PLUGIN html
lang: "C++"
version: "1.0"
date: "2022-03-20"
author: "Julien BRUGUIER"
maintainer: "Julien BRUGUIER <projet.svm@pappy.tf>"
synopsis: "Plugin to manage HTML documents"
description:
%{
This plugin is an HTML document manager allowing operations on the DOM.
%}

comment flex: "/*" " * " " */"
comment bison: "/*" " * " " */"

includes:
%{
#include <iostream>
#include <algorithm>
#include <string.h>
#include <src/html.h>
#include <src/parser/includes.h>
%}

code:
%{
struct yy_buffer_state;

void htmlparserlex_init(void **);
void htmlparserlex_destroy(void *);
yy_buffer_state* htmlparser_scan_buffer(char *, size_t, void*);
void htmlparser_delete_buffer(yy_buffer_state *buffer, void *scanner);
int htmlparserparse(void *scanner, Html::Dom &dom);
%}

file source: "src/html.h"
%{
#pragma once

#include <iostream>
#include <sstream>
#include <memory>
#include <vector>
#include <set>
#include <map>

namespace Html
{

template<typename E>
struct Compare
{
	bool operator() (const std::weak_ptr<E>& l, const std::weak_ptr<E>& r)
	{
		return l.lock()<r.lock();
	}
};

struct Element : public std::enable_shared_from_this<Element>
{
	typedef std::shared_ptr<Element> SP;
	typedef std::weak_ptr<Element> WP;
	virtual ~Element() {}
	virtual Element::SP clone() const = 0;

	virtual Element::SP id(const std::string& id)
	{
		return Element::SP();
	}
	virtual std::vector<Element::SP> in_class(const std::string& class_name)
	{
		std::vector<Element::SP> elements;
		return elements;
	}
	template<typename oStream>
	friend oStream& operator<<(oStream& os, const Element::SP& e)
	{
		e->print(os);
		return os;
	}
	virtual void print(std::ostream& os) const = 0;
	std::set<Element::WP,Compare<Element> > _parents;
	bool verification(const Element::SP& child) const
	{
		if(child==this->shared_from_this())
		{
			return false;
		}
		for(const auto& p:_parents)
		{
			auto pp = p.lock();
			if(not pp) continue;
			if(not pp->verification(child)) return false;
		}
		return true;
	}
};

struct Text : public Element
{
	Text(const std::string& text)
	:_text(text) {}
	virtual Element::SP clone() const override
	{
		return std::make_shared<Text>(_text);
	}

	virtual void print(std::ostream& os) const override
	{
		os << _text;
	}

	std::string _text;
};

struct Comment : public Element
{
	Comment(const std::string& text)
	:_text(text) {}
	virtual Element::SP clone() const override
	{
		return std::make_shared<Comment>(_text);
	}

	virtual void print(std::ostream& os) const override
	{
		os << "<!--" << _text << "-->";
	}
	std::string _text;
};

struct Meta : public Element
{
	Meta(const std::string& text)
	:_text(text) {}
	virtual Element::SP clone() const override
	{
		return std::make_shared<Meta>(_text);
	}

	virtual void print(std::ostream& os) const override
	{
		os << "<?" << _text << "?>";
	}
	std::string _text;
};

struct Node : public Element
{
	Node(const std::string& type)
	:_type(type) {}
	virtual Element::SP clone() const override
	{
		auto e = std::make_shared<Node>(_type);
		e->_id = _id;
		e->_class = _class;
		e->_attributes = _attributes;
		for(const auto& c: _children)
		{
			e->_children.push_back(c->clone());
		}
		return e;
	}
	void id_and_class()
	{
		auto it = _attributes.find("id");
		if(it!=_attributes.end())
		{
			_id = it->second;
		}
		it = _attributes.find("class");
		if(it!=_attributes.end())
		{
			_class.clear();
			auto c = it->second;
			for( ; ; )
			{
				auto itt=c.find(" ");
				if(itt==std::string::npos)
				{
					_class.insert(c);
					break;
				}
				if(itt>0)
				{
					_class.insert(c.substr(0,itt));
				}
				c = c.substr(itt+1);
			}
		}
	}

	virtual Element::SP id(const std::string& id)
	{
		if(_id==id) return this->shared_from_this();
		for(auto& c:_children)
		{
			auto e = c->id(id);
			if(static_cast<bool>(e)) return e;
		}
		return Element::SP();
	}
	virtual std::vector<Element::SP> in_class(const std::string& class_name)
	{
		std::vector<Element::SP> elements;
		auto it = _class.find(class_name);
		if(it!=_class.end())
		{
			elements.push_back(this->shared_from_this());
		}
		for(auto& c:_children)
		{
			auto e = c->in_class(class_name);
			elements.insert(elements.end(),e.begin(),e.end());
		}
		return elements;
	}
	virtual void print(std::ostream& os) const override
	{
		os << "<" << _type;
		for(const auto& a:_attributes)
		{
			os << " " << a.first << "=\"" << a.second << "\"";
		}
		if(_children.empty())
		{
			os << "/>";
			return;
		}
		os << ">";
		for(const auto& c:_children)
		{
			os << c;
		}
		os << "</" << _type << ">";
	}

	std::string _type;
	std::string _id;
	std::set<std::string> _class;
	std::map<std::string,std::string> _attributes;
	std::vector<Element::SP> _children;
};

struct Dom
{
	using SP = std::shared_ptr<Dom>;
	Dom() = default;
	Dom(const Dom& dom)
	:_error(dom._error)
	{
		for(const auto& r:dom._root)
		{
			_root.push_back(r->clone());
		}
	}
	std::vector<Element::SP> _root;
	std::string _error;

	Element::SP id(const std::string& id) const
	{
		for(auto& r:_root)
		{
			auto e = r->id(id);
			if(static_cast<bool>(e)) return e;
		}
		return Element::SP();
	}

	std::vector<Element::SP> in_class(const std::string& class_name) const
	{
		std::vector<Element::SP> elements;
		for(auto& r:_root)
		{
			auto e = r->in_class(class_name);
			elements.insert(elements.end(),e.begin(),e.end());
		}
		return elements;
	}

	template<typename oStream>
	friend oStream& operator<<(oStream& os, const Dom& d)
	{
		if(not d._error.empty())
		{
			os << "Error: " << d._error;
		}
		else
		{
			for(auto& e:d._root)
			{
				os << e;
			}
		}
		return os;
	}
};
}
%}

file source: "src/html.cpp"
%{
#include <src/html.h>
%}

file flex: "src/parser/parser.lex.lpp"
${
%{
#include <algorithm>
#include <src/parser/includes.h>

#define YY_USER_ACTION yylloc->first_line = yylloc->last_line = yylineno; 

%}

%option nounput
%option reentrant
%option bison-bridge
%option bison-locations
%option noyywrap

%s S_TAG
%s S_COMMENT
%s S_META

%%
<INITIAL>"<"					{ BEGIN(S_TAG); return INFERIOR; }
<S_TAG>">"					{ BEGIN(INITIAL); return SUPERIOR; }
<S_TAG>[a-z][a-z0-9_]*				{ yylval->string = std::string(yytext,yyleng); return IDENTIFIER; }
<S_TAG>\"([^"\n]|\\\\\")*\"			{ std::string token(yytext,yyleng); yylval->string = token.substr(1,token.size()-2); return STRING_VALUE; }
<S_TAG>\"([^"\n]|\\\\\")*\n			{ return _INVALID_; }
<S_TAG>\/					{ return SLASH; }
<S_TAG>=					{ return EQUAL; }
<S_TAG>:					{ return COLON; }
<S_TAG>[ \t]					{ }
<INITIAL>(\n|[^<])+				{ yylval->string = std::string(yytext,yyleng); yylloc->last_line+=std::count(yylval->string.begin(),yylval->string.end(),'\n'); return TEXT; }
<S_TAG>"!--"					{ BEGIN(S_COMMENT); return COMMENT; }
<S_COMMENT>(\n|[^-]|-[^-]|--[^>])*		{ std::string token(yytext,yyleng); yylloc->last_line+=std::count(yylval->string.begin(),yylval->string.end(),'\n'); yylval->string = token; return TEXT; }
<S_COMMENT>"-->"				{ BEGIN(INITIAL); return SUPERIOR; }
<S_TAG>\?					{ BEGIN(S_META); return META; }
<S_META>(\n|[^\?]|\?[^>])*			{ std::string token(yytext,yyleng); yylloc->last_line+=std::count(yylval->string.begin(),yylval->string.end(),'\n'); yylval->string = token; return TEXT; }
<S_META>"?>"					{ BEGIN(INITIAL); return SUPERIOR; }
%%
$}

file bison: "src/parser/parser.syn.ypp"
${
%{
#include <sstream>
#define YYDEBUG 0
#include <src/parser/includes.h>

extern int htmlparsererror(YYLTYPE *llocp, void *scanner, Html::Dom& dom, std::string mesg);
extern int htmlparserlex(YYSTYPE *lvalp, YYLTYPE *llocp, void *scanner);
extern int htmlparserlex_init(void *scanner);
extern int htmlparserlex_destroy(void *scanner);


%}

%locations
%define api.pure full
%define api.value.type { struct ParserValue }
%param { void *scanner }

%parse-param { Html::Dom& dom }

%initial-action { 
#if YYDEBUG==1
	htmlparserdebug=1;
#endif
}
%code requires
{

struct ParserValue
{
	std::string string;
	Html::Element::SP element;
	std::vector<Html::Element::SP> elements;
	std::map<std::string, std::string> attributes;
	std::pair<std::string, std::string> attribute;
};

#   define YYCOPY(Dst, Src, Count)              \
      do                                        \
        {                                       \
          YYSIZE_T yyi;                         \
          for (yyi = 0; yyi < (Count); yyi++)   \
            (Dst)[yyi] = (Src)[yyi];            \
        }                                       \
      while (0)
}

%token _INVALID_
%token<string> IDENTIFIER STRING_VALUE TEXT
%token INFERIOR SUPERIOR SLASH EQUAL COLON COMMENT META

%type<string> tag

%type<element> text comment meta element simple_node complex_node
%type<attribute> attribute

%type<elements> element_list
%type<attributes> attribute_list

%start dom

%%

dom: element_list
{
	dom._root = $1;
}
;

element_list:
{
	$$ = std::vector<Html::Element::SP>();
}
| element_list element
{
	$$=$1;
	$$.push_back($2);
}
;

element: text
{
	$$=$1;
}
| comment
{
	$$=$1;
}
| meta
{
	$$=$1;
}
| simple_node
{
	$$=$1;
}
| complex_node
{
	$$=$1;
}
;

text: TEXT
{
	$$ = std::make_shared<Html::Text>($1);
}
;

comment: INFERIOR COMMENT TEXT SUPERIOR
{
	$$ = std::make_shared<Html::Comment>($3);
}
;

meta: INFERIOR META TEXT SUPERIOR
{
	$$ = std::make_shared<Html::Meta>($3);
}
;

simple_node: INFERIOR tag attribute_list SLASH SUPERIOR
{
	auto node =  std::make_shared<Html::Node>($2);
	node->_attributes = $3;
	node->id_and_class();
	$$=node;
}
;

complex_node: INFERIOR tag attribute_list SUPERIOR element_list INFERIOR SLASH tag SUPERIOR
{
	if($2!=$8)
	{
		htmlparsererror(&@$,scanner,dom,"Mismatched node idendifier");
	}
	auto node =  std::make_shared<Html::Node>($2);
	node->_attributes = $3;
	node->id_and_class();
	node->_children = $5;
	$$=node;
}
;

tag:	IDENTIFIER
{
	$$ = $1;
}
|	IDENTIFIER COLON IDENTIFIER
{
	$$ = $1+":"+$3;
}
;

attribute_list:
{
	$$ = std::map<std::string,std::string>();
}
| attribute_list attribute
{
	$$=$1;
	$$.insert($2);
}
;

attribute: IDENTIFIER EQUAL STRING_VALUE
{
	$$ = std::make_pair($1,$3);
}
|	IDENTIFIER EQUAL IDENTIFIER
{
	$$ = std::make_pair($1,$3);
}
;

%%

int htmlparsererror(YYLTYPE *llocp, void *scanner, Html::Dom& dom, std::string mesg)
{
	std::ostringstream oss;
	oss << "Invalid HTML text, line";
	if(llocp->first_line==llocp->last_line)
	{
		oss << " " << llocp->first_line;
	}
	else
	{
		oss << "s " << llocp->first_line << "-" << llocp->last_line;
	}
	oss << ": " << mesg; 
	dom._error = oss.str();
	return 1;
}
$}

file source: "src/parser/includes.h"
%{
#include <src/html.h>
#include <src/parser/parser.syn.hpp>
%}

file make: "src/parser/Makefile.am"
%{
AM_CPPFLAGS=-I${top_builddir} -I${top_srcdir}

SUBDIRS= 

noinst_LTLIBRARIES=libparser.la

BUILT_SOURCES=parser.lex.cpp parser.syn.cpp

EXTRABUILTSOURCES=parser.syn.h

CLEANFILES=parser.syn.output

AM_YFLAGS=-d -v --file-prefix=y --name-prefix=htmlparser -o y.tab.c
AM_LFLAGS=-P htmlparser -o lex.yy.c

libparser_la_CXXFLAGS=$(AM_CXXFLAGS) -Wno-error=sign-compare

libparser_la_SOURCES=parser.lex.lpp parser.syn.ypp includes.h
libparser_la_LIBADD=
libparser_la_LDFLAGS=-no-undefined -module
%}


patch: "configure.ac"
%{
--- configure.ac.orig	2023-03-24 04:54:45.481596839 +0100
+++ configure.ac	2023-03-24 04:54:45.541597019 +0100
@@ -29,7 +29,10 @@
 
 AC_CHECK_PROG([DIFF],[diff],[diff -u])
 AC_PROG_CXX
+AM_PROG_LEX
+AC_PROG_YACC
 AC_LANG([C++])
+AM_CXXFLAGS="$(AM_CXXFLAGS) -std=c++14"
 AM_PROG_LIBTOOL
 AC_CHECK_TOOL([STRIP],[strip])
 
@@ -54,6 +57,7 @@
 AC_CONFIG_FILES([
 	Makefile
 	src/Makefile
+	src/parser/Makefile
 	doc/Makefile
 	test/Makefile
 ])
%}

patch: "Makefile.am"
%{
--- Makefile.am.orig	2023-03-24 04:54:45.535597001 +0100
+++ Makefile.am	2023-03-24 04:55:50.840792199 +0100
@@ -26,5 +26,5 @@
 
 libsvmhtml_la_SOURCES=
 libsvmhtml_la_LDFLAGS=-module -ldl -Wl,-rpath -Wl,${pkglibdir} -Wl,-L$(SVM) 
-libsvmhtml_la_LIBADD=src/libplugin.la
+libsvmhtml_la_LIBADD=src/libplugin.la src/parser/libparser.la
 libsvmhtml_la_LIBTOOLFLAGS=--tag=disable-static
%}

patch: "Makefile.local"
%{
--- Makefile.local.orig	2023-03-24 04:54:45.535597001 +0100
+++ Makefile.local	2023-03-24 04:54:45.538597010 +0100
@@ -20,8 +20,8 @@
 
 OPTIONS=
 
-DEPENDENCIES=
-GENERATED=
+DEPENDENCIES=src/html.o src/parser/parser.syn.o src/parser/parser.lex.o
+GENERATED=src/parser/parser.lex.cpp src/parser/parser.syn.{cpp,hpp,output}
 
 all: libsvmhtml.so
 
@@ -31,6 +31,12 @@
 .cpp.o:
 	g++ -std=c++14 -o $@ -c $< -fPIC -DPIC $(OPTIONS) -I.
 
+src/parser/parser.lex.cpp: src/parser/parser.lex.lpp
+	flex -P htmlparser -o $@ $<
+
+src/parser/parser.syn.cpp: src/parser/parser.syn.ypp
+	bison -d -v --file-prefix=y --name-prefix=htmlparser -o $@ $<
+ 
 .PHONY: clean
 clean:
 	rm -rf src/plugin.o $(DEPENDENCIES) $(GENERATED) libsvmhtml.so
%}

patch: "src/Makefile.am"
%{
--- src/Makefile.am.orig	2023-03-24 04:54:45.497596887 +0100
+++ src/Makefile.am	2023-03-24 04:54:45.543597025 +0100
@@ -18,10 +18,10 @@
 
 AM_CPPFLAGS=-I${top_builddir} -I${top_srcdir} -std=c++14 
 
-SUBDIRS=
+SUBDIRS=parser
 
 noinst_LTLIBRARIES=libplugin.la
 
-libplugin_la_SOURCES=plugin.cpp plugin.h
+libplugin_la_SOURCES=plugin.cpp plugin.h html.cpp html.h
 libplugin_la_LIBADD=
 libplugin_la_LDFLAGS=-no-undefined
%}

DEFINE

TYPE html.dom
%{
	type_dom()
	:_dom(std::make_shared<Html::Dom>())
	{ }
	type_dom(const type_dom& dom)
	:_dom(std::make_shared<Html::Dom>(*(dom._dom)))
	{
	}
	Html::Dom::SP _dom;
	operator std::string () const
	{
		std::ostringstream oss;
		oss << (*_dom);
		return oss.str();
	}
%}
delete default: %{}
copy default: %{}
constant:
%{
	void *scanner;
	::htmlparserlex_init(&scanner);
	char *src = new char[value.size+2];
	::memcpy(src,value.string,value.size);
	src[value.size] = src[value.size+1] = '\0';
	yy_buffer_state *buffer = ::htmlparser_scan_buffer(src,value.size+2,scanner);
	type_dom *t = new type_dom;
	::htmlparserparse(scanner,*(t->_dom));
	::htmlparser_delete_buffer(buffer,scanner);
	delete [] src;
	::htmlparserlex_destroy(scanner);
	return t;
%}
print default: %{}
help: "This type contains a representation of a full HTML document."

TYPE html.element
%{
	type_element() = default;
	type_element(const type_element& te)
	{
		_element = te._element->clone();
	}
	operator std::string () const
	{
		std::ostringstream oss;
		oss << _element;
		return oss.str();
	}
	Html::Element::SP _element;

%}
delete default: %{}
copy default: %{}
print default: %{}
help: "This type contains a representation of an HTML node or text."

INSTRUCTION html.text STR -> html.element
%{
	auto text = ARGV_VALUE(0,string);
	type_element *t = new type_element;
	t->_element = std::make_shared<Html::Text>(std::string(text.string,text.size));
	return NEW_PLUGIN(html,element,t);
%}
help: "This instruction creates an HTML element containing a raw text."

INSTRUCTION html.comment STR -> html.element
%{
	auto text = ARGV_VALUE(0,string);
	type_element *t = new type_element;
	t->_element = std::make_shared<Html::Comment>(std::string(text.string,text.size));
	return NEW_PLUGIN(html,element,t);
%}
help: "This instruction creates an HTML element containing the text surrounded by <!-- and -->."

INSTRUCTION html.meta STR -> html.element
%{
	auto text = ARGV_VALUE(0,string);
	type_element *t = new type_element;
	t->_element = std::make_shared<Html::Meta>(std::string(text.string,text.size));
	return NEW_PLUGIN(html,element,t);
%}
help: "This instruction creates an HTML element containing the text surrounded by <? and ?>."

INSTRUCTION html.node STR : type ( , STR : attribute_key = STR : attribute_value ) * ( { html.element + } ) ? -> html.element
%{
	auto type = ARGV_VALUE(0,string);
	auto node = std::make_shared<Html::Node>(std::string(type.string,type.size));
	std::map<std::string, std::string> attributes;
	size_t index = 1;
	for( ; index<argc ; index+=4)
	{
		auto marker = ARGV_MARKER(index);
		if(marker=="{") break;
		auto key = ARGV_VALUE(index+1,string);
		auto value = ARGV_VALUE(index+3,string);
		attributes.insert(std::make_pair(std::string(key.string,key.size),std::string(value.string,value.size)));
	}
	std::vector<Html::Element::SP> children;
	for( ++index ; index<argc ; ++index)
	{
		if(::svm_parameter_type_is_marker(svm,argv[index])) break;
		auto child = ARGV_PLUGIN(index,html,element);
		child->_element->_parents.insert(node);
		children.push_back(child->_element);
	}
	type_element *t = new type_element;
	node->_attributes = attributes;
	node->_children = children;
	node->id_and_class();
	t->_element = node;
	return NEW_PLUGIN(html,element,t);

%}
help:
%{
This instruction creates an HTML node with a type (the name between < and >), attributes (key="value") and optional content (between <name> and </name>).
%}

INSTRUCTION html.insert MUTABLE html.element : parent INT : index 'END' ? html.element : child
%{
	auto raw_parent = ARGV_PLUGIN(0,html,element);
	auto parent = std::dynamic_pointer_cast<Html::Node>(raw_parent->_element);
	if(not parent)
	{
		ERROR_INTERNAL(FAILURE,"Parent is not a node");
	}
	auto index = ARGV_VALUE(1,integer);
	size_t position = 2;
	if(::svm_parameter_type_is_keyword(svm,argv[position]))
	{
		++position;
		index += parent->_children.size();
	}
	auto child = ARGV_PLUGIN(position,html,element);
	if((index>=0) and (index<parent->_children.size()))
	{
		parent->_children.insert(parent->_children.begin()+index,child->_element);
	}
	else if(index==parent->_children.size())
	{
		if(not parent->verification(child->_element))
		{
			ERROR_INTERNAL(FAILURE,"HTML element cycle detected");
		}
		parent->_children.push_back(child->_element);
		child->_element->_parents.insert(parent);
	}
	else
	{
		ERROR_INTERNAL(FAILURE,"Out of range");
	}
%}
help:
%{
This instruction inserts into a node a child element.

The child element is insert at the specified index.
When the keyword END is present, the index 0 matches the element after the last element (Inserting at 0 END means adding at the end).

If the parent element is not a node, or when the insertion index is outside the node children list, a FAILURE interruption is raised.

.I Adding as child an element being the parent of the node will also raise a FAILURE interruption.
%}

INSTRUCTION html.replace MUTABLE html.element : parent INT : index 'END' ? html.element : child
%{
	auto raw_parent = ARGV_PLUGIN(0,html,element);
	auto parent = std::dynamic_pointer_cast<Html::Node>(raw_parent->_element);
	if(not parent)
	{
		ERROR_INTERNAL(FAILURE,"Parent is not a node");
	}
	auto index = ARGV_VALUE(1,integer);
	size_t position = 2;
	if(::svm_parameter_type_is_keyword(svm,argv[position]))
	{
		++position;
		index += parent->_children.size();
	}
	auto child = ARGV_PLUGIN(position,html,element);
	if((index>=0) and (index<parent->_children.size()))
	{
		if(not parent->verification(child->_element))
		{
			ERROR_INTERNAL(FAILURE,"HTML element cycle detected");
		}
		auto it = parent->_children[index]->_parents.find(parent);
		parent->_children[index]->_parents.erase(it);
		parent->_children[index] = child->_element;
		child->_element->_parents.insert(parent);
	}
	else
	{
		ERROR_INTERNAL(FAILURE,"Out of range");
	}
%}
help:
%{
This instruction replaces a child of a node by another element.

The child element is replaced at the specified index.
When the keyword END is present, the index 0 matches the element after the last element (Inserting at 0 END means adding at the end).

If the parent element is not a node, or when the replacement index is outside the node children list, a FAILURE interruption is raised.

.I Adding as child an element being the parent of the node will also raise a FAILURE interruption.
%}

INSTRUCTION html.remove MUTABLE html.element : parent ( INT : index 'END' ? | html.element : child )
%{
	auto raw_parent = ARGV_PLUGIN(0,html,element);
	auto parent = std::dynamic_pointer_cast<Html::Node>(raw_parent->_element);
	if(not parent)
	{
		ERROR_INTERNAL(FAILURE,"Parent is not a node");
	}
	SVM_Value value = ::svm_parameter_value_get(svm,argv[1]);
	if(::svm_value_type_is_integer(svm,value))
	{
		auto index = ::svm_value_integer_get(svm,value);
		size_t position = 2;
		if(::svm_parameter_type_is_keyword(svm,argv[position]))
		{
			++position;
			index += parent->_children.size();
		}
		if((index>=0) and (index<parent->_children.size()))
		{
			auto it = parent->_children[index]->_parents.find(parent);
			parent->_children[index]->_parents.erase(it);
			parent->_children.erase(parent->_children.begin()+index);
		}
		else
		{
			ERROR_INTERNAL(FAILURE,"Out of range");
		}
	}
	else
	{
		auto child = ARGV_PLUGIN(1,html,element);
		auto it = std::find(parent->_children.begin(),parent->_children.end(),child->_element);
		if(it!=parent->_children.end())
		{
			auto itt = (*it)->_parents.find(parent);
			(*it)->_parents.erase(itt);
			parent->_children.erase(it);
		}
	}
%}
help:
%{
This instruction removes a child of a node.

The child element is removed at the specified index.
When the keyword END is present, the index 0 matches the element after the last element (Inserting at 0 END means adding at the end).

If the parent element is not a node, or when the replacement index is outside the node children list, a FAILURE interruption is raised.
%}

INSTRUCTION html.dom html.element + -> html.dom
%{
	type_dom *t = new type_dom;
	for(size_t index=0 ; index<argc ; ++index)
	{
		auto element = ARGV_PLUGIN(index,html,element);
		t->_dom->_root.push_back(element->_element);
	}
	return NEW_PLUGIN(html,dom,t);
%}
help:
%{
This instruction transforms a list of HTML element into an HTML DOM.
%}

INSTRUCTION html.id html.dom STR : id -> html.element ?
%{
	auto dom = ARGV_PLUGIN(0,html,dom);
	auto id = ARGV_VALUE(1,string);
	auto element = dom->_dom->id(std::string(id.string,id.size));
	if(not element)
	{
		return NEW_NULL_PLUGIN(html,element);
	}
	type_element *t = new type_element();
	t->_element = element;
	return NEW_PLUGIN(html,element,t);
%}
help:
%{
This instruction returns the first HTML element within the DOM having the "id" attribute set to the parameter.

When not found, the null HTML element is returned.
%}

INSTRUCTION html.class html.dom STR : class -> PTR
%{
	auto dom = ARGV_PLUGIN(0,html,dom);
	auto class_name = ARGV_VALUE(1,string);
	auto elements = dom->_dom->in_class(std::string(class_name.string,class_name.size));
	SVM_Memory_Zone zone = ::svm_memory_zone_new(svm);
	::svm_memory_zone_append_external__raw(svm,zone,CONST_PEP(html,element),elements.size());
	SVM_Value_Pointer p = ::svm_memory_allocate(svm,CURRENT(kernel),zone);
	SVM_Address a = ::svm_value_pointer_get_address(svm,p);
	for(auto& e:elements)
	{
		type_element *t = new type_element();
		t->_element = e;
		::svm_memory_write_address(svm,CURRENT(kernel),a++,NEW_PLUGIN(html,element,t));
	}
	return p;
%}
help:
%{
This instruction returns a pointer on an array of HTML elements within the DOM having the "class" attribute containing the parameter.
%}