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Use operator sugar in the expansion of #[deriving(PartialEq)]

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This commit is contained in:
Jorge Aparicio 2014-10-29 18:31:41 -05:00
parent 63c4f22f2b
commit 88ed2d1c41
1 changed files with 31 additions and 5 deletions
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36
src/libsyntax/ext/deriving/cmp/eq.rs
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@ -8,7 +8,7 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use ast::{MetaItem, Item, Expr};
use ast::{MetaItem, Item, Expr, mod};
use codemap::Span;
use ext::base::ExtCtxt;
use ext::build::AstBuilder;
@ -25,12 +25,38 @@ pub fn expand_deriving_eq(cx: &mut ExtCtxt,
// structures are equal if all fields are equal, and non equal, if
// any fields are not equal or if the enum variants are different
fn cs_eq(cx: &mut ExtCtxt, span: Span, substr: &Substructure) -> P<Expr> {
cs_and(|cx, span, _, _| cx.expr_bool(span, false),
cx, span, substr)
cs_fold(
true, // use foldl
|cx, span, subexpr, self_f, other_fs| {
let other_f = match other_fs {
[ref o_f] => o_f,
_ => cx.span_bug(span, "not exactly 2 arguments in `deriving(Eq)`")
};
let eq = cx.expr_binary(span, ast::BiEq, self_f, other_f.clone());
cx.expr_binary(span, ast::BiAnd, subexpr, eq)
},
cx.expr_bool(span, true),
|cx, span, _, _| cx.expr_bool(span, false),
cx, span, substr)
}
fn cs_ne(cx: &mut ExtCtxt, span: Span, substr: &Substructure) -> P<Expr> {
cs_or(|cx, span, _, _| cx.expr_bool(span, true),
cx, span, substr)
cs_fold(
true, // use foldl
|cx, span, subexpr, self_f, other_fs| {
let other_f = match other_fs {
[ref o_f] => o_f,
_ => cx.span_bug(span, "not exactly 2 arguments in `deriving(Eq)`")
};
let eq = cx.expr_binary(span, ast::BiNe, self_f, other_f.clone());
cx.expr_binary(span, ast::BiOr, subexpr, eq)
},
cx.expr_bool(span, false),
|cx, span, _, _| cx.expr_bool(span, true),
cx, span, substr)
}
macro_rules! md (