test whether the root of a tree contains a tag node.

see also: isNsTag

namespace aware test whether the root of a tree contains a tag node. Parameters are the local part and namespace. Only usable after namespace propagation.

see also: isTag

test whether the node of a tree is a XTag node or a XPi node with an attibute of a specific name

see also: isAttr, hasNsAttr

test whether the tree is a XTag node with an attibute of a specific local name and namespace uri

see also: hasAttr, isNsAttr

test whether the given node is a XTag node or a XPI node with an attribute with a value with a specific property. In case of a match, the attribute value represented by a text node is returned as single element list, else the empty list is the result.

see also : getValue

namespace aware test whether the tree contains an attribute node. Parameters are the local part of the atribute name and the namespace. Only usable after namespace propagation.

see also: isNsTag, isAttr, hasNsAttr

constructor filter for a tag node. a new tree is constructed. the attributes and the children are computed by applying the aproprate filter to the input tree

• 1.parameter n : the tag name
• 2.parameter af : the filter for the attribute list
• 3.parameter cf : the filter for the children
• returns : the constructor filter

constructor filter for a tag node. a new tree is constructed. the attributes and the children are computed by applying the aproprate filter to the input tree

• 1.parameter n : the tag name in form of prefix:localpart
• 2.parameter ns: the namespace uri
• 3.parameter af : the filter for the attribute list
• 4.parameter cf : the filter for the children
• returns : the constructor filter

filter for selecting the value of an attribute in a tag node. Result of the filter is a single element list with a text node or the empty list

see also : hasValue, getNsValue

filter for selecting the value of an attribute with namespace in a tag node. Result of the filter is a single element list with a text node or the empty list

see also : getValue, isNsAttr

edit filter for changing the text of a text node. result of the filter is a single element list with a text node or the empty list

example for editing all text nodes of a tree with an edit function f:

processBottomUp (modifyText f `when` isXText)

elementwise processing of the attributes of a tag. for other trees this filter acts like none

see also : processAttrl

add an attribute to the attribute list of a tag. If the attribute already exists, it's substituted,

see also: sattr, +=

adds an attribute list computed by a filter, uses add1Attr.

see also: +=

edit filter for changing the value of an attribute in a tag node. result of the filter is a single element list with the tag node or the empty list.

• 1.parameter n : the name of the attribute
• 2.parameter f : the edit function for the attribute value
• returns : the edit filter

convenient function for tag node tree construction

infixl 7

filter combinator for tag tree constrcution take a 1. filter for computing a tag node tree (or a whole list of tag node trees) then add all trees computed by the 2. filter to the attribute list when they represent attributes else append them to the list of children.

if the 1. filter computes a list of tag nodes, the results of the 2. filter are added to all trees

example: etag "a" += sattr "href" "#42" += txt "the answer" gives the tree <a href="#42">the answer</a>

example: ( etag "a" +++ etag "b" ) += sattr "x" "42" gives the tree <a x="42"/><b x="42"/>

see also : etag, tag, add1Attr, modifyChildren, ++=

convenient filter function adding a whole list of trees, just for not writing to many ( ... ).

infixl 7

 f ++= gl  == f += cat gl

see also : +=

variant of mkXTag with a list of filters for the attributes and a list of filters for the children. this variant leads to a more readable source for a complicated construction filter than the simple solution with a combination of mkXTag and cat.

see also : mkXTag, stag, etag, cat, +=

variant of tag, useful for tags without attributes and with a list of filters for constructing the children

see also : mkXTag, tag, etag, cat, +=

variant of tag, useful for tags with attributes but without children

see also : mkXTag, tag, stag, etag, cat

Short cut for empty tags without attributes

see also : tag, atag, stag, mkXTag and +=

filter for creating a document root node with a list of filters for the attributes and a list of filters for the document.

see also : tag

short cut for attribute construction with string constants

set also : attr, mkXAttr and mkXText

short cut for simple comment the input tree is ignored

see also : mkXCmt

short cut for generating simple processing instructions (spi) the input tree is ignored

spi "xyz" "abc" is equal to mkXPi "xyz" (txt "abc") (the name pi is already used in prelude)

short cut for mkXError c_warn.

see also : mkXError

short cut for mkXError c_fatal.

see also : mkXError

short cut for mkXError c_fatal.

see also : mkXError

check whether an option is set

reads the value of an attribute, usually applied to a document root node, and checks if the value represents True. The following strings are interpreted as true: "1", "True", "true", "yes", "Yes".