Struct blather::types::params::Params

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pub struct Params { /* private fields */ }

Expand description

Key/value parameters storage with helper methods to make adding and getting common value types slightly more ergonomic and using a plain HashMap.

Uses Strings for both keys and values internally.

Implementations§

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impl Params

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pub fn new() -> Self

Create a new empty parameters object.

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pub fn clear(&mut self)

Reset all the key/values in Params object.

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pub fn len(&self) -> usize

Return the number of key/value pairs in the parameter buffer.

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pub fn is_empty(&self) -> bool

Returns true if the Params collection does not contain any key/value pairs.

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pub fn get_inner(&self) -> &HashMap<String, String>

Return reference to inner HashMap.

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pub fn add_param<T: ToString, U: ToString>( &mut self, key: T, value: U ) -> Result<(), Error>

Add a parameter to the parameter.

The key and value parameters are generic over the trait ToString, allowing a polymorphic behavior.

§Examples

use blather::Params;

let mut params = Params::new();
params.add_param("integer", 42).unwrap();
params.add_param("string", "hello").unwrap();

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pub fn add_str(&mut self, key: &str, value: &str) -> Result<(), Error>

Add a string parameter to the parameter.

§Notes

This method exists for parity with a C++ interface and is a less flexible version of add_param(), which application should use instead.

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pub fn add_strit<I, S>(&mut self, key: &str, c: I) -> Result<(), Error>
where I: IntoIterator<Item = S>, S: AsRef<str>,

Add parameter where the value is generated from an iterator over strings, where entries are comma-separated.

§Examples

use std::collections::HashSet;
use blather::Params;

let mut params = Params::new();

params.add_strit("Cat", &["meow", "paws", "tail"]).unwrap();
assert_eq!(params.get_str("Cat"), Some("meow,paws,tail"));

let v = vec!["meow", "paws", "tail"];
params.add_strit("CatToo", v.into_iter()).unwrap();
assert_eq!(params.get_str("CatToo"), Some("meow,paws,tail"));

let mut hs = HashSet::new();
hs.insert("Elena");
hs.insert("Drake");
params.add_strit("Uncharted", hs.into_iter()).unwrap();

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pub fn add_bool<K: ToString>( &mut self, key: K, value: bool ) -> Result<(), Error>

Add a boolean parameter.

§Examples

use blather::Params;

let mut params = Params::new();
params.add_bool("should_be_true", true).unwrap();
params.add_bool("should_be_false", false).unwrap();
assert_eq!(params.get_bool("should_be_true"), Ok(true));
assert_eq!(params.get_bool("should_be_false"), Ok(false));

§Notes

Applications should not make assumptions about the specific string value added by this function. Do not treat boolean values as strings; use the get_bool() method instead.

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pub fn have(&self, key: &str) -> bool

Returns true if the parameter with key exists. Returns false otherwise.

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pub fn get_param<T: FromStr>(&self, key: &str) -> Result<T, Error>

Get a parameter and convert it to a requested type, fail if key isn’t found.

§Examples

use blather::{Params, Error};

let mut params = Params::new();
params.add_param("arthur", 42);
let fourtytwo = params.get_param::<u32>("arthur").unwrap();
assert_eq!(fourtytwo, 42);
let nonexist = params.get_param::<u32>("ford");
assert_eq!(nonexist, Err(Error::KeyNotFound("ford".to_string())));

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pub fn get_param_def<T: FromStr>(&self, key: &str, def: T) -> Result<T, Error>

Get a parameter and convert it to a requested type, return a default value if key isn’t found.

§Examples

use blather::Params;

let mut params = Params::new();
let val = params.get_param_def::<u32>("nonexist", 11);
assert_eq!(val, Ok(11));

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pub fn get_str(&self, key: &str) -> Option<&str>

Get string representation of a value for a requested key. Returns None if the key is not found in the inner storage. Returns Some(&str) if parameter exists.

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pub fn get_str_def<'a>(&'a self, key: &str, def: &'a str) -> &'a str

Get string representation of a value for a requested key. Returns a default value if key does not exist in parameter buffer.

§Examples

use blather::Params;

let params = Params::new();
let e = params.get_str_def("nonexist", "elena");
assert_eq!(e, "elena");

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pub fn get_int<T: FromStr>(&self, key: &str) -> Result<T, Error>

Get a parameter and convert it to an integer type.

§Examples

use blather::Params;

let mut params = Params::new();
params.add_param("Num", 7);
assert_eq!(params.get_int::<usize>("Num").unwrap(), 7);

§Notes

This method exists primarily to achive some sort of parity with a corresponding C++ library. It is recommended that applications use Params::get_param() instead.

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pub fn get_int_def<T: FromStr>(&self, key: &str, def: T) -> Result<T, Error>

Try to get the value of a key and interpret it as an integer. If the key does not exist then return a default value supplied by the caller.

§Examples

use blather::Params;

let mut params = Params::new();
params.add_param("num", 11);
assert_eq!(params.get_int_def::<u32>("num", 5).unwrap(), 11);
assert_eq!(params.get_int_def::<u32>("nonexistent", 17).unwrap(), 17);

§Notes

It is recommended that application use Params::get_param_def() instead.

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pub fn get_bool(&self, key: &str) -> Result<bool, Error>

Get a boolean value; return error if key wasn’t found.

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pub fn get_bool_def(&self, key: &str, def: bool) -> Result<bool, Error>

Get a boolean value; return a default value if key wasn’t found.

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pub fn get_strvec(&self, key: &str) -> Result<Vec<String>, Error>

Parse the value of a key as a comma-separated list of strings and return it. Only non-empty entries are returned.

§Examples

use blather::Params;

let mut params = Params::new();
params.add_param("csv", "elena,chloe,drake");
let sv = params.get_strvec("csv").unwrap();
assert_eq!(sv, vec!["elena", "chloe", "drake"]);

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pub fn get_hashset(&self, key: &str) -> Result<HashSet<String>, Error>

Parse the value of a key as a comma-separated list of uniqie strings and return them in a HashSet. Only non-empty entries are returned.

§Examples

use blather::Params;

let mut params = Params::new();
params.add_param("set", "elena,chloe");
let set = params.get_hashset("set").unwrap();
assert_eq!(set.len(), 2);
assert_eq!(set.contains("elena"), true);
assert_eq!(set.contains("chloe"), true);
assert_eq!(set.contains("drake"), false);

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pub fn calc_buf_size(&self) -> usize

Calculate the size of the buffer in serialized form. Each entry will be a newline terminated utf-8 line. Last line will be a single newline character.

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