#2900 -- parameter-less catch clause.

Plus some minor cleanup after f8c6b494aa

lib/coffee-script/grammar.js

@@ -350,6 +350,8 @@
         return [$2, $3];
       }), o('CATCH Object Block', function() {
         return [LOC(2)(new Value($2)), $3];
+      }), o('CATCH Block', function() {
+        return [null, $2];
       })
     ],
     Throw: [

lib/coffee-script/nodes.js

@@ -2460,10 +2460,10 @@
     };
 
     Try.prototype.compileNode = function(o) {
-      var catchPart, ensurePart, placeholder, tryPart, _ref4;
+      var catchPart, ensurePart, placeholder, tryPart;
       o.indent += TAB;
       tryPart = this.attempt.compileToFragments(o, LEVEL_TOP);
-      catchPart = this.recovery ? (placeholder = new Literal('_error'), this.recovery.unshift(new Assign(this.errorVariable, placeholder)), this.errorVariable = placeholder, (_ref4 = this.errorVariable.value, __indexOf.call(STRICT_PROSCRIBED, _ref4) >= 0) ? this.errorVariable.error("catch variable may not be \"" + this.errorVariable.value + "\"") : void 0, [].concat(this.makeCode(" catch ("), this.errorVariable.compileToFragments(o), this.makeCode(") {\n"), this.recovery.compileToFragments(o, LEVEL_TOP), this.makeCode("\n" + this.tab + "}"))) : !(this.ensure || this.recovery) ? [this.makeCode(' catch (_error) {}')] : [];
+      catchPart = this.recovery ? (placeholder = new Literal('_error'), this.errorVariable ? this.recovery.unshift(new Assign(this.errorVariable, placeholder)) : void 0, [].concat(this.makeCode(" catch ("), placeholder.compileToFragments(o), this.makeCode(") {\n"), this.recovery.compileToFragments(o, LEVEL_TOP), this.makeCode("\n" + this.tab + "}"))) : !(this.ensure || this.recovery) ? [this.makeCode(' catch (_error) {}')] : [];
       ensurePart = this.ensure ? [].concat(this.makeCode(" finally {\n"), this.ensure.compileToFragments(o, LEVEL_TOP), this.makeCode("\n" + this.tab + "}")) : [];
       return [].concat(this.makeCode("" + this.tab + "try {\n"), tryPart, this.makeCode("\n" + this.tab + "}"), catchPart, ensurePart);
     };

lib/coffee-script/rewriter.js

@@ -365,7 +365,7 @@
         return this.tokens.splice((this.tag(i - 1) === ',' ? i - 1 : i), 0, outdent);
       };
       return this.scanTokens(function(token, i, tokens) {
-        var tag, _ref, _ref1;
+        var j, tag, _i, _ref, _ref1;
         tag = token[0];
         if (tag === 'TERMINATOR' && this.tag(i + 1) === 'THEN') {
           tokens.splice(i, 1);
@@ -375,9 +375,14 @@
           tokens.splice.apply(tokens, [i, 0].concat(__slice.call(this.indentation())));
           return 2;
         }
-        if (tag === 'CATCH' && ((_ref = this.tag(i + 2)) === 'OUTDENT' || _ref === 'TERMINATOR' || _ref === 'FINALLY')) {
-          tokens.splice.apply(tokens, [i + 2, 0].concat(__slice.call(this.indentation())));
-          return 4;
+        if (tag === 'CATCH') {
+          for (j = _i = 1; _i <= 2; j = ++_i) {
+            if (!((_ref = this.tag(i + j)) === 'OUTDENT' || _ref === 'TERMINATOR' || _ref === 'FINALLY')) {
+              continue;
+            }
+            tokens.splice.apply(tokens, [i + j, 0].concat(__slice.call(this.indentation())));
+            return 2 + j;
+          }
         }
         if (__indexOf.call(SINGLE_LINERS, tag) >= 0 && this.tag(i + 1) !== 'INDENT' && !(tag === 'ELSE' && this.tag(i + 1) === 'IF')) {
           starter = tag;

src/grammar.coffee

@@ -401,6 +401,7 @@ grammar =
   Catch: [
     o 'CATCH Identifier Block',                 -> [$2, $3]
     o 'CATCH Object Block',                     -> [LOC(2)(new Value($2)), $3]
+    o 'CATCH Block',                            -> [null, $2]
   ]
 
   # Throw an exception object.

src/nodes.coffee

@@ -1733,11 +1733,8 @@ exports.Try = class Try extends Base
 
     catchPart = if @recovery
       placeholder = new Literal '_error'
-      @recovery.unshift new Assign @errorVariable, placeholder
-      @errorVariable = placeholder
-      if @errorVariable.value in STRICT_PROSCRIBED
-        @errorVariable.error "catch variable may not be \"#{@errorVariable.value}\""
-      [].concat @makeCode(" catch ("), @errorVariable.compileToFragments(o), @makeCode(") {\n"),
+      @recovery.unshift new Assign @errorVariable, placeholder if @errorVariable
+      [].concat @makeCode(" catch ("), placeholder.compileToFragments(o), @makeCode(") {\n"),
         @recovery.compileToFragments(o, LEVEL_TOP), @makeCode("\n#{@tab}}")
     else unless @ensure or @recovery
       [@makeCode(' catch (_error) {}')]

src/rewriter.coffee

@@ -375,9 +375,10 @@ class exports.Rewriter
       if tag is 'ELSE' and @tag(i - 1) isnt 'OUTDENT'
         tokens.splice i, 0, @indentation()...
         return 2
-      if tag is 'CATCH' and @tag(i + 2) in ['OUTDENT', 'TERMINATOR', 'FINALLY']
-        tokens.splice i + 2, 0, @indentation()...
-        return 4
+      if tag is 'CATCH'
+        for j in [1..2] when @tag(i + j) in ['OUTDENT', 'TERMINATOR', 'FINALLY']
+          tokens.splice i + j, 0, @indentation()...
+          return 2 + j
       if tag in SINGLE_LINERS and @tag(i + 1) isnt 'INDENT' and
          not (tag is 'ELSE' and @tag(i + 1) is 'IF')
         starter = tag

test/exception_handling.coffee

@@ -129,3 +129,14 @@ test "Try catch finally as implicit arguments", ->
     bar = yes
   catch e
   eq bar, yes
+
+# Catch Should Not Require Param: #2900
+test "parameter-less catch clause", ->
+  try
+    throw new Error 'failed'
+  catch
+    ok true
+
+  try throw new Error 'failed' catch finally ok true
+
+  ok try throw new Error 'failed' catch then true