src/libsyntax/ext/build.rs

   1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use abi;
  12 use ast::{P, Ident, Generics, NodeId, Expr};
  13 use ast;
  14 use ast_util;
  15 use attr;
  16 use codemap::{Span, respan, Spanned, DUMMY_SP, Pos};
  17 use ext::base::ExtCtxt;
  18 use fold::Folder;
  19 use owned_slice::OwnedSlice;
  20 use parse::token::special_idents;
  21 use parse::token::InternedString;
  22 use parse::token;
  23
  24 use std::gc::{Gc, GC};
  25
  26 // Transitional reexports so qquote can find the paths it is looking for
  27 mod syntax {
  28     pub use ext;
  29     pub use parse;
  30 }
  31
  32 pub trait AstBuilder {
  33     // paths
  34     fn path(&self, span: Span, strs: Vec<ast::Ident> ) -> ast::Path;
  35     fn path_ident(&self, span: Span, id: ast::Ident) -> ast::Path;
  36     fn path_global(&self, span: Span, strs: Vec<ast::Ident> ) -> ast::Path;
  37     fn path_all(&self, sp: Span,
  38                 global: bool,
  39                 idents: Vec<ast::Ident> ,
  40                 lifetimes: Vec<ast::Lifetime>,
  41                 types: Vec<P<ast::Ty>> )
  42         -> ast::Path;
  43
  44     // types
  45     fn ty_mt(&self, ty: P<ast::Ty>, mutbl: ast::Mutability) -> ast::MutTy;
  46
  47     fn ty(&self, span: Span, ty: ast::Ty_) -> P<ast::Ty>;
  48     fn ty_path(&self, ast::Path, Option<OwnedSlice<ast::TyParamBound>>) -> P<ast::Ty>;
  49     fn ty_ident(&self, span: Span, idents: ast::Ident) -> P<ast::Ty>;
  50
  51     fn ty_rptr(&self, span: Span,
  52                ty: P<ast::Ty>,
  53                lifetime: Option<ast::Lifetime>,
  54                mutbl: ast::Mutability) -> P<ast::Ty>;
  55     fn ty_ptr(&self, span: Span,
  56               ty: P<ast::Ty>,
  57               mutbl: ast::Mutability) -> P<ast::Ty>;
  58     fn ty_uniq(&self, span: Span, ty: P<ast::Ty>) -> P<ast::Ty>;
  59
  60     fn ty_option(&self, ty: P<ast::Ty>) -> P<ast::Ty>;
  61     fn ty_infer(&self, sp: Span) -> P<ast::Ty>;
  62     fn ty_nil(&self) -> P<ast::Ty>;
  63
  64     fn ty_vars(&self, ty_params: &OwnedSlice<ast::TyParam>) -> Vec<P<ast::Ty>> ;
  65     fn ty_vars_global(&self, ty_params: &OwnedSlice<ast::TyParam>) -> Vec<P<ast::Ty>> ;
  66     fn ty_field_imm(&self, span: Span, name: Ident, ty: P<ast::Ty>) -> ast::TypeField;
  67     fn strip_bounds(&self, bounds: &Generics) -> Generics;
  68
  69     fn typaram(&self,
  70                span: Span,
  71                id: ast::Ident,
  72                bounds: OwnedSlice<ast::TyParamBound>,
  73                unbound: Option<ast::TyParamBound>,
  74                default: Option<P<ast::Ty>>) -> ast::TyParam;
  75
  76     fn trait_ref(&self, path: ast::Path) -> ast::TraitRef;
  77     fn typarambound(&self, path: ast::Path) -> ast::TyParamBound;
  78     fn lifetime(&self, span: Span, ident: ast::Name) -> ast::Lifetime;
  79     fn lifetime_def(&self,
  80                     span: Span,
  81                     name: ast::Name,
  82                     bounds: Vec<ast::Lifetime>)
  83                     -> ast::LifetimeDef;
  84
  85     // statements
  86     fn stmt_expr(&self, expr: Gc<ast::Expr>) -> Gc<ast::Stmt>;
  87     fn stmt_let(&self, sp: Span, mutbl: bool, ident: ast::Ident,
  88                 ex: Gc<ast::Expr>) -> Gc<ast::Stmt>;
  89     fn stmt_let_typed(&self,
  90                       sp: Span,
  91                       mutbl: bool,
  92                       ident: ast::Ident,
  93                       typ: P<ast::Ty>,
  94                       ex: Gc<ast::Expr>)
  95                       -> Gc<ast::Stmt>;
  96     fn stmt_item(&self, sp: Span, item: Gc<ast::Item>) -> Gc<ast::Stmt>;
  97
  98     // blocks
  99     fn block(&self, span: Span, stmts: Vec<Gc<ast::Stmt>>,
 100              expr: Option<Gc<ast::Expr>>) -> P<ast::Block>;
 101     fn block_expr(&self, expr: Gc<ast::Expr>) -> P<ast::Block>;
 102     fn block_all(&self, span: Span,
 103                  view_items: Vec<ast::ViewItem> ,
 104                  stmts: Vec<Gc<ast::Stmt>> ,
 105                  expr: Option<Gc<ast::Expr>>) -> P<ast::Block>;
 106
 107     // expressions
 108     fn expr(&self, span: Span, node: ast::Expr_) -> Gc<ast::Expr>;
 109     fn expr_path(&self, path: ast::Path) -> Gc<ast::Expr>;
 110     fn expr_ident(&self, span: Span, id: ast::Ident) -> Gc<ast::Expr>;
 111
 112     fn expr_self(&self, span: Span) -> Gc<ast::Expr>;
 113     fn expr_binary(&self, sp: Span, op: ast::BinOp,
 114                    lhs: Gc<ast::Expr>, rhs: Gc<ast::Expr>) -> Gc<ast::Expr>;
 115     fn expr_deref(&self, sp: Span, e: Gc<ast::Expr>) -> Gc<ast::Expr>;
 116     fn expr_unary(&self, sp: Span, op: ast::UnOp, e: Gc<ast::Expr>) -> Gc<ast::Expr>;
 117
 118     fn expr_managed(&self, sp: Span, e: Gc<ast::Expr>) -> Gc<ast::Expr>;
 119     fn expr_addr_of(&self, sp: Span, e: Gc<ast::Expr>) -> Gc<ast::Expr>;
 120     fn expr_mut_addr_of(&self, sp: Span, e: Gc<ast::Expr>) -> Gc<ast::Expr>;
 121     fn expr_field_access(&self, span: Span, expr: Gc<ast::Expr>,
 122                          ident: ast::Ident) -> Gc<ast::Expr>;
 123     fn expr_tup_field_access(&self, sp: Span, expr: Gc<ast::Expr>,
 124                              idx: uint) -> Gc<ast::Expr>;
 125     fn expr_call(&self, span: Span, expr: Gc<ast::Expr>,
 126                  args: Vec<Gc<ast::Expr>>) -> Gc<ast::Expr>;
 127     fn expr_call_ident(&self, span: Span, id: ast::Ident,
 128                        args: Vec<Gc<ast::Expr>>) -> Gc<ast::Expr>;
 129     fn expr_call_global(&self, sp: Span, fn_path: Vec<ast::Ident> ,
 130                         args: Vec<Gc<ast::Expr>>) -> Gc<ast::Expr>;
 131     fn expr_method_call(&self, span: Span,
 132                         expr: Gc<ast::Expr>, ident: ast::Ident,
 133                         args: Vec<Gc<ast::Expr>> ) -> Gc<ast::Expr>;
 134     fn expr_block(&self, b: P<ast::Block>) -> Gc<ast::Expr>;
 135     fn expr_cast(&self, sp: Span, expr: Gc<ast::Expr>,
 136                  ty: P<ast::Ty>) -> Gc<ast::Expr>;
 137
 138     fn field_imm(&self, span: Span, name: Ident, e: Gc<ast::Expr>) -> ast::Field;
 139     fn expr_struct(&self, span: Span, path: ast::Path,
 140                    fields: Vec<ast::Field> ) -> Gc<ast::Expr>;
 141     fn expr_struct_ident(&self, span: Span, id: ast::Ident,
 142                          fields: Vec<ast::Field> ) -> Gc<ast::Expr>;
 143
 144     fn expr_lit(&self, sp: Span, lit: ast::Lit_) -> Gc<ast::Expr>;
 145
 146     fn expr_uint(&self, span: Span, i: uint) -> Gc<ast::Expr>;
 147     fn expr_int(&self, sp: Span, i: int) -> Gc<ast::Expr>;
 148     fn expr_u8(&self, sp: Span, u: u8) -> Gc<ast::Expr>;
 149     fn expr_bool(&self, sp: Span, value: bool) -> Gc<ast::Expr>;
 150
 151     fn expr_vec(&self, sp: Span, exprs: Vec<Gc<ast::Expr>> ) -> Gc<ast::Expr>;
 152     fn expr_vec_ng(&self, sp: Span) -> Gc<ast::Expr>;
 153     fn expr_vec_slice(&self, sp: Span, exprs: Vec<Gc<ast::Expr>> ) -> Gc<ast::Expr>;
 154     fn expr_str(&self, sp: Span, s: InternedString) -> Gc<ast::Expr>;
 155
 156     fn expr_some(&self, sp: Span, expr: Gc<ast::Expr>) -> Gc<ast::Expr>;
 157     fn expr_none(&self, sp: Span) -> Gc<ast::Expr>;
 158
 159     fn expr_tuple(&self, sp: Span, exprs: Vec<Gc<ast::Expr>>) -> Gc<ast::Expr>;
 160
 161     fn expr_fail(&self, span: Span, msg: InternedString) -> Gc<ast::Expr>;
 162     fn expr_unreachable(&self, span: Span) -> Gc<ast::Expr>;
 163
 164     fn expr_ok(&self, span: Span, expr: Gc<ast::Expr>) -> Gc<ast::Expr>;
 165     fn expr_err(&self, span: Span, expr: Gc<ast::Expr>) -> Gc<ast::Expr>;
 166     fn expr_try(&self, span: Span, head: Gc<ast::Expr>) -> Gc<ast::Expr>;
 167
 168     fn pat(&self, span: Span, pat: ast::Pat_) -> Gc<ast::Pat>;
 169     fn pat_wild(&self, span: Span) -> Gc<ast::Pat>;
 170     fn pat_lit(&self, span: Span, expr: Gc<ast::Expr>) -> Gc<ast::Pat>;
 171     fn pat_ident(&self, span: Span, ident: ast::Ident) -> Gc<ast::Pat>;
 172
 173     fn pat_ident_binding_mode(&self,
 174                               span: Span,
 175                               ident: ast::Ident,
 176                               bm: ast::BindingMode) -> Gc<ast::Pat>;
 177     fn pat_enum(&self, span: Span, path: ast::Path,
 178                 subpats: Vec<Gc<ast::Pat>>) -> Gc<ast::Pat>;
 179     fn pat_struct(&self, span: Span,
 180                   path: ast::Path, field_pats: Vec<ast::FieldPat> ) -> Gc<ast::Pat>;
 181     fn pat_tuple(&self, span: Span, pats: Vec<Gc<ast::Pat>>) -> Gc<ast::Pat>;
 182
 183     fn pat_some(&self, span: Span, pat: Gc<ast::Pat>) -> Gc<ast::Pat>;
 184     fn pat_none(&self, span: Span) -> Gc<ast::Pat>;
 185
 186     fn pat_ok(&self, span: Span, pat: Gc<ast::Pat>) -> Gc<ast::Pat>;
 187     fn pat_err(&self, span: Span, pat: Gc<ast::Pat>) -> Gc<ast::Pat>;
 188
 189     fn arm(&self, span: Span, pats: Vec<Gc<ast::Pat>> , expr: Gc<ast::Expr>) -> ast::Arm;
 190     fn arm_unreachable(&self, span: Span) -> ast::Arm;
 191
 192     fn expr_match(&self, span: Span, arg: Gc<ast::Expr>, arms: Vec<ast::Arm> ) -> Gc<ast::Expr>;
 193     fn expr_if(&self, span: Span,
 194                cond: Gc<ast::Expr>, then: Gc<ast::Expr>,
 195                els: Option<Gc<ast::Expr>>) -> Gc<ast::Expr>;
 196     fn expr_loop(&self, span: Span, block: P<ast::Block>) -> Gc<ast::Expr>;
 197
 198     fn lambda_fn_decl(&self, span: Span,
 199                       fn_decl: P<ast::FnDecl>, blk: P<ast::Block>) -> Gc<ast::Expr>;
 200
 201     fn lambda(&self, span: Span, ids: Vec<ast::Ident> , blk: P<ast::Block>) -> Gc<ast::Expr>;
 202     fn lambda0(&self, span: Span, blk: P<ast::Block>) -> Gc<ast::Expr>;
 203     fn lambda1(&self, span: Span, blk: P<ast::Block>, ident: ast::Ident) -> Gc<ast::Expr>;
 204
 205     fn lambda_expr(&self, span: Span, ids: Vec<ast::Ident> , blk: Gc<ast::Expr>) -> Gc<ast::Expr>;
 206     fn lambda_expr_0(&self, span: Span, expr: Gc<ast::Expr>) -> Gc<ast::Expr>;
 207     fn lambda_expr_1(&self, span: Span, expr: Gc<ast::Expr>, ident: ast::Ident) -> Gc<ast::Expr>;
 208
 209     fn lambda_stmts(&self, span: Span, ids: Vec<ast::Ident>,
 210                     blk: Vec<Gc<ast::Stmt>>) -> Gc<ast::Expr>;
 211     fn lambda_stmts_0(&self, span: Span,
 212                       stmts: Vec<Gc<ast::Stmt>>) -> Gc<ast::Expr>;
 213     fn lambda_stmts_1(&self, span: Span,
 214                       stmts: Vec<Gc<ast::Stmt>>, ident: ast::Ident) -> Gc<ast::Expr>;
 215
 216     // items
 217     fn item(&self, span: Span,
 218             name: Ident, attrs: Vec<ast::Attribute>,
 219             node: ast::Item_) -> Gc<ast::Item>;
 220
 221     fn arg(&self, span: Span, name: Ident, ty: P<ast::Ty>) -> ast::Arg;
 222     // FIXME unused self
 223     fn fn_decl(&self, inputs: Vec<ast::Arg> , output: P<ast::Ty>) -> P<ast::FnDecl>;
 224
 225     fn item_fn_poly(&self,
 226                     span: Span,
 227                     name: Ident,
 228                     inputs: Vec<ast::Arg> ,
 229                     output: P<ast::Ty>,
 230                     generics: Generics,
 231                     body: P<ast::Block>) -> Gc<ast::Item>;
 232     fn item_fn(&self,
 233                span: Span,
 234                name: Ident,
 235                inputs: Vec<ast::Arg> ,
 236                output: P<ast::Ty>,
 237                body: P<ast::Block>) -> Gc<ast::Item>;
 238
 239     fn variant(&self, span: Span, name: Ident, tys: Vec<P<ast::Ty>> ) -> ast::Variant;
 240     fn item_enum_poly(&self,
 241                       span: Span,
 242                       name: Ident,
 243                       enum_definition: ast::EnumDef,
 244                       generics: Generics) -> Gc<ast::Item>;
 245     fn item_enum(&self, span: Span, name: Ident,
 246                  enum_def: ast::EnumDef) -> Gc<ast::Item>;
 247
 248     fn item_struct_poly(&self,
 249                         span: Span,
 250                         name: Ident,
 251                         struct_def: ast::StructDef,
 252                         generics: Generics) -> Gc<ast::Item>;
 253     fn item_struct(&self, span: Span, name: Ident,
 254                    struct_def: ast::StructDef) -> Gc<ast::Item>;
 255
 256     fn item_mod(&self, span: Span, inner_span: Span,
 257                 name: Ident, attrs: Vec<ast::Attribute>,
 258                 vi: Vec<ast::ViewItem>,
 259                 items: Vec<Gc<ast::Item>>) -> Gc<ast::Item>;
 260
 261     fn item_static(&self,
 262                    span: Span,
 263                    name: Ident,
 264                    ty: P<ast::Ty>,
 265                    mutbl: ast::Mutability,
 266                    expr: Gc<ast::Expr>)
 267                    -> Gc<ast::Item>;
 268
 269     fn item_ty_poly(&self,
 270                     span: Span,
 271                     name: Ident,
 272                     ty: P<ast::Ty>,
 273                     generics: Generics) -> Gc<ast::Item>;
 274     fn item_ty(&self, span: Span, name: Ident, ty: P<ast::Ty>) -> Gc<ast::Item>;
 275
 276     fn attribute(&self, sp: Span, mi: Gc<ast::MetaItem>) -> ast::Attribute;
 277
 278     fn meta_word(&self, sp: Span, w: InternedString) -> Gc<ast::MetaItem>;
 279     fn meta_list(&self,
 280                  sp: Span,
 281                  name: InternedString,
 282                  mis: Vec<Gc<ast::MetaItem>>)
 283                  -> Gc<ast::MetaItem>;
 284     fn meta_name_value(&self,
 285                        sp: Span,
 286                        name: InternedString,
 287                        value: ast::Lit_)
 288                        -> Gc<ast::MetaItem>;
 289
 290     fn view_use(&self, sp: Span,
 291                 vis: ast::Visibility, vp: Gc<ast::ViewPath>) -> ast::ViewItem;
 292     fn view_use_simple(&self, sp: Span, vis: ast::Visibility, path: ast::Path) -> ast::ViewItem;
 293     fn view_use_simple_(&self, sp: Span, vis: ast::Visibility,
 294                         ident: ast::Ident, path: ast::Path) -> ast::ViewItem;
 295     fn view_use_list(&self, sp: Span, vis: ast::Visibility,
 296                      path: Vec<ast::Ident> , imports: &[ast::Ident]) -> ast::ViewItem;
 297     fn view_use_glob(&self, sp: Span,
 298                      vis: ast::Visibility, path: Vec<ast::Ident> ) -> ast::ViewItem;
 299 }
 300
 301 impl<'a> AstBuilder for ExtCtxt<'a> {
 302     fn path(&self, span: Span, strs: Vec<ast::Ident> ) -> ast::Path {
 303         self.path_all(span, false, strs, Vec::new(), Vec::new())
 304     }
 305     fn path_ident(&self, span: Span, id: ast::Ident) -> ast::Path {
 306         self.path(span, vec!(id))
 307     }
 308     fn path_global(&self, span: Span, strs: Vec<ast::Ident> ) -> ast::Path {
 309         self.path_all(span, true, strs, Vec::new(), Vec::new())
 310     }
 311     fn path_all(&self,
 312                 sp: Span,
 313                 global: bool,
 314                 mut idents: Vec<ast::Ident> ,
 315                 lifetimes: Vec<ast::Lifetime>,
 316                 types: Vec<P<ast::Ty>> )
 317                 -> ast::Path {
 318         let last_identifier = idents.pop().unwrap();
 319         let mut segments: Vec<ast::PathSegment> = idents.move_iter()
 320                                                       .map(|ident| {
 321             ast::PathSegment {
 322                 identifier: ident,
 323                 lifetimes: Vec::new(),
 324                 types: OwnedSlice::empty(),
 325             }
 326         }).collect();
 327         segments.push(ast::PathSegment {
 328             identifier: last_identifier,
 329             lifetimes: lifetimes,
 330             types: OwnedSlice::from_vec(types),
 331         });
 332         ast::Path {
 333             span: sp,
 334             global: global,
 335             segments: segments,
 336         }
 337     }
 338
 339     fn ty_mt(&self, ty: P<ast::Ty>, mutbl: ast::Mutability) -> ast::MutTy {
 340         ast::MutTy {
 341             ty: ty,
 342             mutbl: mutbl
 343         }
 344     }
 345
 346     fn ty(&self, span: Span, ty: ast::Ty_) -> P<ast::Ty> {
 347         P(ast::Ty {
 348             id: ast::DUMMY_NODE_ID,
 349             span: span,
 350             node: ty
 351         })
 352     }
 353
 354     fn ty_path(&self, path: ast::Path, bounds: Option<OwnedSlice<ast::TyParamBound>>)
 355               -> P<ast::Ty> {
 356         self.ty(path.span,
 357                 ast::TyPath(path, bounds, ast::DUMMY_NODE_ID))
 358     }
 359
 360     // Might need to take bounds as an argument in the future, if you ever want
 361     // to generate a bounded existential trait type.
 362     fn ty_ident(&self, span: Span, ident: ast::Ident)
 363         -> P<ast::Ty> {
 364         self.ty_path(self.path_ident(span, ident), None)
 365     }
 366
 367     fn ty_rptr(&self,
 368                span: Span,
 369                ty: P<ast::Ty>,
 370                lifetime: Option<ast::Lifetime>,
 371                mutbl: ast::Mutability)
 372         -> P<ast::Ty> {
 373         self.ty(span,
 374                 ast::TyRptr(lifetime, self.ty_mt(ty, mutbl)))
 375     }
 376
 377     fn ty_ptr(&self,
 378               span: Span,
 379               ty: P<ast::Ty>,
 380               mutbl: ast::Mutability)
 381         -> P<ast::Ty> {
 382         self.ty(span,
 383                 ast::TyPtr(self.ty_mt(ty, mutbl)))
 384     }
 385     fn ty_uniq(&self, span: Span, ty: P<ast::Ty>) -> P<ast::Ty> {
 386         self.ty(span, ast::TyUniq(ty))
 387     }
 388
 389     fn ty_option(&self, ty: P<ast::Ty>) -> P<ast::Ty> {
 390         self.ty_path(
 391             self.path_all(DUMMY_SP,
 392                           true,
 393                           vec!(
 394                               self.ident_of("std"),
 395                               self.ident_of("option"),
 396                               self.ident_of("Option")
 397                           ),
 398                           Vec::new(),
 399                           vec!( ty )), None)
 400     }
 401
 402     fn ty_field_imm(&self, span: Span, name: Ident, ty: P<ast::Ty>) -> ast::TypeField {
 403         ast::TypeField {
 404             ident: name,
 405             mt: ast::MutTy { ty: ty, mutbl: ast::MutImmutable },
 406             span: span,
 407         }
 408     }
 409
 410     fn ty_infer(&self, span: Span) -> P<ast::Ty> {
 411         self.ty(span, ast::TyInfer)
 412     }
 413
 414     fn ty_nil(&self) -> P<ast::Ty> {
 415         P(ast::Ty {
 416             id: ast::DUMMY_NODE_ID,
 417             node: ast::TyNil,
 418             span: DUMMY_SP,
 419         })
 420     }
 421
 422     fn typaram(&self,
 423                span: Span,
 424                id: ast::Ident,
 425                bounds: OwnedSlice<ast::TyParamBound>,
 426                unbound: Option<ast::TyParamBound>,
 427                default: Option<P<ast::Ty>>) -> ast::TyParam {
 428         ast::TyParam {
 429             ident: id,
 430             id: ast::DUMMY_NODE_ID,
 431             bounds: bounds,
 432             unbound: unbound,
 433             default: default,
 434             span: span
 435         }
 436     }
 437
 438     // these are strange, and probably shouldn't be used outside of
 439     // pipes. Specifically, the global version possible generates
 440     // incorrect code.
 441     fn ty_vars(&self, ty_params: &OwnedSlice<ast::TyParam>) -> Vec<P<ast::Ty>> {
 442         ty_params.iter().map(|p| self.ty_ident(DUMMY_SP, p.ident)).collect()
 443     }
 444
 445     fn ty_vars_global(&self, ty_params: &OwnedSlice<ast::TyParam>) -> Vec<P<ast::Ty>> {
 446         ty_params.iter().map(|p| self.ty_path(
 447                 self.path_global(DUMMY_SP, vec!(p.ident)), None)).collect()
 448     }
 449
 450     fn strip_bounds(&self, generics: &Generics) -> Generics {
 451         let new_params = generics.ty_params.map(|ty_param| {
 452             ast::TyParam { bounds: OwnedSlice::empty(), unbound: None, ..*ty_param }
 453         });
 454         Generics {
 455             ty_params: new_params,
 456             .. (*generics).clone()
 457         }
 458     }
 459
 460     fn trait_ref(&self, path: ast::Path) -> ast::TraitRef {
 461         ast::TraitRef {
 462             path: path,
 463             ref_id: ast::DUMMY_NODE_ID
 464         }
 465     }
 466
 467     fn typarambound(&self, path: ast::Path) -> ast::TyParamBound {
 468         ast::TraitTyParamBound(self.trait_ref(path))
 469     }
 470
 471     fn lifetime(&self, span: Span, name: ast::Name) -> ast::Lifetime {
 472         ast::Lifetime { id: ast::DUMMY_NODE_ID, span: span, name: name }
 473     }
 474
 475     fn lifetime_def(&self,
 476                     span: Span,
 477                     name: ast::Name,
 478                     bounds: Vec<ast::Lifetime>)
 479                     -> ast::LifetimeDef {
 480         ast::LifetimeDef {
 481             lifetime: self.lifetime(span, name),
 482             bounds: bounds
 483         }
 484     }
 485
 486     fn stmt_expr(&self, expr: Gc<ast::Expr>) -> Gc<ast::Stmt> {
 487         box(GC) respan(expr.span, ast::StmtSemi(expr, ast::DUMMY_NODE_ID))
 488     }
 489
 490     fn stmt_let(&self, sp: Span, mutbl: bool, ident: ast::Ident,
 491                 ex: Gc<ast::Expr>) -> Gc<ast::Stmt> {
 492         let pat = if mutbl {
 493             self.pat_ident_binding_mode(sp, ident, ast::BindByValue(ast::MutMutable))
 494         } else {
 495             self.pat_ident(sp, ident)
 496         };
 497         let local = box(GC) ast::Local {
 498             ty: self.ty_infer(sp),
 499             pat: pat,
 500             init: Some(ex),
 501             id: ast::DUMMY_NODE_ID,
 502             span: sp,
 503             source: ast::LocalLet,
 504         };
 505         let decl = respan(sp, ast::DeclLocal(local));
 506         box(GC) respan(sp, ast::StmtDecl(box(GC) decl, ast::DUMMY_NODE_ID))
 507     }
 508
 509     fn stmt_let_typed(&self,
 510                       sp: Span,
 511                       mutbl: bool,
 512                       ident: ast::Ident,
 513                       typ: P<ast::Ty>,
 514                       ex: Gc<ast::Expr>)
 515                       -> Gc<ast::Stmt> {
 516         let pat = if mutbl {
 517             self.pat_ident_binding_mode(sp, ident, ast::BindByValue(ast::MutMutable))
 518         } else {
 519             self.pat_ident(sp, ident)
 520         };
 521         let local = box(GC) ast::Local {
 522             ty: typ,
 523             pat: pat,
 524             init: Some(ex),
 525             id: ast::DUMMY_NODE_ID,
 526             span: sp,
 527             source: ast::LocalLet,
 528         };
 529         let decl = respan(sp, ast::DeclLocal(local));
 530         box(GC) respan(sp, ast::StmtDecl(box(GC) decl, ast::DUMMY_NODE_ID))
 531     }
 532
 533     fn block(&self,
 534              span: Span,
 535              stmts: Vec<Gc<ast::Stmt>>,
 536              expr: Option<Gc<Expr>>)
 537              -> P<ast::Block> {
 538         self.block_all(span, Vec::new(), stmts, expr)
 539     }
 540
 541     fn stmt_item(&self, sp: Span, item: Gc<ast::Item>) -> Gc<ast::Stmt> {
 542         let decl = respan(sp, ast::DeclItem(item));
 543         box(GC) respan(sp, ast::StmtDecl(box(GC) decl, ast::DUMMY_NODE_ID))
 544     }
 545
 546     fn block_expr(&self, expr: Gc<ast::Expr>) -> P<ast::Block> {
 547         self.block_all(expr.span, Vec::new(), Vec::new(), Some(expr))
 548     }
 549     fn block_all(&self,
 550                  span: Span,
 551                  view_items: Vec<ast::ViewItem> ,
 552                  stmts: Vec<Gc<ast::Stmt>>,
 553                  expr: Option<Gc<ast::Expr>>) -> P<ast::Block> {
 554             P(ast::Block {
 555                view_items: view_items,
 556                stmts: stmts,
 557                expr: expr,
 558                id: ast::DUMMY_NODE_ID,
 559                rules: ast::DefaultBlock,
 560                span: span,
 561             })
 562     }
 563
 564     fn expr(&self, span: Span, node: ast::Expr_) -> Gc<ast::Expr> {
 565         box(GC) ast::Expr {
 566             id: ast::DUMMY_NODE_ID,
 567             node: node,
 568             span: span,
 569         }
 570     }
 571
 572     fn expr_path(&self, path: ast::Path) -> Gc<ast::Expr> {
 573         self.expr(path.span, ast::ExprPath(path))
 574     }
 575
 576     fn expr_ident(&self, span: Span, id: ast::Ident) -> Gc<ast::Expr> {
 577         self.expr_path(self.path_ident(span, id))
 578     }
 579     fn expr_self(&self, span: Span) -> Gc<ast::Expr> {
 580         self.expr_ident(span, special_idents::self_)
 581     }
 582
 583     fn expr_binary(&self, sp: Span, op: ast::BinOp,
 584                    lhs: Gc<ast::Expr>, rhs: Gc<ast::Expr>) -> Gc<ast::Expr> {
 585         self.expr(sp, ast::ExprBinary(op, lhs, rhs))
 586     }
 587
 588     fn expr_deref(&self, sp: Span, e: Gc<ast::Expr>) -> Gc<ast::Expr> {
 589         self.expr_unary(sp, ast::UnDeref, e)
 590     }
 591     fn expr_unary(&self, sp: Span, op: ast::UnOp, e: Gc<ast::Expr>) -> Gc<ast::Expr> {
 592         self.expr(sp, ast::ExprUnary(op, e))
 593     }
 594
 595     fn expr_managed(&self, sp: Span, e: Gc<ast::Expr>) -> Gc<ast::Expr> {
 596         self.expr_unary(sp, ast::UnBox, e)
 597     }
 598
 599     fn expr_field_access(&self, sp: Span, expr: Gc<ast::Expr>, ident: ast::Ident) -> Gc<ast::Expr> {
 600         let field_name = token::get_ident(ident);
 601         let field_span = Span {
 602             lo: sp.lo - Pos::from_uint(field_name.get().len()),
 603             hi: sp.hi,
 604             expn_info: sp.expn_info,
 605         };
 606
 607         let id = Spanned { node: ident, span: field_span };
 608         self.expr(sp, ast::ExprField(expr, id, Vec::new()))
 609     }
 610     fn expr_tup_field_access(&self, sp: Span, expr: Gc<ast::Expr>, idx: uint) -> Gc<ast::Expr> {
 611         let field_span = Span {
 612             lo: sp.lo - Pos::from_uint(idx.to_string().len()),
 613             hi: sp.hi,
 614             expn_info: sp.expn_info,
 615         };
 616
 617         let id = Spanned { node: idx, span: field_span };
 618         self.expr(sp, ast::ExprTupField(expr, id, Vec::new()))
 619     }
 620     fn expr_addr_of(&self, sp: Span, e: Gc<ast::Expr>) -> Gc<ast::Expr> {
 621         self.expr(sp, ast::ExprAddrOf(ast::MutImmutable, e))
 622     }
 623     fn expr_mut_addr_of(&self, sp: Span, e: Gc<ast::Expr>) -> Gc<ast::Expr> {
 624         self.expr(sp, ast::ExprAddrOf(ast::MutMutable, e))
 625     }
 626
 627     fn expr_call(&self, span: Span, expr: Gc<ast::Expr>,
 628                  args: Vec<Gc<ast::Expr>>) -> Gc<ast::Expr> {
 629         self.expr(span, ast::ExprCall(expr, args))
 630     }
 631     fn expr_call_ident(&self, span: Span, id: ast::Ident,
 632                        args: Vec<Gc<ast::Expr>>) -> Gc<ast::Expr> {
 633         self.expr(span, ast::ExprCall(self.expr_ident(span, id), args))
 634     }
 635     fn expr_call_global(&self, sp: Span, fn_path: Vec<ast::Ident> ,
 636                       args: Vec<Gc<ast::Expr>> ) -> Gc<ast::Expr> {
 637         let pathexpr = self.expr_path(self.path_global(sp, fn_path));
 638         self.expr_call(sp, pathexpr, args)
 639     }
 640     fn expr_method_call(&self, span: Span,
 641                         expr: Gc<ast::Expr>,
 642                         ident: ast::Ident,
 643                         mut args: Vec<Gc<ast::Expr>> ) -> Gc<ast::Expr> {
 644         let id = Spanned { node: ident, span: span };
 645         args.unshift(expr);
 646         self.expr(span, ast::ExprMethodCall(id, Vec::new(), args))
 647     }
 648     fn expr_block(&self, b: P<ast::Block>) -> Gc<ast::Expr> {
 649         self.expr(b.span, ast::ExprBlock(b))
 650     }
 651     fn field_imm(&self, span: Span, name: Ident, e: Gc<ast::Expr>) -> ast::Field {
 652         ast::Field { ident: respan(span, name), expr: e, span: span }
 653     }
 654     fn expr_struct(&self, span: Span, path: ast::Path, fields: Vec<ast::Field> ) -> Gc<ast::Expr> {
 655         self.expr(span, ast::ExprStruct(path, fields, None))
 656     }
 657     fn expr_struct_ident(&self, span: Span,
 658                          id: ast::Ident, fields: Vec<ast::Field> ) -> Gc<ast::Expr> {
 659         self.expr_struct(span, self.path_ident(span, id), fields)
 660     }
 661
 662     fn expr_lit(&self, sp: Span, lit: ast::Lit_) -> Gc<ast::Expr> {
 663         self.expr(sp, ast::ExprLit(box(GC) respan(sp, lit)))
 664     }
 665     fn expr_uint(&self, span: Span, i: uint) -> Gc<ast::Expr> {
 666         self.expr_lit(span, ast::LitInt(i as u64, ast::UnsignedIntLit(ast::TyU)))
 667     }
 668     fn expr_int(&self, sp: Span, i: int) -> Gc<ast::Expr> {
 669         self.expr_lit(sp, ast::LitInt(i as u64, ast::SignedIntLit(ast::TyI, ast::Sign::new(i))))
 670     }
 671     fn expr_u8(&self, sp: Span, u: u8) -> Gc<ast::Expr> {
 672         self.expr_lit(sp, ast::LitInt(u as u64, ast::UnsignedIntLit(ast::TyU8)))
 673     }
 674     fn expr_bool(&self, sp: Span, value: bool) -> Gc<ast::Expr> {
 675         self.expr_lit(sp, ast::LitBool(value))
 676     }
 677
 678     fn expr_vec(&self, sp: Span, exprs: Vec<Gc<ast::Expr>> ) -> Gc<ast::Expr> {
 679         self.expr(sp, ast::ExprVec(exprs))
 680     }
 681     fn expr_vec_ng(&self, sp: Span) -> Gc<ast::Expr> {
 682         self.expr_call_global(sp,
 683                               vec!(self.ident_of("std"),
 684                                    self.ident_of("vec"),
 685                                    self.ident_of("Vec"),
 686                                    self.ident_of("new")),
 687                               Vec::new())
 688     }
 689     fn expr_vec_slice(&self, sp: Span, exprs: Vec<Gc<ast::Expr>> ) -> Gc<ast::Expr> {
 690         self.expr_addr_of(sp, self.expr_vec(sp, exprs))
 691     }
 692     fn expr_str(&self, sp: Span, s: InternedString) -> Gc<ast::Expr> {
 693         self.expr_lit(sp, ast::LitStr(s, ast::CookedStr))
 694     }
 695
 696     fn expr_cast(&self, sp: Span, expr: Gc<ast::Expr>, ty: P<ast::Ty>) -> Gc<ast::Expr> {
 697         self.expr(sp, ast::ExprCast(expr, ty))
 698     }
 699
 700
 701     fn expr_some(&self, sp: Span, expr: Gc<ast::Expr>) -> Gc<ast::Expr> {
 702         let some = vec!(
 703             self.ident_of("std"),
 704             self.ident_of("option"),
 705             self.ident_of("Some"));
 706         self.expr_call_global(sp, some, vec!(expr))
 707     }
 708
 709     fn expr_none(&self, sp: Span) -> Gc<ast::Expr> {
 710         let none = self.path_global(sp, vec!(
 711             self.ident_of("std"),
 712             self.ident_of("option"),
 713             self.ident_of("None")));
 714         self.expr_path(none)
 715     }
 716
 717     fn expr_tuple(&self, sp: Span, exprs: Vec<Gc<ast::Expr>>) -> Gc<ast::Expr> {
 718         self.expr(sp, ast::ExprTup(exprs))
 719     }
 720
 721     fn expr_fail(&self, span: Span, msg: InternedString) -> Gc<ast::Expr> {
 722         let loc = self.codemap().lookup_char_pos(span.lo);
 723         let expr_file = self.expr_str(span,
 724                                       token::intern_and_get_ident(loc.file
 725                                                                   .name
 726                                                                   .as_slice()));
 727         let expr_line = self.expr_uint(span, loc.line);
 728         let expr_file_line_tuple = self.expr_tuple(span, vec!(expr_file, expr_line));
 729         let expr_file_line_ptr = self.expr_addr_of(span, expr_file_line_tuple);
 730         self.expr_call_global(
 731             span,
 732             vec!(
 733                 self.ident_of("std"),
 734                 self.ident_of("rt"),
 735                 self.ident_of("begin_unwind")),
 736             vec!(
 737                 self.expr_str(span, msg),
 738                 expr_file_line_ptr))
 739     }
 740
 741     fn expr_unreachable(&self, span: Span) -> Gc<ast::Expr> {
 742         self.expr_fail(span,
 743                        InternedString::new(
 744                            "internal error: entered unreachable code"))
 745     }
 746
 747     fn expr_ok(&self, sp: Span, expr: Gc<ast::Expr>) -> Gc<ast::Expr> {
 748         let ok = vec!(
 749             self.ident_of("std"),
 750             self.ident_of("result"),
 751             self.ident_of("Ok"));
 752         self.expr_call_global(sp, ok, vec!(expr))
 753     }
 754
 755     fn expr_err(&self, sp: Span, expr: Gc<ast::Expr>) -> Gc<ast::Expr> {
 756         let err = vec!(
 757             self.ident_of("std"),
 758             self.ident_of("result"),
 759             self.ident_of("Err"));
 760         self.expr_call_global(sp, err, vec!(expr))
 761     }
 762
 763     fn expr_try(&self, sp: Span, head: Gc<ast::Expr>) -> Gc<ast::Expr> {
 764         let ok = self.ident_of("Ok");
 765         let ok_path = self.path_ident(sp, ok);
 766         let err = self.ident_of("Err");
 767         let err_path = self.path_ident(sp, err);
 768
 769         let binding_variable = self.ident_of("__try_var");
 770         let binding_pat = self.pat_ident(sp, binding_variable);
 771         let binding_expr = self.expr_ident(sp, binding_variable);
 772
 773         // Ok(__try_var) pattern
 774         let ok_pat = self.pat_enum(sp, ok_path, vec!(binding_pat));
 775
 776         // Err(__try_var)  (pattern and expression resp.)
 777         let err_pat = self.pat_enum(sp, err_path, vec!(binding_pat));
 778         let err_inner_expr = self.expr_call_ident(sp, err, vec!(binding_expr));
 779         // return Err(__try_var)
 780         let err_expr = self.expr(sp, ast::ExprRet(Some(err_inner_expr)));
 781
 782         // Ok(__try_var) => __try_var
 783         let ok_arm = self.arm(sp, vec!(ok_pat), binding_expr);
 784         // Err(__try_var) => return Err(__try_var)
 785         let err_arm = self.arm(sp, vec!(err_pat), err_expr);
 786
 787         // match head { Ok() => ..., Err() => ... }
 788         self.expr_match(sp, head, vec!(ok_arm, err_arm))
 789     }
 790
 791
 792     fn pat(&self, span: Span, pat: ast::Pat_) -> Gc<ast::Pat> {
 793         box(GC) ast::Pat { id: ast::DUMMY_NODE_ID, node: pat, span: span }
 794     }
 795     fn pat_wild(&self, span: Span) -> Gc<ast::Pat> {
 796         self.pat(span, ast::PatWild(ast::PatWildSingle))
 797     }
 798     fn pat_lit(&self, span: Span, expr: Gc<ast::Expr>) -> Gc<ast::Pat> {
 799         self.pat(span, ast::PatLit(expr))
 800     }
 801     fn pat_ident(&self, span: Span, ident: ast::Ident) -> Gc<ast::Pat> {
 802         self.pat_ident_binding_mode(span, ident, ast::BindByValue(ast::MutImmutable))
 803     }
 804
 805     fn pat_ident_binding_mode(&self,
 806                               span: Span,
 807                               ident: ast::Ident,
 808                               bm: ast::BindingMode) -> Gc<ast::Pat> {
 809         let pat = ast::PatIdent(bm, Spanned{span: span, node: ident}, None);
 810         self.pat(span, pat)
 811     }
 812     fn pat_enum(&self, span: Span, path: ast::Path, subpats: Vec<Gc<ast::Pat>> ) -> Gc<ast::Pat> {
 813         let pat = ast::PatEnum(path, Some(subpats));
 814         self.pat(span, pat)
 815     }
 816     fn pat_struct(&self, span: Span,
 817                   path: ast::Path, field_pats: Vec<ast::FieldPat> ) -> Gc<ast::Pat> {
 818         let pat = ast::PatStruct(path, field_pats, false);
 819         self.pat(span, pat)
 820     }
 821     fn pat_tuple(&self, span: Span, pats: Vec<Gc<ast::Pat>>) -> Gc<ast::Pat> {
 822         let pat = ast::PatTup(pats);
 823         self.pat(span, pat)
 824     }
 825
 826     fn pat_some(&self, span: Span, pat: Gc<ast::Pat>) -> Gc<ast::Pat> {
 827         let some = vec!(
 828             self.ident_of("std"),
 829             self.ident_of("option"),
 830             self.ident_of("Some"));
 831         let path = self.path_global(span, some);
 832         self.pat_enum(span, path, vec!(pat))
 833     }
 834
 835     fn pat_none(&self, span: Span) -> Gc<ast::Pat> {
 836         let some = vec!(
 837             self.ident_of("std"),
 838             self.ident_of("option"),
 839             self.ident_of("None"));
 840         let path = self.path_global(span, some);
 841         self.pat_enum(span, path, vec!())
 842     }
 843
 844     fn pat_ok(&self, span: Span, pat: Gc<ast::Pat>) -> Gc<ast::Pat> {
 845         let some = vec!(
 846             self.ident_of("std"),
 847             self.ident_of("result"),
 848             self.ident_of("Ok"));
 849         let path = self.path_global(span, some);
 850         self.pat_enum(span, path, vec!(pat))
 851     }
 852
 853     fn pat_err(&self, span: Span, pat: Gc<ast::Pat>) -> Gc<ast::Pat> {
 854         let some = vec!(
 855             self.ident_of("std"),
 856             self.ident_of("result"),
 857             self.ident_of("Err"));
 858         let path = self.path_global(span, some);
 859         self.pat_enum(span, path, vec!(pat))
 860     }
 861
 862     fn arm(&self, _span: Span, pats: Vec<Gc<ast::Pat>> , expr: Gc<ast::Expr>) -> ast::Arm {
 863         ast::Arm {
 864             attrs: vec!(),
 865             pats: pats,
 866             guard: None,
 867             body: expr
 868         }
 869     }
 870
 871     fn arm_unreachable(&self, span: Span) -> ast::Arm {
 872         self.arm(span, vec!(self.pat_wild(span)), self.expr_unreachable(span))
 873     }
 874
 875     fn expr_match(&self, span: Span, arg: Gc<ast::Expr>,
 876                   arms: Vec<ast::Arm>) -> Gc<Expr> {
 877         self.expr(span, ast::ExprMatch(arg, arms))
 878     }
 879
 880     fn expr_if(&self, span: Span,
 881                cond: Gc<ast::Expr>, then: Gc<ast::Expr>,
 882                els: Option<Gc<ast::Expr>>) -> Gc<ast::Expr> {
 883         let els = els.map(|x| self.expr_block(self.block_expr(x)));
 884         self.expr(span, ast::ExprIf(cond, self.block_expr(then), els))
 885     }
 886
 887     fn expr_loop(&self, span: Span, block: P<ast::Block>) -> Gc<ast::Expr> {
 888         self.expr(span, ast::ExprLoop(block, None))
 889     }
 890
 891     fn lambda_fn_decl(&self, span: Span,
 892                       fn_decl: P<ast::FnDecl>, blk: P<ast::Block>) -> Gc<ast::Expr> {
 893         self.expr(span, ast::ExprFnBlock(ast::CaptureByRef, fn_decl, blk))
 894     }
 895     fn lambda(&self, span: Span, ids: Vec<ast::Ident> , blk: P<ast::Block>) -> Gc<ast::Expr> {
 896         let fn_decl = self.fn_decl(
 897             ids.iter().map(|id| self.arg(span, *id, self.ty_infer(span))).collect(),
 898             self.ty_infer(span));
 899
 900         self.expr(span, ast::ExprFnBlock(ast::CaptureByRef, fn_decl, blk))
 901     }
 902     fn lambda0(&self, span: Span, blk: P<ast::Block>) -> Gc<ast::Expr> {
 903         self.lambda(span, Vec::new(), blk)
 904     }
 905
 906     fn lambda1(&self, span: Span, blk: P<ast::Block>, ident: ast::Ident) -> Gc<ast::Expr> {
 907         self.lambda(span, vec!(ident), blk)
 908     }
 909
 910     fn lambda_expr(&self, span: Span, ids: Vec<ast::Ident> , expr: Gc<ast::Expr>) -> Gc<ast::Expr> {
 911         self.lambda(span, ids, self.block_expr(expr))
 912     }
 913     fn lambda_expr_0(&self, span: Span, expr: Gc<ast::Expr>) -> Gc<ast::Expr> {
 914         self.lambda0(span, self.block_expr(expr))
 915     }
 916     fn lambda_expr_1(&self, span: Span, expr: Gc<ast::Expr>, ident: ast::Ident) -> Gc<ast::Expr> {
 917         self.lambda1(span, self.block_expr(expr), ident)
 918     }
 919
 920     fn lambda_stmts(&self,
 921                     span: Span,
 922                     ids: Vec<ast::Ident>,
 923                     stmts: Vec<Gc<ast::Stmt>>)
 924                     -> Gc<ast::Expr> {
 925         self.lambda(span, ids, self.block(span, stmts, None))
 926     }
 927     fn lambda_stmts_0(&self, span: Span,
 928                       stmts: Vec<Gc<ast::Stmt>>) -> Gc<ast::Expr> {
 929         self.lambda0(span, self.block(span, stmts, None))
 930     }
 931     fn lambda_stmts_1(&self, span: Span, stmts: Vec<Gc<ast::Stmt>>,
 932                       ident: ast::Ident) -> Gc<ast::Expr> {
 933         self.lambda1(span, self.block(span, stmts, None), ident)
 934     }
 935
 936     fn arg(&self, span: Span, ident: ast::Ident, ty: P<ast::Ty>) -> ast::Arg {
 937         let arg_pat = self.pat_ident(span, ident);
 938         ast::Arg {
 939             ty: ty,
 940             pat: arg_pat,
 941             id: ast::DUMMY_NODE_ID
 942         }
 943     }
 944
 945     // FIXME unused self
 946     fn fn_decl(&self, inputs: Vec<ast::Arg> , output: P<ast::Ty>) -> P<ast::FnDecl> {
 947         P(ast::FnDecl {
 948             inputs: inputs,
 949             output: output,
 950             cf: ast::Return,
 951             variadic: false
 952         })
 953     }
 954
 955     fn item(&self, span: Span,
 956             name: Ident, attrs: Vec<ast::Attribute>,
 957             node: ast::Item_) -> Gc<ast::Item> {
 958         // FIXME: Would be nice if our generated code didn't violate
 959         // Rust coding conventions
 960         box(GC) ast::Item { ident: name,
 961                     attrs: attrs,
 962                     id: ast::DUMMY_NODE_ID,
 963                     node: node,
 964                     vis: ast::Inherited,
 965                     span: span }
 966     }
 967
 968     fn item_fn_poly(&self,
 969                     span: Span,
 970                     name: Ident,
 971                     inputs: Vec<ast::Arg> ,
 972                     output: P<ast::Ty>,
 973                     generics: Generics,
 974                     body: P<ast::Block>) -> Gc<ast::Item> {
 975         self.item(span,
 976                   name,
 977                   Vec::new(),
 978                   ast::ItemFn(self.fn_decl(inputs, output),
 979                               ast::NormalFn,
 980                               abi::Rust,
 981                               generics,
 982                               body))
 983     }
 984
 985     fn item_fn(&self,
 986                span: Span,
 987                name: Ident,
 988                inputs: Vec<ast::Arg> ,
 989                output: P<ast::Ty>,
 990                body: P<ast::Block>
 991               ) -> Gc<ast::Item> {
 992         self.item_fn_poly(
 993             span,
 994             name,
 995             inputs,
 996             output,
 997             ast_util::empty_generics(),
 998             body)
 999     }
1000
1001     fn variant(&self, span: Span, name: Ident, tys: Vec<P<ast::Ty>> ) -> ast::Variant {
1002         let args = tys.move_iter().map(|ty| {
1003             ast::VariantArg { ty: ty, id: ast::DUMMY_NODE_ID }
1004         }).collect();
1005
1006         respan(span,
1007                ast::Variant_ {
1008                    name: name,
1009                    attrs: Vec::new(),
1010                    kind: ast::TupleVariantKind(args),
1011                    id: ast::DUMMY_NODE_ID,
1012                    disr_expr: None,
1013                    vis: ast::Public
1014                })
1015     }
1016
1017     fn item_enum_poly(&self, span: Span, name: Ident,
1018                       enum_definition: ast::EnumDef,
1019                       generics: Generics) -> Gc<ast::Item> {
1020         self.item(span, name, Vec::new(), ast::ItemEnum(enum_definition, generics))
1021     }
1022
1023     fn item_enum(&self, span: Span, name: Ident,
1024                  enum_definition: ast::EnumDef) -> Gc<ast::Item> {
1025         self.item_enum_poly(span, name, enum_definition,
1026                             ast_util::empty_generics())
1027     }
1028
1029     fn item_struct(&self, span: Span, name: Ident,
1030                    struct_def: ast::StructDef) -> Gc<ast::Item> {
1031         self.item_struct_poly(
1032             span,
1033             name,
1034             struct_def,
1035             ast_util::empty_generics()
1036         )
1037     }
1038
1039     fn item_struct_poly(&self, span: Span, name: Ident,
1040         struct_def: ast::StructDef, generics: Generics) -> Gc<ast::Item> {
1041         self.item(span, name, Vec::new(), ast::ItemStruct(box(GC) struct_def, generics))
1042     }
1043
1044     fn item_mod(&self, span: Span, inner_span: Span, name: Ident,
1045                 attrs: Vec<ast::Attribute> ,
1046                 vi: Vec<ast::ViewItem> ,
1047                 items: Vec<Gc<ast::Item>>) -> Gc<ast::Item> {
1048         self.item(
1049             span,
1050             name,
1051             attrs,
1052             ast::ItemMod(ast::Mod {
1053                 inner: inner_span,
1054                 view_items: vi,
1055                 items: items,
1056             })
1057         )
1058     }
1059
1060     fn item_static(&self,
1061                    span: Span,
1062                    name: Ident,
1063                    ty: P<ast::Ty>,
1064                    mutbl: ast::Mutability,
1065                    expr: Gc<ast::Expr>)
1066                    -> Gc<ast::Item> {
1067         self.item(span, name, Vec::new(), ast::ItemStatic(ty, mutbl, expr))
1068     }
1069
1070     fn item_ty_poly(&self, span: Span, name: Ident, ty: P<ast::Ty>,
1071                     generics: Generics) -> Gc<ast::Item> {
1072         self.item(span, name, Vec::new(), ast::ItemTy(ty, generics))
1073     }
1074
1075     fn item_ty(&self, span: Span, name: Ident, ty: P<ast::Ty>) -> Gc<ast::Item> {
1076         self.item_ty_poly(span, name, ty, ast_util::empty_generics())
1077     }
1078
1079     fn attribute(&self, sp: Span, mi: Gc<ast::MetaItem>) -> ast::Attribute {
1080         respan(sp, ast::Attribute_ {
1081             id: attr::mk_attr_id(),
1082             style: ast::AttrOuter,
1083             value: mi,
1084             is_sugared_doc: false,
1085         })
1086     }
1087
1088     fn meta_word(&self, sp: Span, w: InternedString) -> Gc<ast::MetaItem> {
1089         box(GC) respan(sp, ast::MetaWord(w))
1090     }
1091     fn meta_list(&self,
1092                  sp: Span,
1093                  name: InternedString,
1094                  mis: Vec<Gc<ast::MetaItem>> )
1095                  -> Gc<ast::MetaItem> {
1096         box(GC) respan(sp, ast::MetaList(name, mis))
1097     }
1098     fn meta_name_value(&self,
1099                        sp: Span,
1100                        name: InternedString,
1101                        value: ast::Lit_)
1102                        -> Gc<ast::MetaItem> {
1103         box(GC) respan(sp, ast::MetaNameValue(name, respan(sp, value)))
1104     }
1105
1106     fn view_use(&self, sp: Span,
1107                 vis: ast::Visibility, vp: Gc<ast::ViewPath>) -> ast::ViewItem {
1108         ast::ViewItem {
1109             node: ast::ViewItemUse(vp),
1110             attrs: Vec::new(),
1111             vis: vis,
1112             span: sp
1113         }
1114     }
1115
1116     fn view_use_simple(&self, sp: Span, vis: ast::Visibility, path: ast::Path) -> ast::ViewItem {
1117         let last = path.segments.last().unwrap().identifier;
1118         self.view_use_simple_(sp, vis, last, path)
1119     }
1120
1121     fn view_use_simple_(&self, sp: Span, vis: ast::Visibility,
1122                         ident: ast::Ident, path: ast::Path) -> ast::ViewItem {
1123         self.view_use(sp, vis,
1124                       box(GC) respan(sp,
1125                            ast::ViewPathSimple(ident,
1126                                                path,
1127                                                ast::DUMMY_NODE_ID)))
1128     }
1129
1130     fn view_use_list(&self, sp: Span, vis: ast::Visibility,
1131                      path: Vec<ast::Ident> , imports: &[ast::Ident]) -> ast::ViewItem {
1132         let imports = imports.iter().map(|id| {
1133             respan(sp, ast::PathListIdent { name: *id, id: ast::DUMMY_NODE_ID })
1134         }).collect();
1135
1136         self.view_use(sp, vis,
1137                       box(GC) respan(sp,
1138                            ast::ViewPathList(self.path(sp, path),
1139                                              imports,
1140                                              ast::DUMMY_NODE_ID)))
1141     }
1142
1143     fn view_use_glob(&self, sp: Span,
1144                      vis: ast::Visibility, path: Vec<ast::Ident> ) -> ast::ViewItem {
1145         self.view_use(sp, vis,
1146                       box(GC) respan(sp,
1147                            ast::ViewPathGlob(self.path(sp, path), ast::DUMMY_NODE_ID)))
1148     }
1149 }
1150
1151 struct Duplicator<'a>;
1152
1153 impl<'a> Folder for Duplicator<'a> {
1154     fn new_id(&mut self, _: NodeId) -> NodeId {
1155         ast::DUMMY_NODE_ID
1156     }
1157 }
1158
1159 pub trait Duplicate {
1160     //
1161     // Duplication functions
1162     //
1163     // These functions just duplicate AST nodes.
1164     //
1165
1166     fn duplicate(&self, cx: &ExtCtxt) -> Self;
1167 }
1168
1169 impl Duplicate for Gc<ast::Expr> {
1170     fn duplicate(&self, _: &ExtCtxt) -> Gc<ast::Expr> {
1171         let mut folder = Duplicator;
1172         folder.fold_expr(*self)
1173     }
1174 }