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Left Hand Pointer

$ASCII

Annotations

Right Hand Pointer

$ASCII function

Some of the sentences in the original descriptions of the transition diagrams have a period at the end, some sentences don't.
The editor ensured that there are periods at the end of each sentence.

The texts for the 1977 and 1984 standards mention the "null string".

Note that a null string in a language like C looks like:
   char str [] = {0};
or
   char str = "";
and is stored in memory as an array or "short integers", where the array length is 1 element, and the value of that element is 0 (zero).

In M[UMPS], however, one can Set str=$Char(65,66,0,67,0,68) and thus create a string that consists of 6 characters, two of them being the control-character commonly known as "the NULL character".

If a C program would create a string like
   char str [] = {65, 66, 0, 67, 0, 68};
the length of that string would be considered to be 2 (two) characters, and the string-related functions of the language would not "see" beyond the first "null" character.

Since it is possible in M[UMPS] to have a string that is equal to $Char(0), the meaning of the term "null string" is considered to be ambiguous (it can mean either a string of zero characters, or a string of one character, that character being the NULL character). As a result, the standard does not use the term "null string" in any of the formal parts, but instead uses the term "empty string" when referring to a string consisting of 0 (zero) characters. When referring to the other possible meaning, the standard refers to the ASCII NULL character.

Button for 1977 Button for 1984 Button for 1990 Button for 1995 Button for MDC Button for notes Button for examples

Copyright © Standard Documents; 1977-2018 MUMPS Development Committee;
Copyright © Examples: 1995-2018 Ed de Moel;
Copyright © Annotations: 2003-2008 Jacquard Systems Research
Copyright © Annotations: 2008-2018 Ed de Moel.

Some specifications are "approved for inclusion in a future standard". Note that the MUMPS Development Committee cannot guarantee that such future standards will indeed be published.

This page most recently updated on 13-Sep-2014, 17:09:17 .

For comments, contact Ed de Moel (demoel@jacquardsystems.com)