From Newsgroup: comp.lang.tcl

I have this string formatting command:

format "%#9i" 123

With Tcl 8 I get " 123"

With Tcl 9 I get " 0d123"

The usage of the "#" flag comes from a more general procedure, that
makes sure, that in case of "e" format (scientific notation) there is
always a decimal point available.

In Tcl 8 "#" had no effect on "i" format.

In Tcl 9 it add "0d" to the result.

Is this a bug or intention?
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From Newsgroup: comp.lang.tcl

Am 03.09.2025 um 10:23 schrieb meshparts:

I have this string formatting command:

format "%#9i" 123

With Tcl 8 I get "      123"

With Tcl 9 I get "    0d123"

The usage of the "#" flag comes from a more general procedure, that
makes sure, that in case of "e" format (scientific notation) there is
always a decimal point available.

In Tcl 8 "#" had no effect on "i" format.

In Tcl 9 it add "0d" to the result.

Is this a bug or intention?

I have no idea.
Perhaps open a ticket on tcl?
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From Newsgroup: comp.lang.tcl

* meshparts <[email protected]>
| I have this string formatting command:

| format "%#9i" 123

| With Tcl 8 I get " 123"

| With Tcl 9 I get " 0d123"

| The usage of the "#" flag comes from a more general procedure, that
| makes sure, that in case of "e" format (scientific notation) there is
| always a decimal point available.

| In Tcl 8 "#" had no effect on "i" format.

| In Tcl 9 it add "0d" to the result.

| Is this a bug or intention?

https://www.tcl-lang.org/man/tcl9.1/TclCmd/format.html#M12

#
Requests an alternate output form. For o conversions, 0o will be
added to the beginning of the result unless it is zero. For x or X
conversions, 0x will be added to the beginning of the result unless
it is zero. For b conversions, 0b will be added to the beginning of
the result unless it is zero.
!! For d conversions, 0d there is no effect unless the 0 specifier is
used as well: In that case, 0d will be added to the beginning.
[...]

The sentence for the 'd' conversion does not really make sense 100% to me (non-english speaker), but it sounds as if "%#9i" should *not* produce
the 0d, since the '0 specifier' is not present.

HTH
R'
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From Newsgroup: comp.lang.tcl

Am 03.09.2025 um 12:41 schrieb Ralf Fassel:

* meshparts <[email protected]>
| I have this string formatting command:

| format "%#9i" 123

| With Tcl 8 I get " 123"

| With Tcl 9 I get " 0d123"

| The usage of the "#" flag comes from a more general procedure, that
| makes sure, that in case of "e" format (scientific notation) there is
| always a decimal point available.

| In Tcl 8 "#" had no effect on "i" format.

| In Tcl 9 it add "0d" to the result.

| Is this a bug or intention?

https://www.tcl-lang.org/man/tcl9.1/TclCmd/format.html#M12

#
Requests an alternate output form. For o conversions, 0o will be
added to the beginning of the result unless it is zero. For x or X
conversions, 0x will be added to the beginning of the result unless
it is zero. For b conversions, 0b will be added to the beginning of
the result unless it is zero.
!! For d conversions, 0d there is no effect unless the 0 specifier is
used as well: In that case, 0d will be added to the beginning.
[...]

The sentence for the 'd' conversion does not really make sense 100% to me (non-english speaker), but it sounds as if "%#9i" should *not* produce
the 0d, since the '0 specifier' is not present.

HTH
R'

Thanks.
I sent a TIP to [email protected]
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From Newsgroup: comp.lang.tcl

On Wed, 03 Sep 2025 12:41:35 +0200, Ralf Fassel wrote:

* meshparts <[email protected]>
| I have this string formatting command:

| format "%#9i" 123

| With Tcl 8 I get " 123"

| With Tcl 9 I get " 0d123"

| The usage of the "#" flag comes from a more general procedure, that
| makes sure, that in case of "e" format (scientific notation) there is
| always a decimal point available.

| In Tcl 8 "#" had no effect on "i" format.

| In Tcl 9 it add "0d" to the result.

| Is this a bug or intention?

https://www.tcl-lang.org/man/tcl9.1/TclCmd/format.html#M12

#
Requests an alternate output form. For o conversions, 0o will be
added to the beginning of the result unless it is zero. For x or X
conversions, 0x will be added to the beginning of the result unless
it is zero. For b conversions, 0b will be added to the beginning of
the result unless it is zero.
!! For d conversions, 0d there is no effect unless the 0 specifier is
used as well: In that case, 0d will be added to the beginning.
[...]

The sentence for the 'd' conversion does not really make sense 100% to me (non-english speaker), but it sounds as if "%#9i" should *not* produce
the 0d, since the '0 specifier' is not present.

HTH
R'

I suggest replacing:

For d conversions, 0d there is no effect unless the 0 specifier is used
as well: In that case, 0d will be added to the beginning.

with:

For d conversions, 0d has no effect; whereas both #d and #0d produce an
0d prefix.

Might also be worth adding:

Note that width includes any prefix. For example "%06d" shows
at least 6 digits, but "%#06d" shows at least 4 digits.

Evidence:

Main console display active (Tcl9.0.2 / Tk9.0.2)
(mark) 61 % format "%d %0d %06d %#d %#0d %#06d" 12 13 14 15 16 17
12 13 000014 0d15 0d16 0d0017

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From Newsgroup: comp.lang.tcl

I suggest replacing:

For d conversions, 0d there is no effect unless the 0 specifier is used
as well: In that case, 0d will be added to the beginning.

with:

For d conversions, 0d has no effect; whereas both #d and #0d produce an
0d prefix.

Might also be worth adding:

Note that width includes any prefix. For example "%06d" shows
at least 6 digits, but "%#06d" shows at least 4 digits.

Evidence:

Main console display active (Tcl9.0.2 / Tk9.0.2)
(mark) 61 % format "%d %0d %06d %#d %#0d %#06d" 12 13 14 15 16 17
12 13 000014 0d15 0d16 0d0017

Thanks, Marc.
I added this information to a ticket: https://core.tcl-lang.org/tcl/info/af4780b0b5245f03

It might be good to add this to the migration hints, as the Tcl 8.6
result is quite different:

% format "%d %0d %06d %#d %#0d %#06d" 12 13 14 15 16 17
12 13 000014 15 16 000017

Do you have the rationale for this change? It looks like intention and
not a bugfix.

Thanks for all,
Harald
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