HELP STRNUMBER Aaron Sloman June 1990
strnumber(<string or word>) -> number or false
This procedure takes a string or word containing the character codes for
an number, and returns a number. If the string does not contain
appropriate characters for a number as recognised by the itemiser
(leading or trailing spaces are ignored), or if the string is empty, the
result is FALSE. E.g.:
strnumber('1234') =>
** 1234
strnumber(' -1234.5') =>
** -1234.5
strnumber('twenty') =>
** <false>
strnumber("'32'") =>
** 32
strnumber("cat") =>
** <false>
Thus STRNUMBER can also be used to TEST whether a string or word
contains characters appropriate for a number.
If applied to anything but a string or word it will cause a mishap.
strnumber is useful if -unpackitem- is used to transform a word into
a list of words and you want to get numbers back. E.g.
unpackitem("cat3") =>
** [c a t 3]
The last element is a WORD not a number, but strnumber can be used to
convert it.
See also
HELP * STRINGIN
HELP * STRINGS
HELP * WORDS
HELP * MATH
HELP * UNPACKITEM
--- C.all/help/strnumber
--- Copyright University of Sussex 1990. All rights reserved. ----------