Tree package:tagsoup

module Text.HTML.TagSoup.Tree

NOTE: This module is preliminary and may change at a future date. This module is intended to help converting a list of tags into a tree of tags.

data TagTree str

tagsoup Text.HTML.TagSoup.Tree

A tree of Tag values.

flattenTree :: [TagTree str] -> [Tag str]

tagsoup Text.HTML.TagSoup.Tree

Flatten a TagTree back to a list of Tag.

parseTree :: StringLike str => str -> [TagTree str]

tagsoup Text.HTML.TagSoup.Tree

Build a TagTree from a string.

parseTreeOptions :: StringLike str => ParseOptions str -> str -> [TagTree str]

tagsoup Text.HTML.TagSoup.Tree

Build a TagTree from a string, specifying the ParseOptions.

renderTree :: StringLike str => [TagTree str] -> str

tagsoup Text.HTML.TagSoup.Tree

Render a TagTree.

renderTreeOptions :: StringLike str => RenderOptions str -> [TagTree str] -> str

tagsoup Text.HTML.TagSoup.Tree

Render a TagTree with some RenderOptions.

tagTree :: Eq str => [Tag str] -> [TagTree str]

tagsoup Text.HTML.TagSoup.Tree

Convert a list of tags into a tree. This version is not lazy at all, that is saved for version 2.

transformTree :: (TagTree str -> [TagTree str]) -> [TagTree str] -> [TagTree str]

tagsoup Text.HTML.TagSoup.Tree

This operation is based on the Uniplate transform function. Given a list of trees, it applies the function to every tree in a bottom-up manner. This operation is useful for manipulating a tree - for example to make all tag names upper case:

upperCase = transformTree f
where f (TagBranch name atts inner) = [TagBranch (map toUpper name) atts inner]
f x = [x]

universeTree :: [TagTree str] -> [TagTree str]

tagsoup Text.HTML.TagSoup.Tree

This operation is based on the Uniplate universe function. Given a list of trees, it returns those trees, and all the children trees at any level. For example:

universeTree
[TagBranch "a" [("href","url")] [TagBranch "b" [] [TagLeaf (TagText "text")]]]
== [TagBranch "a" [("href","url")] [TagBranch "b" [] [TagLeaf (TagText "text")]]]
,TagBranch "b" [] [TagLeaf (TagText "text")]]

This operation is particularly useful for queries. To collect all "a" tags in a tree, simply do:

[x | x@(TagBranch "a" _ _) <- universeTree tree]