+++ /dev/null
------------------------------------------------------------------------------
--- |
--- Module : Text.Html.BlockTable
--- Copyright : (c) Andy Gill and OGI, 1999-2001
--- License : BSD-style (see the file libraries/base/LICENSE)
---
--- Maintainer : Andy Gill <andy@galconn.com>
--- Stability : experimental
--- Portability : portable
---
--- An Html combinator library
---
------------------------------------------------------------------------------
-
-module Text.Html.BlockTable (
-
--- Datatypes:
-
- BlockTable, -- abstract
-
--- Contruction Functions:
-
- single,
- empty,
- above,
- beside,
-
--- Investigation Functions:
-
- getMatrix,
- showsTable,
- showTable,
-
- ) where
-
-import Prelude
-
-infixr 4 `beside`
-infixr 3 `above`
-
--- These combinators can be used to build formated 2D tables.
--- The specific target useage is for HTML table generation.
-
-{-
- Examples of use:
-
- > table1 :: BlockTable String
- > table1 = single "Hello" +-----+
- |Hello|
- This is a 1x1 cell +-----+
- Note: single has type
-
- single :: a -> BlockTable a
-
- So the cells can contain anything.
-
- > table2 :: BlockTable String
- > table2 = single "World" +-----+
- |World|
- +-----+
-
-
- > table3 :: BlockTable String
- > table3 = table1 %-% table2 +-----%-----+
- |Hello%World|
- % is used to indicate +-----%-----+
- the join edge between
- the two Tables.
-
- > table4 :: BlockTable String
- > table4 = table3 %/% table2 +-----+-----+
- |Hello|World|
- Notice the padding on the %%%%%%%%%%%%%
- smaller (bottom) cell to |World |
- force the table to be a +-----------+
- rectangle.
-
- > table5 :: BlockTable String
- > table5 = table1 %-% table4 +-----%-----+-----+
- |Hello%Hello|World|
- Notice the padding on the | %-----+-----+
- leftmost cell, again to | %World |
- force the table to be a +-----%-----------+
- rectangle.
-
- Now the table can be rendered with processTable, for example:
- Main> processTable table5
- [[("Hello",(1,2)),
- ("Hello",(1,1)),
- ("World",(1,1))],
- [("World",(2,1))]] :: [[([Char],(Int,Int))]]
- Main>
--}
-
--- ---------------------------------------------------------------------------
--- Contruction Functions
-
--- Perhaps one day I'll write the Show instance
--- to show boxes aka the above ascii renditions.
-
-instance (Show a) => Show (BlockTable a) where
- showsPrec _ = showsTable
-
-type TableI a = [[(a,(Int,Int))]] -> [[(a,(Int,Int))]]
-
-data BlockTable a = Table (Int -> Int -> TableI a) Int Int
-
-
--- You can create a (1x1) table entry
-
-single :: a -> BlockTable a
-single a = Table (\ x y r -> [(a,(x+1,y+1))] : r) 1 1
-
-empty :: BlockTable a
-empty = Table (\ _ _ r -> r) 0 0
-
-
--- You can compose tables, horizonally and vertically
-
-above :: BlockTable a -> BlockTable a -> BlockTable a
-beside :: BlockTable a -> BlockTable a -> BlockTable a
-
-t1 `above` t2 = trans (combine (trans t1) (trans t2) (.))
-
-t1 `beside` t2 = combine t1 t2 (\ lst1 lst2 r ->
- let
- -- Note this depends on the fact that
- -- that the result has the same number
- -- of lines as the y dimention; one list
- -- per line. This is not true in general
- -- but is always true for these combinators.
- -- I should assert this!
- -- I should even prove this.
- beside' (x:xs) (y:ys) = (x ++ y) : beside' xs ys
- beside' (x:xs) [] = x : xs ++ r
- beside' [] (y:ys) = y : ys ++ r
- beside' [] [] = r
- in
- beside' (lst1 []) (lst2 []))
-
--- trans flips (transposes) over the x and y axis of
--- the table. It is only used internally, and typically
--- in pairs, ie. (flip ... munge ... (un)flip).
-
-trans :: BlockTable a -> BlockTable a
-trans (Table f1 x1 y1) = Table (flip f1) y1 x1
-
-combine :: BlockTable a
- -> BlockTable b
- -> (TableI a -> TableI b -> TableI c)
- -> BlockTable c
-combine (Table f1 x1 y1) (Table f2 x2 y2) comb = Table new_fn (x1+x2) max_y
- where
- max_y = max y1 y2
- new_fn x y =
- case compare y1 y2 of
- EQ -> comb (f1 0 y) (f2 x y)
- GT -> comb (f1 0 y) (f2 x (y + y1 - y2))
- LT -> comb (f1 0 (y + y2 - y1)) (f2 x y)
-
--- ---------------------------------------------------------------------------
--- Investigation Functions
-
--- This is the other thing you can do with a Table;
--- turn it into a 2D list, tagged with the (x,y)
--- sizes of each cell in the table.
-
-getMatrix :: BlockTable a -> [[(a,(Int,Int))]]
-getMatrix (Table r _ _) = r 0 0 []
-
--- You can also look at a table
-
-showsTable :: (Show a) => BlockTable a -> ShowS
-showsTable table = shows (getMatrix table)
-
-showTable :: (Show a) => BlockTable a -> String
-showTable table = showsTable table ""
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