Changeset 111:16d9f3a0dc29 for nagslang

Timestamp:

Sep 2, 2013, 12:45:18 PM (7 years ago)

Author:

Stefano Rivera <stefano@…>

Branch:

default

amend_source:

8a314fe69efa27db6994429ce49b0090335e05e9

Message:

Refactored as classes for readability and to make it easier to support more types

File:

• nagslang/yamlish.py (modified) (1 diff)

nagslang/yamlish.py

@@ -9 +9 @@
 
 def dump(data, file_object):
-    file_object.write('\n'.join(_dump(data, 0)))
+    file_object.write(dump_s(data))
 
 
-def _dump(obj, indent):
-    if isinstance(obj, list):
-        for item in obj:
-            yield '%s- %s' % (' ' * indent,
-                              '\n'.join(_dump(item, indent + 2)).strip())
-    elif isinstance(obj, dict):
-        for k, v in obj.iteritems():
-            if isinstance(v, basestring):
-                yield '%s%s: %s' % (' ' * indent, k, v)
-            else:
-                extra = 0 if isinstance(v, list) else 2
-                yield '%s%s:\n%s' % (' ' * indent, k,
-                                     '\n'.join(_dump(v, indent + extra)))
-    elif isinstance(obj, basestring):
-        yield '%s%s' % (' ' * indent, obj)
-
-
-spaces_re = re.compile(r'^(\s*)(.*)')
-list_re = re.compile(r'^(-\s+)(.*)')
-dict_re = re.compile(r'^([^-:]+):\s?(.*)')
+def dump_s(data):
+    return Dumper().dump(data)
 
 
 def load(file_object):
-    # Stack of (indent level, container object)
-    stack = [(0, {})]
-    indent = lambda: stack[-1][0]
-    obj = lambda: stack[-1][1]
+    yaml = file_object.read()
+    return load_s(yaml)
 
-    # When a dict's value is a nested block, remember the key
-    parent_key = None
 
-    for line in file_object:
-        spaces, line = spaces_re.match(line).groups()
+def load_s(yaml):
+    return Parser().parse(yaml)
 
-        while len(spaces) < indent():
-            stack.pop()
 
-        lm = list_re.match(line)
-        dm = dict_re.match(line)
-        if len(spaces) == indent():
+
+class Dumper(object):
+    def dump(self, data):
+        return '\n'.join(self._dump(data))
+
+    def _dump(self, data, indent=0):
+        for type_ in (list, dict, basestring):
+            if isinstance(data, type_):
+                f = getattr(self, '_dump_%s' % type_.__name__)
+                return f(data, indent)
+        raise NotImplementedError()
+
+    def _dump_list(self, data, indent):
+        output = []
+        for item in data:
+            dumped = self._dump(item, indent + 2)
+            dumped[0] = '%s- %s' % (' ' * indent, dumped[0][indent + 2:])
+            output += dumped
+        return output
+
+    def _dump_dict(self, data, indent):
+        output = []
+        for k, v in data.iteritems():
+            output.append('%s%s:' % (' ' * indent, k))
+            if isinstance(v, dict):
+                output += self._dump(v, indent + 2)
+            elif isinstance(v, list):
+                output += self._dump(v, indent)
+            else:
+                value = self._dump(v)
+                assert len(value) == 1
+                output[-1] += ' %s' % value[0]
+        return output
+
+    def _dump_basestring(self, data, indent):
+        return [' ' * indent + data]
+
+
+class Parser(object):
+    _spaces_re = re.compile(r'^(\s*)(.*)')
+    _list_re = re.compile(r'^(-\s+)(.*)')
+    _dict_re = re.compile(r'^([^-:]+):\s?(.*)')
+
+    def __init__(self):
+        # Stack of (indent level, container object)
+        self._stack = [(0, {})]
+        # When a dict's value is a nested block, remember the key
+        self._parent_key = None
+
+    @property
+    def _indent(self):
+        return self._stack[-1][0]
+
+    @property
+    def _container(self):
+        return self._stack[-1][1]
+
+    @property
+    def _in_list(self):
+        return isinstance(self._container, list)
+
+    @property
+    def _in_dict(self):
+        return isinstance(self._container, dict)
+
+    def _push(self, container, indent=None):
+        in_list = self._in_list
+        assert in_list or self._parent_key
+
+        if indent is None:
+            indent = self._indent
+        self._stack.append((indent, container()))
+        if in_list:
+            self._stack[-2][1].append(self._container)
+        else:
+            self._stack[-2][1][self._parent_key] = self._container
+            self._parent_key = None
+
+    def parse(self, yaml):
+        for line in yaml.splitlines():
+            spaces, line = self._spaces_re.match(line).groups()
+
+            while len(spaces) < self._indent:
+                self._stack.pop()
+
+            lm = self._list_re.match(line)
+            dm = self._dict_re.match(line)
+            if len(spaces) == self._indent:
+                if lm and self._in_dict:
+                    # Starting a list in a dict
+                    self._push(list)
+                elif dm and self._in_list:
+                    # Left an embedded list
+                    self._stack.pop()
+
+            if len(spaces) > self._indent:
+                assert self._parent_key
+                if dm:
+                    # Nested dict
+                    self._push(dict, len(spaces))
+                elif lm:
+                    # Over-indented list in a dict
+                    self._push(list, len(spaces))
+
+            indent = self._indent
+            while lm and lm.group(2).startswith('- '):
+                # Nested lists
+                prefix, line = lm.groups()
+                indent += len(prefix)
+                self._push(list, indent)
+                lm = self._list_re.match(line)
+            del indent
+
             if lm:
-                assert isinstance(obj(), list) or parent_key
-                if isinstance(obj(), dict) and parent_key:
-                    # Starting a list in a dict
-                    stack.append((indent(), []))
-                    stack[-2][1][parent_key] = obj()
-                    parent_key = None
-            elif dm and isinstance(obj(), list):
-                # Left an embedded list
-                stack.pop()
+                prefix, line = lm.groups()
+                dm = self._dict_re.match(line)
+                if dm:
+                    self._push(dict, self._indent + len(prefix))
+                else:
+                    assert self._in_list
+                    self._container.append(line)
 
-        if len(spaces) > indent():
-            assert parent_key
             if dm:
-                # Nested dict
-                stack.append((len(spaces), {}))
-            elif lm:
-                # Over-indented list in a dict
-                stack.append((len(spaces), []))
-            stack[-2][1][parent_key] = obj()
-            parent_key = None
+                key, value = dm.groups()
+                if value:
+                    assert self._in_dict
+                    self._container[key] = value
+                else:
+                    self._parent_key = key
 
-        while lm and lm.group(2).startswith('- '):
-            # Nested lists
-            prefix, line = lm.groups()
-            stack.append((indent() + len(prefix), []))
-            stack[-2][1].append(obj())
-            lm = list_re.match(line)
-
-        if lm:
-            prefix, line = lm.groups()
-            dm = dict_re.match(line)
-            if dm:
-                stack.append((indent() + len(prefix), {}))
-                stack[-2][1].append(obj())
-            else:
-                obj().append(line)
-
-        if dm:
-            key, value = dm.groups()
-            if value:
-                obj()[key] = value
-            else:
-                parent_key = key
-
-    return stack[0][1]
+        return self._stack[0][1]