+ if parse_error_cb?
+ parse_error_cb cur
+ else
+ console.log "Parse error at character #{cur} of #{txt.length}"
+
+
+ # the functions below impliment the Tree Contstruction algorithm
+ # http://www.w3.org/TR/html5/syntax.html#tree-construction
+
+ # But first... the helpers
+ template_tag_is_open = ->
+ for t in open_els
+ if t.name is 'template' # maybe should also check: and t.namespace is 'html'
+ return true
+ return false
+ is_in_scope_x = (tag_name, scope, namespace) ->
+ for t in open_els
+ if t.name is tag_name and (namespace is null or namespace is t.namespace)
+ return true
+ if scope[t.name] is t.namespace
+ return false
+ return false
+ is_in_scope_x_y = (tag_name, scope, scope2, namespace) ->
+ for t in open_els
+ if t.name is tag_name and (namespace is null or namespace is t.namespace)
+ return true
+ if scope[t.name] is t.namespace
+ return false
+ if scope2[t.name] is t.namespace
+ return false
+ return false
+ standard_scopers = { # FIXME these are supposed to be namespace specific
+ applet: NS_HTML, caption: NS_HTML, html: NS_HTML, table: NS_HTML,
+ td: NS_HTML, th: NS_HTML, marquee: NS_HTML, object: NS_HTML,
+ template: NS_HTML, mi: NS_MATHML,
+
+ mo: NS_MATHML, mn: NS_MATHML, ms: NS_MATHML, mtext: NS_MATHML,
+ 'annotation-xml': NS_MATHML,
+
+ foreignObject: NS_SVG, desc: NS_SVG, title: NS_SVG
+ }
+ button_scopers = button: NS_HTML
+ li_scopers = ol: NS_HTML, ul: NS_HTML
+ table_scopers = html: NS_HTML, table: NS_HTML, template: NS_HTML
+ is_in_scope = (tag_name, namespace = null) ->
+ return is_in_scope_x tag_name, standard_scopers, namespace
+ is_in_button_scope = (tag_name, namespace = null) ->
+ return is_in_scope_x_y tag_name, standard_scopers, button_scopers, namespace
+ is_in_table_scope = (tag_name, namespace = null) ->
+ return is_in_scope_x tag_name, table_scopers, namespace
+ is_in_select_scope = (tag_name, namespace = null) ->
+ for t in open_els
+ if t.name is tag_name and (namespace is null or namespace is t.namespace)
+ return true
+ if t.ns isnt NS_HTML t.name isnt 'optgroup' and t.name isnt 'option'
+ return false
+ return false
+ # this checks for a particular element, not by name
+ el_is_in_scope = (el) ->
+ for t in open_els
+ if t is el
+ return true
+ if standard_scopers[t.name] is t.namespace
+ return false
+ return false
+
+ # http://www.w3.org/TR/html5/syntax.html#reconstruct-the-active-formatting-elements
+ # this implementation is structured (mostly) as described at the link above.
+ # capitalized comments are the "labels" described at the link above.
+ reconstruct_active_formatting_elements = ->
+ return if afe.length is 0
+ if afe[0].type is TYPE_MARKER or afe[0] in open_els
+ return
+ # Rewind
+ i = 0
+ loop
+ if i is afe.length - 1
+ break
+ i += 1
+ if afe[i].type is TYPE_MARKER or afe[i] in open_els
+ i -= 1 # Advance
+ break
+ # Create
+ loop
+ el = afe[i].shallow_clone()
+ tree_insert_element el
+ afe[i] = el
+ break if i is 0
+ i -= 1
+
+ # http://www.w3.org/TR/html5/syntax.html#adoption-agency-algorithm
+ # adoption agency algorithm
+ # overview here:
+ # http://www.w3.org/TR/html5/syntax.html#misnested-tags:-b-i-/b-/i
+ # http://www.w3.org/TR/html5/syntax.html#misnested-tags:-b-p-/b-/p
+ # http://www.w3.org/TR/html5/syntax.html#unclosed-formatting-elements
+ adoption_agency = (subject) ->
+ if open_els[0].name is subject
+ el = open_els[0]
+ open_els.shift()
+ # remove it from the list of active formatting elements (if found)
+ for t, i in afe
+ if t is el
+ afe.splice i, 1
+ break
+ return
+ outer = 0
+ loop
+ if outer >= 8
+ return
+ outer += 1
+ # 5. Let formatting element be the last element in the list of
+ # active formatting elements that: is between the end of the list
+ # and the last scope marker in the list, if any, or the start of
+ # the list otherwise, and has the tag name subject.
+ fe = null
+ for t, fe_of_afe in afe
+ if t.type is TYPE_MARKER
+ break
+ if t.name is subject
+ fe = t
+ break
+ # If there is no such element, then abort these steps and instead
+ # act as described in the "any other end tag" entry above.
+ if fe is null
+ in_body_any_other_end_tag subject
+ return
+ # 6. If formatting element is not in the stack of open elements,
+ # then this is a parse error; remove the element from the list, and
+ # abort these steps.
+ in_open_els = false
+ for t, fe_of_open_els in open_els
+ if t is fe
+ in_open_els = true
+ break
+ unless in_open_els
+ parse_error()
+ # "remove it from the list" must mean afe, since it's not in open_els
+ afe.splice fe_of_afe, 1
+ return
+ # 7. If formatting element is in the stack of open elements, but
+ # the element is not in scope, then this is a parse error; abort
+ # these steps.
+ unless el_is_in_scope fe
+ parse_error()
+ return
+ # 8. If formatting element is not the current node, this is a parse
+ # error. (But do not abort these steps.)
+ unless open_els[0] is fe
+ parse_error()
+ # continue
+ # 9. Let furthest block be the topmost node in the stack of open
+ # elements that is lower in the stack than formatting element, and
+ # is an element in the special category. There might not be one.
+ fb = null
+ fb_of_open_els = null
+ for t, i in open_els
+ if t is fe
+ break
+ if el_is_special t
+ fb = t
+ fb_of_open_els = i
+ # and continue, to see if there's one that's more "topmost"
+ # 10. If there is no furthest block, then the UA must first pop all
+ # the nodes from the bottom of the stack of open elements, from the
+ # current node up to and including formatting element, then remove
+ # formatting element from the list of active formatting elements,
+ # and finally abort these steps.
+ if fb is null
+ loop
+ t = open_els.shift()
+ if t is fe
+ afe.splice fe_of_afe, 1
+ return
+ # 11. Let common ancestor be the element immediately above
+ # formatting element in the stack of open elements.
+ ca = open_els[fe_of_open_els + 1] # common ancestor
+
+ node_above = open_els[fb_of_open_els + 1] # next node if node isn't in open_els anymore
+ # 12. Let a bookmark note the position of formatting element in the list of active formatting elements relative to the elements on either side of it in the list.
+ bookmark = new_aaa_bookmark()
+ for t, i in afe
+ if t is fe
+ afe.splice i, 0, bookmark
+ break
+ node = last_node = fb
+ inner = 0
+ loop
+ inner += 1
+ # 3. Let node be the element immediately above node in the
+ # stack of open elements, or if node is no longer in the stack
+ # of open elements (e.g. because it got removed by this
+ # algorithm), the element that was immediately above node in
+ # the stack of open elements before node was removed.
+ node_next = null
+ for t, i in open_els
+ if t is node
+ node_next = open_els[i + 1]
+ break
+ node = node_next ? node_above
+ debug_log "inner loop #{inner}"
+ debug_log "open_els: #{serialize_els open_els, true, true}"
+ debug_log "tree: #{serialize_els tree.children, false, true}"
+ debug_log "afe: #{serialize_els afe, true, true}"
+ debug_log "ca: #{ca.name}##{ca.id} children: #{serialize_els ca.children, true, true}"
+ debug_log "fe: #{fe.name}##{fe.id} children: #{serialize_els fe.children, true, true}"
+ debug_log "fb: #{fb.name}##{fb.id} children: #{serialize_els fb.children, true, true}"
+ debug_log "node: #{node.serialize true, true}"
+ # TODO make sure node_above gets re-set if/when node is removed from open_els
+
+ # 4. If node is formatting element, then go to the next step in
+ # the overall algorithm.
+ if node is fe
+ break
+ debug_log "the meat"
+ # 5. If inner loop counter is greater than three and node is in
+ # the list of active formatting elements, then remove node from
+ # the list of active formatting elements.
+ node_in_afe = false
+ for t, i in afe
+ if t is node
+ if inner > 3
+ afe.splice i, 1
+ debug_log "max out inner"
+ else
+ node_in_afe = true
+ debug_log "in afe"
+ break
+ # 6. If node is not in the list of active formatting elements,
+ # then remove node from the stack of open elements and then go
+ # back to the step labeled inner loop.
+ unless node_in_afe
+ debug_log "not in afe"
+ for t, i in open_els
+ if t is node
+ node_above = open_els[i + 1]
+ open_els.splice i, 1
+ break
+ continue
+ debug_log "the bones"
+ # 7. create an element for the token for which the element node
+ # was created, in the HTML namespace, with common ancestor as
+ # the intended parent; replace the entry for node in the list
+ # of active formatting elements with an entry for the new
+ # element, replace the entry for node in the stack of open
+ # elements with an entry for the new element, and let node be
+ # the new element.
+ new_node = node.shallow_clone()
+ for t, i in afe
+ if t is node
+ afe[i] = new_node
+ debug_log "replaced in afe"
+ break
+ for t, i in open_els
+ if t is node
+ node_above = open_els[i + 1]
+ open_els[i] = new_node
+ debug_log "replaced in open_els"
+ break
+ node = new_node
+ # 8. If last node is furthest block, then move the
+ # aforementioned bookmark to be immediately after the new node
+ # in the list of active formatting elements.
+ if last_node is fb
+ for t, i in afe
+ if t is bookmark
+ afe.splice i, 1
+ debug_log "removed bookmark"
+ break
+ for t, i in afe
+ if t is node
+ # "after" means lower
+ afe.splice i, 0, bookmark # "after as <-
+ debug_log "placed bookmark after node"
+ debug_log "node: #{node.id} afe: #{serialize_els afe, true, true}"
+ break
+ # 9. Insert last node into node, first removing it from its
+ # previous parent node if any.
+ if last_node.parent?
+ debug_log "last_node has parent"
+ for c, i in last_node.parent.children
+ if c is last_node
+ debug_log "removing last_node from parent"
+ last_node.parent.children.splice i, 1
+ break
+ node.children.push last_node
+ last_node.parent = node
+ # 10. Let last node be node.
+ last_node = node
+ debug_log "at last"
+ # 11. Return to the step labeled inner loop.
+ # 14. Insert whatever last node ended up being in the previous step
+ # at the appropriate place for inserting a node, but using common
+ # ancestor as the override target.
+
+ # JASON: In the case where fe is immediately followed by fb:
+ # * inner loop exits out early (node==fe)
+ # * last_node is fb
+ # * last_node is still in the tree (not a duplicate)
+ if last_node.parent?
+ debug_log "FEFIRST? last_node has parent"
+ for c, i in last_node.parent.children
+ if c is last_node
+ debug_log "removing last_node from parent"
+ last_node.parent.children.splice i, 1
+ break
+
+ debug_log "after aaa inner loop"
+ debug_log "ca: #{ca.name}##{ca.id} children: #{serialize_els ca.children, true, true}"
+ debug_log "fe: #{fe.name}##{fe.id} children: #{serialize_els fe.children, true, true}"
+ debug_log "fb: #{fb.name}##{fb.id} children: #{serialize_els fb.children, true, true}"
+ debug_log "last_node: #{last_node.name}##{last_node.id} children: #{serialize_els last_node.children, true, true}"
+ debug_log "tree: #{serialize_els tree.children, false, true}"
+
+ debug_log "insert"
+
+
+ # can't use standard insert token thing, because it's already in
+ # open_els and must stay at it's current position in open_els
+ dest = adjusted_insertion_location ca
+ dest[0].children.splice dest[1], 0, last_node
+ last_node.parent = dest[0]
+
+
+ debug_log "ca: #{ca.name}##{ca.id} children: #{serialize_els ca.children, true, true}"
+ debug_log "fe: #{fe.name}##{fe.id} children: #{serialize_els fe.children, true, true}"
+ debug_log "fb: #{fb.name}##{fb.id} children: #{serialize_els fb.children, true, true}"
+ debug_log "last_node: #{last_node.name}##{last_node.id} children: #{serialize_els last_node.children, true, true}"
+ debug_log "tree: #{serialize_els tree.children, false, true}"
+
+ # 15. Create an element for the token for which formatting element
+ # was created, in the HTML namespace, with furthest block as the
+ # intended parent.
+ new_element = fe.shallow_clone() # FIXME intended parent thing
+ # 16. Take all of the child nodes of furthest block and append them
+ # to the element created in the last step.
+ while fb.children.length
+ t = fb.children.shift()
+ t.parent = new_element
+ new_element.children.push t
+ # 17. Append that new element to furthest block.
+ new_element.parent = fb
+ fb.children.push new_element
+ # 18. Remove formatting element from the list of active formatting
+ # elements, and insert the new element into the list of active
+ # formatting elements at the position of the aforementioned
+ # bookmark.
+ for t, i in afe
+ if t is fe
+ afe.splice i, 1
+ break
+ for t, i in afe
+ if t is bookmark
+ afe[i] = new_element
+ break
+ # 19. Remove formatting element from the stack of open elements,
+ # and insert the new element into the stack of open elements
+ # immediately below the position of furthest block in that stack.
+ for t, i in open_els
+ if t is fe
+ open_els.splice i, 1
+ break
+ for t, i in open_els
+ if t is fb
+ open_els.splice i, 0, new_element
+ break
+ # 20. Jump back to the step labeled outer loop.
+ debug_log "done wrapping fb's children. new_element: #{new_element.name}##{new_element.id}"
+ debug_log "tree: #{serialize_els tree.children, false, true}"
+ debug_log "open_els: #{serialize_els open_els, true, true}"
+ debug_log "afe: #{serialize_els afe, true, true}"
+ debug_log "AAA DONE"
+
+ # http://www.w3.org/TR/html5/syntax.html#close-a-p-element
+ # FIXME test this (particularly emplied end tags)
+ close_p_element = ->
+ generate_implied_end_tags 'p' # arg is exception
+ if open_els[0].name isnt 'p'
+ parse_error()
+ while open_els.length > 1 # just in case
+ t = open_els.shift()
+ if t.name is 'p'
+ return
+ close_p_if_in_button_scope = ->
+ if is_in_button_scope 'p'
+ close_a_p_element()
+
+ # http://www.w3.org/TR/html5/syntax.html#insert-a-character
+ tree_insert_text = (t) ->
+ dest = adjusted_insertion_location()
+ if dest[1] > 0
+ prev = dest[0].children[dest[1] - 1]
+ if prev.type is TYPE_TEXT
+ prev.text += t.text
+ return
+ dest[0].children.splice dest[1], 0, t
+
+ # 8.2.5.1
+ # http://www.w3.org/TR/html5/syntax.html#creating-and-inserting-nodes
+ # http://www.w3.org/TR/html5/syntax.html#appropriate-place-for-inserting-a-node
+ adjusted_insertion_location = (override_target = null) ->
+ # 1. If there was an override target specified, then let target be the
+ # override target.
+ if override_target?
+ target = override_target
+ else # Otherwise, let target be the current node.
+ target = open_els[0]
+ # 2. Determine the adjusted insertion location using the first matching
+ # steps from the following list:
+ #
+ # If foster parenting is enabled and target is a table, tbody, tfoot,
+ # thead, or tr element Foster parenting happens when content is
+ # misnested in tables.
+ if flag_foster_parenting and target.name in foster_parenting_targets
+ console.log "foster parenting isn't implemented yet" # TODO
+ # 1. Let last template be the last template element in the stack of
+ # open elements, if any.
+ # 2. Let last table be the last table element in the stack of open
+ # elements, if any.
+
+ # 3. If there is a last template and either there is no last table,
+ # or there is one, but last template is lower (more recently added)
+ # than last table in the stack of open elements, then: let adjusted
+ # insertion location be inside last template's template contents,
+ # after its last child (if any), and abort these substeps.
+
+ # 4. If there is no last table, then let adjusted insertion
+ # location be inside the first element in the stack of open
+ # elements (the html element), after its last child (if any), and
+ # abort these substeps. (fragment case)
+
+ # 5. If last table has a parent element, then let adjusted
+ # insertion location be inside last table's parent element,
+ # immediately before last table, and abort these substeps.
+
+ # 6. Let previous element be the element immediately above last
+ # table in the stack of open elements.
+
+ # 7. Let adjusted insertion location be inside previous element,
+ # after its last child (if any).
+
+ # Note: These steps are involved in part because it's possible for
+ # elements, the table element in this case in particular, to have
+ # been moved by a script around in the DOM, or indeed removed from
+ # the DOM entirely, after the element was inserted by the parser.
+ else
+ # Otherwise Let adjusted insertion location be inside target, after
+ # its last child (if any).
+ target_i = target.children.length
+
+ # 3. If the adjusted insertion location is inside a template element,
+ # let it instead be inside the template element's template contents,
+ # after its last child (if any). TODO
+
+ # 4. Return the adjusted insertion location.
+ return [target, target_i]
+
+ # http://www.w3.org/TR/html5/syntax.html#create-an-element-for-the-token
+ # aka create_an_element_for_token
+ token_to_element = (t, namespace, intended_parent) ->
+ t.type = TYPE_TAG # not TYPE_OPEN_TAG
+ # convert attributes into a hash
+ attrs = {}
+ while t.attrs_a.length
+ a = t.attrs_a.pop()
+ attrs[a[0]] = a[1] # TODO check what to do with dupilcate attrs
+ el = new Node TYPE_TAG, name: t.name, namespace: namespace, attrs: attrs
+
+ # TODO 2. If the newly created element has an xmlns attribute in the
+ # XMLNS namespace whose value is not exactly the same as the element's
+ # namespace, that is a parse error. Similarly, if the newly created
+ # element has an xmlns:xlink attribute in the XMLNS namespace whose
+ # value is not the XLink Namespace, that is a parse error.
+
+ # fixfull: the spec says stuff about form pointers and ownerDocument
+
+ return el
+
+ # http://www.w3.org/TR/html5/syntax.html#insert-a-foreign-element
+ insert_foreign_element = (token, namespace) ->
+ ail = adjusted_insertion_location()
+ ail_el = ail[0]
+ ail_i = ail[1]
+ el = token_to_element token, namespace, ail_el
+ # TODO skip this next step if it's broken (eg ail_el is document with child already)
+ el.parent = ail_el
+ ail_el.children.splice ail_i, 0, el
+ open_els.unshift el
+ return el
+ # http://www.w3.org/TR/html5/syntax.html#insert-an-html-element
+ insert_html_element = insert_foreign_element # (token, namespace) ->
+
+ # FIXME read implement "foster parenting" part
+ # FIXME read spec, do this right
+ # FIXME implement the override target thing
+ # note: this assumes it's an open tag
+ # FIXME what part of the spec is this?
+ # TODO look through all callers of this, and see what they should really be doing.
+ # eg probably insert_html_element for tokens
+ tree_insert_element = (el, override_target = null, namespace = null) ->
+ if namespace?
+ el.namespace = namespace
+ dest = adjusted_insertion_location override_target
+ if el.type is TYPE_OPEN_TAG # means it's a "token"
+ el = token_to_element el, namespace, dest[0]
+ unless el.namespace?
+ namespace = dest.namespace
+ # fixfull: Document nodes sometimes can't accept more chidren
+ dest[0].children.splice dest[1], 0, el
+ el.parent = dest[0]
+ open_els.unshift el
+ return el
+
+ # http://www.w3.org/TR/html5/syntax.html#insert-a-comment
+ tree_insert_a_comment = (t) ->
+ # FIXME read spec for "adjusted insertion location, etc, this might be wrong
+ open_els[0].children.push t
+
+ # 8.2.5.3 http://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags
+ # http://www.w3.org/TR/html5/syntax.html#generate-implied-end-tags
+ generate_implied_end_tags = (except = null) ->
+ while end_tag_implied[open_els[0]] and open_els[0].name isnt except
+ open_els.shift()
+
+ # 8.2.5.4 http://www.w3.org/TR/html5/syntax.html#parsing-main-inbody
+ in_body_any_other_end_tag = (name) -> # factored out because adoption agency calls it
+ for node, i in open_els
+ if node.name is name # FIXME check namespace too
+ generate_implied_end_tags name # arg is exception
+ parse_error() unless i is 0
+ while i >= 0
+ open_els.shift()
+ i -= 1
+ return
+ if special_elements[node.name]? # FIXME check namespac too
+ parse_error()
+ return
+ tree_in_body = (t) ->
+ switch t.type
+ when TYPE_TEXT
+ switch t.text
+ when "\u0000"
+ parse_error()
+ when "\t", "\u000a", "\u000c", "\u000d", ' '
+ reconstruct_active_formatting_elements()
+ tree_insert_text t
+ else
+ reconstruct_active_formatting_elements()
+ tree_insert_text t
+ flag_frameset_ok = false
+ when TYPE_COMMENT
+ tree_insert_a_comment t
+ when TYPE_DOCTYPE
+ parse_error()
+ when TYPE_OPEN_TAG
+ switch t.name
+ when 'html'
+ parse_error()
+ return if template_tag_is_open()
+ root_attrs = open_els[open_els.length - 1].attrs
+ for k, v of t.attrs
+ root_attrs[k] = v unless root_attrs[k]?
+ when 'base', 'basefont', 'bgsound', 'link', 'meta', 'noframes', 'script', 'style', 'template', 'title'
+ # FIXME also do this for </template> (end tag)
+ return tree_in_head t
+ when 'body'
+ parse_error()
+ # TODO
+ when 'frameset'
+ parse_error()
+ # TODO
+ when 'address', 'article', 'aside', 'blockquote', 'center', 'details', 'dialog', 'dir', 'div', 'dl', 'fieldset', 'figcaption', 'figure', 'footer', 'header', 'hgroup', 'main', 'nav', 'ol', 'p', 'section', 'summary', 'ul'
+ close_p_if_in_button_scope()
+ insert_html_element t
+ when 'h1', 'h2', 'h3', 'h4', 'h5', 'h6'
+ close_p_if_in_button_scope()
+ if open_els[0].name in ['h1', 'h2', 'h3', 'h4', 'h5', 'h6']
+ parse_error()
+ open_els.shift()
+ insert_html_element t
+ # TODO lots more to implement here
+ when 'a'
+ # If the list of active formatting elements
+ # contains an a element between the end of the list and
+ # the last marker on the list (or the start of the list
+ # if there is no marker on the list), then this is a
+ # parse error; run the adoption agency algorithm for
+ # the tag name "a", then remove that element from the
+ # list of active formatting elements and the stack of
+ # open elements if the adoption agency algorithm didn't
+ # already remove it (it might not have if the element
+ # is not in table scope).
+ found = false
+ for el in afe
+ if el.type is TYPE_MARKER
+ break
+ if el.name is 'a'
+ found = el
+ if found?
+ parse_error()
+ adoption_agency 'a'
+ for el, i in afe
+ if el is found
+ afe.splice i, 1
+ for el, i in open_els
+ if el is found
+ open_els.splice i, 1
+ reconstruct_active_formatting_elements()
+ el = tree_insert_element t
+ afe.unshift el
+ when 'b', 'big', 'code', 'em', 'font', 'i', 's', 'small', 'strike', 'strong', 'tt', 'u'
+ reconstruct_active_formatting_elements()
+ el = tree_insert_element t
+ afe.unshift el
+ # TODO lots more to implement here
+ else # any other start tag
+ reconstruct_active_formatting_elements()
+ tree_insert_element t
+ when TYPE_EOF
+ ok_tags = {
+ dd: true, dt: true, li: true, p: true, tbody: true, td: true,
+ tfoot: true, th: true, thead: true, tr: true, body: true, html: true,
+ }
+ for t in open_els
+ unless ok_tags[t.name]?
+ parse_error()
+ break
+ # TODO stack of template insertion modes thing
+ flag_parsing = false # stop parsing
+ when TYPE_END_TAG
+ switch t.name
+ when 'body'
+ unless is_in_scope 'body'
+ parse_error()
+ return
+ # TODO implement parse error and move to tree_after_body
+ when 'html'
+ unless is_in_scope 'body' # weird, but it's what the spec says
+ parse_error()
+ return
+ # TODO implement parse error and move to tree_after_body, reprocess
+ when 'address', 'article', 'aside', 'blockquote', 'button', 'center', 'details', 'dialog', 'dir', 'div', 'dl', 'fieldset', 'figcaption', 'figure', 'footer', 'header', 'hgroup', 'listing', 'main', 'nav', 'ol', 'pre', 'section', 'summary', 'ul'
+ unless is_in_scope t.name, NS_HTML
+ parse_error()
+ return
+ generate_implied_end_tags()
+ unless open_els[0].name is t.name and open_els[0].namespace is NS_HTML
+ parse_error()
+ loop
+ el = open_els.shift()
+ if el.name is t.name and el.namespace is NS_HTML
+ return
+ # TODO lots more close tags to implement here
+ when 'p'
+ unless is_in_button_scope 'p'
+ parse_error()
+ insert_html_element new_open_tag 'p'
+ close_p_element()
+ # TODO lots more close tags to implement here
+ when 'a', 'b', 'big', 'code', 'em', 'font', 'i', 'nobr', 's', 'small', 'strike', 'strong', 'tt', 'u'
+ adoption_agency t.name
+ # TODO lots more close tags to implement here
+ else
+ in_body_any_other_end_tag t.name
+ return
+