scss-library/components/00_Tools/_bemGenerator.styl

_bem_context = {
	_alias_map: {}
	_alias_stacks: {
	}
}
			
work_stack(stack, callback)
	while length(stack) > 0
		entry = pop(stack)
		if entry != ()
			callback(entry)

set_alias(alias, name)
	if name != null && alias != null
		_bem_context._alias_map[alias] = name
		
lookup_alias(name)
	if name in _bem_context._alias_map
		return _bem_context._alias_map[name]
	else
		return name



store_alias(alias)
	level_name = called-from[1]
	if not level_name in _bem_context._alias_stacks
		_bem_context._alias_stacks[level_name] = () ()
	
	if alias != null
		push(_bem_context._alias_stacks[level_name], alias)
	
pop_last_alias()
	level_name = called-from[1]
	if not level_name in _bem_context._alias_stacks
		return null
	return pop(_bem_context._alias_stacks[level_name])

apply_alias_stack(name)
	level_name = called-from[1]
	if level_name in _bem_context._alias_stacks
		work_stack(_bem_context._alias_stacks[level_name], @(element){
			set_alias(element, name)
		})



auto_name(delimiter)
	if length(called-from) < 3
		return null
	block_name = called-from[2]
	if delimiter == null
		return block_name
	name = split(delimiter, block_name)[-1]
	if name in ('RV-Element' 'RV-Block' 'RV-Block--shorthand' 'RV-Element--modifier' 'RV-Block--modifier' 'RV-Generate')
		return null
	return name

is_nested(mixin_name=null)
	_free_hits = 0
	if mixin_name == null
		shift(called-from)
		mixin_name = shift(called-from)
	else 
		_free_hits = 1
	for parent in called-from
		if parent == mixin_name
			if _free_hits == 0
				return true
			else
				_free_hits = _free_hits - 1
	return false

is_nested_in(parent_name)
	return parent_name in called-from
	
not_nested_in(parent_name)
	return !(parent_name in called-from)
	
is_any_parent_nested()
	//RV-Level RV-Element--modifier RV-Element RV-Block--modifier RV-BreakPoint--horizontal RV-Block--modifier 	RV-Fan--horizontal RV-Block
	for i in (length(called-from)...0)
		i = i - 1
		if i != index(called-from, called-from[i])
			return true
	return false

RV-Level(name_delimiter, allowed_parent_levels=null, selector_callback, squash_if_parent_nested=false)
	name = auto_name(name_delimiter)
	not_in_parent = true
	for parent_level in allowed_parent_levels
		not_in_parent = not_in_parent && not_nested_in(parent_level)
	if not_in_parent //|| is_nested_in('RV-Squash')
		{block}
	else if is_nested()
		store_alias(name)
		{block}
	else
		if name == null
			name = pop_last_alias()
		name = lookup_alias(name)
		apply_alias_stack(name)
		
		if squash_if_parent_nested && is_any_parent_nested()
			{block}
		else
			selector_name = selector_callback(name)
			if name == ''
				selector_name = split(name_delimiter, selector_name)[0]
			{selector_name}
				{block}

// RV-Fan--horizontal RV-Fan--horizontal __ Base -- wurst
// RV-BreakPoint__Item--outside RV-Fan--horizontal__Base RV-Fan--horizontal

RV-Block(name)
	.{name}
		{block}
	
	_bem_context._alias_map = {}
	_bem_context._alias_stacks = {}

RV-Generate()
	{block}
	
	_bem_context._alias_map = {}
	_bem_context._alias_stacks = {}

RV-Block()
	+RV-Level(null, ('RV-Generate'), @(name){
		define('current_block', name, true)
		return '.'+name
	})
		{block}
		
RV-Block--shorthand(name)
	+RV-Block(name)
		{block}

RV-Element()
	+RV-Level('__', ('RV-Generate' 'RV-Block--modifier'), @(name){
		return '& .' + current_block +'__' + name
	})
		{block}
		
		
RV-Element--modifier()
	+RV-Level('--', ('RV-Element'), @(name){return '&--' + name}, true)
		{block}
		
RV-Block--modifier()
	+RV-Level('--', ('RV-Generate' 'RV-Block--shorthand'), @(name){
		'.' + current_block +'--' + name
	}, true)
		if is_nested_in('RV-Block--shorthand') && length(called-from) > 0
			mixin_name = split('--', called-from[0])[0]
			convert(unquote(mixin_name)+'()')
		{block}
		
RV-Squash()
	{block}

filter(list, value)
	filtered = ()
	for element in list
		if element != value
			push(filtered, element)
	return filtered



_level_types = {
	'': 'block'
	'__': 'element'
	'--': 'modifier'
}

get_first_level_name(mixin_name)
	shortest_split = null
	for delimiter, level_type in _level_types
		if length(delimiter) > 0
			current_split = split(delimiter, mixin_name)[0]
			if shortest_split == null || length(current_split) <= length(shortest_split)
				shortest_split = current_split
	
	return shortest_split

string_contains(smaller, greater)
	if smaller == null || greater == null
		return false
	
	if length(smaller) > length(greater)
		return false

	p('%s'%smaller length('%s'%smaller))

	for i in range(0, length(smaller))
		if smaller[i] != greater[i]
			return false
	return true

is_contigious(call_stack)
	for i in range(0, length(call_stack) - 1)
		p(call_stack[i+1] call_stack[i])
		p(string_contains(call_stack[i+1], call_stack[i]))
		if !call_stack[i+1] in call_stack[i]
			return false
	return true

determine_level_type(mixin_name)
	candidate = null
	candidate_level = null
	candidate_delimiter = null

	// This is why humanity is doomed
	mixin_name = split('äöü', mixin_name)[0]
	for delimiter, level in _level_types
		if length(delimiter) <= 0
			splited_level = mixin_name
		else
			splited_level = split(delimiter, mixin_name)[-1]
		if candidate == null || length(candidate) > length(splited_level)
			candidate = splited_level
			candidate_level = level
			candidate_delimiter = delimiter

	return unquote(candidate) candidate_level unquote(candidate_delimiter)

generate_selector(mixin_name)
	block_name = get_first_level_name(mixin_name)
	level_info = determine_level_type(mixin_name)
	return '&%s%s' % (level_info[2] level_info[0])


RV-BEM()
	call_stack = filter(called-from, 'RV-BEM')
	p(cs call_stack)
	if is_contigious(call_stack)
		{generate_selector(called-from[0])}
			{block}
	p('###')