Documentation

Represents a hierarchy of a currently parsing position in an HtmlTag tree.

For example, if an scanHtml has read "<a href="#"><b><i>foo</i> bar" it is represented as HtmlTagStack [B, A].

Note that the tags are stored in reverse order, from the deepest to the shallowest, to make inserting a more deeper tag efficient.

Determine whether any element of the tag stack satisfies the predicate.

>>> :set -XOverloadedLists
>>> Text.Seonbi.Html.TagStack.any ((== Void) . htmlTagKind) [Div, P, Script]
False
>>> Text.Seonbi.Html.TagStack.any ((== Void) . htmlTagKind) [BR, P, Script]
True

Check if a node (HtmlEntity) that a HtmlTagStack (the first argument) refers is contained by a node that another HtmlTagStack (the second argument), or they are sibling at least.

>>> :set -XOverloadedLists
>>> descendsFrom [Div, P, A, Em] [Div, P, A]
True
>>> descendsFrom [Div, P, A] [Div, P, A]
True
>>> descendsFrom [Div, P, Em] [Div, P, A]
False
>>> descendsFrom [Div, P] [Div, P, A]
False

Determine whether the element occurs in the tag stack.

>>> :set -XOverloadedLists
>>> A `Text.Seonbi.Html.TagStack.elem` [A, B, Code]
True
>>> Em `Text.Seonbi.Html.TagStack.elem` [A, B, Code]
False

Count the depth of a stack.

>>> :set -XOverloadedLists
>>> depth empty
0
>>> depth [Div, Article, P, Em]
4

An empty stack.

The fromList function constructs the structure l from the given list of Item l

Get the deepest tag from a HtmlTagStack.

>>> :set -XOverloadedLists
>>> let stack = [Div, Article, P, Em] :: HtmlTagStack
>>> last stack
Just Em
>>> last []
Nothing

Pop the deepest tag from a HtmlTagStack.

>>> :set -XOverloadedLists
>>> pop Em [A, B, Em]
fromList [A,B]

It may pop a tag in the middle if a tag looking for is not the deepest:

>>> pop B [A, B, Em]
fromList [A,Em]

It does not affect to the input if there is no such tag in the input:

>>> pop P [A, B, Em]
fromList [A,B,Em]
>>> pop A empty
fromList []

Push one deeper tag to a HtmlTagStack.

>>> push A empty
fromList [A]
>>> push B (push A empty)
fromList [A,B]

Build a new stack from a stack by replacing its bottom with a new base.

>>> :set -XOverloadedLists
>>> rebase [Article, BlockQuote] [Div] [Article, BlockQuote, P, Em]
fromList [Div,P,Em]

If there are no such bottom elements, it replaces nothing.

>>> rebase [Div, Article, BlockQuote] [Div] [Article, BlockQuote, P, Em]
fromList [Article,BlockQuote,P,Em]

The toList function extracts a list of Item l from the structure l. It should satisfy fromList . toList = id.