Convert std::io to istrs. Issue #855

23 files changed, 203 insertions, 160 deletions

diff --git a/src/comp/driver/rustc.rs b/src/comp/driver/rustc.rs
index 1ef81eb35ed..08f00479871 100644
--- a/src/comp/driver/rustc.rs
+++ b/src/comp/driver/rustc.rs
@@ -100,7 +100,7 @@ fn parse_input_src(sess: session::session, cfg: &ast::crate_cfg, infile: str)
    -> {crate: @ast::crate, src: str} {
     let srcbytes =
         if infile != "-" {
-            io::file_reader(infile)
+            io::file_reader(istr::from_estr(infile))
         } else { io::stdin() }.read_whole_stream();
     let src = str::unsafe_from_bytes(srcbytes);
     let crate =
@@ -238,18 +238,21 @@ fn pretty_print_input(sess: session::session, cfg: ast::crate_cfg, input: str,
       ppm_normal. { ann = pprust::no_ann(); }
     }
     pprust::print_crate(sess.get_codemap(), crate, input,
-                        io::string_reader(src), io::stdout(), ann);
+                        io::string_reader(istr::from_estr(src)),
+                        io::stdout(), ann);
 }
 
 fn version(argv0: str) {
     let vers = "unknown version";
     let env_vers = #env["CFG_VERSION"];
     if str::byte_len(env_vers) != 0u { vers = env_vers; }
-    io::stdout().write_str(#fmt["%s %s\n", argv0, vers]);
+    io::stdout().write_str(
+        istr::from_estr(#fmt["%s %s\n", argv0, vers]));
 }
 
 fn usage(argv0: str) {
-    io::stdout().write_str(#fmt["usage: %s [options] <input>\n", argv0] +
+    io::stdout().write_str(istr::from_estr(
+        #fmt["usage: %s [options] <input>\n", argv0] +
                                "
 options:
 
@@ -283,7 +286,7 @@ options:
     --test             build test harness
     --gc               garbage collect shared data (experimental/temporary)
 
-");
+"));
 }
 
 fn get_os(triple: str) -> session::os {
diff --git a/src/comp/metadata/creader.rs b/src/comp/metadata/creader.rs
index c13de2d6f9d..e06f0ca455f 100644
--- a/src/comp/metadata/creader.rs
+++ b/src/comp/metadata/creader.rs
@@ -86,7 +86,8 @@ fn list_file_metadata(path: str, out: io::writer) {
     alt get_metadata_section(path) {
       option::some(bytes) { decoder::list_crate_metadata(bytes, out); }
       option::none. {
-        out.write_str("Could not find metadata in " + path + ".\n");
+        out.write_str(
+            istr::from_estr("Could not find metadata in " + path + ".\n"));
       }
     }
 }
diff --git a/src/comp/metadata/decoder.rs b/src/comp/metadata/decoder.rs
index 0476fd88605..522aba23b6f 100644
--- a/src/comp/metadata/decoder.rs
+++ b/src/comp/metadata/decoder.rs
@@ -4,6 +4,7 @@ import std::ebml;
 import std::vec;
 import std::option;
 import std::str;
+import std::istr;
 import std::io;
 import std::map::hashmap;
 import syntax::ast;
@@ -346,18 +347,20 @@ fn get_attributes(md: &ebml::doc) -> [ast::attribute] {
 
 fn list_meta_items(meta_items: &ebml::doc, out: io::writer) {
     for mi: @ast::meta_item in get_meta_items(meta_items) {
-        out.write_str(#fmt["%s\n", pprust::meta_item_to_str(*mi)]);
+        out.write_str(
+            istr::from_estr(#fmt["%s\n", pprust::meta_item_to_str(*mi)]));
     }
 }
 
 fn list_crate_attributes(md: &ebml::doc, out: io::writer) {
-    out.write_str("=Crate Attributes=\n");
+    out.write_str(~"=Crate Attributes=\n");
 
     for attr: ast::attribute in get_attributes(md) {
-        out.write_str(#fmt["%s\n", pprust::attribute_to_str(attr)]);
+        out.write_str(
+            istr::from_estr(#fmt["%s\n", pprust::attribute_to_str(attr)]));
     }
 
-    out.write_str("\n\n");
+    out.write_str(~"\n\n");
 }
 
 fn get_crate_attributes(data: @[u8]) -> [ast::attribute] {
@@ -380,17 +383,18 @@ fn get_crate_deps(data: @[u8]) -> [crate_dep] {
 }
 
 fn list_crate_deps(data: @[u8], out: io::writer) {
-    out.write_str("=External Dependencies=\n");
+    out.write_str(~"=External Dependencies=\n");
 
     for dep: crate_dep in get_crate_deps(data) {
-        out.write_str(#fmt["%d %s\n", dep.cnum, dep.ident]);
+        out.write_str(
+            istr::from_estr(#fmt["%d %s\n", dep.cnum, dep.ident]));
     }
 
-    out.write_str("\n");
+    out.write_str(~"\n");
 }
 
 fn list_crate_items(bytes: &@[u8], md: &ebml::doc, out: io::writer) {
-    out.write_str("=Items=\n");
+    out.write_str(~"=Items=\n");
     let paths = ebml::get_doc(md, tag_paths);
     let items = ebml::get_doc(md, tag_items);
     let index = ebml::get_doc(paths, tag_index);
@@ -403,11 +407,12 @@ fn list_crate_items(bytes: &@[u8], md: &ebml::doc, out: io::writer) {
             let def = ebml::doc_at(bytes, data.pos);
             let did_doc = ebml::get_doc(def, tag_def_id);
             let did = parse_def_id(ebml::doc_data(did_doc));
-            out.write_str(#fmt["%s (%s)\n", data.path,
-                               describe_def(items, did)]);
+            out.write_str(
+                istr::from_estr(#fmt["%s (%s)\n", data.path,
+                                     describe_def(items, did)]));
         }
     }
-    out.write_str("\n");
+    out.write_str(~"\n");
 }
 
 fn list_crate_metadata(bytes: &@[u8], out: io::writer) {
diff --git a/src/comp/metadata/encoder.rs b/src/comp/metadata/encoder.rs
index b2d76729361..12db17936dd 100644
--- a/src/comp/metadata/encoder.rs
+++ b/src/comp/metadata/encoder.rs
@@ -2,6 +2,7 @@
 
 import std::vec;
 import std::str;
+import std::istr;
 import std::uint;
 import std::io;
 import std::option;
@@ -435,7 +436,9 @@ fn encode_index<T>(ebml_w: &ebml::writer, buckets: &[@[entry<T>]],
     ebml::end_tag(ebml_w);
 }
 
-fn write_str(writer: &io::writer, s: &str) { writer.write_str(s); }
+fn write_str(writer: &io::writer, s: &str) {
+    writer.write_str(istr::from_estr(s));
+}
 
 fn write_int(writer: &io::writer, n: &int) {
     writer.write_be_uint(n as uint, 4u);
@@ -616,7 +619,7 @@ fn encode_metadata(cx: &@crate_ctxt, crate: &@crate) -> str {
     // remaining % 4 bytes.
 
     buf_w.write([0u8, 0u8, 0u8, 0u8]);
-    ret string_w.get_str();
+    ret istr::to_estr(string_w.get_str());
 }
 
 // Get the encoded string for a type
@@ -624,7 +627,7 @@ fn encoded_ty(tcx: &ty::ctxt, t: ty::t) -> str {
     let cx = @{ds: def_to_str, tcx: tcx, abbrevs: tyencode::ac_no_abbrevs};
     let sw = io::string_writer();
     tyencode::enc_ty(sw.get_writer(), cx, t);
-    ret sw.get_str();
+    ret istr::to_estr(sw.get_str());
 }
 
 
diff --git a/src/comp/metadata/tyencode.rs b/src/comp/metadata/tyencode.rs
index 34a810adb3b..399ab85fd30 100644
--- a/src/comp/metadata/tyencode.rs
+++ b/src/comp/metadata/tyencode.rs
@@ -46,15 +46,15 @@ fn enc_ty(w: &io::writer, cx: &@ctxt, t: ty::t) {
           none. {
             let sw = io::string_writer();
             enc_sty(sw.get_writer(), cx, ty::struct(cx.tcx, t));
-            result_str = sw.get_str();
+            result_str = istr::to_estr(sw.get_str());
             cx.tcx.short_names_cache.insert(t, result_str);
           }
         }
-        w.write_str(result_str);
+        w.write_str(istr::from_estr(result_str));
       }
       ac_use_abbrevs(abbrevs) {
         alt abbrevs.find(t) {
-          some(a) { w.write_str(a.s); ret; }
+          some(a) { w.write_str(istr::from_estr(a.s)); ret; }
           none. {
             let pos = w.get_buf_writer().tell();
             enc_sty(w, cx, ty::struct(cx.tcx, t));
@@ -100,30 +100,30 @@ fn enc_sty(w: &io::writer, cx: &@ctxt, st: &ty::sty) {
       ty::ty_float. { w.write_char('l'); }
       ty::ty_machine(mach) {
         alt mach {
-          ty_u8. { w.write_str("Mb"); }
-          ty_u16. { w.write_str("Mw"); }
-          ty_u32. { w.write_str("Ml"); }
-          ty_u64. { w.write_str("Md"); }
-          ty_i8. { w.write_str("MB"); }
-          ty_i16. { w.write_str("MW"); }
-          ty_i32. { w.write_str("ML"); }
-          ty_i64. { w.write_str("MD"); }
-          ty_f32. { w.write_str("Mf"); }
-          ty_f64. { w.write_str("MF"); }
+          ty_u8. { w.write_str(~"Mb"); }
+          ty_u16. { w.write_str(~"Mw"); }
+          ty_u32. { w.write_str(~"Ml"); }
+          ty_u64. { w.write_str(~"Md"); }
+          ty_i8. { w.write_str(~"MB"); }
+          ty_i16. { w.write_str(~"MW"); }
+          ty_i32. { w.write_str(~"ML"); }
+          ty_i64. { w.write_str(~"MD"); }
+          ty_f32. { w.write_str(~"Mf"); }
+          ty_f64. { w.write_str(~"MF"); }
         }
       }
       ty::ty_char. { w.write_char('c'); }
       ty::ty_str. { w.write_char('s'); }
       ty::ty_istr. { w.write_char('S'); }
       ty::ty_tag(def, tys) {
-        w.write_str("t[");
-        w.write_str(cx.ds(def));
+        w.write_str(~"t[");
+        w.write_str(istr::from_estr(cx.ds(def)));
         w.write_char('|');
         for t: ty::t in tys { enc_ty(w, cx, t); }
         w.write_char(']');
       }
       ty::ty_tup(ts) {
-        w.write_str("T[");
+        w.write_str(~"T[");
         for t in ts { enc_ty(w, cx, t); }
         w.write_char(']');
       }
@@ -132,9 +132,9 @@ fn enc_sty(w: &io::writer, cx: &@ctxt, st: &ty::sty) {
       ty::ty_ptr(mt) { w.write_char('*'); enc_mt(w, cx, mt); }
       ty::ty_vec(mt) { w.write_char('I'); enc_mt(w, cx, mt); }
       ty::ty_rec(fields) {
-        w.write_str("R[");
+        w.write_str(~"R[");
         for field: ty::field in fields {
-            w.write_str(field.ident);
+            w.write_str(istr::from_estr(field.ident));
             w.write_char('=');
             enc_mt(w, cx, field.mt);
         }
@@ -156,17 +156,17 @@ fn enc_sty(w: &io::writer, cx: &@ctxt, st: &ty::sty) {
         enc_ty_fn(w, cx, args, out, return, []);
       }
       ty::ty_obj(methods) {
-        w.write_str("O[");
+        w.write_str(~"O[");
         for m: ty::method in methods {
             enc_proto(w, m.proto);
-            w.write_str(m.ident);
+            w.write_str(istr::from_estr(m.ident));
             enc_ty_fn(w, cx, m.inputs, m.output, m.cf, m.constrs);
         }
         w.write_char(']');
       }
       ty::ty_res(def, ty, tps) {
-        w.write_str("r[");
-        w.write_str(cx.ds(def));
+        w.write_str(~"r[");
+        w.write_str(istr::from_estr(cx.ds(def)));
         w.write_char('|');
         enc_ty(w, cx, ty);
         for t: ty::t in tps { enc_ty(w, cx, t); }
@@ -174,24 +174,24 @@ fn enc_sty(w: &io::writer, cx: &@ctxt, st: &ty::sty) {
       }
       ty::ty_var(id) {
         w.write_char('X');
-        w.write_str(istr::to_estr(int::str(id)));
+        w.write_str(int::str(id));
       }
       ty::ty_native(def) {
         w.write_char('E');
-        w.write_str(cx.ds(def));
+        w.write_str(istr::from_estr(cx.ds(def)));
         w.write_char('|');
       }
       ty::ty_param(id, k) {
         alt k {
-          kind_unique. { w.write_str("pu"); }
-          kind_shared. { w.write_str("ps"); }
-          kind_pinned. { w.write_str("pp"); }
+          kind_unique. { w.write_str(~"pu"); }
+          kind_shared. { w.write_str(~"ps"); }
+          kind_pinned. { w.write_str(~"pp"); }
         }
-        w.write_str(istr::to_estr(uint::str(id)));
+        w.write_str(uint::str(id));
       }
       ty::ty_type. { w.write_char('Y'); }
       ty::ty_constr(ty, cs) {
-        w.write_str("A[");
+        w.write_str(~"A[");
         enc_ty(w, cx, ty);
         for tc: @ty::type_constr in cs { enc_ty_constr(w, cx, tc); }
         w.write_char(']');
@@ -235,9 +235,9 @@ fn enc_ty_fn(w: &io::writer, cx: &@ctxt, args: &[ty::arg], out: ty::t,
 
 // FIXME less copy-and-paste
 fn enc_constr(w: &io::writer, cx: &@ctxt, c: &@ty::constr) {
-    w.write_str(path_to_str(c.node.path));
+    w.write_str(istr::from_estr(path_to_str(c.node.path)));
     w.write_char('(');
-    w.write_str(cx.ds(c.node.id));
+    w.write_str(istr::from_estr(cx.ds(c.node.id)));
     w.write_char('|');
     let semi = false;
     for a: @constr_arg in c.node.args {
@@ -245,24 +245,28 @@ fn enc_constr(w: &io::writer, cx: &@ctxt, c: &@ty::constr) {
         alt a.node {
           carg_base. { w.write_char('*'); }
           carg_ident(i) { w.write_uint(i); }
-          carg_lit(l) { w.write_str(lit_to_str(l)); }
+          carg_lit(l) {
+            w.write_str(istr::from_estr(lit_to_str(l)));
+          }
         }
     }
     w.write_char(')');
 }
 
 fn enc_ty_constr(w: &io::writer, cx: &@ctxt, c: &@ty::type_constr) {
-    w.write_str(path_to_str(c.node.path));
+    w.write_str(istr::from_estr(path_to_str(c.node.path)));
     w.write_char('(');
-    w.write_str(cx.ds(c.node.id));
+    w.write_str(istr::from_estr(cx.ds(c.node.id)));
     w.write_char('|');
     let semi = false;
     for a: @ty::ty_constr_arg in c.node.args {
         if semi { w.write_char(';'); } else { semi = true; }
         alt a.node {
           carg_base. { w.write_char('*'); }
-          carg_ident(p) { w.write_str(path_to_str(p)); }
-          carg_lit(l) { w.write_str(lit_to_str(l)); }
+          carg_ident(p) {
+            w.write_str(istr::from_estr(path_to_str(p))); }
+          carg_lit(l) {
+            w.write_str(istr::from_estr(lit_to_str(l))); }
         }
     }
     w.write_char(')');
diff --git a/src/comp/syntax/codemap.rs b/src/comp/syntax/codemap.rs
index e522becd3e0..d9aff69acfa 100644
--- a/src/comp/syntax/codemap.rs
+++ b/src/comp/syntax/codemap.rs
@@ -1,6 +1,7 @@
 import std::vec;
 import std::uint;
 import std::str;
+import std::istr;
 import std::term;
 import std::io;
 import std::option;
@@ -108,13 +109,13 @@ fn emit_diagnostic(sp: &option::t<span>, msg: &str, kind: &str, color: u8,
       }
       none. { }
     }
-    io::stdout().write_str(ss);
+    io::stdout().write_str(istr::from_estr(ss));
     if term::color_supported() {
         term::fg(io::stdout().get_buf_writer(), color);
     }
-    io::stdout().write_str(#fmt["%s:", kind]);
+    io::stdout().write_str(istr::from_estr(#fmt["%s:", kind]));
     if term::color_supported() { term::reset(io::stdout().get_buf_writer()); }
-    io::stdout().write_str(#fmt[" %s\n", msg]);
+    io::stdout().write_str(istr::from_estr(#fmt[" %s\n", msg]));
 
     maybe_highlight_lines(sp, cm, maybe_lines);
 }
@@ -130,7 +131,8 @@ fn maybe_highlight_lines(sp: &option::t<span>, cm: &codemap,
 
         // FIXME: reading in the entire file is the worst possible way to
         //        get access to the necessary lines.
-        let file = io::read_whole_file_str(lines.name);
+        let file = istr::to_estr(
+            io::read_whole_file_str(istr::from_estr(lines.name)));
         let fm = get_filemap(cm, lines.name);
 
         // arbitrarily only print up to six lines of the error
@@ -143,18 +145,19 @@ fn maybe_highlight_lines(sp: &option::t<span>, cm: &codemap,
         }
         // Print the offending lines
         for line: uint in display_lines {
-            io::stdout().write_str(#fmt["%s:%u ", fm.name, line + 1u]);
+            io::stdout().write_str(
+                istr::from_estr(#fmt["%s:%u ", fm.name, line + 1u]));
             let s = get_line(fm, line as int, file);
             if !str::ends_with(s, "\n") { s += "\n"; }
-            io::stdout().write_str(s);
+            io::stdout().write_str(istr::from_estr(s));
         }
         if elided {
             let last_line = display_lines[vec::len(display_lines) - 1u];
             let s = #fmt["%s:%u ", fm.name, last_line + 1u];
             let indent = str::char_len(s);
-            let out = "";
-            while indent > 0u { out += " "; indent -= 1u; }
-            out += "...\n";
+            let out = ~"";
+            while indent > 0u { out += ~" "; indent -= 1u; }
+            out += ~"...\n";
             io::stdout().write_str(out);
         }
 
@@ -180,7 +183,7 @@ fn maybe_highlight_lines(sp: &option::t<span>, cm: &codemap,
                 let width = hi.col - lo.col - 1u;
                 while width > 0u { str::push_char(s, '~'); width -= 1u; }
             }
-            io::stdout().write_str(s + "\n");
+            io::stdout().write_str(istr::from_estr(s + "\n"));
         }
       }
       _ { }
diff --git a/src/comp/syntax/ext/log_syntax.rs b/src/comp/syntax/ext/log_syntax.rs
index a03ff11a66d..3cf240097dc 100644
--- a/src/comp/syntax/ext/log_syntax.rs
+++ b/src/comp/syntax/ext/log_syntax.rs
@@ -1,12 +1,14 @@
 import std::option;
 import base::*;
 import syntax::ast;
+import std::istr;
 
 fn expand_syntax_ext(cx: &ext_ctxt, sp: codemap::span, arg: @ast::expr,
                      _body: option::t<str>) -> @ast::expr {
 
     cx.print_backtrace();
-    std::io::stdout().write_line(print::pprust::expr_to_str(arg));
+    std::io::stdout().write_line(
+        istr::from_estr(print::pprust::expr_to_str(arg)));
 
     //trivial expression
     ret @{id: cx.next_id(), node: ast::expr_rec([], option::none), span: sp};
diff --git a/src/comp/syntax/parse/parser.rs b/src/comp/syntax/parse/parser.rs
index 59cea6e131d..b5d71a6ee9c 100644
--- a/src/comp/syntax/parse/parser.rs
+++ b/src/comp/syntax/parse/parser.rs
@@ -63,7 +63,7 @@ type parser =
 fn new_parser_from_file(sess: parse_sess, cfg: ast::crate_cfg, path: str,
                         chpos: uint, byte_pos: uint, ftype: file_type) ->
    parser {
-    let src = io::read_whole_file_str(path);
+    let src = istr::to_estr(io::read_whole_file_str(istr::from_estr(path)));
     let filemap = codemap::new_filemap(path, chpos, byte_pos);
     sess.cm.files += [filemap];
     let itr = @interner::mk(str::hash, str::eq);
diff --git a/src/comp/syntax/print/pp.rs b/src/comp/syntax/print/pp.rs
index adeccd4150c..3ad514fdb2e 100644
--- a/src/comp/syntax/print/pp.rs
+++ b/src/comp/syntax/print/pp.rs
@@ -2,7 +2,7 @@
 import std::io;
 import std::vec;
 import std::str;
-
+import std::istr;
 
 /*
  * This pretty-printer is a direct reimplementation of Philip Karlton's
@@ -391,7 +391,7 @@ obj printer(out: io::writer,
     }
     fn print_newline(amount: int) {
         log #fmt["NEWLINE %d", amount];
-        out.write_str("\n");
+        out.write_str(~"\n");
         pending_indentation = 0;
         self.indent(amount);
     }
@@ -407,10 +407,10 @@ obj printer(out: io::writer,
     }
     fn write_str(s: str) {
         while pending_indentation > 0 {
-            out.write_str(" ");
+            out.write_str(~" ");
             pending_indentation -= 1;
         }
-        out.write_str(s);
+        out.write_str(istr::from_estr(s));
     }
     fn print(x: token, L: int) {
         log #fmt["print %s %d (remaining line space=%d)", tok_str(x), L,
diff --git a/src/comp/syntax/print/pprust.rs b/src/comp/syntax/print/pprust.rs
index bf3942f1eab..9dcd56407f7 100644
--- a/src/comp/syntax/print/pprust.rs
+++ b/src/comp/syntax/print/pprust.rs
@@ -112,7 +112,7 @@ fn fun_to_str(f: &ast::_fn, name: str, params: &[ast::ty_param]) -> str {
     let s = rust_printer(writer.get_writer());
     print_fn(s, f.decl, f.proto, name, params, f.decl.constraints);
     eof(s.s);
-    ret writer.get_str();
+    ret istr::to_estr(writer.get_str());
 }
 
 fn block_to_str(blk: &ast::blk) -> str {
@@ -126,7 +126,7 @@ fn block_to_str(blk: &ast::blk) -> str {
     ibox(s, 0u);
     print_block(s, blk);
     eof(s.s);
-    ret writer.get_str();
+    ret istr::to_estr(writer.get_str());
 }
 
 fn meta_item_to_str(mi: &ast::meta_item) -> str {
@@ -1621,7 +1621,7 @@ fn to_str<T>(t: &T, f: fn(&ps, &T)) -> str {
     let s = rust_printer(writer.get_writer());
     f(s, t);
     eof(s.s);
-    ret writer.get_str();
+    ret istr::to_estr(writer.get_str());
 }
 
 fn next_comment(s: &ps) -> option::t<lexer::cmnt> {
diff --git a/src/etc/combine-tests.py b/src/etc/combine-tests.py
index 2c51722c940..c6656014525 100755
--- a/src/etc/combine-tests.py
+++ b/src/etc/combine-tests.py
@@ -58,7 +58,7 @@ i = 0
 for t in stage2_tests:
     p = os.path.join("test", "run-pass", t)
     p = p.replace("\\", "\\\\")
-    d.write("    out.write_str(\"run-pass [stage2]: %s\\n\");\n" % p)
+    d.write("    out.write_str(~\"run-pass [stage2]: %s\\n\");\n" % p)
     if t in take_args:
         d.write("    t_%d::main([\"arg0\"]);\n" % i)
     else:
diff --git a/src/fuzzer/fuzzer.rs b/src/fuzzer/fuzzer.rs
index 0d4a546902e..99d633427be 100644
--- a/src/fuzzer/fuzzer.rs
+++ b/src/fuzzer/fuzzer.rs
@@ -22,13 +22,13 @@ import rustc::syntax::parse::parser;
 import rustc::syntax::print::pprust;
 
 fn write_file(filename: &str, content: &str) {
-    io::file_writer(filename, [io::create, io::truncate]).write_str(content);
+    io::file_writer(istr::from_estr(filename), [io::create, io::truncate]).write_str(istr::from_estr(content));
     // Work around https://github.com/graydon/rust/issues/726
     std::run::run_program(~"chmod", [~"644", istr::from_estr(filename)]);
 }
 
 fn file_contains(filename: &str, needle: &str) -> bool {
-    let contents = io::read_whole_file_str(filename);
+    let contents = istr::to_estr(io::read_whole_file_str(istr::from_estr(filename)));
     ret str::find(contents, needle) != -1;
 }
 
@@ -154,7 +154,7 @@ fn devnull() -> io::writer { std::io::string_writer().get_writer() }
 fn as_str(f: fn(io::writer)) -> str {
     let w = std::io::string_writer();
     f(w.get_writer());
-    ret w.get_str();
+    ret istr::to_estr(w.get_str());
 }
 
 fn check_variants_of_ast(crate: &ast::crate, codemap: &codemap::codemap,
@@ -171,7 +171,7 @@ fn check_variants_of_ast(crate: &ast::crate, codemap: &codemap::codemap,
                 // string for stability is easier and ok for now.
                 let str3 =
                     as_str(bind pprust::print_crate(codemap, crate2, filename,
-                                                    io::string_reader(""), _,
+                                                    io::string_reader(~""), _,
                                                     pprust::no_ann()));
                 // 1u would be sane here, but the pretty-printer currently has lots of whitespace and paren issues,
                 // and https://github.com/graydon/rust/issues/766 is hilarious.
@@ -254,7 +254,7 @@ fn parse_and_print(code: &str) -> str {
     //write_file(filename, code);
     let crate = parser::parse_crate_from_source_str(filename, code, [], sess);
     ret as_str(bind pprust::print_crate(sess.cm, crate, filename,
-                                        io::string_reader(code), _,
+                                        io::string_reader(istr::from_estr(code)), _,
                                         pprust::no_ann()));
 }
 
@@ -340,7 +340,7 @@ fn check_convergence(files: &[str]) {
     log_err #fmt["pp convergence tests: %u files", vec::len(files)];
     for file in files {
         if !file_is_confusing(file) {
-            let s = io::read_whole_file_str(file);
+            let s = istr::to_estr(io::read_whole_file_str(istr::from_estr(file)));
             if !content_is_confusing(s) {
                 log_err #fmt["pp converge: %s", file];
                 // Change from 7u to 2u when https://github.com/graydon/rust/issues/759 is fixed
@@ -353,7 +353,7 @@ fn check_convergence(files: &[str]) {
 fn check_variants(files: &[str]) {
     for file in files {
         if !file_is_confusing(file) {
-            let s = io::read_whole_file_str(file);
+            let s = istr::to_estr(io::read_whole_file_str(istr::from_estr(file)));
             if content_is_dangerous_to_modify(s) || content_is_confusing(s) {
                 cont;
             }
@@ -362,7 +362,7 @@ fn check_variants(files: &[str]) {
             let crate =
                 parser::parse_crate_from_source_str(file, s, [], sess);
             log_err as_str(bind pprust::print_crate(sess.cm, crate, file,
-                                                    io::string_reader(s), _,
+                                                    io::string_reader(istr::from_estr(s)), _,
                                                     pprust::no_ann()));
             check_variants_of_ast(*crate, sess.cm, file);
         }
diff --git a/src/lib/io.rs b/src/lib/io.rs
index 95945425a1d..4be9d380c8d 100644
--- a/src/lib/io.rs
+++ b/src/lib/io.rs
@@ -39,8 +39,8 @@ type reader =
         fn read_bytes(uint) -> [u8];
         fn read_char() -> char;
         fn eof() -> bool;
-        fn read_line() -> str;
-        fn read_c_str() -> str;
+        fn read_line() -> istr;
+        fn read_c_str() -> istr;
         fn read_le_uint(uint) -> uint;
         fn read_le_int(uint) -> int;
         fn read_be_uint(uint) -> uint;
@@ -104,7 +104,7 @@ obj new_reader(rdr: buf_reader) {
         ret val as char;
     }
     fn eof() -> bool { ret rdr.eof(); }
-    fn read_line() -> str {
+    fn read_line() -> istr {
         let buf: [u8] = [];
         // No break yet in rustc
 
@@ -115,16 +115,16 @@ obj new_reader(rdr: buf_reader) {
                 go_on = false;
             } else { buf += [ch as u8]; }
         }
-        ret str::unsafe_from_bytes(buf);
+        ret istr::unsafe_from_bytes(buf);
     }
-    fn read_c_str() -> str {
+    fn read_c_str() -> istr {
         let buf: [u8] = [];
         let go_on = true;
         while go_on {
             let ch = rdr.read_byte();
             if ch < 1 { go_on = false; } else { buf += [ch as u8]; }
         }
-        ret str::unsafe_from_bytes(buf);
+        ret istr::unsafe_from_bytes(buf);
     }
 
     // FIXME deal with eof?
@@ -172,8 +172,10 @@ fn stdin() -> reader {
     ret new_reader(FILE_buf_reader(rustrt::rust_get_stdin(), option::none));
 }
 
-fn file_reader(path: str) -> reader {
-    let f = os::libc::fopen(str::buf(path), str::buf("r"));
+fn file_reader(path: &istr) -> reader {
+    let path = istr::to_estr(path);
+    let mode = "r";
+    let f = os::libc::fopen(str::buf(path), str::buf(mode));
     if f as uint == 0u { log_err "error opening " + path; fail; }
     ret new_reader(FILE_buf_reader(f, option::some(@FILE_res(f))));
 }
@@ -213,8 +215,8 @@ fn new_byte_buf_reader(buf: &[u8]) -> buf_reader {
     ret byte_buf_reader(@{buf: buf, mutable pos: 0u});
 }
 
-fn string_reader(s: &str) -> reader {
-    ret new_reader(new_byte_buf_reader(str::bytes(s)));
+fn string_reader(s: &istr) -> reader {
+    ret new_reader(new_byte_buf_reader(istr::bytes(s)));
 }
 
 
@@ -273,7 +275,8 @@ obj fd_buf_writer(fd: int, res: option::t<@fd_res>) {
     }
 }
 
-fn file_buf_writer(path: str, flags: &[fileflag]) -> buf_writer {
+fn file_buf_writer(path: &istr, flags: &[fileflag]) -> buf_writer {
+    let path = istr::to_estr(path);
     let fflags: int =
         os::libc_constants::O_WRONLY() | os::libc_constants::O_BINARY();
     for f: fileflag in flags {
@@ -301,8 +304,8 @@ type writer =
     // function will be provided for general encoded string output
     obj {
         fn get_buf_writer() -> buf_writer;
-        fn write_str(str);
-        fn write_line(str);
+        fn write_str(&istr);
+        fn write_line(&istr);
         fn write_char(char);
         fn write_int(int);
         fn write_uint(uint);
@@ -327,20 +330,20 @@ fn uint_to_be_bytes(n: uint, size: uint) -> [u8] {
 
 obj new_writer(out: buf_writer) {
     fn get_buf_writer() -> buf_writer { ret out; }
-    fn write_str(s: str) { out.write(str::bytes(s)); }
-    fn write_line(s: str) {
-        out.write(str::bytes(s));
-        out.write(str::bytes("\n"));
+    fn write_str(s: &istr) { out.write(istr::bytes(s)); }
+    fn write_line(s: &istr) {
+        out.write(istr::bytes(s));
+        out.write(istr::bytes(~"\n"));
     }
     fn write_char(ch: char) {
         // FIXME needlessly consy
 
-        out.write(str::bytes(str::from_char(ch)));
+        out.write(istr::bytes(istr::from_char(ch)));
     }
-    fn write_int(n: int) { out.write(str::bytes(
-        istr::to_estr(int::to_str(n, 10u)))); }
-    fn write_uint(n: uint) { out.write(str::bytes(
-        istr::to_estr(uint::to_str(n, 10u)))); }
+    fn write_int(n: int) { out.write(istr::bytes(
+        int::to_str(n, 10u))); }
+    fn write_uint(n: uint) { out.write(istr::bytes(
+        uint::to_str(n, 10u))); }
     fn write_bytes(bytes: &[u8]) { out.write(bytes); }
     fn write_le_uint(n: uint, size: uint) {
         out.write(uint_to_le_bytes(n, size));
@@ -353,14 +356,16 @@ obj new_writer(out: buf_writer) {
     }
 }
 
-fn file_writer(path: str, flags: &[fileflag]) -> writer {
+fn file_writer(path: &istr, flags: &[fileflag]) -> writer {
     ret new_writer(file_buf_writer(path, flags));
 }
 
 
 // FIXME: fileflags
-fn buffered_file_buf_writer(path: str) -> buf_writer {
-    let f = os::libc::fopen(str::buf(path), str::buf("w"));
+fn buffered_file_buf_writer(path: &istr) -> buf_writer {
+    let path = istr::to_estr(path);
+    let mode = "w";
+    let f = os::libc::fopen(str::buf(path), str::buf(mode));
     if f as uint == 0u { log_err "error opening " + path; fail; }
     ret FILE_writer(f, option::some(@FILE_res(f)));
 }
@@ -372,7 +377,7 @@ fn stdout() -> writer { ret new_writer(fd_buf_writer(1, option::none)); }
 type str_writer =
     obj {
         fn get_writer() -> writer;
-        fn get_str() -> str;
+        fn get_str() -> istr;
     };
 
 type mutable_byte_buf = @{mutable buf: [mutable u8], mutable pos: uint};
@@ -415,7 +420,7 @@ fn string_writer() -> str_writer {
     let buf: mutable_byte_buf = @{mutable buf: b, mutable pos: 0u};
     obj str_writer_wrap(wr: writer, buf: mutable_byte_buf) {
         fn get_writer() -> writer { ret wr; }
-        fn get_str() -> str { ret str::unsafe_from_bytes(buf.buf); }
+        fn get_str() -> istr { ret istr::unsafe_from_bytes(buf.buf); }
     }
     ret str_writer_wrap(new_writer(byte_buf_writer(buf)), buf);
 }
@@ -435,11 +440,11 @@ fn seek_in_buf(offset: int, pos: uint, len: uint, whence: seek_style) ->
     ret bpos as uint;
 }
 
-fn read_whole_file_str(file: &str) -> str {
-    str::unsafe_from_bytes(read_whole_file(file))
+fn read_whole_file_str(file: &istr) -> istr {
+    istr::unsafe_from_bytes(read_whole_file(file))
 }
 
-fn read_whole_file(file: &str) -> [u8] {
+fn read_whole_file(file: &istr) -> [u8] {
 
     // FIXME: There's a lot of copying here
     file_reader(file).read_whole_stream()
diff --git a/src/lib/test.rs b/src/lib/test.rs
index ef3348dc36b..5c087b64814 100644
--- a/src/lib/test.rs
+++ b/src/lib/test.rs
@@ -119,26 +119,30 @@ fn run_tests_console_(opts: &test_opts, tests: &[test_desc],
         alt event {
           te_filtered(filtered_tests) {
             st.total = vec::len(filtered_tests);
-            st.out.write_line(#fmt["\nrunning %u tests", st.total]);
+            st.out.write_line(
+                istr::from_estr(#fmt["\nrunning %u tests", st.total]));
+          }
+          te_wait(test) {
+            st.out.write_str(
+                istr::from_estr(#fmt["test %s ... ", test.name]));
           }
-          te_wait(test) { st.out.write_str(#fmt["test %s ... ", test.name]); }
           te_result(test, result) {
             alt result {
               tr_ok. {
                 st.passed += 1u;
                 write_ok(st.out, st.use_color);
-                st.out.write_line("");
+                st.out.write_line(~"");
               }
               tr_failed. {
                 st.failed += 1u;
                 write_failed(st.out, st.use_color);
-                st.out.write_line("");
+                st.out.write_line(~"");
                 st.failures += [test];
               }
               tr_ignored. {
                 st.ignored += 1u;
                 write_ignored(st.out, st.use_color);
-                st.out.write_line("");
+                st.out.write_line(~"");
               }
             }
           }
@@ -160,20 +164,22 @@ fn run_tests_console_(opts: &test_opts, tests: &[test_desc],
     let success = st.failed == 0u;
 
     if !success {
-        st.out.write_line("\nfailures:");
+        st.out.write_line(~"\nfailures:");
         for test: test_desc in st.failures {
             let testname = test.name; // Satisfy alias analysis
-            st.out.write_line(#fmt["    %s", testname]);
+            st.out.write_line(istr::from_estr(#fmt["    %s", testname]));
         }
     }
 
-    st.out.write_str(#fmt["\nresult: "]);
+    st.out.write_str(istr::from_estr(#fmt["\nresult: "]));
     if success {
         // There's no parallelism at this point so it's safe to use color
         write_ok(st.out, true);
     } else { write_failed(st.out, true); }
-    st.out.write_str(#fmt[". %u passed; %u failed; %u ignored\n\n", st.passed,
-                          st.failed, st.ignored]);
+    st.out.write_str(
+        istr::from_estr(
+            #fmt[". %u passed; %u failed; %u ignored\n\n", st.passed,
+                          st.failed, st.ignored]));
 
     ret success;
 
@@ -194,7 +200,7 @@ fn run_tests_console_(opts: &test_opts, tests: &[test_desc],
         if use_color && term::color_supported() {
             term::fg(out.get_buf_writer(), color);
         }
-        out.write_str(word);
+        out.write_str(istr::from_estr(word));
         if use_color && term::color_supported() {
             term::reset(out.get_buf_writer());
         }
diff --git a/src/test/bench/shootout-pfib.rs b/src/test/bench/shootout-pfib.rs
index c0710c9018c..9a09e9d0bd0 100644
--- a/src/test/bench/shootout-pfib.rs
+++ b/src/test/bench/shootout-pfib.rs
@@ -107,8 +107,10 @@ fn main(argv: [str]) {
 
                     let elapsed = stop - start;
 
-                    out.write_line(#fmt["%d\t%d\t%s", n, fibn,
-                                        istr::to_estr(u64::str(elapsed))]);
+                    out.write_line(
+                        istr::from_estr(
+                            #fmt["%d\t%d\t%s", n, fibn,
+                                 istr::to_estr(u64::str(elapsed))]));
                 }
             }
         }
diff --git a/src/test/bench/task-perf-word-count-generic.rs b/src/test/bench/task-perf-word-count-generic.rs
index c3fd544aa3d..0f1db55e886 100644
--- a/src/test/bench/task-perf-word-count-generic.rs
+++ b/src/test/bench/task-perf-word-count-generic.rs
@@ -31,7 +31,7 @@ import std::comm::recv;
 import std::comm::send;
 
 fn map(filename: &[u8], emit: &map_reduce::putter<[u8], int>) {
-    let f = io::file_reader(str::unsafe_from_bytes(filename));
+    let f = io::file_reader(istr::unsafe_from_bytes(filename));
 
     while true {
         alt read_word(f) {
@@ -202,7 +202,8 @@ fn main(argv: [str]) {
     if vec::len(argv) < 2u {
         let out = io::stdout();
 
-        out.write_line(#fmt["Usage: %s <filename> ...", argv[0]]);
+        out.write_line(
+            istr::from_estr(#fmt["Usage: %s <filename> ...", argv[0]]));
 
         // TODO: run something just to make sure the code hasn't
         // broken yet. This is the unit test mode of this program.
diff --git a/src/test/bench/task-perf-word-count.rs b/src/test/bench/task-perf-word-count.rs
index 703072eb511..e5355fdc955 100644
--- a/src/test/bench/task-perf-word-count.rs
+++ b/src/test/bench/task-perf-word-count.rs
@@ -14,6 +14,7 @@ import option = std::option::t;
 import std::option::some;
 import std::option::none;
 import std::str;
+import std::istr;
 import std::map;
 import std::vec;
 import std::io;
@@ -30,7 +31,7 @@ import std::comm::recv;
 import std::comm::send;
 
 fn map(filename: str, emit: map_reduce::putter) {
-    let f = io::file_reader(filename);
+    let f = io::file_reader(istr::from_estr(filename));
 
 
     while true {
@@ -196,7 +197,8 @@ fn main(argv: [str]) {
     if vec::len(argv) < 2u {
         let out = io::stdout();
 
-        out.write_line(#fmt["Usage: %s <filename> ...", argv[0]]);
+        out.write_line(istr::from_estr(
+            #fmt["Usage: %s <filename> ...", argv[0]]));
 
         // TODO: run something just to make sure the code hasn't
         // broken yet. This is the unit test mode of this program.
diff --git a/src/test/compiletest/header.rs b/src/test/compiletest/header.rs
index 61cd178a62e..0d1121e4b6b 100644
--- a/src/test/compiletest/header.rs
+++ b/src/test/compiletest/header.rs
@@ -71,9 +71,9 @@ fn is_test_ignored(config: &config, testfile: &str) -> bool {
 }
 
 iter iter_header(testfile: &str) -> str {
-    let rdr = io::file_reader(testfile);
+    let rdr = io::file_reader(istr::from_estr(testfile));
     while !rdr.eof() {
-        let ln = rdr.read_line();
+        let ln = istr::to_estr(rdr.read_line());
 
         // Assume that any directives will be found before the first
         // module or function. This doesn't seem to be an optimization
diff --git a/src/test/compiletest/procsrv.rs b/src/test/compiletest/procsrv.rs
index 140821473ad..0e4c2c87d83 100644
--- a/src/test/compiletest/procsrv.rs
+++ b/src/test/compiletest/procsrv.rs
@@ -73,7 +73,7 @@ fn run(handle: &handle, lib_path: &str, prog: &str, args: &[str],
 fn writeclose(fd: int, s: &option::t<str>) {
     if option::is_some(s) {
         let writer = io::new_writer(io::fd_buf_writer(fd, option::none));
-        writer.write_str(option::get(s));
+        writer.write_str(istr::from_estr(option::get(s)));
     }
 
     os::libc::close(fd);
diff --git a/src/test/compiletest/runtest.rs b/src/test/compiletest/runtest.rs
index ac883256157..a4e1b26b7ed 100644
--- a/src/test/compiletest/runtest.rs
+++ b/src/test/compiletest/runtest.rs
@@ -23,7 +23,7 @@ fn run(cx: &cx, _testfile: -[u8]) {
     let testfile = str::unsafe_from_bytes(_testfile);
     if cx.config.verbose {
         // We're going to be dumping a lot of info. Start on a new line.
-        io::stdout().write_str("\n\n");
+        io::stdout().write_str(~"\n\n");
     }
     log #fmt["running %s", testfile];
     let props = load_props(testfile);
@@ -87,7 +87,8 @@ fn run_pretty_test(cx: &cx, props: &test_props, testfile: &str) {
     let rounds =
         alt props.pp_exact { option::some(_) { 1 } option::none. { 2 } };
 
-    let srcs = [io::read_whole_file_str(testfile)];
+    let srcs = [istr::to_estr(io::read_whole_file_str(
+        istr::from_estr(testfile)))];
 
     let round = 0;
     while round < rounds {
@@ -108,7 +109,7 @@ fn run_pretty_test(cx: &cx, props: &test_props, testfile: &str) {
           option::some(file) {
             let filepath = fs::connect(fs::dirname(
                 istr::from_estr(testfile)), istr::from_estr(file));
-            io::read_whole_file_str(istr::to_estr(filepath))
+            istr::to_estr(io::read_whole_file_str(filepath))
           }
           option::none. { srcs[vec::len(srcs) - 2u] }
         };
@@ -159,7 +160,7 @@ actual:\n\
 ------------------------------------------\n\
 \n",
                      expected, actual];
-            io::stdout().write_str(msg);
+            io::stdout().write_str(istr::from_estr(msg));
             fail;
         }
     }
@@ -329,8 +330,9 @@ fn dump_output(config: &config, testfile: &str, out: &str, err: &str) {
 fn dump_output_file(config: &config, testfile: &str, out: &str,
                     extension: &str) {
     let outfile = make_out_name(config, testfile, extension);
-    let writer = io::file_writer(outfile, [io::create, io::truncate]);
-    writer.write_str(out);
+    let writer = io::file_writer(istr::from_estr(outfile),
+                                 [io::create, io::truncate]);
+    writer.write_str(istr::from_estr(out));
 }
 
 // FIXME (726): Can't use file_writer on mac
@@ -361,21 +363,23 @@ fn maybe_dump_to_stdout(config: &config, out: &str, err: &str) {
         let sep1 = #fmt["------%s------------------------------", "stdout"];
         let sep2 = #fmt["------%s------------------------------", "stderr"];
         let sep3 = "------------------------------------------";
-        io::stdout().write_line(sep1);
-        io::stdout().write_line(out);
-        io::stdout().write_line(sep2);
-        io::stdout().write_line(err);
-        io::stdout().write_line(sep3);
+        io::stdout().write_line(istr::from_estr(sep1));
+        io::stdout().write_line(istr::from_estr(out));
+        io::stdout().write_line(istr::from_estr(sep2));
+        io::stdout().write_line(istr::from_estr(err));
+        io::stdout().write_line(istr::from_estr(sep3));
     }
 }
 
-fn error(err: &str) { io::stdout().write_line(#fmt["\nerror: %s", err]); }
+fn error(err: &str) {
+    io::stdout().write_line(istr::from_estr(#fmt["\nerror: %s", err]));
+}
 
 fn fatal(err: &str) -> ! { error(err); fail; }
 
 fn fatal_procres(err: &str, procres: procres) -> ! {
     let msg =
-        #fmt["\n\
+        istr::from_estr(#fmt["\n\
 error: %s\n\
 command: %s\n\
 stdout:\n\
@@ -387,7 +391,7 @@ stderr:\n\
 %s\n\
 ------------------------------------------\n\
 \n",
-             err, procres.cmdline, procres.stdout, procres.stderr];
+             err, procres.cmdline, procres.stdout, procres.stderr]);
     io::stdout().write_str(msg);
     fail;
 }
diff --git a/src/test/compiletest/util.rs b/src/test/compiletest/util.rs
index 3dcd8699927..9bbcd6c7e99 100644
--- a/src/test/compiletest/util.rs
+++ b/src/test/compiletest/util.rs
@@ -25,5 +25,7 @@ fn lib_path_env_var() -> str { "PATH" }
 
 fn logv(config: &config, s: &str) {
     log s;
-    if config.verbose { io::stdout().write_line(s); }
+    if config.verbose {
+        io::stdout().write_line(std::istr::from_estr(s));
+    }
 }
diff --git a/src/test/stdtest/io.rs b/src/test/stdtest/io.rs
index 08330c619fc..679466cbece 100644
--- a/src/test/stdtest/io.rs
+++ b/src/test/stdtest/io.rs
@@ -1,15 +1,15 @@
 // -*- rust -*-
 use std;
 import std::io;
-import std::str;
+import std::istr;
 
 #[cfg(target_os = "linux")]
 #[cfg(target_os = "win32")]
 #[test]
 fn test_simple() {
-    let tmpfile: str = "test/run-pass/lib-io-test-simple.tmp";
+    let tmpfile: istr = ~"test/run-pass/lib-io-test-simple.tmp";
     log tmpfile;
-    let frood: str = "A hoopy frood who really knows where his towel is.";
+    let frood: istr = ~"A hoopy frood who really knows where his towel is.";
     log frood;
     {
         let out: io::writer =
@@ -17,9 +17,9 @@ fn test_simple() {
         out.write_str(frood);
     }
     let inp: io::reader = io::file_reader(tmpfile);
-    let frood2: str = inp.read_c_str();
+    let frood2: istr = inp.read_c_str();
     log frood2;
-    assert (str::eq(frood, frood2));
+    assert (istr::eq(frood, frood2));
 }
 
 // FIXME (726)
diff --git a/src/test/stdtest/run.rs b/src/test/stdtest/run.rs
index 54f33b3e057..d3e88b13738 100644
--- a/src/test/stdtest/run.rs
+++ b/src/test/stdtest/run.rs
@@ -3,7 +3,7 @@ import std::run;
 import std::os;
 import std::io;
 import std::option;
-import std::str;
+import std::istr;
 import std::vec;
 
 // Regression test for memory leaks
@@ -36,7 +36,7 @@ fn test_pipes() {
     os::libc::close(pipe_err.out);
 
     if pid == -1 { fail; }
-    let expected = "test";
+    let expected = ~"test";
     writeclose(pipe_in.out, expected);
     let actual = readclose(pipe_out.in);
     readclose(pipe_err.in);
@@ -46,21 +46,21 @@ fn test_pipes() {
     log actual;
     assert (expected == actual);
 
-    fn writeclose(fd: int, s: &str) {
+    fn writeclose(fd: int, s: &istr) {
         let writer = io::new_writer(io::fd_buf_writer(fd, option::none));
         writer.write_str(s);
 
         os::libc::close(fd);
     }
 
-    fn readclose(fd: int) -> str {
+    fn readclose(fd: int) -> istr {
         // Copied from run::program_output
         let file = os::fd_FILE(fd);
         let reader = io::new_reader(io::FILE_buf_reader(file, option::none));
-        let buf = "";
+        let buf = ~"";
         while !reader.eof() {
             let bytes = reader.read_bytes(4096u);
-            buf += str::unsafe_from_bytes(bytes);
+            buf += istr::unsafe_from_bytes(bytes);
         }
         os::libc::fclose(file);
         ret buf;