Expand description
§beard
In opposition to mustache. Here the goal instead of mustache is to leverage as much as possible rust’s type system to detect error case and therefor to make the rendering deterministic. If you are looking for something that is going to be portable outside of rust you should checkout mustache.
beard
is a macro that will generate the necessary rust code
to serialise the given template. You can achieve the same thing
by writing the code yourself (calling std::io::Write appropriate
methods). beard
is simply an help to do that and to make it
easier to maintain the templates.
§How it works
§string literals
Any string literal will be written as is in the output.
use beard::beard;
beard! {
output,
"List of items:\n"
"\n"
"* item 1\n"
"* item 2\n"
};
§serialising any impl of Display
You can intersperse serialised object that implements std::fmt::Display
,
just use the curly bracket as you would if you were to use in
std::format
macro, except outside of the string.
Interestingly it can also do any kind of operations within the brackets
so long it returns something that implements std::fmt::Display
.
use beard::beard;
let value = 42;
beard! {
output,
{ value } "\n"
{ 1 + 2 } "\n"
};
§serialising array of bytes
In case the value is already an array and there is no need to run
std::fmt::Display
’s formatting to String
as intermediate.
use beard::beard;
let value = b"some array";
beard! {
output,
[{ value }] "\n"
};
§Calling function to serialize
Would you need to perform some operation with the std::io::Write
object you can capture the variable by calling a lambda (it’s not
really one).
use beard::beard;
let value = b"some array";
beard! {
output,
|| {
// do other operations
output.write_all(b"some bytes")?;
}
};
§if
and if let
statement
There are times where one needs to serialize or not some parts.
use beard::beard;
let value = false;
let optional = Some("something");
beard! {
output,
if (value) {
"Value is true\n"
} else {
"Value is false\n"
}
"Or do some pattern matching\n"
if let Some(value) = (optional) {
"We have " { value } "\n"
}
};
§for
loop, iterating on items
Shall you need to print the items of a list or anything that
implements std::iter::IntoIterator
.
use beard::beard;
let shopping_list = ["apple", "pasta", "tomatoes", "garlic", "mozzarella"];
beard! {
output,
"Shopping list\n"
"\n"
for (index, item) in (shopping_list.iter().enumerate()) {
{index} ". " { item } "\n"
}
};
§Example
use beard::beard;
let name = "Arthur";
let list = ["Bubble Bath", "Unicorn Crunchy Oat"];
beard! {
output,
"Hi " { name } "\n"
"\n"
"Confirmation order about the following items:\n"
for item in ( list ) {
" * " { item } "\n"
}
"\n"
"Your order will be ship to you once everything is ready.\n"
};
The Example below will generate a string in the output
:
Hi Arthur
Confirmation order about the following items:
* Bubble Bath
* Unicorn Crunch Oat
Your order will be ship to you once everything is ready.
Macros§
- macro to call to generate the function stream of generating formatted output.