interpolator

Runtime implementation of format!.

format

Runtime version of format!.

Takes a string and a context, containing Formattable values, returns a string.

use std::collections::HashMap;use template::{format,Formattable};let formatted = format("{value:+05}",// could be dynamic&[("value",Formattable::display(&12))].into_iter().collect::<HashMap<_,_>>(),).unwrap();assert_eq!(formatted, format!("{:+05}",12));

write

Runtime version of write!.

Takes a mutable Write e.g. &mut String, a format string and a context, containing Formattable values.

use std::collections::HashMap;use template::{write,Formattable};letmut buf = String::new();write(&mut buf,"{value:+05}",// could be dynamic&[("value",Formattable::display(&12))].into_iter().collect::<HashMap<_,_>>(),).unwrap();assert_eq!(buf, format!("{:+05}",12));

i iter format

The feature iter enables an additional format trait i, it allows to format a list of values with a format string and an optional join expression.

The syntax is {list:i(the format string, '{}' is the array element)(the join)}, an empty join can also be omitted {list:i({})}. If join is omitted the format string {} can be omitted as well {list:i}.

Should you need to use ) inside your format string or join, you can add # similar to rust's raw string (i.e. #(({}))#).

It is also possible to only iterate a sub-slice specified through a range before the format string, i.e. {list:i1..4}. For open ranges range bounds can also be omitted. To index from the end, you can use negative range bounds.

It is also possible to index a single value by only specifying an isize{list:i1}.

A Formattable implementing iter is created using Formattable::iter:

// HashMap macrouse collection_literals::hash;use interpolator::{format,Formattable};// Needs to be a slice of references because `Formattable::display` expects a// referencelet items = [&"hello",&"hi",&"hey"].map(Formattable::display);let items = Formattable::iter(&items);let format_str = "Greetings: {items:i..-1(`{it}`)(, )} and {items:i-1..(`{it}`)}";assert_eq!(
format(format_str,&hash!("items" => items))?,"Greetings: `hello`, `hi` and `hey`");
# returnOk::<(), interpolator::Error>(())

Features

By default only Display is supported, the rest of the formatting traits can be enabled through the following features.

• debug enables ?, x? and X? trait specifiers
• number enables x, X, b, o, e and E trait specifiers
• pointer enables p trait specifiers
• iter enables i trait specifier