Module genco::tokens

Expand description

Utilities for working with token streams.

This is typically a module you will use if you intend to provide a manual implementation of FormatInto.

Examples

use genco::quote_in;
use genco::tokens::{from_fn, ItemStr, FormatInto, static_literal};
use genco::lang::Lang;

/// Format a block comment, starting with `/**`, and ending in `*/`.
pub fn block_comment<I, L>(text: I) -> impl FormatInto<L>
where
    I: IntoIterator,
    I::Item: Into<ItemStr>,
    L: Lang,
{
    from_fn(move |t| {
        let mut it = text.into_iter().peekable();

        if it.peek().is_some() {
            quote_in! { *t =>
                #(static_literal("/**"))
                #(for line in it join (#<push>) {
                    #<space>* #(line.into())
                })
                #<space>#(static_literal("*/"))
            }
        }
    })
}

use genco::prelude::*;

let tokens: java::Tokens = quote! {
    #(block_comment(&["This class is used for awesome stuff", "ok?"]))
    public static class Foo {
    }
};

assert_eq!(
    vec![
        "/**",
        " * This class is used for awesome stuff",
        " * ok?",
        " */",
        "public static class Foo {",
        "}"
    ],
    tokens.to_vec()?
);