages! > I believe this is a fortiori true for FORTRAN's signum function because that was a hardware instruction on the 704.
And that Wirth made cardinality a function in Pascal because it was a machine instruction on the CDC 6600. But that had disastrous consequences. Operator precedence in Pascal is pernicious; I suspect that the reason is that Wirth wanted not to allow more nonterminal symbols in the grammar than could be represented in a bitset in a 60-bit word. -- gil
