From a530d73d25b025117a1c56ebf0097fd11e63551e Mon Sep 17 00:00:00 2001
From: Chris Wong <lambda.fairy@gmail.com>
Date: Sat, 14 Mar 2015 21:08:08 +1300
Subject: [PATCH] Implement `for` expressions
---
maud_macros/src/parse.rs | 37 +++++++++++++++++++++++++++++++++++++
maud_macros/src/render.rs | 7 ++++++-
maud_macros/tests/tests.rs | 16 ++++++++++++++++
3 files changed, 59 insertions(+), 1 deletion(-)
diff --git a/maud_macros/src/parse.rs b/maud_macros/src/parse.rs
index bc2a948..26c1460 100644
--- a/maud_macros/src/parse.rs
+++ b/maud_macros/src/parse.rs
@@ -102,6 +102,11 @@ impl<'cx, 's, 'i> Parser<'cx, 's, 'i> {
self.shift(2);
self.if_expr(sp);
},
+ // For
+ [dollar!(), ident!(sp, name), ..] if name.as_str() == "for" => {
+ self.shift(2);
+ self.for_expr(sp);
+ },
// Splice
[ref tt @ dollar!(), dollar!(), ..] => {
self.shift(2);
@@ -192,6 +197,38 @@ impl<'cx, 's, 'i> Parser<'cx, 's, 'i> {
self.render.emit_if(if_cond, if_body, else_body);
}
+ fn for_expr(&mut self, sp: Span) {
+ let mut pattern = vec![];
+ loop { match self.input {
+ [ident!(in_), ..] if in_.as_str() == "in" => {
+ self.shift(1);
+ break;
+ },
+ [ref tt, ..] => {
+ self.shift(1);
+ pattern.push(tt.clone());
+ },
+ _ => self.render.cx.span_fatal(sp, "invalid $for"),
+ }}
+ let pattern = self.new_rust_parser(pattern).parse_pat();
+ let mut iterable = vec![];
+ let body;
+ loop { match self.input {
+ [TtDelimited(sp, ref d), ..] if d.delim == DelimToken::Brace => {
+ self.shift(1);
+ body = self.block(sp, &d.tts);
+ break;
+ },
+ [ref tt, ..] => {
+ self.shift(1);
+ iterable.push(tt.clone());
+ },
+ _ => self.render.cx.span_fatal(sp, "invalid $for"),
+ }}
+ let iterable = self.new_rust_parser(iterable).parse_expr();
+ self.render.emit_for(pattern, iterable, body);
+ }
+
fn splice(&mut self, sp: Span) -> P<Expr> {
let mut tts = vec![];
// First, munch a single token tree
diff --git a/maud_macros/src/render.rs b/maud_macros/src/render.rs
index f415950..20b9810 100644
--- a/maud_macros/src/render.rs
+++ b/maud_macros/src/render.rs
@@ -1,4 +1,4 @@
-use syntax::ast::{Expr, Ident, Stmt};
+use syntax::ast::{Expr, Ident, Pat, Stmt};
use syntax::ext::base::ExtCtxt;
use syntax::ext::build::AstBuilder;
use syntax::parse::token;
@@ -135,4 +135,9 @@ impl<'cx, 's> Renderer<'cx, 's> {
};
self.stmts.push(stmt);
}
+
+ pub fn emit_for(&mut self, pattern: P<Pat>, iterable: P<Expr>, body: Vec<P<Stmt>>) {
+ let stmt = quote_stmt!(self.cx, for $pattern in $iterable { $body });
+ self.stmts.push(stmt);
+ }
}
diff --git a/maud_macros/tests/tests.rs b/maud_macros/tests/tests.rs
index d322049..4ce1763 100644
--- a/maud_macros/tests/tests.rs
+++ b/maud_macros/tests/tests.rs
@@ -201,4 +201,20 @@ mod control {
assert_eq!(s, name);
}
}
+
+ #[test]
+ fn for_expr() {
+ let ponies = ["Apple Bloom", "Scootaloo", "Sweetie Belle"];
+ let s = html! {
+ ul $for pony in &ponies {
+ li $pony
+ }
+ }.to_string();
+ assert_eq!(s, concat!(
+ "<ul>",
+ "<li>Apple Bloom</li>",
+ "<li>Scootaloo</li>",
+ "<li>Sweetie Belle</li>",
+ "</ul>"));
+ }
}