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FAR

Find And Replace string template engine

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Overview

Provided with a template and a map, FAR will attempt to find all the keys (delimited with {{ and }}) in the template and replace them with the corresponding value in the map. By default, map values are rendered by their Display impl. For example:

let template = "{{specific}} are my favorite {{category}}.";

#[derive(Render)]
struct Replacements {
    specific: String,
    category: String,
}

let found = find(template)?;

let replacements = Replacements {
    specific: "Cats".to_owned(),
    category: "animal".to_owned(),
};

let s = found.replace(&replacements);

assert_eq!(s, "Cats are my favorite animal.");

If it fails for some reason, an explanation of why will be returned:

// Note the typo ----------------------------> vvvvvvvv
let template = "{{specific}} are my favorite {{catglory}}.";

#[derive(Debug, Render)]
struct Replacements {
    specific: String,
    category: String,
}

let errors = find::<_, Replacements>(template).unwrap_err();

assert_eq!(
    format!("{}", errors),
    r#"missing key "category", extraneous key "catglory""#
);

Template authors can write {{{{}} or {{}}}} to get a literal {{ or }} respectively.

Additional examples and weird edge-case behaviors can be found in core/src/tests.

License

This project is licensed under either of

at your option.

Structs

Errors that occured while finding and replacing

A cached template

Enums

A single specific error

Strictness setting for parsing templates

Traits

A type whose contents can be rendered into a template

Functions

Find placeholder keys in a string and produce a cached template

find, but with control over what causes an error

Derive Macros

Automatically implement Render