_yaml: Introduce 'MappingNode.values()'

This is to mimic the 'dict.values()' interface.

- Adapt parts of the code calling 'node_items' but ignoring the
first value to use this instead

5 files changed, 17 insertions, 9 deletions

diff --git a/src/buildstream/_context.py b/src/buildstream/_context.py
index 21c272daa..cc31e982a 100644
--- a/src/buildstream/_context.py
+++ b/src/buildstream/_context.py
@@ -313,7 +313,7 @@ class Context():
 
         # Shallow validation of overrides, parts of buildstream which rely
         # on the overrides are expected to validate elsewhere.
-        for _, overrides in _yaml.node_items(self._project_overrides):
+        for overrides in self._project_overrides.values():
             _yaml.node_validate(overrides,
                                 ['artifacts', 'source-caches', 'options',
                                  'strict', 'default-mirror',
diff --git a/src/buildstream/_includes.py b/src/buildstream/_includes.py
index f63e56213..ea2bf484e 100644
--- a/src/buildstream/_includes.py
+++ b/src/buildstream/_includes.py
@@ -83,7 +83,7 @@ class Includes:
 
                 _yaml.composite_and_move(node, include_node)
 
-        for _, value in _yaml.node_items(node):
+        for value in node.values():
             self._process_value(value,
                                 included=included,
                                 current_loader=current_loader,
@@ -129,12 +129,14 @@ class Includes:
                        included=set(),
                        current_loader=None,
                        only_local=False):
-        if _yaml.is_node(value):
+        value_type = type(value)
+
+        if value_type is _yaml.MappingNode:
             self.process(value,
                          included=included,
                          current_loader=current_loader,
                          only_local=only_local)
-        elif isinstance(value, list):
+        elif value_type is _yaml.SequenceNode:
             for v in value:
                 self._process_value(v,
                                     included=included,
diff --git a/src/buildstream/_options/optionpool.py b/src/buildstream/_options/optionpool.py
index 23459d3c5..af0f99b97 100644
--- a/src/buildstream/_options/optionpool.py
+++ b/src/buildstream/_options/optionpool.py
@@ -185,10 +185,11 @@ class OptionPool():
         # Now recurse into nested dictionaries and lists
         # and process any indirectly nested conditionals.
         #
-        for _, value in _yaml.node_items(node):
-            if _yaml.is_node(value):
+        for value in node.values():
+            value_type = type(value)
+            if value_type is _yaml.MappingNode:
                 self.process_node(value)
-            elif isinstance(value, list):
+            elif value_type is _yaml.SequenceNode:
                 self._process_list(value)
 
     #######################################################
@@ -237,9 +238,10 @@ class OptionPool():
     #
     def _process_list(self, values):
         for value in values:
-            if _yaml.is_node(value):
+            value_type = type(value)
+            if value_type is _yaml.MappingNode:
                 self.process_node(value)
-            elif isinstance(value, list):
+            elif value_type is _yaml.SequenceNode:
                 self._process_list(value)
 
     # Process a single conditional, resulting in composition
diff --git a/src/buildstream/_yaml.pxd b/src/buildstream/_yaml.pxd
index b20c798de..e80df7115 100644
--- a/src/buildstream/_yaml.pxd
+++ b/src/buildstream/_yaml.pxd
@@ -41,6 +41,7 @@ cdef class MappingNode(Node):
     cpdef str get_str(self, str key, object default=*)
     cpdef list keys(self)
     cpdef void safe_del(self, str key)
+    cpdef object values(self)
 
 
 cdef class ScalarNode(Node):
diff --git a/src/buildstream/_yaml.pyx b/src/buildstream/_yaml.pyx
index a3692c455..e3d3f7df3 100644
--- a/src/buildstream/_yaml.pyx
+++ b/src/buildstream/_yaml.pyx
@@ -241,6 +241,9 @@ cdef class MappingNode(Node):
         except KeyError:
             pass
 
+    cpdef object values(self):
+        return self.value.values()
+
     def __delitem__(self, str key):
         del self.value[key]