Struct Schema 

pub struct Schema {
    pub args: Vec<ArgSpec>,
    pub options: BTreeMap<String, OptionSpec>,
    pub strict: bool,
    pub description: Option<String>,
    pub commands: BTreeMap<String, Schema>,
}

The schema declared inline in a sub-command’s fdl.yaml. Maps 1:1 to what <entry> --fdl-schema will later emit as JSON. deny_unknown_fields also applies to the --fdl-schema probe JSON: a schema emitted by a NEWER flodl-cli-macros than this fdl knows fails to parse rather than silently dropping the unknown field, and the probe layer falls back to the inline yml schema (or none) — help always renders (see schema_cache).

Fields

args: Vec<ArgSpec>

options: BTreeMap<String, OptionSpec>

strict: bool

When true, the fdl layer rejects options not declared in the schema before the sub-command’s entry ever runs. Two validation points:

1. Load time — preset options: maps are checked against the enclosing schema.options (see super::validation::validate_presets_strict). A typo like options: { batchsize: 32 } when the schema declares batch-size is a loud load error.
2. Dispatch time — the user’s extra argv tail is tokenized against the schema (see super::validation::validate_tail). Unknown flags error out with a “did you mean” suggestion instead of being silently forwarded.

Validation NOT gated by strict — always-on for declared items, so positive assertions from the schema always hold:

• choices: on options: the user’s value and any preset YAML value must be in the list.
• choices: on positional args: the user’s value must be in the list (when strict is off, this may mis-fire if unknown flags push orphan values into positional slots — opt into strict for clean positional handling).

strict is purely about unknown options/args, not about validating declared contracts.

description: Option<String>

One-line human description of this node. Usually unset for the root of a flat schema (help banners come from the binary’s struct doc); for a child under Self::commands it carries the subcommand’s summary (the enum variant’s doc-comment), rendered in the parent --help COMMANDS list.

commands: BTreeMap<String, Schema>

Sub-command tree. Empty for a leaf — the common case: a single #[derive(FdlArgs)] struct. Non-empty for a variant-shaped CLI (#[derive(FdlArgs)] on an enum of newtype variants), where each key is a subcommand name and each value is that subcommand’s own schema.

A node is either a leaf (args / options) or a branch (commands), never both — enforced by validate_schema. The shape mirrors the recursive commands: map already used by CommandConfig/super::ProjectConfig at the yaml layer.

Trait Implementations

impl Clone for Schema

fn clone(&self) -> Schema

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Schema

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Schema

fn default() -> Schema

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Schema

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Schema

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.