Copyright | (c) Andrey Mokhov 2016-2018 |
---|---|
License | MIT (see the file LICENSE) |
Maintainer | andrey.mokhov@gmail.com |
Stability | experimental |
Safe Haskell | None |
Language | Haskell2010 |
Alga is a library for algebraic construction and manipulation of graphs in Haskell. See this paper for the motivation behind the library, the underlying theory, and implementation details.
This module defines basic functionality for exporting graphs in textual and binary formats. Algebra.Graph.Export.Dot provides DOT-specific functions.
- data Doc s
- literal :: s -> Doc s
- render :: Monoid s => Doc s -> s
- (<+>) :: (Eq s, IsString s, Monoid s) => Doc s -> Doc s -> Doc s
- brackets :: IsString s => Doc s -> Doc s
- doubleQuotes :: IsString s => Doc s -> Doc s
- indent :: IsString s => Int -> Doc s -> Doc s
- unlines :: IsString s => [Doc s] -> Doc s
- export :: (Ord a, ToGraph g, ToVertex g ~ a) => (a -> Doc s) -> (a -> a -> Doc s) -> g -> Doc s
Constructing and exporting documents
An abstract document data type with O(1) time concatenation (the current
implementation uses difference lists). Here s
is the type of abstract
symbols or strings (text or binary). Doc
s
is a Monoid
, therefore
mempty
corresponds to the empty document and two documents can be
concatenated with mappend
(or operator <>
). Documents
comprising a single symbol or string can be constructed using the function
literal
. Alternatively, you can construct documents as string literals, e.g.
simply as "alga"
, by using the OverloadedStrings
GHC extension. To extract
the document contents use the function render
. See some examples below.
literal :: s -> Doc s Source #
Construct a document comprising a single symbol or string. If s
is an
instance of class IsString
, then documents of type Doc
s
can be
constructed directly from string literals (see the second example below).
literal "Hello, "<>
literal "World!" == literal "Hello, World!" literal "I am just a string literal" == "I am just a string literal" literalmempty
==mempty
render
. literal ==id
literal .render
==id
Common combinators for text documents
brackets :: IsString s => Doc s -> Doc s Source #
Wrap a document in square brackets.
brackets "i" == "[i]"
brackets mempty
== "[]"
doubleQuotes :: IsString s => Doc s -> Doc s Source #
Wrap a document into double quotes.
doubleQuotes "/path/with spaces" == "\"/path/with spaces\""
doubleQuotes (doubleQuotes mempty
) == "\"\"\"\""
Generic graph export
export :: (Ord a, ToGraph g, ToVertex g ~ a) => (a -> Doc s) -> (a -> a -> Doc s) -> g -> Doc s Source #
Export a graph into a document given two functions that construct documents
for individual vertices and edges. The order of export is: vertices, sorted
by Ord
a
, and then edges, sorted by Ord
(a, a)
.
For example:
vDoc x =literal
(show
x) <> "\n" eDoc x y =literal
(show
x) <> " -> " <>literal
(show
y) <> "\n" > putStrLn $render
$ export vDoc eDoc (1 + 2 * (3 + 4) ::Graph
Int) 1 2 3 4 2 -> 3 2 -> 4