Module yaml 

Format-preserving YAML editing for app.yaml.

Serializing a serde_yaml::Value back to a string drops the user’s formatting (comments, key order, blank lines, quoting). apply_app_config_to_yaml instead edits the original text in place with [yaml_edit], rewriting only the nodes whose value changed.

Functions

apply_app_config_to_yaml 🔒

Apply target onto the original app YAML text, preserving the formatting of everything that did not change.

apply_app_config_to_yaml_file 🔒

Convenience wrapper: read the original text from path, apply target onto it, and return the format-preserved result. If the file does not exist or cannot be read, falls back to a plain serialization of target.

leading_trivia 🔒

Return the leading run of blank and comment-only lines at the top of text.

merge_into_mapping 🔒

Recursively merge target into mapping, using original (the semantic parse of the same subtree) to skip unchanged keys. remove_missing (true only at the top level) drops keys absent from target.

scalar_key 🔒

Extract a scalar mapping key as a string. Non-scalar keys are skipped.

scalar_key_node 🔒

set_value 🔒

Set mapping[key] = value. Only scalars are supported: yaml_edit incorrectly renders block values when setting them (as of 0.2, #6803), so structured values error out and the caller falls back to a plain rewrite.

stale_top_level_keys 🔒

try_format_preserving_edit 🔒