[rustc.git] / src / test / run-pass / html-literals.rs

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// A test of the macro system. Can we do HTML literals?

/*

This is an HTML parser written as a macro. It's all CPS, and we have
to carry around a bunch of state. The arguments to macros all look like this:

{ tag_stack* # expr* # tokens }

The stack keeps track of where we are in the tree. The expr is a list
of children of the current node. The tokens are everything that's
left.

*/
use HTMLFragment::{tag, text};

macro_rules! html {
    ( $($body:tt)* ) => (
        parse_node!( []; []; $($body)* )
    )
}

macro_rules! parse_node {
    (
        [:$head:ident ($(:$head_nodes:expr),*)
         $(:$tags:ident ($(:$tag_nodes:expr),*))*];
        [$(:$nodes:expr),*];
        </$tag:ident> $($rest:tt)*
    ) => (
        parse_node!(
            [$(: $tags ($(:$tag_nodes),*))*];
            [$(:$head_nodes,)* :tag(stringify!($head).to_string(),
                                    vec![$($nodes),*])];
            $($rest)*
        )
    );

    (
        [$(:$tags:ident ($(:$tag_nodes:expr),*) )*];
        [$(:$nodes:expr),*];
        <$tag:ident> $($rest:tt)*
    ) => (
        parse_node!(
            [:$tag ($(:$nodes)*) $(: $tags ($(:$tag_nodes),*) )*];
            [];
            $($rest)*
        )
    );

    (
        [$(:$tags:ident ($(:$tag_nodes:expr),*) )*];
        [$(:$nodes:expr),*];
        . $($rest:tt)*
    ) => (
        parse_node!(
            [$(: $tags ($(:$tag_nodes),*))*];
            [$(:$nodes,)* :text(".".to_string())];
            $($rest)*
        )
    );

    (
        [$(:$tags:ident ($(:$tag_nodes:expr),*) )*];
        [$(:$nodes:expr),*];
        $word:ident $($rest:tt)*
    ) => (
        parse_node!(
            [$(: $tags ($(:$tag_nodes),*))*];
            [$(:$nodes,)* :text(stringify!($word).to_string())];
            $($rest)*
        )
    );

    ( []; [:$e:expr]; ) => ( $e );
}

pub fn main() {
    let _page = html! (
        <html>
            <head><title>This is the title.</title></head>
            <body>
            <p>This is some text</p>
            </body>
        </html>
    );
}

enum HTMLFragment {
    tag(String, Vec<HTMLFragment> ),
    text(String),
}
Commit	Line	Data
223e47cc LB	1	// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
	2	// file at the top-level directory of this distribution and at
	3	// http://rust-lang.org/COPYRIGHT.
	4	//
	5	// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
	6	// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
	7	// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
	8	// option. This file may not be copied, modified, or distributed
	9	// except according to those terms.
	10
	11	// A test of the macro system. Can we do HTML literals?
	12
223e47cc LB	13	/*
	14
	15	This is an HTML parser written as a macro. It's all CPS, and we have
	16	to carry around a bunch of state. The arguments to macros all look like this:
	17
	18	{ tag_stack* # expr* # tokens }
	19
	20	The stack keeps track of where we are in the tree. The expr is a list
	21	of children of the current node. The tokens are everything that's
	22	left.
	23
	24	*/
1a4d82fc	25	use HTMLFragment::{tag, text};
223e47cc	26
1a4d82fc	27	macro_rules! html {
223e47cc LB	28	( $($body:tt)* ) => (
	29	parse_node!( []; []; $($body)* )
	30	)
1a4d82fc	31	}
223e47cc	32
1a4d82fc	33	macro_rules! parse_node {
223e47cc LB	34	(
	35	[:$head:ident ($(:$head_nodes:expr),*)
	36	$(:$tags:ident ($(:$tag_nodes:expr),))];
	37	[$(:$nodes:expr),*];
	38	</$tag:ident> $($rest:tt)*
	39	) => (
	40	parse_node!(
	41	[$(: $tags ($(:$tag_nodes),))];
1a4d82fc	42	[$(:$head_nodes,)* :tag(stringify!($head).to_string(),
c30ab7b3	43	vec![$($nodes),*])];
223e47cc LB	44	$($rest)*
	45	)
	46	);
	47
	48	(
	49	[$(:$tags:ident ($(:$tag_nodes:expr),) )];
	50	[$(:$nodes:expr),*];
	51	<$tag:ident> $($rest:tt)*
	52	) => (
	53	parse_node!(
	54	[:$tag ($(:$nodes)) $(: $tags ($(:$tag_nodes),) )*];
	55	[];
	56	$($rest)*
	57	)
	58	);
	59
	60	(
	61	[$(:$tags:ident ($(:$tag_nodes:expr),) )];
	62	[$(:$nodes:expr),*];
	63	. $($rest:tt)*
	64	) => (
	65	parse_node!(
	66	[$(: $tags ($(:$tag_nodes),))];
1a4d82fc	67	[$(:$nodes,)* :text(".".to_string())];
223e47cc LB	68	$($rest)*
	69	)
	70	);
	71
	72	(
	73	[$(:$tags:ident ($(:$tag_nodes:expr),) )];
	74	[$(:$nodes:expr),*];
	75	$word:ident $($rest:tt)*
	76	) => (
	77	parse_node!(
	78	[$(: $tags ($(:$tag_nodes),))];
1a4d82fc	79	[$(:$nodes,)* :text(stringify!($word).to_string())];
223e47cc LB	80	$($rest)*
	81	)
	82	);
	83
	84	( []; [:$e:expr]; ) => ( $e );
1a4d82fc	85	}
223e47cc LB	86
223e47cc LB	87	pub fn main() {
1a4d82fc	88	let _page = html! (
223e47cc LB	89	<html>
	90	<head><title>This is the title.</title></head>
	91	<body>
	92	<p>This is some text</p>
	93	</body>
	94	</html>
	95	);
	96	}
	97
	98	enum HTMLFragment {
1a4d82fc JJ	99	tag(String, Vec<HTMLFragment> ),
1a4d82fc JJ	100	text(String),
223e47cc	101	}