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Q59085: Replacing Normal String Takes Longer Than Regular Expression

Article: Q59085
Product(s): See article
Version(s): 1.00 1.02 | 1.00 1.02
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | buglist1.00 buglist1.02 | mspl13_basic
Last Modified: 15-MAR-1990

Replacing a regular expression takes less time than replacing a normal
string in the Microsoft M Editor, Versions 1.00 and 1.02. To
demonstrate the time difference, perform test replacements in the
following manner:

1. Load the M Editor with a large file -- greater than 5000 lines.

2. Perform and time a replacement on a regular expression, one that
   fails to match in the file, for example:

      arg arg CTRL+L     zzzz   <- search for this regular expression
                         zzzz   <- replace with this regular expression

3. Perform and time a replacement on a normal string (one that fails
   to match in the file), for example:

      arg CTRL+L     zzzz   <- search for this string
                     zzzz   <- replace with this string

The string replacement may take twice as long as the
regular-expression replacement. To obtain the higher replace speed,
use the regular-expression replacement (arg arg CTRL+L) even when you
are not fully using the regular-expression syntax.

Note that a psearch on a regular expression psearch is NOT quicker
than a psearch on a normal string.

Microsoft has confirmed this to be a problem in Versions 1.00 and
1.02. We are researching this problem and will post new information
here as it becomes available.

For details on regular expression, refer to the "Microsoft Editor
User's Guide," Chapter 5, "Regular Expressions."

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