Prettyprinter.Render.Util.SimpleDocTree

A SimpleDocStream is a linked list of different annotated cons cells (SText and then some further SimpleDocStream, SLine and then some further SimpleDocStream, …). This format is very suitable as a target for a layout engine, but not very useful for rendering to a structured format such as HTML, where we don’t want to do a lookahead until the end of some markup. These formats benefit from a tree-like structure that explicitly marks its contents as annotated. SimpleDocTree is that format.

Convert a SimpleDocStream to its SimpleDocTree representation.

Remove all annotations. unAnnotate for SimpleDocTree.

Change the annotation of a document. reAnnotate for SimpleDocTree.

Change the annotation of a document to a different annotation, or none at all. alterAnnotations for SimpleDocTree.

Note that this is as powerful as alterAnnotations, allowing one annotation to become multiple ones, contrary to alterAnnotationsS, which cannot do this.

Simplest possible tree-based renderer.

For example, here is a document annotated with (), and the behaviour is to surround annotated regions with »>>>« and »<<<«:

>>> let doc = "hello" <+> annotate () "world" <> "!">>> let stdoc = treeForm (layoutPretty defaultLayoutOptions doc)>>> T.putStrLn (renderSimplyDecorated id (\() x -> ">>>" <> x <> "<<<") stdoc)hello >>>world<<<!

Version of renderSimplyDecoratedA that allows for Applicative effects.