Add syntax for ranges

Nick Cameron · Nick Cameron · commit 8a357e1d8797 · 2014-12-24T09:12:45.000+13:00
diff --git a/src/librustc/middle/cfg/construct.rs b/src/librustc/middle/cfg/construct.rs
@@ -439,6 +439,10 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
                           start.iter().chain(end.iter()).map(|x| &**x))
             }
 
+            ast::ExprRange(..) => {
+                self.tcx.sess.span_bug(expr.span, "non-desugared range");
+            }
+
             ast::ExprUnary(_, ref e) if self.is_method_call(expr) => {
                 self.call(expr, pred, &**e, None::<ast::Expr>.iter())
             }
diff --git a/src/librustc/middle/expr_use_visitor.rs b/src/librustc/middle/expr_use_visitor.rs
@@ -465,6 +465,10 @@ impl<'d,'t,'tcx,TYPER:mc::Typer<'tcx>> ExprUseVisitor<'d,'t,'tcx,TYPER> {
                 assert!(overloaded);
             }
 
+            ast::ExprRange(..) => {
+                self.tcx().sess.span_bug(expr.span, "non-desugared range");
+            }
+
             ast::ExprCall(ref callee, ref args) => {    // callee(args)
                 self.walk_callee(expr, &**callee);
                 self.consume_exprs(args);
diff --git a/src/librustc/middle/liveness.rs b/src/librustc/middle/liveness.rs
@@ -486,6 +486,9 @@ fn visit_expr(ir: &mut IrMaps, expr: &Expr) {
       ast::ExprWhileLet(..) => {
           ir.tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");
       }
+      ast::ExprRange(..) => {
+          ir.tcx.sess.span_bug(expr.span, "non-desugared range");
+      }
       ast::ExprForLoop(ref pat, _, _, _) => {
         pat_util::pat_bindings(&ir.tcx.def_map, &**pat, |bm, p_id, sp, path1| {
             debug!("adding local variable {} from for loop with bm {}",
@@ -1197,6 +1200,10 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
             self.propagate_through_expr(&**e1, succ)
           }
 
+          ast::ExprRange(..) => {
+              self.ir.tcx.sess.span_bug(expr.span, "non-desugared range");
+          }
+
           ast::ExprBox(None, ref e) |
           ast::ExprAddrOf(_, ref e) |
           ast::ExprCast(ref e, _) |
@@ -1498,6 +1505,9 @@ fn check_expr(this: &mut Liveness, expr: &Expr) {
       ast::ExprWhileLet(..) => {
         this.ir.tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");
       }
+      ast::ExprRange(..) => {
+        this.ir.tcx.sess.span_bug(expr.span, "non-desugared range");
+      }
     }
 }
 
diff --git a/src/librustc/middle/mem_categorization.rs b/src/librustc/middle/mem_categorization.rs
@@ -559,6 +559,9 @@ impl<'t,'tcx,TYPER:Typer<'tcx>> MemCategorizationContext<'t,TYPER> {
           ast::ExprWhileLet(..) => {
             self.tcx().sess.span_bug(expr.span, "non-desugared ExprWhileLet");
           }
+          ast::ExprRange(..) => {
+            self.tcx().sess.span_bug(expr.span, "non-desugared range");
+          }
         }
     }
 
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
@@ -4273,6 +4273,9 @@ pub fn expr_kind(tcx: &ctxt, expr: &ast::Expr) -> ExprKind {
         ast::ExprWhileLet(..) => {
             tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");
         }
+        ast::ExprRange(..) => {
+            tcx.sess.span_bug(expr.span, "non-desugared range");
+        }
 
         ast::ExprLit(ref lit) if lit_is_str(&**lit) => {
             RvalueDpsExpr
diff --git a/src/librustc_back/svh.rs b/src/librustc_back/svh.rs
@@ -247,6 +247,7 @@ mod svh_visitor {
         SawExprAssignOp(ast::BinOp),
         SawExprIndex,
         SawExprSlice,
+        SawExprRange,
         SawExprPath,
         SawExprAddrOf(ast::Mutability),
         SawExprRet,
@@ -280,6 +281,7 @@ mod svh_visitor {
             ExprTupField(_, id)      => SawExprTupField(id.node),
             ExprIndex(..)            => SawExprIndex,
             ExprSlice(..)            => SawExprSlice,
+            ExprRange(..)            => SawExprRange,
             ExprPath(..)             => SawExprPath,
             ExprAddrOf(m, _)         => SawExprAddrOf(m),
             ExprBreak(id)            => SawExprBreak(id.map(content)),
diff --git a/src/librustc_trans/trans/debuginfo.rs b/src/librustc_trans/trans/debuginfo.rs
@@ -3494,6 +3494,11 @@ fn populate_scope_map(cx: &CrateContext,
                 end.as_ref().map(|x| walk_expr(cx, &**x, scope_stack, scope_map));
             }
 
+            ast::ExprRange(..) => {
+                cx.sess().span_bug(exp.span, "debuginfo::populate_scope_map() - \
+                                              Found unexpanded range.");
+            }
+
             ast::ExprVec(ref init_expressions) |
             ast::ExprTup(ref init_expressions) => {
                 for ie in init_expressions.iter() {
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
@@ -4278,6 +4278,10 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,
               }
           }
        }
+       ast::ExprRange(..) => {
+         tcx.sess.span_bug(expr.span, "non-desugared range");
+       }
+
     }
 
     debug!("type of expr({}) {} is...", expr.id,
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
@@ -724,6 +724,7 @@ pub enum Expr_ {
     ExprTupField(P<Expr>, Spanned<uint>),
     ExprIndex(P<Expr>, P<Expr>),
     ExprSlice(P<Expr>, Option<P<Expr>>, Option<P<Expr>>, Mutability),
+    ExprRange(P<Expr>, Option<P<Expr>>),
 
     /// Variable reference, possibly containing `::` and/or
     /// type parameters, e.g. foo::bar::<baz>
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
@@ -1390,6 +1390,10 @@ pub fn noop_fold_expr<T: Folder>(Expr {id, node, span}: Expr, folder: &mut T) ->
                           e2.map(|x| folder.fold_expr(x)),
                           m)
             }
+            ExprRange(e1, e2) => {
+                ExprRange(folder.fold_expr(e1),
+                          e2.map(|x| folder.fold_expr(x)))
+            }
             ExprPath(pth) => ExprPath(folder.fold_path(pth)),
             ExprBreak(opt_ident) => ExprBreak(opt_ident.map(|x| folder.fold_ident(x))),
             ExprAgain(opt_ident) => ExprAgain(opt_ident.map(|x| folder.fold_ident(x))),
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
@@ -26,7 +26,7 @@ use ast::{Expr, Expr_, ExprAddrOf, ExprMatch, ExprAgain};
 use ast::{ExprAssign, ExprAssignOp, ExprBinary, ExprBlock, ExprBox};
 use ast::{ExprBreak, ExprCall, ExprCast};
 use ast::{ExprField, ExprTupField, ExprClosure, ExprIf, ExprIfLet, ExprIndex, ExprSlice};
-use ast::{ExprLit, ExprLoop, ExprMac};
+use ast::{ExprLit, ExprLoop, ExprMac, ExprRange};
 use ast::{ExprMethodCall, ExprParen, ExprPath};
 use ast::{ExprRepeat, ExprRet, ExprStruct, ExprTup, ExprUnary};
 use ast::{ExprVec, ExprWhile, ExprWhileLet, ExprForLoop, Field, FnDecl};
@@ -95,7 +95,8 @@ bitflags! {
         const UNRESTRICTED                  = 0b0000,
         const RESTRICTION_STMT_EXPR         = 0b0001,
         const RESTRICTION_NO_BAR_OP         = 0b0010,
-        const RESTRICTION_NO_STRUCT_LITERAL = 0b0100
+        const RESTRICTION_NO_STRUCT_LITERAL = 0b0100,
+        const RESTRICTION_NO_DOTS           = 0b1000,
     }
 }
 
@@ -1547,7 +1548,7 @@ impl<'a> Parser<'a> {
 
             // Parse the `; e` in `[ int; e ]`
             // where `e` is a const expression
-            let t = match self.maybe_parse_fixed_vstore() {
+            let t = match self.maybe_parse_fixed_length_of_vec() {
                 None => TyVec(t),
                 Some(suffix) => TyFixedLengthVec(t, suffix)
             };
@@ -1707,12 +1708,12 @@ impl<'a> Parser<'a> {
         }
     }
 
-    pub fn maybe_parse_fixed_vstore(&mut self) -> Option<P<ast::Expr>> {
+    pub fn maybe_parse_fixed_length_of_vec(&mut self) -> Option<P<ast::Expr>> {
         if self.check(&token::Comma) &&
                 self.look_ahead(1, |t| *t == token::DotDot) {
             self.bump();
             self.bump();
-            Some(self.parse_expr())
+            Some(self.parse_expr_res(RESTRICTION_NO_DOTS))
         } else if self.check(&token::Semi) {
             self.bump();
             Some(self.parse_expr())
@@ -2130,14 +2131,22 @@ impl<'a> Parser<'a> {
         ExprIndex(expr, idx)
     }
 
-    pub fn mk_slice(&mut self, expr: P<Expr>,
+    pub fn mk_slice(&mut self,
+                    expr: P<Expr>,
                     start: Option<P<Expr>>,
                     end: Option<P<Expr>>,
                     mutbl: Mutability)
                     -> ast::Expr_ {
         ExprSlice(expr, start, end, mutbl)
     }
 
+    pub fn mk_range(&mut self,
+                    start: P<Expr>,
+                    end: Option<P<Expr>>)
+                    -> ast::Expr_ {
+        ExprRange(start, end)
+    }
+
     pub fn mk_field(&mut self, expr: P<Expr>, ident: ast::SpannedIdent) -> ast::Expr_ {
         ExprField(expr, ident)
     }
@@ -2615,7 +2624,7 @@ impl<'a> Parser<'a> {
                     }
                     // e[e] | e[e..] | e[e..e]
                     _ => {
-                        let ix = self.parse_expr();
+                        let ix = self.parse_expr_res(RESTRICTION_NO_DOTS);
                         match self.token {
                             // e[e..] | e[e..e]
                             token::DotDot => {
@@ -2628,7 +2637,7 @@ impl<'a> Parser<'a> {
                                     }
                                     // e[e..e]
                                     _ => {
-                                        let e2 = self.parse_expr();
+                                        let e2 = self.parse_expr_res(RESTRICTION_NO_DOTS);
                                         self.commit_expr_expecting(&*e2,
                                             token::CloseDelim(token::Bracket));
                                         Some(e2)
@@ -2654,6 +2663,21 @@ impl<'a> Parser<'a> {
                 }
               }
 
+              // A range expression, either `expr..expr` or `expr..`.
+              token::DotDot if !self.restrictions.contains(RESTRICTION_NO_DOTS) => {
+                self.bump();
+
+                let opt_end = if self.token.can_begin_expr() {
+                    let end = self.parse_expr_res(RESTRICTION_NO_DOTS);
+                    Some(end)
+                } else {
+                    None
+                };
+
+                let hi = self.span.hi;
+                let range = self.mk_range(e, opt_end);
+                return self.mk_expr(lo, hi, range);
+              }
               _ => return e
             }
         }
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
@@ -1759,6 +1759,13 @@ impl<'a> State<'a> {
                 }
                 try!(word(&mut self.s, "]"));
             }
+            ast::ExprRange(ref start, ref end) => {
+                try!(self.print_expr(&**start));
+                try!(word(&mut self.s, ".."));
+                if let &Some(ref e) = end {
+                    try!(self.print_expr(&**e));
+                }
+            }
             ast::ExprPath(ref path) => try!(self.print_path(path, true)),
             ast::ExprBreak(opt_ident) => {
                 try!(word(&mut self.s, "break"));
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
@@ -871,6 +871,10 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
             walk_expr_opt(visitor, start);
             walk_expr_opt(visitor, end)
         }
+        ExprRange(ref start, ref end) => {
+            visitor.visit_expr(&**start);
+            walk_expr_opt(visitor, end)
+        }
         ExprPath(ref path) => {
             visitor.visit_path(path, expression.id)
         }

Original file line number	Diff line number	Diff line change
`@@ -439,6 +439,10 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {`
`439`	`439`	`start.iter().chain(end.iter()).map(\|x\| &**x))`
`440`	`440`	`}`
`441`	`441`
	`442`	`+ ast::ExprRange(..) => {`
	`443`	`+ self.tcx.sess.span_bug(expr.span, "non-desugared range");`
	`444`	`+ }`
	`445`	`+`
`442`	`446`	`ast::ExprUnary(_, ref e) if self.is_method_call(expr) => {`
`443`	`447`	`self.call(expr, pred, &**e, None::<ast::Expr>.iter())`
`444`	`448`	`}`
Original file line number	Diff line number	Diff line change
`@@ -486,6 +486,9 @@ fn visit_expr(ir: &mut IrMaps, expr: &Expr) {`
`486`	`486`	`ast::ExprWhileLet(..) => {`
`487`	`487`	`ir.tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");`
`488`	`488`	`}`
	`489`	`+ ast::ExprRange(..) => {`
	`490`	`+ ir.tcx.sess.span_bug(expr.span, "non-desugared range");`
	`491`	`+ }`
`489`	`492`	`ast::ExprForLoop(ref pat, _, _, _) => {`
`490`	`493`	`pat_util::pat_bindings(&ir.tcx.def_map, &**pat, \|bm, p_id, sp, path1\| {`
`491`	`494`	`debug!("adding local variable {} from for loop with bm {}",`
`@@ -1197,6 +1200,10 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {`
`1197`	`1200`	`self.propagate_through_expr(&**e1, succ)`
`1198`	`1201`	`}`
`1199`	`1202`
	`1203`	`+ ast::ExprRange(..) => {`
	`1204`	`+ self.ir.tcx.sess.span_bug(expr.span, "non-desugared range");`
	`1205`	`+ }`
	`1206`	`+`
`1200`	`1207`	`ast::ExprBox(None, ref e) \|`
`1201`	`1208`	`ast::ExprAddrOf(_, ref e) \|`
`1202`	`1209`	`ast::ExprCast(ref e, _) \|`
`@@ -1498,6 +1505,9 @@ fn check_expr(this: &mut Liveness, expr: &Expr) {`
`1498`	`1505`	`ast::ExprWhileLet(..) => {`
`1499`	`1506`	`this.ir.tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");`
`1500`	`1507`	`}`
	`1508`	`+ ast::ExprRange(..) => {`
	`1509`	`+ this.ir.tcx.sess.span_bug(expr.span, "non-desugared range");`
	`1510`	`+ }`
`1501`	`1511`	`}`
`1502`	`1512`	`}`
`1503`	`1513`
Original file line number	Diff line number	Diff line change
`@@ -559,6 +559,9 @@ impl<'t,'tcx,TYPER:Typer<'tcx>> MemCategorizationContext<'t,TYPER> {`
`559`	`559`	`ast::ExprWhileLet(..) => {`
`560`	`560`	`self.tcx().sess.span_bug(expr.span, "non-desugared ExprWhileLet");`
`561`	`561`	`}`
	`562`	`+ ast::ExprRange(..) => {`
	`563`	`+ self.tcx().sess.span_bug(expr.span, "non-desugared range");`
	`564`	`+ }`
`562`	`565`	`}`
`563`	`566`	`}`
`564`	`567`
Original file line number	Diff line number	Diff line change
`@@ -4273,6 +4273,9 @@ pub fn expr_kind(tcx: &ctxt, expr: &ast::Expr) -> ExprKind {`
`4273`	`4273`	`ast::ExprWhileLet(..) => {`
`4274`	`4274`	`tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");`
`4275`	`4275`	`}`
	`4276`	`+ ast::ExprRange(..) => {`
	`4277`	`+ tcx.sess.span_bug(expr.span, "non-desugared range");`
	`4278`	`+ }`
`4276`	`4279`
`4277`	`4280`	`ast::ExprLit(ref lit) if lit_is_str(&**lit) => {`
`4278`	`4281`	`RvalueDpsExpr`
Original file line number	Diff line number	Diff line change
`@@ -4278,6 +4278,10 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,`
`4278`	`4278`	`}`
`4279`	`4279`	`}`
`4280`	`4280`	`}`
	`4281`	`+ ast::ExprRange(..) => {`
	`4282`	`+ tcx.sess.span_bug(expr.span, "non-desugared range");`
	`4283`	`+ }`
	`4284`	`+`
`4281`	`4285`	`}`
`4282`	`4286`
`4283`	`4287`	`debug!("type of expr({}) {} is...", expr.id,`