Struct Params 

pub struct Params(/* private fields */);

The parameters of a custom control kind, by name.

These are every field a manifest carried beside kind for a kind the library does not know, kept as data so the factory registered for the kind can read them. The accessors answer None when a parameter is absent or of another type, so a factory reports what it needed rather than guessing.

Examples

use pamoja_profile::{Param, Params};

let params = Params::new()
    .with("warn_below", 2.0)
    .with("latching", true)
    .with("zone", "north");
assert_eq!(params.number("warn_below"), Some(2.0));
assert_eq!(params.flag("latching"), Some(true));
assert_eq!(params.text("zone"), Some("north"));
assert_eq!(params.number("zone"), None);
assert_eq!(params.get("missing"), None);
assert!(matches!(params.get("zone"), Some(Param::Text(_))));

Implementations

impl Params

pub fn new() -> Self

Starts with no parameters.

Returns

An empty set.

pub fn with(self, name: impl Into<String>, value: impl Into<Param>) -> Self

Adds a parameter, replacing one of the same name.

Arguments

• name - the parameter’s name, as the manifest writes it.
• value - a number, a flag, or text.

Returns

The parameters, for chaining.

pub fn get(&self, name: &str) -> Option<&Param>

Looks a parameter up by name.

Arguments

• name - the parameter’s name.

Returns

The parameter, or None when the manifest carried none of that name.

pub fn number(&self, name: &str) -> Option<f64>

Reads a numeric parameter.

Arguments

• name - the parameter’s name.

Returns

The number, or None when the parameter is absent or not a number.

pub fn flag(&self, name: &str) -> Option<bool>

Reads a flag parameter.

Arguments

• name - the parameter’s name.

Returns

The flag, or None when the parameter is absent or not a flag.

pub fn text(&self, name: &str) -> Option<&str>

Reads a text parameter.

Arguments

• name - the parameter’s name.

Returns

The text, or None when the parameter is absent or not text.

pub fn from_json(text: &str) -> Result<Self>

Loads parameters from the JSON object a manifest carries beside a custom kind.

Arguments

• text - the JSON object.

Returns

The parameters.

Errors

Returns Error::Codec if the text is not an object of numbers, flags, and text.

pub fn to_json(&self) -> Result<String>

Writes the parameters as the JSON object a manifest carries beside a custom kind.

Returns

The JSON text, on one line.

Errors

Returns Error::Codec if the parameters cannot be serialized.

pub fn iter(&self) -> impl Iterator<Item = (&str, &Param)>

Walks the parameters in name order.

Returns

Each name with its parameter.

pub fn len(&self) -> usize

Counts the parameters.

Returns

How many the manifest carried.

pub fn is_empty(&self) -> bool

Whether there are no parameters.

Returns

true when the manifest carried only the kind.

Trait Implementations

impl Clone for Params

fn clone(&self) -> Params

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Params

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

Formats the value using the given formatter.

impl Default for Params

fn default() -> Params

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Params

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<BTreeMap<String, Param>> for Params

fn from(map: BTreeMap<String, Param>) -> Self

Converts to this type from the input type.

impl From<Params> for BTreeMap<String, Param>

fn from(params: Params) -> Self

Converts to this type from the input type.

impl PartialEq for Params

fn eq(&self, other: &Params) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for Params

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Params