RE: [Mybusinessbasic-devel] Thoughts on file types and I/O
Status: Alpha
Brought to you by:
mikecurry1974
From: Michael S. L. <mi...@ha...> - 2003-12-30 19:34:05
|
Gary McClellan <mailto:ga...@bb...> wrote: >> 6) Fields in Multi-keyed files should be named and access should be >> permitted by name as well as by field number. For instance if field >> number 8 in a file is named "Partnum" then an IOLIST could be >> written as either "IOLIST #8=PART$" or "IOLIST #PARTNUM=PART$" or >> more traditionally as "IOLIST *,*,*,*,*,*,*,PART$" >> >> 7) Fields in direct files should not be named and access should be >> permitted only by field number. For instance if field number 8 in a >> file contains the "Partnum" information then an IOLIST could be >> written as either "IOLIST #8=PART$" or more traditionally as "IOLIST >> *,*,*,*,*,*,*,PART$" >> >> 8) The key fields in multi-keyed files can be used in the "KEY=" >> function to specify which of the keys to use for access. For >> instance if the "Partnum" field is designated as a key field then a >> read command could be written as follows "READ >> (1,KEY=#PARTNUM=PART$)A1$,A2$,A3$..." or as "READ >> (1,KEY=#8=PART$)A1$,A2$,A3$..." > > Just out of curiousity, which BB uses this syntax? It's part OpenBasic and part BBx. > Why the special exception for Direct files (#7)? Because in every flavor of BB that I've used, Direct files do not have named fields. > What is the syntax for defining the field names (#PARTNUM) and key > names? A good point. I need to define the command that will create multi-keyed files as that will determine the format string containing the field definitions and names. I'll make a suggestion based on how it works in OpenBasic and you folks can hammer on it. ;-) > Should we also allow for the ProvideX method of having an embedded > data dictionary and IOLIST? (OPEN (chan,iol=*) means use the embedded > IOLIST on all future I/O operations where an IOLIST is not > specififed). It specifies the variable names to be used? Wow... that's interesting. Comments anyone? -- Michael St. Laurent Hartwell Corporation |