auto merge of #13016 : huonw/rust/new-opt-vec, r=cmr

Replace syntax::opt_vec with syntax::owned_slice

The `owned_slice::OwnedSlice` is  `(*T, uint)` (i.e. a direct equivalent to DSTs `~[T]`).

This shaves two words off the old OptVec type; and also makes substituting in other implementations easy, by removing all the mutation methods. (And also everything that's very rarely/never used.)

Author: bors

src/librustc/front/std_inject.rs

@@ -18,7 +18,7 @@ use syntax::codemap::DUMMY_SP;
 use syntax::codemap;
 use syntax::fold::Folder;
 use syntax::fold;
-use syntax::opt_vec;
+use syntax::owned_slice::OwnedSlice;
 use syntax::parse::token::InternedString;
 use syntax::parse::token;
 use syntax::util::small_vector::SmallVector;
@@ -156,12 +156,12 @@ impl<'a> fold::Folder for PreludeInjector<'a> {
                 ast::PathSegment {
                     identifier: token::str_to_ident("std"),
                     lifetimes: Vec::new(),
-                    types: opt_vec::Empty,
+                    types: OwnedSlice::empty(),
                 },
                 ast::PathSegment {
                     identifier: token::str_to_ident("prelude"),
                     lifetimes: Vec::new(),
-                    types: opt_vec::Empty,
+                    types: OwnedSlice::empty(),
                 }),
         };
 

src/librustc/front/test.rs

@@ -31,7 +31,7 @@ use syntax::ext::base::ExtCtxt;
 use syntax::ext::expand::ExpansionConfig;
 use syntax::fold::Folder;
 use syntax::fold;
-use syntax::opt_vec;
+use syntax::owned_slice::OwnedSlice;
 use syntax::parse::token::InternedString;
 use syntax::parse::token;
 use syntax::print::pprust;
@@ -377,7 +377,7 @@ fn path_node(ids: Vec<ast::Ident> ) -> ast::Path {
         segments: ids.move_iter().map(|identifier| ast::PathSegment {
             identifier: identifier,
             lifetimes: Vec::new(),
-            types: opt_vec::Empty,
+            types: OwnedSlice::empty(),
         }).collect()
     }
 }
@@ -389,7 +389,7 @@ fn path_node_global(ids: Vec<ast::Ident> ) -> ast::Path {
         segments: ids.move_iter().map(|identifier| ast::PathSegment {
             identifier: identifier,
             lifetimes: Vec::new(),
-            types: opt_vec::Empty,
+            types: OwnedSlice::empty(),
         }).collect()
     }
 }

src/librustc/metadata/tydecode.rs

@@ -24,7 +24,7 @@ use syntax::abi::AbiSet;
 use syntax::abi;
 use syntax::ast;
 use syntax::ast::*;
-use syntax::opt_vec;
+use syntax::owned_slice::OwnedSlice;
 use syntax::parse::token;
 
 // Compact string representation for ty::t values. API ty_str &
@@ -192,13 +192,13 @@ fn parse_region_substs(st: &mut PState, conv: conv_did) -> ty::RegionSubsts {
     match next(st) {
         'e' => ty::ErasedRegions,
         'n' => {
-            let mut regions = opt_vec::Empty;
+            let mut regions = vec!();
             while peek(st) != '.' {
                 let r = parse_region(st, |x,y| conv(x,y));
                 regions.push(r);
             }
             assert_eq!(next(st), '.');
-            ty::NonerasedRegions(regions)
+            ty::NonerasedRegions(OwnedSlice::from_vec(regions))
         }
         _ => fail!("parse_bound_region: bad input")
     }

src/librustc/middle/borrowck/move_data.rs

@@ -26,8 +26,6 @@ use middle::typeck;
 use syntax::ast;
 use syntax::ast_util;
 use syntax::codemap::Span;
-use syntax::opt_vec::OptVec;
-use syntax::opt_vec;
 use util::ppaux::Repr;
 
 pub struct MoveData {
@@ -316,15 +314,15 @@ impl MoveData {
 
     fn existing_base_paths(&self,
                            lp: @LoanPath)
-                           -> OptVec<MovePathIndex> {
-        let mut result = opt_vec::Empty;
+                           -> Vec<MovePathIndex> {
+        let mut result = vec!();
         self.add_existing_base_paths(lp, &mut result);
         result
     }
 
     fn add_existing_base_paths(&self,
                                lp: @LoanPath,
-                               result: &mut OptVec<MovePathIndex>) {
+                               result: &mut Vec<MovePathIndex>) {
         /*!
          * Adds any existing move path indices for `lp` and any base
          * paths of `lp` to `result`, but does not add new move paths

src/librustc/middle/cfg/construct.rs

@@ -14,7 +14,6 @@ use middle::typeck;
 use middle::ty;
 use syntax::ast;
 use syntax::ast_util;
-use syntax::opt_vec;
 use util::nodemap::NodeMap;
 
 struct CFGBuilder<'a> {
@@ -470,7 +469,7 @@ impl<'a> CFGBuilder<'a> {
     fn add_contained_edge(&mut self,
                           source: CFGIndex,
                           target: CFGIndex) {
-        let data = CFGEdgeData {exiting_scopes: opt_vec::Empty};
+        let data = CFGEdgeData {exiting_scopes: vec!() };
         self.graph.add_edge(source, target, data);
     }
 
@@ -479,9 +478,10 @@ impl<'a> CFGBuilder<'a> {
                         from_index: CFGIndex,
                         to_loop: LoopScope,
                         to_index: CFGIndex) {
-        let mut data = CFGEdgeData {exiting_scopes: opt_vec::Empty};
+        let mut data = CFGEdgeData {exiting_scopes: vec!() };
         let mut scope_id = from_expr.id;
         while scope_id != to_loop.loop_id {
+
             data.exiting_scopes.push(scope_id);
             scope_id = self.tcx.region_maps.encl_scope(scope_id);
         }

src/librustc/middle/cfg/mod.rs

@@ -19,7 +19,6 @@ use middle::graph;
 use middle::ty;
 use middle::typeck;
 use syntax::ast;
-use syntax::opt_vec::OptVec;
 use util::nodemap::NodeMap;
 
 mod construct;
@@ -36,7 +35,7 @@ pub struct CFGNodeData {
 }
 
 pub struct CFGEdgeData {
-    exiting_scopes: OptVec<ast::NodeId>
+    exiting_scopes: Vec<ast::NodeId>
 }
 
 pub type CFGIndex = graph::NodeIndex;

src/librustc/middle/kind.rs

@@ -19,7 +19,7 @@ use util::ppaux::UserString;
 use syntax::ast::*;
 use syntax::attr;
 use syntax::codemap::Span;
-use syntax::opt_vec;
+use syntax::owned_slice::OwnedSlice;
 use syntax::print::pprust::expr_to_str;
 use syntax::{visit,ast_util};
 use syntax::visit::Visitor;
@@ -92,7 +92,7 @@ fn check_struct_safe_for_destructor(cx: &mut Context,
     let struct_tpt = ty::lookup_item_type(cx.tcx, struct_did);
     if !struct_tpt.generics.has_type_params() {
         let struct_ty = ty::mk_struct(cx.tcx, struct_did, ty::substs {
-            regions: ty::NonerasedRegions(opt_vec::Empty),
+            regions: ty::NonerasedRegions(OwnedSlice::empty()),
             self_ty: None,
             tps: Vec::new()
         });

src/librustc/middle/privacy.rs

@@ -28,7 +28,7 @@ use syntax::ast_util::{is_local, def_id_of_def, local_def};
 use syntax::attr;
 use syntax::codemap::Span;
 use syntax::parse::token;
-use syntax::opt_vec;
+use syntax::owned_slice::OwnedSlice;
 use syntax::visit;
 use syntax::visit::Visitor;
 
@@ -842,7 +842,7 @@ impl<'a> Visitor<()> for PrivacyVisitor<'a> {
                                 let seg = ast::PathSegment {
                                     identifier: pid.node.name,
                                     lifetimes: Vec::new(),
-                                    types: opt_vec::Empty,
+                                    types: OwnedSlice::empty(),
                                 };
                                 let segs = vec!(seg);
                                 let path = ast::Path {

src/librustc/middle/resolve.rs

@@ -27,7 +27,7 @@ use syntax::parse::token::special_idents;
 use syntax::parse::token;
 use syntax::print::pprust::path_to_str;
 use syntax::codemap::{Span, DUMMY_SP, Pos};
-use syntax::opt_vec::OptVec;
+use syntax::owned_slice::OwnedSlice;
 use syntax::visit;
 use syntax::visit::Visitor;
 
@@ -3969,7 +3969,7 @@ impl<'a> Resolver<'a> {
     }
 
     fn resolve_type_parameters(&mut self,
-                                   type_parameters: &OptVec<TyParam>) {
+                                   type_parameters: &OwnedSlice<TyParam>) {
         for type_parameter in type_parameters.iter() {
             for bound in type_parameter.bounds.iter() {
                 self.resolve_type_parameter_bound(type_parameter.id, bound);

src/librustc/middle/resolve_lifetime.rs

@@ -21,8 +21,7 @@ use driver::session::Session;
 use util::nodemap::NodeMap;
 use syntax::ast;
 use syntax::codemap::Span;
-use syntax::opt_vec;
-use syntax::opt_vec::OptVec;
+use syntax::owned_slice::OwnedSlice;
 use syntax::parse::token::special_idents;
 use syntax::parse::token;
 use syntax::print::pprust::{lifetime_to_str};
@@ -413,22 +412,22 @@ pub fn early_bound_lifetimes<'a>(generics: &'a ast::Generics) -> Vec<ast::Lifeti
         .collect()
 }
 
-pub fn free_lifetimes(ty_params: &OptVec<ast::TyParam>) -> OptVec<ast::Name> {
+pub fn free_lifetimes(ty_params: &OwnedSlice<ast::TyParam>) -> Vec<ast::Name> {
     /*!
      * Gathers up and returns the names of any lifetimes that appear
      * free in `ty_params`. Of course, right now, all lifetimes appear
      * free, since we don't currently have any binders in type parameter
      * declarations; just being forwards compatible with future extensions.
      */
 
-    let mut collector = FreeLifetimeCollector { names: opt_vec::Empty };
+    let mut collector = FreeLifetimeCollector { names: vec!() };
     for ty_param in ty_params.iter() {
         visit::walk_ty_param_bounds(&mut collector, &ty_param.bounds, ());
     }
     return collector.names;
 
     struct FreeLifetimeCollector {
-        names: OptVec<ast::Name>,
+        names: Vec<ast::Name>,
     }
 
     impl Visitor<()> for FreeLifetimeCollector {