hoisted catchee (jashkenas/coffeescript#2422)

lib/ast.js

@@ -2814,7 +2814,7 @@ exports.Try = Try = (function(superclass){
   var prototype = extend$(Try, superclass).prototype, constructor = Try;
   function Try(attempt, thrown, recovery, ensure){
     this.attempt = attempt;
-    this.thrown = thrown != null ? thrown : 'e$';
+    this.thrown = thrown;
     this.recovery = recovery;
     this.ensure = ensure;
   }
@@ -2839,15 +2839,22 @@ exports.Try = Try = (function(superclass){
     return this;
   };
   prototype.compileNode = function(o){
-    var code, v;
+    var code, that;
     o.indent += TAB;
-    code = "try " + this.compileBlock(o, this.attempt);
+    code = 'try ' + this.compileBlock(o, this.attempt);
     if (this.recovery || !this.ensure) {
-      o.scope.check(v = this.thrown || 'e') || o.scope.add(v, 'catch');
-      code += " catch (" + v + ") " + this.compileBlock(o, this.recovery);
+      code += ' catch (e$) {';
+      if (this.recovery) {
+        code += '\n' + o.indent + o.scope.declare(this.thrown || 'e', this) + ' = e$;';
+        if (that = this.recovery.compile(o)) {
+          code += '\n' + that;
+        }
+        code += '\n' + this.tab;
+      }
+      code += '}';
     }
-    if (this.ensure) {
-      code += " finally " + this.compileBlock(o, this.ensure);
+    if (that = this.ensure) {
+      code += ' finally ' + this.compileBlock(o, that);
     }
     return code;
   };

lib/browser.js

@@ -1,10 +1,12 @@
 var type, sink, i$, ref$, len$, script, that;
 Coco.stab = function(code, callback, filename, error){
+  var e;
   try {
     Coco.run(code, {
       filename: filename
     });
-  } catch (e) {
+  } catch (e$) {
+    e = e$;
     error = e;
   }
   return callback(error);

lib/coco.js

@@ -18,10 +18,11 @@ parser.lexer = {
 };
 exports.VERSION = '0.7.7b';
 exports.compile = function(code, options){
-  var that;
+  var e, that;
   try {
     return parser.parse(lexer.lex(code)).compileRoot(options);
-  } catch (e) {
+  } catch (e$) {
+    e = e$;
     if (that = options != null ? options.filename : void 8) {
       e.message += "\nat " + that;
     }

lib/command.js

@@ -189,7 +189,8 @@ function compileScript(filename, input, base){
     } else {
       writeJS(filename, t.output, base);
     }
-  } catch (e) {
+  } catch (e$) {
+    e = e$;
     if (e != null) {
       if (Coco.listeners('failure').length) {
         Coco.emit('failure', e, t);
@@ -308,10 +309,11 @@ function repl(){
     global.exports = exports;
     global.require = require;
     server = (ref$ = clone$(require('repl').REPLServer.prototype), ref$.context = global, ref$.commands = [], ref$.useGlobal = true, ref$.useColors = process.env.NODE_DISABLE_COLORS, ref$.eval = function(code, arg$, arg1$, cb){
-      var res, err;
+      var res, e, err;
       try {
         res = vm.runInThisContext(code, 'repl');
-      } catch (e) {
+      } catch (e$) {
+        e = e$;
         err = e;
       }
       cb(err, res);
@@ -329,7 +331,7 @@ function repl(){
   });
   rl.on('close', bind$(process, 'exit'));
   rl.on('line', function(it){
-    var _;
+    var e, _;
     if (0 < cont && cont < 3) {
       code += it + '\n';
       this.output.write(repeatString$('.', prompt.length) + '. ');
@@ -354,7 +356,8 @@ function repl(){
           say(_);
         }
       }
-    } catch (e) {
+    } catch (e$) {
+      e = e$;
       say(e);
     }
     reset();

lib/grammar.js

@@ -68,7 +68,7 @@ bnf = {
   OptComma: [o(''), o(',')],
   Lines: [
     o('', function(){
-      return Block();
+      return L(Block());
     }), o('Line', function(){
       return Block($1);
     }), o('Lines NEWLINE Line', function(){

lib/lexer.js

@@ -86,7 +86,7 @@ exports.tokenize = function(code, o){
 };
 exports.dent = 0;
 exports.doID = function(code, index){
-  var match, input, id, last, ref$, tag, that;
+  var match, input, id, e, last, ref$, tag, that;
   input = (match = (ID.lastIndex = index, ID).exec(code))[0];
   if (!input) {
     return 0;
@@ -95,7 +95,8 @@ exports.doID = function(code, index){
   if (NONASCII.test(id)) {
     try {
       Function("var " + id);
-    } catch (e) {
+    } catch (e$) {
+      e = e$;
       this.carp("invalid identifier \"" + id + "\"");
     }
   }
@@ -860,9 +861,11 @@ exports.strnum = function(it){
   this.token('STRNUM', it, this.adi() || this.last[0] === 'DOT');
 };
 exports.regex = function(body, flag){
+  var e;
   try {
     RegExp(body);
-  } catch (e) {
+  } catch (e$) {
+    e = e$;
     this.carp(e.message);
   }
   if (flag === '$') {

lib/node.js

@@ -4,7 +4,7 @@ module.exports = function(Coco){
   fs = require('fs');
   path = require('path');
   Coco.run = function(code, options, js){
-    var filename, main, dirname, ref$;
+    var filename, main, dirname, ref$, e;
     if (options != null) {
       filename = options.filename;
     }
@@ -19,20 +19,22 @@ module.exports = function(Coco){
     js || (code = Coco.compile(code, (ref$ = {}, import$(ref$, options), ref$.bare = true, ref$)));
     try {
       return main._compile(code, filename);
-    } catch (e) {
+    } catch (e$) {
+      e = e$;
       throw hackTrace(e, code, filename);
     }
   };
   importAll$(Coco, require('events').EventEmitter.prototype);
   require.extensions['.co'] = function(module, filename){
-    var js;
+    var js, e;
     js = Coco.compile(fs.readFileSync(filename, 'utf8'), {
       filename: filename,
       bare: true
     });
     try {
       return module._compile(js, filename);
-    } catch (e) {
+    } catch (e$) {
+      e = e$;
       throw hackTrace(e, js, filename);
     }
   };

src/ast.co

@@ -1719,7 +1719,7 @@ class exports.For extends While
 #### Try
 # Classic `try`-`catch`-`finally` block with optional `catch`.
 class exports.Try extends Node
-  (@attempt, @thrown ? \e$, @recovery, @ensure) ->
+  (@attempt, @thrown, @recovery, @ensure) ->
 
   children: <[ attempt recovery ensure ]>
 
@@ -1738,12 +1738,16 @@ class exports.Try extends Node
 
   compileNode: (o) ->
     o.indent += TAB
-    code = "try #{@compileBlock o, @attempt}"
+    code = 'try ' + @compileBlock o, @attempt
     if @recovery or not @ensure
-      o.scope.check(v = @thrown or \e) or o.scope.add v, \catch
-      code += " catch (#v) #{ @compileBlock o, @recovery }"
-    if @ensure
-      code += " finally #{ @compileBlock o, @ensure }"
+      code += ' catch (e$) {'
+      if @recovery
+        code += \\n + o.indent +
+                o.scope.declare(@thrown or \e, this) + ' = e$;'
+        code += \\n + that if @recovery.compile o
+        code += \\n + @tab
+      code += \}
+    code += ' finally ' + @compileBlock o, that if @ensure
     code
 
 #### Switch

src/grammar.co

@@ -107,7 +107,7 @@ bnf =
 
   # A list of lines, separated by newlines or semicolons.
   Lines:
-    o ''                   -> Block!
+    o ''                   -> L Block!
     o \Line                -> Block $1
     o 'Lines NEWLINE Line' -> $1.add $3
     o 'Lines NEWLINE'

test/operator.co

@@ -221,6 +221,18 @@ eq(+ +1, - -1)
 eq -1, - --[2]0
 
 
+### `throw`
+throws 'up' -> throw Error 'up'
+
+# from anywhere.
+try [throw 0] catch
+  eq e, 0
+
+# `null` when empty.
+try throw catch
+  eq e, null
+
+
 ### `do`
 eq '', do do do -> -> -> do String
 eq 1, do -> 1

test/try.co

@@ -1,25 +1,42 @@
-# Basic exception throwing.
-throws 'up', -> throw Error 'up'
+n = 1
+try
+  n *= 2
+  throw \error
+  n *= 3
+catch error
+  n *= 5
+finally
+  n *= 7
+eq n, 70
 
+# Hoist `catch`ee.
+eq error, \error
 
-# Basic try/catch.
-eq 5, try throw 'error' catch err err.length
 
-eq 2, try
-  throw 'up'
-catch e
-  e.length
+# Allow one-liners.
+try x = 0 catch _ ok false finally ++x
+eq x, 1
 
-eq 1, try
-  throw o = i: 0
-catch e
-  ++e.i
-finally
-  ++o.i
-eq o.i, 2
 
+# Declare `e` by default.
+try throw 0 catch
+eq e, 0
+
+
+# Return results.
+eq 1 let
+  try 1
+  finally 2
+
+eq 2 let
+  try throw 1
+  catch 2
+  finally 3
+
+eq 3 try 3
 
-# try/catch with empty clauses still compiles.
+
+# Tolerate empty blocks.
 try
 
 try catch
@@ -36,16 +53,6 @@ finally
   #!nothing
 
 
-# Nested implicit indentations
+# Tolerate nested implicit blocks.
 eq 1, do -> try 1
 eq 2, do -> try do -> throw 1 catch do -> 2 finally
-
-
-# Empty `throw`
-try throw
-catch
-  eq null e
-
-
-# `throw` from anywhere
-eq 0, try [throw 0] catch then e