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syntax: correct the modifications to deriving(Ord) so that it works.

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This commit is contained in:
Huon Wilson 2013-06-07 21:53:04 +10:00
parent ebf7281b7b
commit a965f4981a
1 changed files with 13 additions and 30 deletions
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43
src/libsyntax/ext/deriving/cmp/ord.rs
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@ -22,7 +22,7 @@ pub fn expand_deriving_ord(cx: @ExtCtxt,
mitem: @meta_item,
in_items: ~[@item]) -> ~[@item] {
macro_rules! md (
($name:expr, $func:expr, $op:expr) => {
($name:expr, $op:expr, $equal:expr) => {
MethodDef {
name: $name,
generics: LifetimeBounds::empty(),
@ -30,7 +30,7 @@ pub fn expand_deriving_ord(cx: @ExtCtxt,
args: ~[borrowed_self()],
ret_ty: Literal(Path::new(~["bool"])),
const_nonmatching: false,
combine_substructure: |cx, span, substr| $func($op, cx, span, substr)
combine_substructure: |cx, span, substr| cs_op($op, $equal, cx, span, substr)
}
}
);
@ -40,17 +40,17 @@ pub fn expand_deriving_ord(cx: @ExtCtxt,
additional_bounds: ~[],
generics: LifetimeBounds::empty(),
methods: ~[
md!("lt", cs_strict, true),
md!("le", cs_nonstrict, true), // inverse operation
md!("gt", cs_strict, false),
md!("ge", cs_nonstrict, false)
md!("lt", true, false),
md!("le", true, true),
md!("gt", false, false),
md!("ge", false, true)
]
};
trait_def.expand(cx, span, mitem, in_items)
}
/// Strict inequality.
fn cs_strict(less: bool, cx: @ExtCtxt, span: span, substr: &Substructure) -> @expr {
fn cs_op(less: bool, equal: bool, cx: @ExtCtxt, span: span, substr: &Substructure) -> @expr {
let op = if less {ast::lt} else {ast::gt};
cs_fold(
false, // need foldr,
@ -81,16 +81,15 @@ fn cs_strict(less: bool, cx: @ExtCtxt, span: span, substr: &Substructure) -> @ex
cx.expr_deref(span, self_f),
cx.expr_deref(span, other_f));
let not_cmp = cx.expr_binary(span, op,
cx.expr_deref(span, other_f),
cx.expr_deref(span, self_f));
let not_cmp = cx.expr_unary(span, ast::not, not_cmp);
let not_cmp = cx.expr_unary(span, ast::not,
cx.expr_binary(span, op,
cx.expr_deref(span, other_f),
cx.expr_deref(span, self_f)));
let and = cx.expr_binary(span, ast::and,
not_cmp, subexpr);
let and = cx.expr_binary(span, ast::and, not_cmp, subexpr);
cx.expr_binary(span, ast::or, cmp, and)
},
cx.expr_bool(span, false),
cx.expr_bool(span, equal),
|cx, span, args, _| {
// nonmatching enums, order by the order the variants are
// written
@ -108,19 +107,3 @@ fn cs_strict(less: bool, cx: @ExtCtxt, span: span, substr: &Substructure) -> @ex
},
cx, span, substr)
}
fn cs_nonstrict(less: bool, cx: @ExtCtxt, span: span, substr: &Substructure) -> @expr {
// Example: ge becomes !(*self < *other), le becomes !(*self > *other)
let inverse_op = if less {ast::gt} else {ast::lt};
match substr.self_args {
[self_, other] => {
let inverse_cmp = cx.expr_binary(span, inverse_op,
cx.expr_deref(span, self_),
cx.expr_deref(span, other));
cx.expr_unary(span, ast::not, inverse_cmp)
}
_ => cx.span_bug(span, "Not exactly 2 arguments in `deriving(Ord)`")
}
}