On Thu, 18 Jul 2013 08:13:02 -0400, John Gilmore wrote: >COBOL optimization has always been problematic for two reasons. > >The less important of them is that, until now at least, some >syntactically interesting features of the language have been >implemented very poorly. Some COBOL EVALUATEs are, for example, >functionally very like a C switch or a PL/I select(<single >character>). They have not, however, been inplemented in COBOL using >a branch table, as such constructs are in C and PL/I, but as if nested >IFs had been written. > Which might be the proper implementation if the cases are sparse. Best to start with the median case value and bisect recursively. Storage is cheap nowadays, particularly if it's not accessed. But a large and sparse branch table is an invitation to page faults.
>More important, COBOL arrays were for long too small to meet the >requirements of many applications. For this reason, the practice of >extending these arrays informally by (mis)appropriating the storage >immediately following too-small ones for phantom elements addressed >using formally illicit subscripts has been common. > In the past, you've deplored as "nanny languages" (IIRC) those which generate code to prevent such abuses. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
