Chapter 1 Introduction to PRESCRIBE
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TEXT "You’re about to enter PRESCRIBE.";
TEXT ’ " " " ’;
In the first command above, the character string starts with a double quotation mark. The
printing system therefore expects the string to end with a double quotation mark, and
regards the apostrophe in the word You ’re as an ordinary character, not as the string ter-
minator.
Similarly, the double quotation marks in the second command above are recognized as
ordinary characters, not as string terminators.
Since an apostrophe or quotation mark can start a character string anywhere in a PRE-
SCRIBE command sequence, it is important not to start character strings unintentionally.
The following examples demonstrate incorrect use of apostrophes and double quotation
marks.
Incorrect:
!R! CMNT Don’t leave stray apostrophes; EXIT;
Incorrect:
!R! CMNT The symbol " means inches; EXIT;
In both of the above cases, the printing system assumes that the expression EXIT; is part
of a character string started by the preceding apostrophe or quotation mark, and fails to
exit the PRESCRIBE mode. The correct way to write these comments is:
Correct:
!R! CMNT "Don’t leave stray apostrophes"; EXIT;
Correct:
!R! CMNT ’The symbol " means inches’; EXIT;
Character strings must not exceed the 255-character limit on total command length. If a
character string exceeds this limit, the printing system terminates it forcibly and begins
looking for the next PRESCRIBE command.
Upper and Lowercase Letters
Regarding upper and lowercase characters, PRESCRIBE follows the same rule as many
computer programming languages: it discriminates case inside character strings and
ignores it elsewhere. You can type command names in upper or lowercase.
Correct:
!R! TEXT ’A’; CIR 1; EXIT;
Also correct:
!R! text ’A’; cir 1; exit;
Also correct:
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