1 files changed, 119 insertions, 0 deletions
diff --git a/powerline/lint/markedjson/composer.py b/powerline/lint/markedjson/composer.py
new file mode 100644
index 0000000..bd5620d
--- /dev/null
+++ b/powerline/lint/markedjson/composer.py
@@ -0,0 +1,119 @@
+# vim:fileencoding=utf-8:noet
+from __future__ import (unicode_literals, division, absolute_import, print_function)
+
+from powerline.lint.markedjson import nodes
+from powerline.lint.markedjson import events
+from powerline.lint.markedjson.error import MarkedError
+
+
+__all__ = ['Composer', 'ComposerError']
+
+
+class ComposerError(MarkedError):
+	pass
+
+
+class Composer:
+	def __init__(self):
+		pass
+
+	def check_node(self):
+		# Drop the STREAM-START event.
+		if self.check_event(events.StreamStartEvent):
+			self.get_event()
+
+		# If there are more documents available?
+		return not self.check_event(events.StreamEndEvent)
+
+	def get_node(self):
+		# Get the root node of the next document.
+		if not self.check_event(events.StreamEndEvent):
+			return self.compose_document()
+
+	def get_single_node(self):
+		# Drop the STREAM-START event.
+		self.get_event()
+
+		# Compose a document if the stream is not empty.
+		document = None
+		if not self.check_event(events.StreamEndEvent):
+			document = self.compose_document()
+
+		# Ensure that the stream contains no more documents.
+		if not self.check_event(events.StreamEndEvent):
+			event = self.get_event()
+			raise ComposerError(
+				'expected a single document in the stream',
+				document.start_mark,
+				'but found another document',
+				event.start_mark
+			)
+
+		# Drop the STREAM-END event.
+		self.get_event()
+
+		return document
+
+	def compose_document(self):
+		# Drop the DOCUMENT-START event.
+		self.get_event()
+
+		# Compose the root node.
+		node = self.compose_node(None, None)
+
+		# Drop the DOCUMENT-END event.
+		self.get_event()
+
+		return node
+
+	def compose_node(self, parent, index):
+		self.descend_resolver(parent, index)
+		if self.check_event(events.ScalarEvent):
+			node = self.compose_scalar_node()
+		elif self.check_event(events.SequenceStartEvent):
+			node = self.compose_sequence_node()
+		elif self.check_event(events.MappingStartEvent):
+			node = self.compose_mapping_node()
+		self.ascend_resolver()
+		return node
+
+	def compose_scalar_node(self):
+		event = self.get_event()
+		tag = event.tag
+		if tag is None or tag == '!':
+			tag = self.resolve(nodes.ScalarNode, event.value, event.implicit, event.start_mark)
+		node = nodes.ScalarNode(tag, event.value, event.start_mark, event.end_mark, style=event.style)
+		return node
+
+	def compose_sequence_node(self):
+		start_event = self.get_event()
+		tag = start_event.tag
+		if tag is None or tag == '!':
+			tag = self.resolve(nodes.SequenceNode, None, start_event.implicit)
+		node = nodes.SequenceNode(tag, [], start_event.start_mark, None, flow_style=start_event.flow_style)
+		index = 0
+		while not self.check_event(events.SequenceEndEvent):
+			node.value.append(self.compose_node(node, index))
+			index += 1
+		end_event = self.get_event()
+		node.end_mark = end_event.end_mark
+		return node
+
+	def compose_mapping_node(self):
+		start_event = self.get_event()
+		tag = start_event.tag
+		if tag is None or tag == '!':
+			tag = self.resolve(nodes.MappingNode, None, start_event.implicit)
+		node = nodes.MappingNode(tag, [], start_event.start_mark, None, flow_style=start_event.flow_style)
+		while not self.check_event(events.MappingEndEvent):
+			# key_event = self.peek_event()
+			item_key = self.compose_node(node, None)
+			# if item_key in node.value:
+			# 	 raise ComposerError('while composing a mapping', start_event.start_mark,
+			# 			 'found duplicate key', key_event.start_mark)
+			item_value = self.compose_node(node, item_key)
+			# node.value[item_key] = item_value
+			node.value.append((item_key, item_value))
+		end_event = self.get_event()
+		node.end_mark = end_event.end_mark
+		return node