1 files changed, 68 insertions, 0 deletions
diff --git a/lib/yaml/resolver.py b/lib/yaml/resolver.py
new file mode 100644
index 0000000..7cff321
--- /dev/null
+++ b/lib/yaml/resolver.py
@@ -0,0 +1,68 @@
+
+from nodes import *
+
+class BaseResolver:
+
+    DEFAULT_SCALAR_TAG = u'tag:yaml.org,2002:str'
+    DEFAULT_SEQUENCE_TAG = u'tag:yaml.org,2002:seq'
+    DEFAULT_MAPPING_TAG = u'tag:yaml.org,2002:map'
+
+    def __init__(self, composer):
+        self.composer = composer
+        self.resolved_nodes = {}
+
+    def check(self):
+        # If there are more documents available?
+        return self.composer.check()
+
+    def get(self):
+        # Resolve and return the root node of the next document.
+        if self.composer.check():
+            return self.resolve_document(self.composer.get())
+
+    def __iter__(self):
+        # Iterator protocol.
+        while self.composer.check():
+            yield self.resolve_document(self.composer.get())
+
+    def resolve_document(self, node):
+        self.resolve_node([], node)
+        return node
+        self.resolved_nodes = {}
+
+    def resolve_node(self, path, node):
+        if node in self.resolved_nodes:
+            return
+        self.resolved_nodes[node] = None
+        if isinstance(node, ScalarNode):
+            self.resolve_scalar(path, node)
+        elif isinstance(node, SequenceNode):
+            self.resolve_sequence(path, node)
+            for index in len(node.value):
+                self.resolve_node(path+[node, index], node.value[index])
+        elif isinstance(node, MappingNode):
+            self.resolve_mapping(path, node)
+            for key, value in node.value:
+                self.resolve_node(path+[node, None], key)
+                self.resolve_node(path+[node, key], value)
+
+    def resolve_scalar(self, node):
+        if node.tag is None:
+            node.tag = self.detect_scalar(node.value)
+        if node.tag is None or node.tag == u'!':
+            node.tag = self.DEFAULT_SCALAR_TAG
+
+    def resolve_sequence(self, node):
+        if node.tag is None or node.tag == u'!':
+            node.tag = self.DEFAULT_SEQUENCE_TAG
+
+    def resolve_mapping(self, node):
+        if node.tag is None or node.tag == u'!':
+            node.tag = self.DEFAULT_MAPPING_TAG
+
+    def detect_scalar(self, value):
+        return None
+
+class Resolver(BaseResolver):
+    pass
+