--- /dev/null
+-----------------------------------------------------------------------------
+--
+-- Module : Text.Html.BlockTable
+-- Copyright : (c) Andy Gill, and the Oregon Graduate Institute of
+-- Science and Technology, 1999-2001
+-- License : BSD-style (see the file libraries/core/LICENSE)
+--
+-- Maintainer : Andy Gill <andy@galconn.com>
+-- Stability : experimental
+-- Portability : portable
+--
+-- $Id: BlockTable.hs,v 1.1 2001/08/01 13:53:07 simonmar Exp $
+--
+-- An Html combinator library
+--
+-----------------------------------------------------------------------------
+
+module Text.Html.BlockTable (
+
+-- Datatypes:
+
+ BlockTable, -- abstract
+
+-- Contruction Functions:
+
+ single,
+ 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 p = 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 z -> [(a,(x+1,y+1))] : z) 1 1
+
+
+-- 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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