Re: Distinguishing between characters and numbers

glen herrmannsfeldt wrote:
Dick Hendrickson wrote:
(snip)

I believe a plus or minus sign that is not followed by some
digits is an error.

10.6.1.2.1 F editing says
"The input field is either an IEEE exceptional specification or
consists of an optional sign, followed by a string of one or
more digits optionally containing a decimal symbol, including
any blanks interpreted as zeros."

In Fortran 66 formatted (before list directed) input, blanks were
considered as zeros. A completely blank field was a legal zero,
and I don't believe that a sign would have been illegal.

The last phrase on the quote above might only apply when
BLANK="ZERO" is used on the OPEN statement. If blanks are
interpreted as zero, input like +E and -E- should be legal
by the standard.


Blanks aren't interpreted as zero in list directed input. They're
value separators (unless they are in a character input string).

Also, 10.7.6 on the BN abd BZ edit descriptors says
"The blank interpretation mode affects only numeric editing (10.6.1)
and generalized numeric editing (10.6.4.1) on input."
Tracing back the references leads to the formatted edit
descriptors like I, F, G, etc. Not to list directed input.

Dick Hendrickson
I used to know calculators that would add a 1 if the EE
(enter exponent) key was pressed before any digits.
Convenient for entering powers of ten.

-- glen

.

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