// except according to those terms.
/*!
-The compiler code necessary for #[deriving(Decodable)]. See
+The compiler code necessary for `#[deriving(Decodable)]`. See
encodable.rs for more.
*/
+use ast;
use ast::{MetaItem, Item, Expr, MutMutable, Ident};
use codemap::Span;
use ext::base::ExtCtxt;
use parse::token::InternedString;
use parse::token;
-pub fn expand_deriving_decodable(cx: &ExtCtxt,
+pub fn expand_deriving_decodable(cx: &mut ExtCtxt,
span: Span,
mitem: @MetaItem,
- in_items: ~[@Item]) -> ~[@Item] {
+ item: @Item,
+ push: |@Item|) {
let trait_def = TraitDef {
- cx: cx, span: span,
-
- path: Path::new_(~["serialize", "Decodable"], None,
- ~[~Literal(Path::new_local("__D"))], true),
- additional_bounds: ~[],
+ span: span,
+ attributes: Vec::new(),
+ path: Path::new_(vec!("serialize", "Decodable"), None,
+ vec!(~Literal(Path::new_local("__D")),
+ ~Literal(Path::new_local("__E"))), true),
+ additional_bounds: Vec::new(),
generics: LifetimeBounds {
- lifetimes: ~[],
- bounds: ~[("__D", ~[Path::new(~["serialize", "Decoder"])])],
+ lifetimes: Vec::new(),
+ bounds: vec!(("__D", ast::StaticSize, vec!(Path::new_(
+ vec!("serialize", "Decoder"), None,
+ vec!(~Literal(Path::new_local("__E"))), true))),
+ ("__E", ast::StaticSize, vec!()))
},
- methods: ~[
+ methods: vec!(
MethodDef {
name: "decode",
generics: LifetimeBounds::empty(),
explicit_self: None,
- args: ~[Ptr(~Literal(Path::new_local("__D")),
- Borrowed(None, MutMutable))],
- ret_ty: Self,
- inline: false,
+ args: vec!(Ptr(~Literal(Path::new_local("__D")),
+ Borrowed(None, MutMutable))),
+ ret_ty: Literal(Path::new_(vec!("std", "result", "Result"), None,
+ vec!(~Self, ~Literal(Path::new_local("__E"))), true)),
+ attributes: Vec::new(),
const_nonmatching: true,
- combine_substructure: decodable_substructure,
- },
- ]
+ combine_substructure: combine_substructure(|a, b, c| {
+ decodable_substructure(a, b, c)
+ }),
+ })
};
- trait_def.expand(mitem, in_items)
+ trait_def.expand(cx, mitem, item, push)
}
-fn decodable_substructure(cx: &ExtCtxt, trait_span: Span,
+fn decodable_substructure(cx: &mut ExtCtxt, trait_span: Span,
substr: &Substructure) -> @Expr {
let decoder = substr.nonself_args[0];
- let recurse = ~[cx.ident_of("serialize"),
+ let recurse = vec!(cx.ident_of("serialize"),
cx.ident_of("Decodable"),
- cx.ident_of("decode")];
+ cx.ident_of("decode"));
// throw an underscore in front to suppress unused variable warnings
let blkarg = cx.ident_of("_d");
let blkdecoder = cx.expr_ident(trait_span, blkarg);
- let calldecode = cx.expr_call_global(trait_span, recurse, ~[blkdecoder]);
+ let calldecode = cx.expr_call_global(trait_span, recurse, vec!(blkdecoder));
let lambdadecode = cx.lambda_expr_1(trait_span, calldecode, blkarg);
return match *substr.fields {
trait_span,
substr.type_ident,
summary,
- |span, name, field| {
- cx.expr_method_call(span, blkdecoder, read_struct_field,
- ~[cx.expr_str(span, name),
- cx.expr_uint(span, field),
- lambdadecode])
+ |cx, span, name, field| {
+ cx.expr_try(span,
+ cx.expr_method_call(span, blkdecoder, read_struct_field,
+ vec!(cx.expr_str(span, name),
+ cx.expr_uint(span, field),
+ lambdadecode)))
});
+ let result = cx.expr_ok(trait_span, result);
cx.expr_method_call(trait_span,
decoder,
cx.ident_of("read_struct"),
- ~[
- cx.expr_str(trait_span,
- token::get_ident(substr.type_ident.name)),
+ vec!(
+ cx.expr_str(trait_span, token::get_ident(substr.type_ident)),
cx.expr_uint(trait_span, nfields),
cx.lambda_expr_1(trait_span, result, blkarg)
- ])
+ ))
}
StaticEnum(_, ref fields) => {
let variant = cx.ident_of("i");
- let mut arms = ~[];
- let mut variants = ~[];
+ let mut arms = Vec::new();
+ let mut variants = Vec::new();
let rvariant_arg = cx.ident_of("read_enum_variant_arg");
for (i, &(name, v_span, ref parts)) in fields.iter().enumerate() {
- variants.push(cx.expr_str(v_span,
- token::get_ident(name.name)));
+ variants.push(cx.expr_str(v_span, token::get_ident(name)));
let decoded = decode_static_fields(cx,
v_span,
name,
parts,
- |span, _, field| {
- cx.expr_method_call(span, blkdecoder, rvariant_arg,
- ~[cx.expr_uint(span, field),
- lambdadecode])
+ |cx, span, _, field| {
+ let idx = cx.expr_uint(span, field);
+ cx.expr_try(span,
+ cx.expr_method_call(span, blkdecoder, rvariant_arg,
+ vec!(idx, lambdadecode)))
});
arms.push(cx.arm(v_span,
- ~[cx.pat_lit(v_span, cx.expr_uint(v_span, i))],
+ vec!(cx.pat_lit(v_span, cx.expr_uint(v_span, i))),
decoded));
}
arms.push(cx.arm_unreachable(trait_span));
- let result = cx.expr_match(trait_span, cx.expr_ident(trait_span, variant), arms);
- let lambda = cx.lambda_expr(trait_span, ~[blkarg, variant], result);
+ let result = cx.expr_ok(trait_span,
+ cx.expr_match(trait_span,
+ cx.expr_ident(trait_span, variant), arms));
+ let lambda = cx.lambda_expr(trait_span, vec!(blkarg, variant), result);
let variant_vec = cx.expr_vec(trait_span, variants);
let result = cx.expr_method_call(trait_span, blkdecoder,
cx.ident_of("read_enum_variant"),
- ~[variant_vec, lambda]);
+ vec!(variant_vec, lambda));
cx.expr_method_call(trait_span,
decoder,
cx.ident_of("read_enum"),
- ~[
- cx.expr_str(trait_span,
- token::get_ident(substr.type_ident.name)),
+ vec!(
+ cx.expr_str(trait_span, token::get_ident(substr.type_ident)),
cx.lambda_expr_1(trait_span, result, blkarg)
- ])
+ ))
}
_ => cx.bug("expected StaticEnum or StaticStruct in deriving(Decodable)")
};
/// Create a decoder for a single enum variant/struct:
/// - `outer_pat_ident` is the name of this enum variant/struct
/// - `getarg` should retrieve the `uint`-th field with name `@str`.
-fn decode_static_fields(cx: &ExtCtxt,
+fn decode_static_fields(cx: &mut ExtCtxt,
trait_span: Span,
outer_pat_ident: Ident,
fields: &StaticFields,
- getarg: |Span, InternedString, uint| -> @Expr)
+ getarg: |&mut ExtCtxt, Span, InternedString, uint| -> @Expr)
-> @Expr {
match *fields {
Unnamed(ref fields) => {
cx.expr_ident(trait_span, outer_pat_ident)
} else {
let fields = fields.iter().enumerate().map(|(i, &span)| {
- getarg(span,
+ getarg(cx, span,
token::intern_and_get_ident(format!("_field{}",
i)),
i)
Named(ref fields) => {
// use the field's span to get nicer error messages.
let fields = fields.iter().enumerate().map(|(i, &(name, span))| {
- cx.field_imm(span,
- name,
- getarg(span, token::get_ident(name.name), i))
+ let arg = getarg(cx, span, token::get_ident(name), i);
+ cx.field_imm(span, name, arg)
}).collect();
cx.expr_struct_ident(trait_span, outer_pat_ident, fields)
}
projects / rust.git / blobdiff