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::Abi;
  12 use ast::{self, Ident, Generics, Expr, BlockCheckMode, UnOp, PatKind};
  13 use attr;
  14 use codemap::{Span, respan, Spanned, DUMMY_SP, Pos};
  15 use ext::base::ExtCtxt;
  16 use parse::token::{self, keywords, InternedString};
  17 use ptr::P;
  18
  19 // Transitional reexports so qquote can find the paths it is looking for
  20 mod syntax {
  21     pub use ext;
  22     pub use parse;
  23 }
  24
  25 pub trait AstBuilder {
  26     // paths
  27     fn path(&self, span: Span, strs: Vec<ast::Ident> ) -> ast::Path;
  28     fn path_ident(&self, span: Span, id: ast::Ident) -> ast::Path;
  29     fn path_global(&self, span: Span, strs: Vec<ast::Ident> ) -> ast::Path;
  30     fn path_all(&self, sp: Span,
  31                 global: bool,
  32                 idents: Vec<ast::Ident> ,
  33                 lifetimes: Vec<ast::Lifetime>,
  34                 types: Vec<P<ast::Ty>>,
  35                 bindings: Vec<ast::TypeBinding> )
  36         -> ast::Path;
  37
  38     fn qpath(&self, self_type: P<ast::Ty>,
  39              trait_path: ast::Path,
  40              ident: ast::Ident)
  41              -> (ast::QSelf, ast::Path);
  42     fn qpath_all(&self, self_type: P<ast::Ty>,
  43                 trait_path: ast::Path,
  44                 ident: ast::Ident,
  45                 lifetimes: Vec<ast::Lifetime>,
  46                 types: Vec<P<ast::Ty>>,
  47                 bindings: Vec<ast::TypeBinding>)
  48                 -> (ast::QSelf, ast::Path);
  49
  50     // types
  51     fn ty_mt(&self, ty: P<ast::Ty>, mutbl: ast::Mutability) -> ast::MutTy;
  52
  53     fn ty(&self, span: Span, ty: ast::TyKind) -> P<ast::Ty>;
  54     fn ty_path(&self, ast::Path) -> P<ast::Ty>;
  55     fn ty_sum(&self, ast::Path, ast::TyParamBounds) -> P<ast::Ty>;
  56     fn ty_ident(&self, span: Span, idents: ast::Ident) -> P<ast::Ty>;
  57
  58     fn ty_rptr(&self, span: Span,
  59                ty: P<ast::Ty>,
  60                lifetime: Option<ast::Lifetime>,
  61                mutbl: ast::Mutability) -> P<ast::Ty>;
  62     fn ty_ptr(&self, span: Span,
  63               ty: P<ast::Ty>,
  64               mutbl: ast::Mutability) -> P<ast::Ty>;
  65
  66     fn ty_option(&self, ty: P<ast::Ty>) -> P<ast::Ty>;
  67     fn ty_infer(&self, sp: Span) -> P<ast::Ty>;
  68
  69     fn ty_vars(&self, ty_params: &P<[ast::TyParam]>) -> Vec<P<ast::Ty>> ;
  70     fn ty_vars_global(&self, ty_params: &P<[ast::TyParam]>) -> Vec<P<ast::Ty>> ;
  71
  72     fn typaram(&self,
  73                span: Span,
  74                id: ast::Ident,
  75                bounds: ast::TyParamBounds,
  76                default: Option<P<ast::Ty>>) -> ast::TyParam;
  77
  78     fn trait_ref(&self, path: ast::Path) -> ast::TraitRef;
  79     fn poly_trait_ref(&self, span: Span, path: ast::Path) -> ast::PolyTraitRef;
  80     fn typarambound(&self, path: ast::Path) -> ast::TyParamBound;
  81     fn lifetime(&self, span: Span, ident: ast::Name) -> ast::Lifetime;
  82     fn lifetime_def(&self,
  83                     span: Span,
  84                     name: ast::Name,
  85                     bounds: Vec<ast::Lifetime>)
  86                     -> ast::LifetimeDef;
  87
  88     // statements
  89     fn stmt_expr(&self, expr: P<ast::Expr>) -> ast::Stmt;
  90     fn stmt_semi(&self, expr: P<ast::Expr>) -> ast::Stmt;
  91     fn stmt_let(&self, sp: Span, mutbl: bool, ident: ast::Ident, ex: P<ast::Expr>) -> ast::Stmt;
  92     fn stmt_let_typed(&self,
  93                       sp: Span,
  94                       mutbl: bool,
  95                       ident: ast::Ident,
  96                       typ: P<ast::Ty>,
  97                       ex: P<ast::Expr>)
  98                       -> P<ast::Stmt>;
  99     fn stmt_item(&self, sp: Span, item: P<ast::Item>) -> ast::Stmt;
 100
 101     // blocks
 102     fn block(&self, span: Span, stmts: Vec<ast::Stmt>) -> P<ast::Block>;
 103     fn block_expr(&self, expr: P<ast::Expr>) -> P<ast::Block>;
 104
 105     // expressions
 106     fn expr(&self, span: Span, node: ast::ExprKind) -> P<ast::Expr>;
 107     fn expr_path(&self, path: ast::Path) -> P<ast::Expr>;
 108     fn expr_qpath(&self, span: Span, qself: ast::QSelf, path: ast::Path) -> P<ast::Expr>;
 109     fn expr_ident(&self, span: Span, id: ast::Ident) -> P<ast::Expr>;
 110
 111     fn expr_self(&self, span: Span) -> P<ast::Expr>;
 112     fn expr_binary(&self, sp: Span, op: ast::BinOpKind,
 113                    lhs: P<ast::Expr>, rhs: P<ast::Expr>) -> P<ast::Expr>;
 114     fn expr_deref(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr>;
 115     fn expr_unary(&self, sp: Span, op: ast::UnOp, e: P<ast::Expr>) -> P<ast::Expr>;
 116
 117     fn expr_addr_of(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr>;
 118     fn expr_mut_addr_of(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr>;
 119     fn expr_field_access(&self, span: Span, expr: P<ast::Expr>, ident: ast::Ident) -> P<ast::Expr>;
 120     fn expr_tup_field_access(&self, sp: Span, expr: P<ast::Expr>,
 121                              idx: usize) -> P<ast::Expr>;
 122     fn expr_call(&self, span: Span, expr: P<ast::Expr>, args: Vec<P<ast::Expr>>) -> P<ast::Expr>;
 123     fn expr_call_ident(&self, span: Span, id: ast::Ident, args: Vec<P<ast::Expr>>) -> P<ast::Expr>;
 124     fn expr_call_global(&self, sp: Span, fn_path: Vec<ast::Ident>,
 125                         args: Vec<P<ast::Expr>> ) -> P<ast::Expr>;
 126     fn expr_method_call(&self, span: Span,
 127                         expr: P<ast::Expr>, ident: ast::Ident,
 128                         args: Vec<P<ast::Expr>> ) -> P<ast::Expr>;
 129     fn expr_block(&self, b: P<ast::Block>) -> P<ast::Expr>;
 130     fn expr_cast(&self, sp: Span, expr: P<ast::Expr>, ty: P<ast::Ty>) -> P<ast::Expr>;
 131
 132     fn field_imm(&self, span: Span, name: Ident, e: P<ast::Expr>) -> ast::Field;
 133     fn expr_struct(&self, span: Span, path: ast::Path, fields: Vec<ast::Field>) -> P<ast::Expr>;
 134     fn expr_struct_ident(&self, span: Span, id: ast::Ident,
 135                          fields: Vec<ast::Field>) -> P<ast::Expr>;
 136
 137     fn expr_lit(&self, sp: Span, lit: ast::LitKind) -> P<ast::Expr>;
 138
 139     fn expr_usize(&self, span: Span, i: usize) -> P<ast::Expr>;
 140     fn expr_isize(&self, sp: Span, i: isize) -> P<ast::Expr>;
 141     fn expr_u8(&self, sp: Span, u: u8) -> P<ast::Expr>;
 142     fn expr_u32(&self, sp: Span, u: u32) -> P<ast::Expr>;
 143     fn expr_bool(&self, sp: Span, value: bool) -> P<ast::Expr>;
 144
 145     fn expr_vec(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr>;
 146     fn expr_vec_ng(&self, sp: Span) -> P<ast::Expr>;
 147     fn expr_vec_slice(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr>;
 148     fn expr_str(&self, sp: Span, s: InternedString) -> P<ast::Expr>;
 149
 150     fn expr_some(&self, sp: Span, expr: P<ast::Expr>) -> P<ast::Expr>;
 151     fn expr_none(&self, sp: Span) -> P<ast::Expr>;
 152
 153     fn expr_break(&self, sp: Span) -> P<ast::Expr>;
 154
 155     fn expr_tuple(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr>;
 156
 157     fn expr_fail(&self, span: Span, msg: InternedString) -> P<ast::Expr>;
 158     fn expr_unreachable(&self, span: Span) -> P<ast::Expr>;
 159
 160     fn expr_ok(&self, span: Span, expr: P<ast::Expr>) -> P<ast::Expr>;
 161     fn expr_err(&self, span: Span, expr: P<ast::Expr>) -> P<ast::Expr>;
 162     fn expr_try(&self, span: Span, head: P<ast::Expr>) -> P<ast::Expr>;
 163
 164     fn pat(&self, span: Span, pat: PatKind) -> P<ast::Pat>;
 165     fn pat_wild(&self, span: Span) -> P<ast::Pat>;
 166     fn pat_lit(&self, span: Span, expr: P<ast::Expr>) -> P<ast::Pat>;
 167     fn pat_ident(&self, span: Span, ident: ast::Ident) -> P<ast::Pat>;
 168
 169     fn pat_ident_binding_mode(&self,
 170                               span: Span,
 171                               ident: ast::Ident,
 172                               bm: ast::BindingMode) -> P<ast::Pat>;
 173     fn pat_enum(&self, span: Span, path: ast::Path, subpats: Vec<P<ast::Pat>> ) -> P<ast::Pat>;
 174     fn pat_struct(&self, span: Span,
 175                   path: ast::Path, field_pats: Vec<Spanned<ast::FieldPat>> ) -> P<ast::Pat>;
 176     fn pat_tuple(&self, span: Span, pats: Vec<P<ast::Pat>>) -> P<ast::Pat>;
 177
 178     fn pat_some(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat>;
 179     fn pat_none(&self, span: Span) -> P<ast::Pat>;
 180
 181     fn pat_ok(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat>;
 182     fn pat_err(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat>;
 183
 184     fn arm(&self, span: Span, pats: Vec<P<ast::Pat>>, expr: P<ast::Expr>) -> ast::Arm;
 185     fn arm_unreachable(&self, span: Span) -> ast::Arm;
 186
 187     fn expr_match(&self, span: Span, arg: P<ast::Expr>, arms: Vec<ast::Arm> ) -> P<ast::Expr>;
 188     fn expr_if(&self, span: Span,
 189                cond: P<ast::Expr>, then: P<ast::Expr>, els: Option<P<ast::Expr>>) -> P<ast::Expr>;
 190     fn expr_loop(&self, span: Span, block: P<ast::Block>) -> P<ast::Expr>;
 191
 192     fn lambda_fn_decl(&self,
 193                       span: Span,
 194                       fn_decl: P<ast::FnDecl>,
 195                       blk: P<ast::Block>,
 196                       fn_decl_span: Span)
 197                       -> P<ast::Expr>;
 198
 199     fn lambda(&self, span: Span, ids: Vec<ast::Ident>, blk: P<ast::Block>) -> P<ast::Expr>;
 200     fn lambda0(&self, span: Span, blk: P<ast::Block>) -> P<ast::Expr>;
 201     fn lambda1(&self, span: Span, blk: P<ast::Block>, ident: ast::Ident) -> P<ast::Expr>;
 202
 203     fn lambda_expr(&self, span: Span, ids: Vec<ast::Ident> , blk: P<ast::Expr>) -> P<ast::Expr>;
 204     fn lambda_expr_0(&self, span: Span, expr: P<ast::Expr>) -> P<ast::Expr>;
 205     fn lambda_expr_1(&self, span: Span, expr: P<ast::Expr>, ident: ast::Ident) -> P<ast::Expr>;
 206
 207     fn lambda_stmts(&self, span: Span, ids: Vec<ast::Ident>,
 208                     blk: Vec<ast::Stmt>) -> P<ast::Expr>;
 209     fn lambda_stmts_0(&self, span: Span, stmts: Vec<ast::Stmt>) -> P<ast::Expr>;
 210     fn lambda_stmts_1(&self, span: Span, stmts: Vec<ast::Stmt>,
 211                       ident: ast::Ident) -> P<ast::Expr>;
 212
 213     // items
 214     fn item(&self, span: Span,
 215             name: Ident, attrs: Vec<ast::Attribute> , node: ast::ItemKind) -> P<ast::Item>;
 216
 217     fn arg(&self, span: Span, name: Ident, ty: P<ast::Ty>) -> ast::Arg;
 218     // FIXME unused self
 219     fn fn_decl(&self, inputs: Vec<ast::Arg> , output: P<ast::Ty>) -> P<ast::FnDecl>;
 220
 221     fn item_fn_poly(&self,
 222                     span: Span,
 223                     name: Ident,
 224                     inputs: Vec<ast::Arg> ,
 225                     output: P<ast::Ty>,
 226                     generics: Generics,
 227                     body: P<ast::Block>) -> P<ast::Item>;
 228     fn item_fn(&self,
 229                span: Span,
 230                name: Ident,
 231                inputs: Vec<ast::Arg> ,
 232                output: P<ast::Ty>,
 233                body: P<ast::Block>) -> P<ast::Item>;
 234
 235     fn variant(&self, span: Span, name: Ident, tys: Vec<P<ast::Ty>> ) -> ast::Variant;
 236     fn item_enum_poly(&self,
 237                       span: Span,
 238                       name: Ident,
 239                       enum_definition: ast::EnumDef,
 240                       generics: Generics) -> P<ast::Item>;
 241     fn item_enum(&self, span: Span, name: Ident, enum_def: ast::EnumDef) -> P<ast::Item>;
 242
 243     fn item_struct_poly(&self,
 244                         span: Span,
 245                         name: Ident,
 246                         struct_def: ast::VariantData,
 247                         generics: Generics) -> P<ast::Item>;
 248     fn item_struct(&self, span: Span, name: Ident, struct_def: ast::VariantData) -> P<ast::Item>;
 249
 250     fn item_mod(&self, span: Span, inner_span: Span,
 251                 name: Ident, attrs: Vec<ast::Attribute>,
 252                 items: Vec<P<ast::Item>>) -> P<ast::Item>;
 253
 254     fn item_static(&self,
 255                    span: Span,
 256                    name: Ident,
 257                    ty: P<ast::Ty>,
 258                    mutbl: ast::Mutability,
 259                    expr: P<ast::Expr>)
 260                    -> P<ast::Item>;
 261
 262     fn item_const(&self,
 263                    span: Span,
 264                    name: Ident,
 265                    ty: P<ast::Ty>,
 266                    expr: P<ast::Expr>)
 267                    -> P<ast::Item>;
 268
 269     fn item_ty_poly(&self,
 270                     span: Span,
 271                     name: Ident,
 272                     ty: P<ast::Ty>,
 273                     generics: Generics) -> P<ast::Item>;
 274     fn item_ty(&self, span: Span, name: Ident, ty: P<ast::Ty>) -> P<ast::Item>;
 275
 276     fn attribute(&self, sp: Span, mi: P<ast::MetaItem>) -> ast::Attribute;
 277
 278     fn meta_word(&self, sp: Span, w: InternedString) -> P<ast::MetaItem>;
 279     fn meta_list(&self,
 280                  sp: Span,
 281                  name: InternedString,
 282                  mis: Vec<P<ast::MetaItem>> )
 283                  -> P<ast::MetaItem>;
 284     fn meta_name_value(&self,
 285                        sp: Span,
 286                        name: InternedString,
 287                        value: ast::LitKind)
 288                        -> P<ast::MetaItem>;
 289
 290     fn item_use(&self, sp: Span,
 291                 vis: ast::Visibility, vp: P<ast::ViewPath>) -> P<ast::Item>;
 292     fn item_use_simple(&self, sp: Span, vis: ast::Visibility, path: ast::Path) -> P<ast::Item>;
 293     fn item_use_simple_(&self, sp: Span, vis: ast::Visibility,
 294                         ident: ast::Ident, path: ast::Path) -> P<ast::Item>;
 295     fn item_use_list(&self, sp: Span, vis: ast::Visibility,
 296                      path: Vec<ast::Ident>, imports: &[ast::Ident]) -> P<ast::Item>;
 297     fn item_use_glob(&self, sp: Span,
 298                      vis: ast::Visibility, path: Vec<ast::Ident>) -> P<ast::Item>;
 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(), 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(), 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                 bindings: Vec<ast::TypeBinding> )
 318                 -> ast::Path {
 319         let last_identifier = idents.pop().unwrap();
 320         let mut segments: Vec<ast::PathSegment> = idents.into_iter()
 321                                                       .map(|ident| {
 322             ast::PathSegment {
 323                 identifier: ident,
 324                 parameters: ast::PathParameters::none(),
 325             }
 326         }).collect();
 327         segments.push(ast::PathSegment {
 328             identifier: last_identifier,
 329             parameters: ast::PathParameters::AngleBracketed(ast::AngleBracketedParameterData {
 330                 lifetimes: lifetimes,
 331                 types: P::from_vec(types),
 332                 bindings: P::from_vec(bindings),
 333             })
 334         });
 335         ast::Path {
 336             span: sp,
 337             global: global,
 338             segments: segments,
 339         }
 340     }
 341
 342     /// Constructs a qualified path.
 343     ///
 344     /// Constructs a path like `<self_type as trait_path>::ident`.
 345     fn qpath(&self,
 346              self_type: P<ast::Ty>,
 347              trait_path: ast::Path,
 348              ident: ast::Ident)
 349              -> (ast::QSelf, ast::Path) {
 350         self.qpath_all(self_type, trait_path, ident, vec![], vec![], vec![])
 351     }
 352
 353     /// Constructs a qualified path.
 354     ///
 355     /// Constructs a path like `<self_type as trait_path>::ident<'a, T, A=Bar>`.
 356     fn qpath_all(&self,
 357                  self_type: P<ast::Ty>,
 358                  trait_path: ast::Path,
 359                  ident: ast::Ident,
 360                  lifetimes: Vec<ast::Lifetime>,
 361                  types: Vec<P<ast::Ty>>,
 362                  bindings: Vec<ast::TypeBinding>)
 363                  -> (ast::QSelf, ast::Path) {
 364         let mut path = trait_path;
 365         path.segments.push(ast::PathSegment {
 366             identifier: ident,
 367             parameters: ast::PathParameters::AngleBracketed(ast::AngleBracketedParameterData {
 368                 lifetimes: lifetimes,
 369                 types: P::from_vec(types),
 370                 bindings: P::from_vec(bindings),
 371             })
 372         });
 373
 374         (ast::QSelf {
 375             ty: self_type,
 376             position: path.segments.len() - 1
 377         }, path)
 378     }
 379
 380     fn ty_mt(&self, ty: P<ast::Ty>, mutbl: ast::Mutability) -> ast::MutTy {
 381         ast::MutTy {
 382             ty: ty,
 383             mutbl: mutbl
 384         }
 385     }
 386
 387     fn ty(&self, span: Span, ty: ast::TyKind) -> P<ast::Ty> {
 388         P(ast::Ty {
 389             id: ast::DUMMY_NODE_ID,
 390             span: span,
 391             node: ty
 392         })
 393     }
 394
 395     fn ty_path(&self, path: ast::Path) -> P<ast::Ty> {
 396         self.ty(path.span, ast::TyKind::Path(None, path))
 397     }
 398
 399     fn ty_sum(&self, path: ast::Path, bounds: ast::TyParamBounds) -> P<ast::Ty> {
 400         self.ty(path.span,
 401                 ast::TyKind::ObjectSum(self.ty_path(path),
 402                                  bounds))
 403     }
 404
 405     // Might need to take bounds as an argument in the future, if you ever want
 406     // to generate a bounded existential trait type.
 407     fn ty_ident(&self, span: Span, ident: ast::Ident)
 408         -> P<ast::Ty> {
 409         self.ty_path(self.path_ident(span, ident))
 410     }
 411
 412     fn ty_rptr(&self,
 413                span: Span,
 414                ty: P<ast::Ty>,
 415                lifetime: Option<ast::Lifetime>,
 416                mutbl: ast::Mutability)
 417         -> P<ast::Ty> {
 418         self.ty(span,
 419                 ast::TyKind::Rptr(lifetime, self.ty_mt(ty, mutbl)))
 420     }
 421
 422     fn ty_ptr(&self,
 423               span: Span,
 424               ty: P<ast::Ty>,
 425               mutbl: ast::Mutability)
 426         -> P<ast::Ty> {
 427         self.ty(span,
 428                 ast::TyKind::Ptr(self.ty_mt(ty, mutbl)))
 429     }
 430
 431     fn ty_option(&self, ty: P<ast::Ty>) -> P<ast::Ty> {
 432         self.ty_path(
 433             self.path_all(DUMMY_SP,
 434                           true,
 435                           self.std_path(&["option", "Option"]),
 436                           Vec::new(),
 437                           vec!( ty ),
 438                           Vec::new()))
 439     }
 440
 441     fn ty_infer(&self, span: Span) -> P<ast::Ty> {
 442         self.ty(span, ast::TyKind::Infer)
 443     }
 444
 445     fn typaram(&self,
 446                span: Span,
 447                id: ast::Ident,
 448                bounds: ast::TyParamBounds,
 449                default: Option<P<ast::Ty>>) -> ast::TyParam {
 450         ast::TyParam {
 451             ident: id,
 452             id: ast::DUMMY_NODE_ID,
 453             bounds: bounds,
 454             default: default,
 455             span: span
 456         }
 457     }
 458
 459     // these are strange, and probably shouldn't be used outside of
 460     // pipes. Specifically, the global version possible generates
 461     // incorrect code.
 462     fn ty_vars(&self, ty_params: &P<[ast::TyParam]>) -> Vec<P<ast::Ty>> {
 463         ty_params.iter().map(|p| self.ty_ident(DUMMY_SP, p.ident)).collect()
 464     }
 465
 466     fn ty_vars_global(&self, ty_params: &P<[ast::TyParam]>) -> Vec<P<ast::Ty>> {
 467         ty_params
 468             .iter()
 469             .map(|p| self.ty_path(self.path_global(DUMMY_SP, vec!(p.ident))))
 470             .collect()
 471     }
 472
 473     fn trait_ref(&self, path: ast::Path) -> ast::TraitRef {
 474         ast::TraitRef {
 475             path: path,
 476             ref_id: ast::DUMMY_NODE_ID,
 477         }
 478     }
 479
 480     fn poly_trait_ref(&self, span: Span, path: ast::Path) -> ast::PolyTraitRef {
 481         ast::PolyTraitRef {
 482             bound_lifetimes: Vec::new(),
 483             trait_ref: self.trait_ref(path),
 484             span: span,
 485         }
 486     }
 487
 488     fn typarambound(&self, path: ast::Path) -> ast::TyParamBound {
 489         ast::TraitTyParamBound(self.poly_trait_ref(path.span, path), ast::TraitBoundModifier::None)
 490     }
 491
 492     fn lifetime(&self, span: Span, name: ast::Name) -> ast::Lifetime {
 493         ast::Lifetime { id: ast::DUMMY_NODE_ID, span: span, name: name }
 494     }
 495
 496     fn lifetime_def(&self,
 497                     span: Span,
 498                     name: ast::Name,
 499                     bounds: Vec<ast::Lifetime>)
 500                     -> ast::LifetimeDef {
 501         ast::LifetimeDef {
 502             lifetime: self.lifetime(span, name),
 503             bounds: bounds
 504         }
 505     }
 506
 507     fn stmt_expr(&self, expr: P<ast::Expr>) -> ast::Stmt {
 508         respan(expr.span, ast::StmtKind::Expr(expr, ast::DUMMY_NODE_ID))
 509     }
 510
 511     fn stmt_semi(&self, expr: P<ast::Expr>) -> ast::Stmt {
 512         respan(expr.span, ast::StmtKind::Semi(expr, ast::DUMMY_NODE_ID))
 513     }
 514
 515     fn stmt_let(&self, sp: Span, mutbl: bool, ident: ast::Ident,
 516                 ex: P<ast::Expr>) -> ast::Stmt {
 517         let pat = if mutbl {
 518             let binding_mode = ast::BindingMode::ByValue(ast::Mutability::Mutable);
 519             self.pat_ident_binding_mode(sp, ident, binding_mode)
 520         } else {
 521             self.pat_ident(sp, ident)
 522         };
 523         let local = P(ast::Local {
 524             pat: pat,
 525             ty: None,
 526             init: Some(ex),
 527             id: ast::DUMMY_NODE_ID,
 528             span: sp,
 529             attrs: None,
 530         });
 531         let decl = respan(sp, ast::DeclKind::Local(local));
 532         respan(sp, ast::StmtKind::Decl(P(decl), ast::DUMMY_NODE_ID))
 533     }
 534
 535     fn stmt_let_typed(&self,
 536                       sp: Span,
 537                       mutbl: bool,
 538                       ident: ast::Ident,
 539                       typ: P<ast::Ty>,
 540                       ex: P<ast::Expr>)
 541                       -> P<ast::Stmt> {
 542         let pat = if mutbl {
 543             let binding_mode = ast::BindingMode::ByValue(ast::Mutability::Mutable);
 544             self.pat_ident_binding_mode(sp, ident, binding_mode)
 545         } else {
 546             self.pat_ident(sp, ident)
 547         };
 548         let local = P(ast::Local {
 549             pat: pat,
 550             ty: Some(typ),
 551             init: Some(ex),
 552             id: ast::DUMMY_NODE_ID,
 553             span: sp,
 554             attrs: None,
 555         });
 556         let decl = respan(sp, ast::DeclKind::Local(local));
 557         P(respan(sp, ast::StmtKind::Decl(P(decl), ast::DUMMY_NODE_ID)))
 558     }
 559
 560     fn stmt_item(&self, sp: Span, item: P<ast::Item>) -> ast::Stmt {
 561         let decl = respan(sp, ast::DeclKind::Item(item));
 562         respan(sp, ast::StmtKind::Decl(P(decl), ast::DUMMY_NODE_ID))
 563     }
 564
 565     fn block_expr(&self, expr: P<ast::Expr>) -> P<ast::Block> {
 566         self.block(expr.span, vec![Spanned {
 567             span: expr.span,
 568             node: ast::StmtKind::Expr(expr, ast::DUMMY_NODE_ID),
 569         }])
 570     }
 571     fn block(&self, span: Span, stmts: Vec<ast::Stmt>) -> P<ast::Block> {
 572         P(ast::Block {
 573            stmts: stmts,
 574            id: ast::DUMMY_NODE_ID,
 575            rules: BlockCheckMode::Default,
 576            span: span,
 577         })
 578     }
 579
 580     fn expr(&self, span: Span, node: ast::ExprKind) -> P<ast::Expr> {
 581         P(ast::Expr {
 582             id: ast::DUMMY_NODE_ID,
 583             node: node,
 584             span: span,
 585             attrs: None,
 586         })
 587     }
 588
 589     fn expr_path(&self, path: ast::Path) -> P<ast::Expr> {
 590         self.expr(path.span, ast::ExprKind::Path(None, path))
 591     }
 592
 593     /// Constructs a QPath expression.
 594     fn expr_qpath(&self, span: Span, qself: ast::QSelf, path: ast::Path) -> P<ast::Expr> {
 595         self.expr(span, ast::ExprKind::Path(Some(qself), path))
 596     }
 597
 598     fn expr_ident(&self, span: Span, id: ast::Ident) -> P<ast::Expr> {
 599         self.expr_path(self.path_ident(span, id))
 600     }
 601     fn expr_self(&self, span: Span) -> P<ast::Expr> {
 602         self.expr_ident(span, keywords::SelfValue.ident())
 603     }
 604
 605     fn expr_binary(&self, sp: Span, op: ast::BinOpKind,
 606                    lhs: P<ast::Expr>, rhs: P<ast::Expr>) -> P<ast::Expr> {
 607         self.expr(sp, ast::ExprKind::Binary(Spanned { node: op, span: sp }, lhs, rhs))
 608     }
 609
 610     fn expr_deref(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr> {
 611         self.expr_unary(sp, UnOp::Deref, e)
 612     }
 613     fn expr_unary(&self, sp: Span, op: ast::UnOp, e: P<ast::Expr>) -> P<ast::Expr> {
 614         self.expr(sp, ast::ExprKind::Unary(op, e))
 615     }
 616
 617     fn expr_field_access(&self, sp: Span, expr: P<ast::Expr>, ident: ast::Ident) -> P<ast::Expr> {
 618         let field_span = Span {
 619             lo: sp.lo - Pos::from_usize(ident.name.as_str().len()),
 620             hi: sp.hi,
 621             expn_id: sp.expn_id,
 622         };
 623
 624         let id = Spanned { node: ident, span: field_span };
 625         self.expr(sp, ast::ExprKind::Field(expr, id))
 626     }
 627     fn expr_tup_field_access(&self, sp: Span, expr: P<ast::Expr>, idx: usize) -> P<ast::Expr> {
 628         let field_span = Span {
 629             lo: sp.lo - Pos::from_usize(idx.to_string().len()),
 630             hi: sp.hi,
 631             expn_id: sp.expn_id,
 632         };
 633
 634         let id = Spanned { node: idx, span: field_span };
 635         self.expr(sp, ast::ExprKind::TupField(expr, id))
 636     }
 637     fn expr_addr_of(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr> {
 638         self.expr(sp, ast::ExprKind::AddrOf(ast::Mutability::Immutable, e))
 639     }
 640     fn expr_mut_addr_of(&self, sp: Span, e: P<ast::Expr>) -> P<ast::Expr> {
 641         self.expr(sp, ast::ExprKind::AddrOf(ast::Mutability::Mutable, e))
 642     }
 643
 644     fn expr_call(&self, span: Span, expr: P<ast::Expr>, args: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 645         self.expr(span, ast::ExprKind::Call(expr, args))
 646     }
 647     fn expr_call_ident(&self, span: Span, id: ast::Ident,
 648                        args: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 649         self.expr(span, ast::ExprKind::Call(self.expr_ident(span, id), args))
 650     }
 651     fn expr_call_global(&self, sp: Span, fn_path: Vec<ast::Ident> ,
 652                       args: Vec<P<ast::Expr>> ) -> P<ast::Expr> {
 653         let pathexpr = self.expr_path(self.path_global(sp, fn_path));
 654         self.expr_call(sp, pathexpr, args)
 655     }
 656     fn expr_method_call(&self, span: Span,
 657                         expr: P<ast::Expr>,
 658                         ident: ast::Ident,
 659                         mut args: Vec<P<ast::Expr>> ) -> P<ast::Expr> {
 660         let id = Spanned { node: ident, span: span };
 661         args.insert(0, expr);
 662         self.expr(span, ast::ExprKind::MethodCall(id, Vec::new(), args))
 663     }
 664     fn expr_block(&self, b: P<ast::Block>) -> P<ast::Expr> {
 665         self.expr(b.span, ast::ExprKind::Block(b))
 666     }
 667     fn field_imm(&self, span: Span, name: Ident, e: P<ast::Expr>) -> ast::Field {
 668         ast::Field { ident: respan(span, name), expr: e, span: span }
 669     }
 670     fn expr_struct(&self, span: Span, path: ast::Path, fields: Vec<ast::Field>) -> P<ast::Expr> {
 671         self.expr(span, ast::ExprKind::Struct(path, fields, None))
 672     }
 673     fn expr_struct_ident(&self, span: Span,
 674                          id: ast::Ident, fields: Vec<ast::Field>) -> P<ast::Expr> {
 675         self.expr_struct(span, self.path_ident(span, id), fields)
 676     }
 677
 678     fn expr_lit(&self, sp: Span, lit: ast::LitKind) -> P<ast::Expr> {
 679         self.expr(sp, ast::ExprKind::Lit(P(respan(sp, lit))))
 680     }
 681     fn expr_usize(&self, span: Span, i: usize) -> P<ast::Expr> {
 682         self.expr_lit(span, ast::LitKind::Int(i as u64, ast::LitIntType::Unsigned(ast::UintTy::Us)))
 683     }
 684     fn expr_isize(&self, sp: Span, i: isize) -> P<ast::Expr> {
 685         if i < 0 {
 686             let i = (-i) as u64;
 687             let lit_ty = ast::LitIntType::Signed(ast::IntTy::Is);
 688             let lit = self.expr_lit(sp, ast::LitKind::Int(i, lit_ty));
 689             self.expr_unary(sp, ast::UnOp::Neg, lit)
 690         } else {
 691             self.expr_lit(sp, ast::LitKind::Int(i as u64, ast::LitIntType::Signed(ast::IntTy::Is)))
 692         }
 693     }
 694     fn expr_u32(&self, sp: Span, u: u32) -> P<ast::Expr> {
 695         self.expr_lit(sp, ast::LitKind::Int(u as u64, ast::LitIntType::Unsigned(ast::UintTy::U32)))
 696     }
 697     fn expr_u8(&self, sp: Span, u: u8) -> P<ast::Expr> {
 698         self.expr_lit(sp, ast::LitKind::Int(u as u64, ast::LitIntType::Unsigned(ast::UintTy::U8)))
 699     }
 700     fn expr_bool(&self, sp: Span, value: bool) -> P<ast::Expr> {
 701         self.expr_lit(sp, ast::LitKind::Bool(value))
 702     }
 703
 704     fn expr_vec(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 705         self.expr(sp, ast::ExprKind::Vec(exprs))
 706     }
 707     fn expr_vec_ng(&self, sp: Span) -> P<ast::Expr> {
 708         self.expr_call_global(sp, self.std_path(&["vec", "Vec", "new"]),
 709                               Vec::new())
 710     }
 711     fn expr_vec_slice(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 712         self.expr_addr_of(sp, self.expr_vec(sp, exprs))
 713     }
 714     fn expr_str(&self, sp: Span, s: InternedString) -> P<ast::Expr> {
 715         self.expr_lit(sp, ast::LitKind::Str(s, ast::StrStyle::Cooked))
 716     }
 717
 718     fn expr_cast(&self, sp: Span, expr: P<ast::Expr>, ty: P<ast::Ty>) -> P<ast::Expr> {
 719         self.expr(sp, ast::ExprKind::Cast(expr, ty))
 720     }
 721
 722
 723     fn expr_some(&self, sp: Span, expr: P<ast::Expr>) -> P<ast::Expr> {
 724         let some = self.std_path(&["option", "Option", "Some"]);
 725         self.expr_call_global(sp, some, vec!(expr))
 726     }
 727
 728     fn expr_none(&self, sp: Span) -> P<ast::Expr> {
 729         let none = self.std_path(&["option", "Option", "None"]);
 730         let none = self.path_global(sp, none);
 731         self.expr_path(none)
 732     }
 733
 734
 735     fn expr_break(&self, sp: Span) -> P<ast::Expr> {
 736         self.expr(sp, ast::ExprKind::Break(None))
 737     }
 738
 739
 740     fn expr_tuple(&self, sp: Span, exprs: Vec<P<ast::Expr>>) -> P<ast::Expr> {
 741         self.expr(sp, ast::ExprKind::Tup(exprs))
 742     }
 743
 744     fn expr_fail(&self, span: Span, msg: InternedString) -> P<ast::Expr> {
 745         let loc = self.codemap().lookup_char_pos(span.lo);
 746         let expr_file = self.expr_str(span,
 747                                       token::intern_and_get_ident(&loc.file.name));
 748         let expr_line = self.expr_u32(span, loc.line as u32);
 749         let expr_file_line_tuple = self.expr_tuple(span, vec!(expr_file, expr_line));
 750         let expr_file_line_ptr = self.expr_addr_of(span, expr_file_line_tuple);
 751         self.expr_call_global(
 752             span,
 753             self.std_path(&["rt", "begin_panic"]),
 754             vec!(
 755                 self.expr_str(span, msg),
 756                 expr_file_line_ptr))
 757     }
 758
 759     fn expr_unreachable(&self, span: Span) -> P<ast::Expr> {
 760         self.expr_fail(span,
 761                        InternedString::new(
 762                            "internal error: entered unreachable code"))
 763     }
 764
 765     fn expr_ok(&self, sp: Span, expr: P<ast::Expr>) -> P<ast::Expr> {
 766         let ok = self.std_path(&["result", "Result", "Ok"]);
 767         self.expr_call_global(sp, ok, vec!(expr))
 768     }
 769
 770     fn expr_err(&self, sp: Span, expr: P<ast::Expr>) -> P<ast::Expr> {
 771         let err = self.std_path(&["result", "Result", "Err"]);
 772         self.expr_call_global(sp, err, vec!(expr))
 773     }
 774
 775     fn expr_try(&self, sp: Span, head: P<ast::Expr>) -> P<ast::Expr> {
 776         let ok = self.std_path(&["result", "Result", "Ok"]);
 777         let ok_path = self.path_global(sp, ok);
 778         let err = self.std_path(&["result", "Result", "Err"]);
 779         let err_path = self.path_global(sp, err);
 780
 781         let binding_variable = self.ident_of("__try_var");
 782         let binding_pat = self.pat_ident(sp, binding_variable);
 783         let binding_expr = self.expr_ident(sp, binding_variable);
 784
 785         // Ok(__try_var) pattern
 786         let ok_pat = self.pat_enum(sp, ok_path, vec!(binding_pat.clone()));
 787
 788         // Err(__try_var)  (pattern and expression resp.)
 789         let err_pat = self.pat_enum(sp, err_path.clone(), vec!(binding_pat));
 790         let err_inner_expr = self.expr_call(sp, self.expr_path(err_path),
 791                                             vec!(binding_expr.clone()));
 792         // return Err(__try_var)
 793         let err_expr = self.expr(sp, ast::ExprKind::Ret(Some(err_inner_expr)));
 794
 795         // Ok(__try_var) => __try_var
 796         let ok_arm = self.arm(sp, vec!(ok_pat), binding_expr);
 797         // Err(__try_var) => return Err(__try_var)
 798         let err_arm = self.arm(sp, vec!(err_pat), err_expr);
 799
 800         // match head { Ok() => ..., Err() => ... }
 801         self.expr_match(sp, head, vec!(ok_arm, err_arm))
 802     }
 803
 804
 805     fn pat(&self, span: Span, pat: PatKind) -> P<ast::Pat> {
 806         P(ast::Pat { id: ast::DUMMY_NODE_ID, node: pat, span: span })
 807     }
 808     fn pat_wild(&self, span: Span) -> P<ast::Pat> {
 809         self.pat(span, PatKind::Wild)
 810     }
 811     fn pat_lit(&self, span: Span, expr: P<ast::Expr>) -> P<ast::Pat> {
 812         self.pat(span, PatKind::Lit(expr))
 813     }
 814     fn pat_ident(&self, span: Span, ident: ast::Ident) -> P<ast::Pat> {
 815         let binding_mode = ast::BindingMode::ByValue(ast::Mutability::Immutable);
 816         self.pat_ident_binding_mode(span, ident, binding_mode)
 817     }
 818
 819     fn pat_ident_binding_mode(&self,
 820                               span: Span,
 821                               ident: ast::Ident,
 822                               bm: ast::BindingMode) -> P<ast::Pat> {
 823         let pat = PatKind::Ident(bm, Spanned{span: span, node: ident}, None);
 824         self.pat(span, pat)
 825     }
 826     fn pat_enum(&self, span: Span, path: ast::Path, subpats: Vec<P<ast::Pat>>) -> P<ast::Pat> {
 827         let pat = if subpats.is_empty() {
 828             PatKind::Path(path)
 829         } else {
 830             PatKind::TupleStruct(path, subpats, None)
 831         };
 832         self.pat(span, pat)
 833     }
 834     fn pat_struct(&self, span: Span,
 835                   path: ast::Path, field_pats: Vec<Spanned<ast::FieldPat>>) -> P<ast::Pat> {
 836         let pat = PatKind::Struct(path, field_pats, false);
 837         self.pat(span, pat)
 838     }
 839     fn pat_tuple(&self, span: Span, pats: Vec<P<ast::Pat>>) -> P<ast::Pat> {
 840         self.pat(span, PatKind::Tuple(pats, None))
 841     }
 842
 843     fn pat_some(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat> {
 844         let some = self.std_path(&["option", "Option", "Some"]);
 845         let path = self.path_global(span, some);
 846         self.pat_enum(span, path, vec!(pat))
 847     }
 848
 849     fn pat_none(&self, span: Span) -> P<ast::Pat> {
 850         let some = self.std_path(&["option", "Option", "None"]);
 851         let path = self.path_global(span, some);
 852         self.pat_enum(span, path, vec!())
 853     }
 854
 855     fn pat_ok(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat> {
 856         let some = self.std_path(&["result", "Result", "Ok"]);
 857         let path = self.path_global(span, some);
 858         self.pat_enum(span, path, vec!(pat))
 859     }
 860
 861     fn pat_err(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat> {
 862         let some = self.std_path(&["result", "Result", "Err"]);
 863         let path = self.path_global(span, some);
 864         self.pat_enum(span, path, vec!(pat))
 865     }
 866
 867     fn arm(&self, _span: Span, pats: Vec<P<ast::Pat>>, expr: P<ast::Expr>) -> ast::Arm {
 868         ast::Arm {
 869             attrs: vec!(),
 870             pats: pats,
 871             guard: None,
 872             body: expr
 873         }
 874     }
 875
 876     fn arm_unreachable(&self, span: Span) -> ast::Arm {
 877         self.arm(span, vec!(self.pat_wild(span)), self.expr_unreachable(span))
 878     }
 879
 880     fn expr_match(&self, span: Span, arg: P<ast::Expr>, arms: Vec<ast::Arm>) -> P<Expr> {
 881         self.expr(span, ast::ExprKind::Match(arg, arms))
 882     }
 883
 884     fn expr_if(&self, span: Span, cond: P<ast::Expr>,
 885                then: P<ast::Expr>, els: Option<P<ast::Expr>>) -> P<ast::Expr> {
 886         let els = els.map(|x| self.expr_block(self.block_expr(x)));
 887         self.expr(span, ast::ExprKind::If(cond, self.block_expr(then), els))
 888     }
 889
 890     fn expr_loop(&self, span: Span, block: P<ast::Block>) -> P<ast::Expr> {
 891         self.expr(span, ast::ExprKind::Loop(block, None))
 892     }
 893
 894     fn lambda_fn_decl(&self,
 895                       span: Span,
 896                       fn_decl: P<ast::FnDecl>,
 897                       blk: P<ast::Block>,
 898                       fn_decl_span: Span) // span of the `|...|` part
 899                       -> P<ast::Expr> {
 900         self.expr(span, ast::ExprKind::Closure(ast::CaptureBy::Ref,
 901                                                fn_decl,
 902                                                blk,
 903                                                fn_decl_span))
 904     }
 905
 906     fn lambda(&self,
 907               span: Span,
 908               ids: Vec<ast::Ident>,
 909               blk: P<ast::Block>)
 910               -> P<ast::Expr> {
 911         let fn_decl = self.fn_decl(
 912             ids.iter().map(|id| self.arg(span, *id, self.ty_infer(span))).collect(),
 913             self.ty_infer(span));
 914
 915         // FIXME -- We are using `span` as the span of the `|...|`
 916         // part of the lambda, but it probably (maybe?) corresponds to
 917         // the entire lambda body. Probably we should extend the API
 918         // here, but that's not entirely clear.
 919         self.expr(span, ast::ExprKind::Closure(ast::CaptureBy::Ref, fn_decl, blk, span))
 920     }
 921
 922     fn lambda0(&self, span: Span, blk: P<ast::Block>) -> P<ast::Expr> {
 923         self.lambda(span, Vec::new(), blk)
 924     }
 925
 926     fn lambda1(&self, span: Span, blk: P<ast::Block>, ident: ast::Ident) -> P<ast::Expr> {
 927         self.lambda(span, vec!(ident), blk)
 928     }
 929
 930     fn lambda_expr(&self, span: Span, ids: Vec<ast::Ident>,
 931                    expr: P<ast::Expr>) -> P<ast::Expr> {
 932         self.lambda(span, ids, self.block_expr(expr))
 933     }
 934     fn lambda_expr_0(&self, span: Span, expr: P<ast::Expr>) -> P<ast::Expr> {
 935         self.lambda0(span, self.block_expr(expr))
 936     }
 937     fn lambda_expr_1(&self, span: Span, expr: P<ast::Expr>, ident: ast::Ident) -> P<ast::Expr> {
 938         self.lambda1(span, self.block_expr(expr), ident)
 939     }
 940
 941     fn lambda_stmts(&self,
 942                     span: Span,
 943                     ids: Vec<ast::Ident>,
 944                     stmts: Vec<ast::Stmt>)
 945                     -> P<ast::Expr> {
 946         self.lambda(span, ids, self.block(span, stmts))
 947     }
 948     fn lambda_stmts_0(&self, span: Span, stmts: Vec<ast::Stmt>) -> P<ast::Expr> {
 949         self.lambda0(span, self.block(span, stmts))
 950     }
 951     fn lambda_stmts_1(&self, span: Span, stmts: Vec<ast::Stmt>,
 952                       ident: ast::Ident) -> P<ast::Expr> {
 953         self.lambda1(span, self.block(span, stmts), ident)
 954     }
 955
 956     fn arg(&self, span: Span, ident: ast::Ident, ty: P<ast::Ty>) -> ast::Arg {
 957         let arg_pat = self.pat_ident(span, ident);
 958         ast::Arg {
 959             ty: ty,
 960             pat: arg_pat,
 961             id: ast::DUMMY_NODE_ID
 962         }
 963     }
 964
 965     // FIXME unused self
 966     fn fn_decl(&self, inputs: Vec<ast::Arg>, output: P<ast::Ty>) -> P<ast::FnDecl> {
 967         P(ast::FnDecl {
 968             inputs: inputs,
 969             output: ast::FunctionRetTy::Ty(output),
 970             variadic: false
 971         })
 972     }
 973
 974     fn item(&self, span: Span, name: Ident,
 975             attrs: Vec<ast::Attribute>, node: ast::ItemKind) -> P<ast::Item> {
 976         // FIXME: Would be nice if our generated code didn't violate
 977         // Rust coding conventions
 978         P(ast::Item {
 979             ident: name,
 980             attrs: attrs,
 981             id: ast::DUMMY_NODE_ID,
 982             node: node,
 983             vis: ast::Visibility::Inherited,
 984             span: span
 985         })
 986     }
 987
 988     fn item_fn_poly(&self,
 989                     span: Span,
 990                     name: Ident,
 991                     inputs: Vec<ast::Arg> ,
 992                     output: P<ast::Ty>,
 993                     generics: Generics,
 994                     body: P<ast::Block>) -> P<ast::Item> {
 995         self.item(span,
 996                   name,
 997                   Vec::new(),
 998                   ast::ItemKind::Fn(self.fn_decl(inputs, output),
 999                               ast::Unsafety::Normal,
1000                               ast::Constness::NotConst,
1001                               Abi::Rust,
1002                               generics,
1003                               body))
1004     }
1005
1006     fn item_fn(&self,
1007                span: Span,
1008                name: Ident,
1009                inputs: Vec<ast::Arg> ,
1010                output: P<ast::Ty>,
1011                body: P<ast::Block>
1012               ) -> P<ast::Item> {
1013         self.item_fn_poly(
1014             span,
1015             name,
1016             inputs,
1017             output,
1018             Generics::default(),
1019             body)
1020     }
1021
1022     fn variant(&self, span: Span, name: Ident, tys: Vec<P<ast::Ty>> ) -> ast::Variant {
1023         let fields: Vec<_> = tys.into_iter().map(|ty| {
1024             ast::StructField {
1025                 span: ty.span,
1026                 ty: ty,
1027                 ident: None,
1028                 vis: ast::Visibility::Inherited,
1029                 attrs: Vec::new(),
1030                 id: ast::DUMMY_NODE_ID,
1031             }
1032         }).collect();
1033
1034         let vdata = if fields.is_empty() {
1035             ast::VariantData::Unit(ast::DUMMY_NODE_ID)
1036         } else {
1037             ast::VariantData::Tuple(fields, ast::DUMMY_NODE_ID)
1038         };
1039
1040         respan(span,
1041                ast::Variant_ {
1042                    name: name,
1043                    attrs: Vec::new(),
1044                    data: vdata,
1045                    disr_expr: None,
1046                })
1047     }
1048
1049     fn item_enum_poly(&self, span: Span, name: Ident,
1050                       enum_definition: ast::EnumDef,
1051                       generics: Generics) -> P<ast::Item> {
1052         self.item(span, name, Vec::new(), ast::ItemKind::Enum(enum_definition, generics))
1053     }
1054
1055     fn item_enum(&self, span: Span, name: Ident,
1056                  enum_definition: ast::EnumDef) -> P<ast::Item> {
1057         self.item_enum_poly(span, name, enum_definition,
1058                             Generics::default())
1059     }
1060
1061     fn item_struct(&self, span: Span, name: Ident,
1062                    struct_def: ast::VariantData) -> P<ast::Item> {
1063         self.item_struct_poly(
1064             span,
1065             name,
1066             struct_def,
1067             Generics::default()
1068         )
1069     }
1070
1071     fn item_struct_poly(&self, span: Span, name: Ident,
1072         struct_def: ast::VariantData, generics: Generics) -> P<ast::Item> {
1073         self.item(span, name, Vec::new(), ast::ItemKind::Struct(struct_def, generics))
1074     }
1075
1076     fn item_mod(&self, span: Span, inner_span: Span, name: Ident,
1077                 attrs: Vec<ast::Attribute>,
1078                 items: Vec<P<ast::Item>>) -> P<ast::Item> {
1079         self.item(
1080             span,
1081             name,
1082             attrs,
1083             ast::ItemKind::Mod(ast::Mod {
1084                 inner: inner_span,
1085                 items: items,
1086             })
1087         )
1088     }
1089
1090     fn item_static(&self,
1091                    span: Span,
1092                    name: Ident,
1093                    ty: P<ast::Ty>,
1094                    mutbl: ast::Mutability,
1095                    expr: P<ast::Expr>)
1096                    -> P<ast::Item> {
1097         self.item(span, name, Vec::new(), ast::ItemKind::Static(ty, mutbl, expr))
1098     }
1099
1100     fn item_const(&self,
1101                   span: Span,
1102                   name: Ident,
1103                   ty: P<ast::Ty>,
1104                   expr: P<ast::Expr>)
1105                   -> P<ast::Item> {
1106         self.item(span, name, Vec::new(), ast::ItemKind::Const(ty, expr))
1107     }
1108
1109     fn item_ty_poly(&self, span: Span, name: Ident, ty: P<ast::Ty>,
1110                     generics: Generics) -> P<ast::Item> {
1111         self.item(span, name, Vec::new(), ast::ItemKind::Ty(ty, generics))
1112     }
1113
1114     fn item_ty(&self, span: Span, name: Ident, ty: P<ast::Ty>) -> P<ast::Item> {
1115         self.item_ty_poly(span, name, ty, Generics::default())
1116     }
1117
1118     fn attribute(&self, sp: Span, mi: P<ast::MetaItem>) -> ast::Attribute {
1119         respan(sp, ast::Attribute_ {
1120             id: attr::mk_attr_id(),
1121             style: ast::AttrStyle::Outer,
1122             value: mi,
1123             is_sugared_doc: false,
1124         })
1125     }
1126
1127     fn meta_word(&self, sp: Span, w: InternedString) -> P<ast::MetaItem> {
1128         P(respan(sp, ast::MetaItemKind::Word(w)))
1129     }
1130     fn meta_list(&self,
1131                  sp: Span,
1132                  name: InternedString,
1133                  mis: Vec<P<ast::MetaItem>> )
1134                  -> P<ast::MetaItem> {
1135         P(respan(sp, ast::MetaItemKind::List(name, mis)))
1136     }
1137     fn meta_name_value(&self,
1138                        sp: Span,
1139                        name: InternedString,
1140                        value: ast::LitKind)
1141                        -> P<ast::MetaItem> {
1142         P(respan(sp, ast::MetaItemKind::NameValue(name, respan(sp, value))))
1143     }
1144
1145     fn item_use(&self, sp: Span,
1146                 vis: ast::Visibility, vp: P<ast::ViewPath>) -> P<ast::Item> {
1147         P(ast::Item {
1148             id: ast::DUMMY_NODE_ID,
1149             ident: keywords::Invalid.ident(),
1150             attrs: vec![],
1151             node: ast::ItemKind::Use(vp),
1152             vis: vis,
1153             span: sp
1154         })
1155     }
1156
1157     fn item_use_simple(&self, sp: Span, vis: ast::Visibility, path: ast::Path) -> P<ast::Item> {
1158         let last = path.segments.last().unwrap().identifier;
1159         self.item_use_simple_(sp, vis, last, path)
1160     }
1161
1162     fn item_use_simple_(&self, sp: Span, vis: ast::Visibility,
1163                         ident: ast::Ident, path: ast::Path) -> P<ast::Item> {
1164         self.item_use(sp, vis,
1165                       P(respan(sp,
1166                                ast::ViewPathSimple(ident,
1167                                                    path))))
1168     }
1169
1170     fn item_use_list(&self, sp: Span, vis: ast::Visibility,
1171                      path: Vec<ast::Ident>, imports: &[ast::Ident]) -> P<ast::Item> {
1172         let imports = imports.iter().map(|id| {
1173             let item = ast::PathListItemKind::Ident {
1174                 name: *id,
1175                 rename: None,
1176                 id: ast::DUMMY_NODE_ID,
1177             };
1178             respan(sp, item)
1179         }).collect();
1180
1181         self.item_use(sp, vis,
1182                       P(respan(sp,
1183                                ast::ViewPathList(self.path(sp, path),
1184                                                  imports))))
1185     }
1186
1187     fn item_use_glob(&self, sp: Span,
1188                      vis: ast::Visibility, path: Vec<ast::Ident>) -> P<ast::Item> {
1189         self.item_use(sp, vis,
1190                       P(respan(sp,
1191                                ast::ViewPathGlob(self.path(sp, path)))))
1192     }
1193 }