When I was in JHS we learned BASIC (and Pascal) with IBM BASICA on PS/2s (80286s with 20 MB HDDs). The assignments required LET.
First Tennessee Bank Mainframe Technical Support -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Paul Gilmartin Sent: Thursday, April 26, 2018 1:21 PM To: [email protected] Subject: Re: RECFM (was: IRS - 60-Year-Old IT System Failed ... ) [External Email] On Thu, 26 Apr 2018 07:34:36 -0700, Phil Smith wrote: > >When you realized that > DO25I=1,10 >defines the start of a loop, but > DO25I=1.10 >is an assignment statement, you really wonder what about the FORTRAN compiler >parser! I'm sure it made sense at the time, and can see how it would be done, >but it still seems to me like a strange way to design a language. > Over a half century ago, a peer told me that FORTRAN, with a preliminary lexical scan, considered any statement with: o an "=" not enclosed by parentheses, and o no "," outside all parentheses ... to be an assignment statement. Anything else starts with a keyword. A professor in the same era told his class that the oldest FORTRAN compiler parsed arithmetic expressions without using a stack. Didn't oldest BASIC interpreters (or perhaps DEC's FOCAL) require that assignments be introduced by a keyword, "SET" or "LET"? I never knew whether this was to simplify the parser or to aid novice (we all were) programmers' understanding tnat "=" meant assignment, not comparison. Some DEC interpreters put assgnment targets on the right. Some DEC shells put RENAME/COPY targets on the left (that's actually the better way.) -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN FIRST TENNESSEE Confidentiality notice: This e-mail message, including any attachments, may contain legally privileged and/or confidential information. If you are not the intended recipient(s), or the employee or agent responsible for delivery of this message to the intended recipient(s), you are hereby notified that any dissemination, distribution, or copying of this e-mail message is strictly prohibited. If you have received this message in error, please immediately notify the sender and delete this e-mail message from your computer. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
