|Portability||semi-portable (uses MPTC and type families)|
This is a handy module with functions for manual and automatic
padding. To pad means to force the length of a string to be of a
minimum size by adding padding characters on either or both sides
of the string (usually spaces). For example, padding the string
"123" to have length of 10 characters would give us the string
" 123" -- if padding on the left "123 " -- if padding on the right " 123 " -- if padding on both sides
We provide two kinds of padding here:
- manual padding
- This is the kind of padding you usually see
in other (non-
dzen) libraries. You give them the type of padding and the minimum length that you want and they will give you back another string. The
pad*functions do this with both plain
DStrings and with the output of
- automatic padding
- This is the same as a "never shrink"
padding. An automatic padder adjusts its minimum length
to be at least the greatest length it has seen so far, which
means that an auto-padded
Printerwill never shrink its size. This is very useful if you don't want everything swinging on your bar everytime the bar is updated.
- padL :: Transform a => Int -> a -> a
- padR :: Transform a => Int -> a -> a
- padC :: Transform a => Int -> a -> a
- pad :: Transform a => Char -> PadWhere -> Int -> a -> a
- data PadWhere
- autoPadL :: Int -> Printer a -> Printer a
- autoPadR :: Int -> Printer a -> Printer a
- autoPadC :: Int -> Printer a -> Printer a
- autoPad :: Char -> PadWhere -> Int -> Printer a -> Printer a
Note that there are commands that generate graphical
outputs, such as
System.Dzen.Graphics.rect, and we can't
tell how many "characters" a graphic object has.
Whenever you apply any of the padding functions below
DString that contains one of these graphical
objects, there will be no padding. Note that colours
do not affect padding as they do not have any width
(and we don't mistake the command characters with
the characters that will be shown).
Pads the given
with spaces to be at least
n chars in length
padL, but insert spaces on the right of the string.
padL, but insert spaces on both sides,
trying to keep the original contents in the middle.
Generic pad function, padding with any character and in any place.
Automatic padding adjusts the number of padding characters
dinamically, increasing the pad everytime the string
size is greater than the pad size. For example, if
autoPadL 3 the following strings
"1" "12" "123" "1234" "12345" "1234" "12" ""
then it will give the following outputs
" 1" " 12" "123" "1234" "12345" " 1234" " 12" " "
autoPadC 3 would give
" 1 " " 12" "123" "1234" "12345" " 1234" " 12 " " "
- If you're lazy you may give an initial number of zero and after some inputs the padding will be fine.
- If the automatic pad finds out that there is a graphical object at some string, then it will continue trying to pad the next strings. Although normally the strings will all contain graphics or not, we consider that the performance loss is negligible (and we do what the user expects).