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// Copyright 2012-2013 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.
use ast::{meta_item, item, expr};
use codemap::span;
use ext::base::ext_ctxt;
use ext::build;
use ext::deriving::generic::*;
pub fn expand_deriving_clone(cx: @ext_ctxt,
span: span,
mitem: @meta_item,
in_items: ~[@item])
-> ~[@item] {
let trait_def = TraitDef {
path: Path::new(~[~"core", ~"clone", ~"Clone"]),
additional_bounds: ~[],
generics: LifetimeBounds::empty(),
methods: ~[
MethodDef {
name: ~"clone",
generics: LifetimeBounds::empty(),
self_ty: borrowed_explicit_self(),
args: ~[],
ret_ty: Self,
const_nonmatching: false,
combine_substructure: cs_clone
}
]
};
expand_deriving_generic(cx, span,
mitem, in_items,
&trait_def)
}
pub fn expand_deriving_obsolete(cx: @ext_ctxt,
span: span,
_mitem: @meta_item,
in_items: ~[@item])
-> ~[@item] {
cx.span_err(span, ~"`#[deriving_clone]` is obsolete; use `#[deriving(Clone)]` instead");
in_items
}
fn cs_clone(cx: @ext_ctxt, span: span,
substr: &Substructure) -> @expr {
let clone_ident = substr.method_ident;
let ctor_ident;
let all_fields;
let subcall = |field|
build::mk_method_call(cx, span, field, clone_ident, ~[]);
match *substr.fields {
Struct(ref af) => {
ctor_ident = ~[ substr.type_ident ];
all_fields = af;
}
EnumMatching(_, variant, ref af) => {
ctor_ident = ~[ variant.node.name ];
all_fields = af;
},
EnumNonMatching(*) => cx.span_bug(span, "Non-matching enum variants in `deriving(Clone)`"),
StaticEnum(*) | StaticStruct(*) => cx.span_bug(span, "Static method in `deriving(Clone)`")
}
match *all_fields {
[(None, _, _), .. _] => {
// enum-like
let subcalls = all_fields.map(|&(_, self_f, _)| subcall(self_f));
build::mk_call(cx, span, ctor_ident, subcalls)
},
_ => {
// struct-like
let fields = do all_fields.map |&(o_id, self_f, _)| {
let ident = match o_id {
Some(i) => i,
None => cx.span_bug(span,
~"unnamed field in normal struct \
in `deriving(Clone)`")
};
build::Field { ident: ident, ex: subcall(self_f) }
};
if fields.is_empty() {
// no fields, so construct like `None`
build::mk_path(cx, span, ctor_ident)
} else {
build::mk_struct_e(cx, span,
ctor_ident,
fields)
}
}
}
}
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