Data.Tree.Render.Text

Configurable text rendering of trees.

Example renderings for:

import Data.Tree

tree :: Tree String
tree =
  Node "Add"
    [ Node "Add"
      [ Node "0" []
      , Node "Mul"
        [ Node "1" []
        , Node "2" []
        ]
      ]
    , Node "Neg"
      [ Node "Max"
        [ Node "3" []
        , Node "4" []
        , Node "5" []
        , Node "Var"
          [ Node "x" []
          ]
        , Node "6" []
        ]
      ]
    ]

renderTree (tracedRenderOptions id) tree

● Add
├─● Add
│ ├─● 0
│ ╰─● Mul
│   ├─● 1
│   ╰─● 2
╰─● Neg
  ╰─● Max
    ├─● 3
    ├─● 4
    ├─● 5
    ├─● Var
    │ ╰─● x
    ╰─● 6

Other renderings by setting 'ParentLocation' and 'ChildOrder' in the options:

  ╭─● 0         ╭─● 0       ● Add             ╭─● 6         ╭─● 6
  │ ╭─● 1     ╭─● Add       ├─● Neg           │ ╭─● x       │ ╭─● x
  │ ├─● 2     │ │ ╭─● 1     │ ╰─● Max         ├─● Var       ├─● Var
  ├─● Mul     │ ╰─● Mul     │   ├─● 6         ├─● 5         ├─● 5
╭─● Add       │   ╰─● 2     │   ├─● Var       ├─● 4       ╭─● Max
│   ╭─● 3     ● Add         │   │ ╰─● x       ├─● 3       │ ├─● 4
│   ├─● 4     ╰─● Neg       │   ├─● 5       ╭─● Max       │ ╰─● 3
│   ├─● 5       │ ╭─● 3     │   ├─● 4     ╭─● Neg       ╭─● Neg
│   │ ╭─● x     │ ├─● 4     │   ╰─● 3     │   ╭─● 2     ● Add
│   ├─● Var     ╰─● Max     ╰─● Add       │   ├─● 1     │   ╭─● 2
│   ├─● 6         ├─● 5       ├─● Mul     │ ╭─● Mul     │ ╭─● Mul
│ ╭─● Max         ├─● Var     │ ├─● 2     │ ├─● 0       │ │ ╰─● 1
├─● Neg           │ ╰─● x     │ ╰─● 1     ├─● Add       ╰─● Add
● Add             ╰─● 6       ╰─● 0       ● Add           ╰─● 0

Documentation

data ParentLocation

Describes where a parent node is rendered, relative to its children.

Constructors

ParentBeforeChildren

ParentAfterChildren

ParentBetweenChildren

Instances

Eq ParentLocation

Defined in Data.Tree.Render.Text

Methods

(==) :: ParentLocation -> ParentLocation -> Bool

(/=) :: ParentLocation -> ParentLocation -> Bool

Ord ParentLocation

Defined in Data.Tree.Render.Text

Methods

compare :: ParentLocation -> ParentLocation -> Ordering

(<) :: ParentLocation -> ParentLocation -> Bool

(<=) :: ParentLocation -> ParentLocation -> Bool

(>) :: ParentLocation -> ParentLocation -> Bool

(>=) :: ParentLocation -> ParentLocation -> Bool

max :: ParentLocation -> ParentLocation -> ParentLocation

min :: ParentLocation -> ParentLocation -> ParentLocation

Show ParentLocation

Defined in Data.Tree.Render.Text

Methods

showsPrec :: Int -> ParentLocation -> ShowS

show :: ParentLocation -> String

showList :: [ParentLocation] -> ShowS

data ChildOrder

Describes the render order of a node's children.

Constructors

FirstToLast

LastToFirst

Instances

Eq ChildOrder

Defined in Data.Tree.Render.Text

Methods

(==) :: ChildOrder -> ChildOrder -> Bool

(/=) :: ChildOrder -> ChildOrder -> Bool

Ord ChildOrder

Defined in Data.Tree.Render.Text

Methods

compare :: ChildOrder -> ChildOrder -> Ordering

(<) :: ChildOrder -> ChildOrder -> Bool

(<=) :: ChildOrder -> ChildOrder -> Bool

(>) :: ChildOrder -> ChildOrder -> Bool

(>=) :: ChildOrder -> ChildOrder -> Bool

max :: ChildOrder -> ChildOrder -> ChildOrder

min :: ChildOrder -> ChildOrder -> ChildOrder

Show ChildOrder

Defined in Data.Tree.Render.Text

Methods

showsPrec :: Int -> ChildOrder -> ShowS

show :: ChildOrder -> String

showList :: [ChildOrder] -> ShowS

data BranchPath

A part of a path along a rendered tree.

Constructors

BranchUp

Describes a turn going up toward the left.

e.g. "╭─"

BranchDown

Describes a turn going down toward the left.

e.g. "╰─"

BranchJoin

Describes a T-join of a path going up and down toward the left.

e.g. "├─"

BranchContinue

Describes a path going up and down.

e.g. "│ "

BranchEmpty

Describes a part that does NOT contain a path piece.

e.g. " "

Instances

Eq BranchPath

Defined in Data.Tree.Render.Text

Methods

(==) :: BranchPath -> BranchPath -> Bool

(/=) :: BranchPath -> BranchPath -> Bool

Ord BranchPath

Defined in Data.Tree.Render.Text

Methods

compare :: BranchPath -> BranchPath -> Ordering

(<) :: BranchPath -> BranchPath -> Bool

(<=) :: BranchPath -> BranchPath -> Bool

(>) :: BranchPath -> BranchPath -> Bool

(>=) :: BranchPath -> BranchPath -> Bool

max :: BranchPath -> BranchPath -> BranchPath

min :: BranchPath -> BranchPath -> BranchPath

Show BranchPath

Defined in Data.Tree.Render.Text

Methods

showsPrec :: Int -> BranchPath -> ShowS

show :: BranchPath -> String

showList :: [BranchPath] -> ShowS

data RenderOptionsM m string label

Options used for rendering a 'Tree label'.

Constructors

RenderOptions

Fields

• oParentLocation :: ParentLocation

  Controls where parent nodes are rendered.

• oChildOrder :: ChildOrder

  Controls the order a node's children are rendered.

• oVerticalPad :: Int

  The amount of vertical spacing between nodes.

• oPrependNewline :: Bool

  If True, a newline is prepended to the rendered output.

• oFromString :: String -> string

  Promotes a String to a string.

• oWrite :: string -> m ()

  Writes a string.

• oShowNodeLabel :: label -> string

  Shows a rootLabel.

• oGetNodeMarker :: label -> string

  Get the marker for a node. Although this takes as input a node's label, this should not render the label itself. The returned value should contain no newlines.

  The label is passed as an argument to allow things such as:

  • Rendering a node marker differently for labels that fail to pass a test.
  • Highlighting a node currently being visited.

  Simple use cases would use a constant function ignoring the label value.

• oForestRootMarker :: string

  The marker used for rendering an artificial root when rendering Forests. The returned value should contain no newlines.

• oShowBranchPath :: BranchPath -> string

  Shows a BranchPath. The returned value should contain no newlines and should all be of the same printed width when rendered as text.

type RenderOptions = RenderOptionsM (Writer (DList Char))

An alias of RenderOptionsM for producing pure String renders.

tracedRenderOptions

Arguments

:: (label -> String)

Shows a rootLabel.

-> RenderOptions String label

Simplified tracedRenderOptionsM when using RenderOptionsM.

tracedRenderOptionsAscii

Arguments

:: (label -> String)

Shows a rootLabel.

-> RenderOptions String label

Simplified tracedRenderOptionsAsciiM when using RenderOptionsM.

renderTree :: RenderOptions String label -> Tree label -> String

Renders a Tree a pretty printed tree as a String.

renderForest :: RenderOptions String label -> Forest label -> String

Renders a Forest a pretty printed tree as a String.

tracedRenderOptionsM

Arguments

:: (String -> string)

Promotes a String to a string.

-> (string -> m ())

Writes a string.

-> (label -> string)

Shows a rootLabel.

-> RenderOptionsM m string label

Options for producing a line-traced tree using unicode drawing characters.

This uses:

BranchUp       -> "╭─"
BranchDown     -> "╰─"
BranchJoin     -> "├─"
BranchContinue -> "│ "
BranchEmpty    -> "  "

tracedRenderOptionsAsciiM

Arguments

:: (String -> string)

Promotes a String to a string.

-> (string -> m ())

Writes a string.

-> (label -> string)

Shows a rootLabel.

-> RenderOptionsM m string label

Options for producing a line-traced tree using ASCII characters.

This uses:

BranchUp       -> ",-"
BranchDown     -> "`-"
BranchJoin     -> "|-"
BranchContinue -> "| "
BranchEmpty    -> "  "

renderTreeM :: Monad m => RenderOptionsM m string label -> Tree label -> m ()

Renders a pretty printed Tree within a monadic context.

renderForestM :: Monad m => RenderOptionsM m string label -> Forest label -> m ()

Renders a pretty printed Forest within a monadic context.