[PATCH v1 1/3] libcamera: yaml_parser: Add `YamlObject::find(key)`

[Barnabás Pőcze]

This function is meant to replace `YamlObject::contains()`
as it can be easily used for the same purpose, i.e. determining
if a certain key exists in a dictionary, but it has the advantage
that the result, if any, is immediately available for use
without having to do a second lookup.

Signed-off-by: Barnabás Pőcze <pobrn at protonmail.com>
---
 include/libcamera/internal/yaml_parser.h |  1 +
 src/libcamera/yaml_parser.cpp            | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/libcamera/internal/yaml_parser.h b/include/libcamera/internal/yaml_parser.h
index 8c791656..796e3e90 100644
--- a/include/libcamera/internal/yaml_parser.h
+++ b/include/libcamera/internal/yaml_parser.h
@@ -209,6 +209,7 @@ public:
 
 	bool contains(std::string_view key) const;
 	const YamlObject &operator[](std::string_view key) const;
+	const YamlObject *find(std::string_view key) const;
 
 private:
 	LIBCAMERA_DISABLE_COPY_AND_MOVE(YamlObject)
diff --git a/src/libcamera/yaml_parser.cpp b/src/libcamera/yaml_parser.cpp
index db256ec5..da8cb61f 100644
--- a/src/libcamera/yaml_parser.cpp
+++ b/src/libcamera/yaml_parser.cpp
@@ -397,6 +397,29 @@ const YamlObject &YamlObject::operator[](std::string_view key) const
 	return *iter->second;
 }
 
+/**
+ * \fn YamlObject::find(std::string_view key) const
+ * \brief Retrieve a member by name from the dictionary
+ *
+ * This function retrieves a member of a YamlObject by name. Only YamlObject
+ * instances of Dictionary type associate elements with names, calling this
+ * function on other types of instances or with a nonexistent key results in
+ * \a nullptr being returned.
+ *
+ * \return The YamlObject corresponding to the \a key member
+ */
+const YamlObject *YamlObject::find(std::string_view key) const
+{
+	if (type_ != Type::Dictionary)
+		return nullptr;
+
+	auto iter = dictionary_.find(key);
+	if (iter == dictionary_.end())
+		return nullptr;
+
+	return iter->second;
+}
+
 #ifndef __DOXYGEN__
 
 class YamlParserContext
-- 
2.47.1