mirror of
https://github.com/pezkuwichain/serde.git
synced 2026-04-22 19:28:01 +00:00
Pull codegen into it's own crate
This commit is contained in:
Erick Tryzelaar
@@ -0,0 +1,825 @@
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use std::collections::HashSet;
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use syntax::ast::{
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Ident,
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MetaItem,
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Item,
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Expr,
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StructDef,
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EnumDef,
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};
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use syntax::ast;
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use syntax::codemap::Span;
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use syntax::ext::base::ExtCtxt;
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use syntax::ext::build::AstBuilder;
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use syntax::owned_slice::OwnedSlice;
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use syntax::ptr::P;
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use aster;
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use attr;
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use field;
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pub fn expand_derive_deserialize(
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cx: &mut ExtCtxt,
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span: Span,
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_mitem: &MetaItem,
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item: &Item,
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push: &mut FnMut(P<ast::Item>)
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) {
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let builder = aster::AstBuilder::new().span(span);
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let generics = match item.node {
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ast::ItemStruct(_, ref generics) => generics,
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ast::ItemEnum(_, ref generics) => generics,
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_ => cx.bug("expected ItemStruct or ItemEnum in #[derive(Deserialize)]")
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};
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let impl_generics = builder.from_generics(generics.clone())
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.add_ty_param_bound(
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builder.path().global().ids(&["serde", "de", "Deserialize"]).build()
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)
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.build();
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let ty = builder.ty().path()
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.segment(item.ident).with_generics(impl_generics.clone()).build()
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.build();
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let body = deserialize_body(
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cx,
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&builder,
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item,
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&impl_generics,
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ty.clone(),
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);
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let where_clause = &impl_generics.where_clause;
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let impl_item = quote_item!(cx,
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#[automatically_derived]
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impl $impl_generics ::serde::de::Deserialize for $ty $where_clause {
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fn deserialize<__D>(deserializer: &mut __D) -> ::std::result::Result<$ty, __D::Error>
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where __D: ::serde::de::Deserializer,
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{
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$body
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}
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}
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).unwrap();
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push(impl_item)
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}
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fn deserialize_body(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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item: &Item,
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impl_generics: &ast::Generics,
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ty: P<ast::Ty>,
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) -> P<ast::Expr> {
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match item.node {
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ast::ItemStruct(ref struct_def, _) => {
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deserialize_item_struct(
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cx,
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builder,
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item,
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impl_generics,
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ty,
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struct_def,
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)
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}
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ast::ItemEnum(ref enum_def, _) => {
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deserialize_item_enum(
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cx,
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builder,
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item.ident,
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impl_generics,
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ty,
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enum_def,
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)
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}
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_ => cx.bug("expected ItemStruct or ItemEnum in #[derive(Deserialize)]")
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}
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}
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fn deserialize_item_struct(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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item: &Item,
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impl_generics: &ast::Generics,
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ty: P<ast::Ty>,
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struct_def: &ast::StructDef,
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) -> P<ast::Expr> {
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let mut named_fields = vec![];
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let mut unnamed_fields = 0;
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for field in struct_def.fields.iter() {
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match field.node.kind {
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ast::NamedField(name, _) => { named_fields.push(name); }
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ast::UnnamedField(_) => { unnamed_fields += 1; }
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}
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}
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match (named_fields.is_empty(), unnamed_fields == 0) {
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(true, true) => {
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deserialize_unit_struct(
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cx,
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&builder,
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item.ident,
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)
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}
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(true, false) => {
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deserialize_tuple_struct(
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cx,
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&builder,
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item.ident,
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impl_generics,
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ty,
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unnamed_fields,
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)
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}
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(false, true) => {
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deserialize_struct(
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cx,
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&builder,
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item.ident,
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impl_generics,
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ty,
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struct_def,
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)
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}
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(false, false) => {
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cx.bug("struct has named and unnamed fields")
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}
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}
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}
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// Build `__Visitor<A, B, ...>(PhantomData<A>, PhantomData<B>, ...)`
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fn deserialize_visitor(
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builder: &aster::AstBuilder,
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trait_generics: &ast::Generics,
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forward_ty_params: Vec<ast::TyParam>,
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forward_tys: Vec<P<ast::Ty>>
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) -> (P<ast::Item>, P<ast::Ty>, P<ast::Expr>, ast::Generics) {
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if trait_generics.ty_params.is_empty() && forward_tys.is_empty() {
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(
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builder.item().tuple_struct("__Visitor").build(),
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builder.ty().id("__Visitor"),
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builder.expr().id("__Visitor"),
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trait_generics.clone(),
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)
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} else {
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let placeholders : Vec<_> = trait_generics.ty_params.iter()
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.map(|t| builder.ty().id(t.ident))
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.collect();
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let mut trait_generics = trait_generics.clone();
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let mut ty_params = forward_ty_params.clone();
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ty_params.extend(trait_generics.ty_params.into_vec());
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trait_generics.ty_params = OwnedSlice::from_vec(ty_params);
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(
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builder.item().tuple_struct("__Visitor")
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.generics().with(trait_generics.clone()).build()
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.with_tys(
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trait_generics.ty_params.iter().map(|ty_param| {
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builder.ty().phantom_data().id(ty_param.ident)
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})
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)
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.build(),
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builder.ty().path()
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.segment("__Visitor").with_generics(trait_generics.clone()).build()
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.build(),
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builder.expr().call()
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.path().segment("__Visitor")
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.with_tys(forward_tys)
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.with_tys(placeholders)
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.build().build()
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.with_args(
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trait_generics.ty_params.iter().map(|_| {
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builder.expr().phantom_data()
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})
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)
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.build(),
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trait_generics,
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)
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}
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}
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fn deserializer_ty_param(builder: &aster::AstBuilder) -> ast::TyParam {
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builder.ty_param("__D")
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.trait_bound(builder.path()
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.global()
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.segment("serde").build()
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.segment("de").build()
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.id("Deserializer")
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.build())
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.build()
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.build()
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}
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fn deserializer_ty_arg(builder: &aster::AstBuilder) -> P<ast::Ty>{
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builder.ty().id("__D")
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}
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fn deserialize_unit_struct(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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type_ident: Ident,
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) -> P<ast::Expr> {
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let type_name = builder.expr().str(type_ident);
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quote_expr!(cx, {
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struct __Visitor;
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impl ::serde::de::Visitor for __Visitor {
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type Value = $type_ident;
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#[inline]
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fn visit_unit<E>(&mut self) -> ::std::result::Result<$type_ident, E>
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where E: ::serde::de::Error,
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{
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Ok($type_ident)
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}
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#[inline]
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fn visit_seq<V>(&mut self, mut visitor: V) -> ::std::result::Result<$type_ident, V::Error>
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where V: ::serde::de::SeqVisitor,
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{
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try!(visitor.end());
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self.visit_unit()
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}
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}
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deserializer.visit_named_unit($type_name, __Visitor)
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})
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}
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fn deserialize_tuple_struct(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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type_ident: Ident,
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impl_generics: &ast::Generics,
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ty: P<ast::Ty>,
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fields: usize,
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) -> P<ast::Expr> {
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let where_clause = &impl_generics.where_clause;
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let (visitor_item, visitor_ty, visitor_expr, visitor_generics) =
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deserialize_visitor(
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builder,
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impl_generics,
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vec![deserializer_ty_param(builder)],
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vec![deserializer_ty_arg(builder)],
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);
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let visit_seq_expr = deserialize_seq(
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cx,
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builder,
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builder.path().id(type_ident).build(),
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fields,
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);
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let type_name = builder.expr().str(type_ident);
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quote_expr!(cx, {
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$visitor_item
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impl $visitor_generics ::serde::de::Visitor for $visitor_ty $where_clause {
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type Value = $ty;
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fn visit_seq<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<$ty, __V::Error>
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where __V: ::serde::de::SeqVisitor,
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{
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$visit_seq_expr
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}
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}
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deserializer.visit_named_seq($type_name, $visitor_expr)
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})
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}
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fn deserialize_seq(
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cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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struct_path: ast::Path,
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fields: usize,
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) -> P<ast::Expr> {
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let let_values: Vec<P<ast::Stmt>> = (0 .. fields)
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.map(|i| {
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let name = builder.id(format!("__field{}", i));
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quote_stmt!(cx,
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let $name = match try!(visitor.visit()) {
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Some(value) => { value },
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None => {
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return Err(::serde::de::Error::end_of_stream_error());
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}
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};
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).unwrap()
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})
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.collect();
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let result = builder.expr().call()
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.build_path(struct_path)
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.with_args((0 .. fields).map(|i| builder.expr().id(format!("__field{}", i))))
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.build();
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quote_expr!(cx, {
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$let_values
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try!(visitor.end());
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Ok($result)
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})
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}
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|
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fn deserialize_struct(
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||||
cx: &ExtCtxt,
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builder: &aster::AstBuilder,
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type_ident: Ident,
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impl_generics: &ast::Generics,
|
||||
ty: P<ast::Ty>,
|
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struct_def: &StructDef,
|
||||
) -> P<ast::Expr> {
|
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let where_clause = &impl_generics.where_clause;
|
||||
|
||||
let (visitor_item, visitor_ty, visitor_expr, visitor_generics) =
|
||||
deserialize_visitor(
|
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builder,
|
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&impl_generics,
|
||||
vec![deserializer_ty_param(builder)],
|
||||
vec![deserializer_ty_arg(builder)],
|
||||
);
|
||||
|
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let (field_visitor, visit_map_expr) = deserialize_struct_visitor(
|
||||
cx,
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builder,
|
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struct_def,
|
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builder.path().id(type_ident).build(),
|
||||
);
|
||||
|
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let type_name = builder.expr().str(type_ident);
|
||||
|
||||
quote_expr!(cx, {
|
||||
$field_visitor
|
||||
|
||||
$visitor_item
|
||||
|
||||
impl $visitor_generics ::serde::de::Visitor for $visitor_ty $where_clause {
|
||||
type Value = $ty;
|
||||
|
||||
#[inline]
|
||||
fn visit_map<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<$ty, __V::Error>
|
||||
where __V: ::serde::de::MapVisitor,
|
||||
{
|
||||
$visit_map_expr
|
||||
}
|
||||
}
|
||||
|
||||
deserializer.visit_named_map($type_name, $visitor_expr)
|
||||
})
|
||||
}
|
||||
|
||||
fn deserialize_item_enum(
|
||||
cx: &ExtCtxt,
|
||||
builder: &aster::AstBuilder,
|
||||
type_ident: Ident,
|
||||
impl_generics: &ast::Generics,
|
||||
ty: P<ast::Ty>,
|
||||
enum_def: &EnumDef,
|
||||
) -> P<ast::Expr> {
|
||||
let where_clause = &impl_generics.where_clause;
|
||||
|
||||
let type_name = builder.expr().str(type_ident);
|
||||
|
||||
let variant_visitor = deserialize_field_visitor(
|
||||
cx,
|
||||
builder,
|
||||
enum_def.variants.iter()
|
||||
.map(|variant|
|
||||
attr::FieldAttrs::new(
|
||||
true,
|
||||
builder.expr().str(variant.node.name)))
|
||||
.collect()
|
||||
);
|
||||
|
||||
// Match arms to extract a variant from a string
|
||||
let variant_arms: Vec<_> = enum_def.variants.iter()
|
||||
.enumerate()
|
||||
.map(|(i, variant)| {
|
||||
let variant_name = builder.pat().enum_()
|
||||
.id("__Field").id(format!("__field{}", i)).build()
|
||||
.build();
|
||||
|
||||
let expr = deserialize_variant(
|
||||
cx,
|
||||
builder,
|
||||
type_ident,
|
||||
impl_generics,
|
||||
ty.clone(),
|
||||
variant,
|
||||
);
|
||||
|
||||
quote_arm!(cx, $variant_name => { $expr })
|
||||
})
|
||||
.collect();
|
||||
|
||||
let (visitor_item, visitor_ty, visitor_expr, visitor_generics) =
|
||||
deserialize_visitor(
|
||||
builder,
|
||||
impl_generics,
|
||||
vec![deserializer_ty_param(builder)],
|
||||
vec![deserializer_ty_arg(builder)],
|
||||
);
|
||||
|
||||
quote_expr!(cx, {
|
||||
$variant_visitor
|
||||
|
||||
$visitor_item
|
||||
|
||||
impl $visitor_generics ::serde::de::EnumVisitor for $visitor_ty $where_clause {
|
||||
type Value = $ty;
|
||||
|
||||
fn visit<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<$ty, __V::Error>
|
||||
where __V: ::serde::de::VariantVisitor,
|
||||
{
|
||||
match try!(visitor.visit_variant()) {
|
||||
$variant_arms
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
deserializer.visit_enum($type_name, $visitor_expr)
|
||||
})
|
||||
}
|
||||
|
||||
fn deserialize_variant(
|
||||
cx: &ExtCtxt,
|
||||
builder: &aster::AstBuilder,
|
||||
type_ident: Ident,
|
||||
generics: &ast::Generics,
|
||||
ty: P<ast::Ty>,
|
||||
variant: &ast::Variant,
|
||||
) -> P<ast::Expr> {
|
||||
let variant_ident = variant.node.name;
|
||||
|
||||
match variant.node.kind {
|
||||
ast::TupleVariantKind(ref args) if args.is_empty() => {
|
||||
quote_expr!(cx, {
|
||||
try!(visitor.visit_unit());
|
||||
Ok($type_ident::$variant_ident)
|
||||
})
|
||||
}
|
||||
ast::TupleVariantKind(ref args) => {
|
||||
deserialize_tuple_variant(
|
||||
cx,
|
||||
builder,
|
||||
type_ident,
|
||||
variant_ident,
|
||||
generics,
|
||||
ty,
|
||||
args.len(),
|
||||
)
|
||||
}
|
||||
ast::StructVariantKind(ref struct_def) => {
|
||||
deserialize_struct_variant(
|
||||
cx,
|
||||
builder,
|
||||
type_ident,
|
||||
variant_ident,
|
||||
generics,
|
||||
ty,
|
||||
struct_def,
|
||||
)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn deserialize_tuple_variant(
|
||||
cx: &ExtCtxt,
|
||||
builder: &aster::AstBuilder,
|
||||
type_ident: ast::Ident,
|
||||
variant_ident: ast::Ident,
|
||||
generics: &ast::Generics,
|
||||
ty: P<ast::Ty>,
|
||||
fields: usize,
|
||||
) -> P<ast::Expr> {
|
||||
let where_clause = &generics.where_clause;
|
||||
|
||||
let (visitor_item, visitor_ty, visitor_expr, visitor_generics) =
|
||||
deserialize_visitor(
|
||||
builder,
|
||||
generics,
|
||||
vec![deserializer_ty_param(builder)],
|
||||
vec![deserializer_ty_arg(builder)],
|
||||
);
|
||||
|
||||
let visit_seq_expr = deserialize_seq(
|
||||
cx,
|
||||
builder,
|
||||
builder.path().id(type_ident).id(variant_ident).build(),
|
||||
fields,
|
||||
);
|
||||
|
||||
quote_expr!(cx, {
|
||||
$visitor_item
|
||||
|
||||
impl $visitor_generics ::serde::de::Visitor for $visitor_ty $where_clause {
|
||||
type Value = $ty;
|
||||
|
||||
fn visit_seq<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<$ty, __V::Error>
|
||||
where __V: ::serde::de::SeqVisitor,
|
||||
{
|
||||
$visit_seq_expr
|
||||
}
|
||||
}
|
||||
|
||||
visitor.visit_seq($visitor_expr)
|
||||
})
|
||||
}
|
||||
|
||||
fn deserialize_struct_variant(
|
||||
cx: &ExtCtxt,
|
||||
builder: &aster::AstBuilder,
|
||||
type_ident: ast::Ident,
|
||||
variant_ident: ast::Ident,
|
||||
generics: &ast::Generics,
|
||||
ty: P<ast::Ty>,
|
||||
struct_def: &ast::StructDef,
|
||||
) -> P<ast::Expr> {
|
||||
let where_clause = &generics.where_clause;
|
||||
|
||||
let (field_visitor, field_expr) = deserialize_struct_visitor(
|
||||
cx,
|
||||
builder,
|
||||
struct_def,
|
||||
builder.path().id(type_ident).id(variant_ident).build(),
|
||||
);
|
||||
|
||||
let (visitor_item, visitor_ty, visitor_expr, visitor_generics) =
|
||||
deserialize_visitor(
|
||||
builder,
|
||||
generics,
|
||||
vec![deserializer_ty_param(builder)],
|
||||
vec![deserializer_ty_arg(builder)],
|
||||
);
|
||||
|
||||
quote_expr!(cx, {
|
||||
$field_visitor
|
||||
|
||||
$visitor_item
|
||||
|
||||
impl $visitor_generics ::serde::de::Visitor for $visitor_ty $where_clause {
|
||||
type Value = $ty;
|
||||
|
||||
fn visit_map<__V>(&mut self, mut visitor: __V) -> ::std::result::Result<$ty, __V::Error>
|
||||
where __V: ::serde::de::MapVisitor,
|
||||
{
|
||||
$field_expr
|
||||
}
|
||||
}
|
||||
|
||||
visitor.visit_map($visitor_expr)
|
||||
})
|
||||
}
|
||||
|
||||
fn deserialize_field_visitor(
|
||||
cx: &ExtCtxt,
|
||||
builder: &aster::AstBuilder,
|
||||
field_attrs: Vec<attr::FieldAttrs>,
|
||||
) -> Vec<P<ast::Item>> {
|
||||
// Create the field names for the fields.
|
||||
let field_idents: Vec<ast::Ident> = (0 .. field_attrs.len())
|
||||
.map(|i| builder.id(format!("__field{}", i)))
|
||||
.collect();
|
||||
|
||||
let field_enum = builder.item()
|
||||
.attr().allow(&["non_camel_case_types"])
|
||||
.enum_("__Field")
|
||||
.with_variants(
|
||||
field_idents.iter().map(|field_ident| {
|
||||
builder.variant(field_ident).tuple().build()
|
||||
})
|
||||
)
|
||||
.build();
|
||||
|
||||
// A set of all the formats that have specialized field attributes
|
||||
let formats = field_attrs.iter()
|
||||
.fold(HashSet::new(), |mut set, field_expr| {
|
||||
set.extend(field_expr.formats());
|
||||
set
|
||||
});
|
||||
|
||||
// Match arms to extract a field from a string
|
||||
let default_field_arms: Vec<_> = field_idents.iter()
|
||||
.zip(field_attrs.iter())
|
||||
.map(|(field_ident, field_expr)| {
|
||||
let expr = field_expr.default_key_expr();
|
||||
quote_arm!(cx, $expr => { Ok(__Field::$field_ident) })
|
||||
})
|
||||
.collect();
|
||||
|
||||
let body = if formats.is_empty() {
|
||||
// No formats specific attributes, so no match on format required
|
||||
quote_expr!(cx,
|
||||
match value {
|
||||
$default_field_arms
|
||||
_ => { Err(::serde::de::Error::unknown_field_error(value)) }
|
||||
})
|
||||
} else {
|
||||
let field_arms : Vec<_> = formats.iter()
|
||||
.map(|fmt| {
|
||||
field_idents.iter()
|
||||
.zip(field_attrs.iter())
|
||||
.map(|(field_ident, field_expr)| {
|
||||
let expr = field_expr.key_expr(fmt);
|
||||
quote_arm!(cx, $expr => { Ok(__Field::$field_ident) })
|
||||
})
|
||||
.collect::<Vec<_>>()
|
||||
})
|
||||
.collect();
|
||||
|
||||
let fmt_matches : Vec<_> = formats.iter()
|
||||
.zip(field_arms.iter())
|
||||
.map(|(ref fmt, ref arms)| {
|
||||
quote_arm!(cx, $fmt => {
|
||||
match value {
|
||||
$arms
|
||||
_ => {
|
||||
Err(::serde::de::Error::unknown_field_error(value))
|
||||
}
|
||||
}})
|
||||
})
|
||||
.collect();
|
||||
|
||||
quote_expr!(cx,
|
||||
match __D::format() {
|
||||
$fmt_matches
|
||||
_ => match value {
|
||||
$default_field_arms
|
||||
_ => { Err(::serde::de::Error::unknown_field_error(value)) }
|
||||
}
|
||||
})
|
||||
};
|
||||
|
||||
vec![
|
||||
field_enum,
|
||||
|
||||
quote_item!(cx,
|
||||
impl ::serde::de::Deserialize for __Field {
|
||||
#[inline]
|
||||
fn deserialize<D>(deserializer: &mut D) -> ::std::result::Result<__Field, D::Error>
|
||||
where D: ::serde::de::Deserializer,
|
||||
{
|
||||
use std::marker::PhantomData;
|
||||
|
||||
struct __FieldVisitor<D> {
|
||||
phantom: PhantomData<D>
|
||||
}
|
||||
|
||||
impl<__D> ::serde::de::Visitor for __FieldVisitor<__D>
|
||||
where __D: ::serde::de::Deserializer
|
||||
{
|
||||
type Value = __Field;
|
||||
|
||||
fn visit_str<E>(&mut self, value: &str) -> ::std::result::Result<__Field, E>
|
||||
where E: ::serde::de::Error,
|
||||
{
|
||||
$body
|
||||
}
|
||||
|
||||
fn visit_bytes<E>(&mut self, value: &[u8]) -> ::std::result::Result<__Field, E>
|
||||
where E: ::serde::de::Error,
|
||||
{
|
||||
// TODO: would be better to generate a byte string literal match
|
||||
match ::std::str::from_utf8(value) {
|
||||
Ok(s) => self.visit_str(s),
|
||||
_ => Err(::serde::de::Error::syntax_error()),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
deserializer.visit(
|
||||
__FieldVisitor::<D>{ phantom: PhantomData })
|
||||
}
|
||||
}
|
||||
).unwrap(),
|
||||
]
|
||||
}
|
||||
|
||||
fn deserialize_struct_visitor(
|
||||
cx: &ExtCtxt,
|
||||
builder: &aster::AstBuilder,
|
||||
struct_def: &ast::StructDef,
|
||||
struct_path: ast::Path,
|
||||
) -> (Vec<P<ast::Item>>, P<ast::Expr>) {
|
||||
let field_visitor = deserialize_field_visitor(
|
||||
cx,
|
||||
builder,
|
||||
field::struct_field_attrs(cx, builder, struct_def),
|
||||
);
|
||||
|
||||
let visit_map_expr = deserialize_map(
|
||||
cx,
|
||||
builder,
|
||||
struct_path,
|
||||
struct_def,
|
||||
);
|
||||
|
||||
(field_visitor, visit_map_expr)
|
||||
}
|
||||
|
||||
fn deserialize_map(
|
||||
cx: &ExtCtxt,
|
||||
builder: &aster::AstBuilder,
|
||||
struct_path: ast::Path,
|
||||
struct_def: &StructDef,
|
||||
) -> P<ast::Expr> {
|
||||
// Create the field names for the fields.
|
||||
let field_names: Vec<ast::Ident> = (0 .. struct_def.fields.len())
|
||||
.map(|i| builder.id(format!("__field{}", i)))
|
||||
.collect();
|
||||
|
||||
// Declare each field.
|
||||
let let_values: Vec<P<ast::Stmt>> = field_names.iter()
|
||||
.map(|field_name| quote_stmt!(cx, let mut $field_name = None;).unwrap())
|
||||
.collect();
|
||||
|
||||
// Match arms to extract a value for a field.
|
||||
let value_arms: Vec<ast::Arm> = field_names.iter()
|
||||
.map(|field_name| {
|
||||
quote_arm!(cx,
|
||||
__Field::$field_name => {
|
||||
$field_name = Some(try!(visitor.visit_value()));
|
||||
}
|
||||
)
|
||||
})
|
||||
.collect();
|
||||
|
||||
let extract_values: Vec<P<ast::Stmt>> = field_names.iter()
|
||||
.zip(field::struct_field_attrs(cx, builder, struct_def).iter())
|
||||
.map(|(field_name, field_attr)| {
|
||||
let missing_expr = if field_attr.use_default() {
|
||||
quote_expr!(cx, ::std::default::Default::default())
|
||||
} else {
|
||||
let formats = field_attr.formats();
|
||||
let arms : Vec<_> = formats.iter()
|
||||
.map(|format| {
|
||||
let key_expr = field_attr.key_expr(format);
|
||||
quote_arm!(cx, $format => { $key_expr })
|
||||
})
|
||||
.collect();
|
||||
let default = field_attr.default_key_expr();
|
||||
if arms.is_empty() {
|
||||
quote_expr!(cx, try!(visitor.missing_field($default)))
|
||||
} else {
|
||||
quote_expr!(
|
||||
cx,
|
||||
try!(visitor.missing_field(
|
||||
match __D::format() {
|
||||
$arms
|
||||
_ => { $default }
|
||||
})))
|
||||
}
|
||||
};
|
||||
|
||||
quote_stmt!(cx,
|
||||
let $field_name = match $field_name {
|
||||
Some($field_name) => $field_name,
|
||||
None => $missing_expr
|
||||
};
|
||||
).unwrap()
|
||||
})
|
||||
.collect();
|
||||
|
||||
let result = builder.expr().struct_path(struct_path)
|
||||
.with_id_exprs(
|
||||
struct_def.fields.iter()
|
||||
.zip(field_names.iter())
|
||||
.map(|(field, field_name)| {
|
||||
(
|
||||
match field.node.kind {
|
||||
ast::NamedField(name, _) => name.clone(),
|
||||
ast::UnnamedField(_) => panic!("struct contains unnamed fields"),
|
||||
},
|
||||
builder.expr().id(field_name),
|
||||
)
|
||||
})
|
||||
)
|
||||
.build();
|
||||
|
||||
quote_expr!(cx, {
|
||||
$let_values
|
||||
|
||||
while let Some(key) = try!(visitor.visit_key()) {
|
||||
match key {
|
||||
$value_arms
|
||||
}
|
||||
}
|
||||
|
||||
$extract_values
|
||||
|
||||
try!(visitor.end());
|
||||
|
||||
Ok($result)
|
||||
})
|
||||
}
|
||||
Reference in New Issue
Block a user