From ebbd5d2e548a857740137e4c08b3914726dbcfbc Mon Sep 17 00:00:00 2001
From: Chris Wong <lambda.fairy@gmail.com>
Date: Mon, 7 Sep 2015 19:43:48 +1200
Subject: [PATCH] Add a `write_html!` macro
This handles the common case of wrapping the stream in a `Utf8Writer`.
---
maud_macros/src/lib.rs | 62 ++++++++++++++++++++++++++++----------
maud_macros/src/parse.rs | 11 ++++---
maud_macros/tests/tests.rs | 9 ++----
3 files changed, 55 insertions(+), 27 deletions(-)
diff --git a/maud_macros/src/lib.rs b/maud_macros/src/lib.rs
index 2f27d9b..09253d2 100644
--- a/maud_macros/src/lib.rs
+++ b/maud_macros/src/lib.rs
@@ -7,35 +7,65 @@ extern crate syntax;
extern crate rustc;
extern crate maud;
-use syntax::ast::TokenTree;
-use syntax::codemap::Span;
+use syntax::ast::{Expr, TokenTree, TtToken};
+use syntax::codemap::{DUMMY_SP, Span};
use syntax::ext::base::{ExtCtxt, MacEager, MacResult};
+use syntax::parse::token;
use syntax::print::pprust;
+use syntax::ptr::P;
use rustc::plugin::Registry;
mod parse;
mod render;
-fn expand_html_common<'cx>(cx: &'cx mut ExtCtxt, sp: Span, args: &[TokenTree],
- debug: bool) -> Box<MacResult + 'cx> {
- let expr = parse::parse(cx, args, sp);
- if debug {
- cx.span_note(sp, &format!("expansion:\n{}",
- pprust::expr_to_string(&expr)));
+fn _expand_html(cx: &mut ExtCtxt, sp: Span, args: &[TokenTree]) -> P<Expr> {
+ let (write, input) = parse::split_comma(cx, sp, args);
+ parse::parse(cx, sp, write, input)
+}
+
+fn _expand_write_html(cx: &mut ExtCtxt, sp: Span, args: &[TokenTree]) -> P<Expr> {
+ let (io_write, input) = parse::split_comma(cx, sp, args);
+ let io_write = io_write.to_vec();
+ let fmt_write = token::gensym_ident("__maud_utf8_writer");
+ let fmt_write = vec![
+ TtToken(DUMMY_SP, token::Ident(fmt_write, token::IdentStyle::Plain))];
+ let expr = parse::parse(cx, sp, &fmt_write, input);
+ quote_expr!(cx,
+ match ::maud::Utf8Writer::new(&mut $io_write) {
+ mut $fmt_write => {
+ let _ = $expr;
+ $fmt_write.into_result()
+ }
+ })
+}
+
+macro_rules! expand {
+ ($name:ident $debug_name:ident $inner_fn:ident) => {
+ fn $name<'cx>(cx: &'cx mut ExtCtxt, sp: Span, args: &[TokenTree])
+ -> Box<MacResult + 'cx>
+ {
+ let expr = $inner_fn(cx, sp, args);
+ MacEager::expr(expr)
+ }
+
+ fn $debug_name<'cx>(cx: &'cx mut ExtCtxt, sp: Span, args: &[TokenTree])
+ -> Box<MacResult + 'cx>
+ {
+ let expr = $inner_fn(cx, sp, args);
+ cx.span_note(sp, &format!("expansion:\n{}",
+ pprust::expr_to_string(&expr)));
+ MacEager::expr(expr)
+ }
}
- MacEager::expr(expr)
}
-fn expand_html<'cx>(cx: &'cx mut ExtCtxt, sp: Span, args: &[TokenTree]) -> Box<MacResult + 'cx> {
- expand_html_common(cx, sp, args, false)
-}
-
-fn expand_html_debug<'cx>(cx: &'cx mut ExtCtxt, sp: Span, args: &[TokenTree]) -> Box<MacResult + 'cx> {
- expand_html_common(cx, sp, args, true)
-}
+expand!(expand_html expand_html_debug _expand_html);
+expand!(expand_write_html expand_write_html_debug _expand_write_html);
#[plugin_registrar]
pub fn plugin_registrar(reg: &mut Registry) {
reg.register_macro("html", expand_html);
reg.register_macro("html_debug", expand_html_debug);
+ reg.register_macro("write_html", expand_write_html);
+ reg.register_macro("write_html_debug", expand_write_html_debug);
}
diff --git a/maud_macros/src/parse.rs b/maud_macros/src/parse.rs
index 7250698..ac5034e 100644
--- a/maud_macros/src/parse.rs
+++ b/maud_macros/src/parse.rs
@@ -42,8 +42,9 @@ macro_rules! ident {
($sp:pat, $x:pat) => (TtToken($sp, token::Ident($x, token::IdentStyle::Plain)))
}
-pub fn parse(cx: &ExtCtxt, input: &[TokenTree], sp: Span) -> P<Expr> {
- let (write, input) = split_comma(cx, input, sp);
+pub fn parse(cx: &ExtCtxt, sp: Span, write: &[TokenTree], input: &[TokenTree])
+ -> P<Expr>
+{
let mut parser = Parser {
in_attr: false,
input: input,
@@ -54,15 +55,15 @@ pub fn parse(cx: &ExtCtxt, input: &[TokenTree], sp: Span) -> P<Expr> {
parser.into_render().into_expr(write.to_vec())
}
-fn split_comma<'a>(cx: &ExtCtxt, input: &'a [TokenTree], sp: Span) -> (&'a [TokenTree], &'a [TokenTree]) {
+pub fn split_comma<'a>(cx: &ExtCtxt, sp: Span, args: &'a [TokenTree]) -> (&'a [TokenTree], &'a [TokenTree]) {
fn is_comma(t: &TokenTree) -> bool {
match *t {
TtToken(_, token::Comma) => true,
_ => false,
}
}
- match input.iter().position(is_comma) {
- Some(i) => (&input[..i], &input[1+i..]),
+ match args.iter().position(is_comma) {
+ Some(i) => (&args[..i], &args[1+i..]),
None => cx.span_fatal(sp, "expected two arguments to `html!`"),
}
}
diff --git a/maud_macros/tests/tests.rs b/maud_macros/tests/tests.rs
index a1f0eb1..6568bc8 100644
--- a/maud_macros/tests/tests.rs
+++ b/maud_macros/tests/tests.rs
@@ -250,11 +250,8 @@ mod control {
}
#[test]
-fn utf8_writer() {
- use maud::Utf8Writer;
- let mut w = Utf8Writer::new(vec![]);
- let _ = html!(w, p "hello");
- let (buf, r) = w.into_inner();
- r.unwrap();
+fn write_html() {
+ let mut buf = vec![];
+ write_html!(buf, p "hello").unwrap();
assert_eq!(buf, b"<p>hello</p>");
}