Merging in Tesco and rofrankel's soaks for function calls. A soaked check that fails will return undefined.

lib/grammar.js

@@ -267,10 +267,17 @@
       })
     ],
     Invocation: [
-      o("Value Arguments", function() {
+      o("Value OptFuncExist Arguments", function() {
-        return new CallNode($1, $2);
+        return new CallNode($1, $3, $2);
-      }), o("Invocation Arguments", function() {
+      }), o("Invocation OptFuncExist Arguments", function() {
-        return new CallNode($1, $2);
+        return new CallNode($1, $3, $2);
+      })
+    ],
+    OptFuncExist: [
+      o("", function() {
+        return false;
+      }), o("FUNC_EXIST", function() {
+        return true;
       })
     ],
     Arguments: [

lib/lexer.js

@@ -317,7 +317,7 @@
       return true;
     };
     Lexer.prototype.literalToken = function() {
-      var _d, match, space, spaced, tag, value;
+      var _d, match, prev, space, spaced, tag, value;
       match = this.chunk.match(OPERATOR);
       value = match && match[1];
       space = match && match[2];
@@ -326,14 +326,14 @@
       }
       value || (value = this.chunk.substr(0, 1));
       this.i += value.length;
-      spaced = this.prev() && this.prev().spaced;
+      spaced = (prev = this.prev()) && prev.spaced;
       tag = value;
       if (value === '=') {
         if (include(JS_FORBIDDEN, this.value())) {
           this.assignmentError();
         }
         if (('or' === (_d = this.value()) || 'and' === _d)) {
-          this.tokens.splice(this.tokens.length - 1, 1, ['COMPOUND_ASSIGN', CONVERSIONS[this.value()] + '=', this.prev()[2]]);
+          this.tokens.splice(this.tokens.length - 1, 1, ['COMPOUND_ASSIGN', CONVERSIONS[this.value()] + '=', prev[2]]);
           return true;
         }
       }
@@ -353,6 +353,9 @@
         tag = 'SHIFT';
       } else if (include(CALLABLE, this.tag()) && !spaced) {
         if (value === '(') {
+          if (prev[0] === '?') {
+            prev[0] = 'FUNC_EXIST';
+          }
           tag = 'CALL_START';
         } else if (value === '[') {
           tag = 'INDEX_START';

lib/nodes.js

@@ -443,13 +443,15 @@
     return CommentNode;
   })();
   exports.CallNode = (function() {
-    CallNode = function(variable, _b) {
+    CallNode = function(variable, _b, _c) {
+      this.exist = _c;
       this.args = _b;
       CallNode.__super__.constructor.call(this);
       this.isNew = false;
       this.isSuper = variable === 'super';
       this.variable = this.isSuper ? null : variable;
       this.args || (this.args = []);
+      this.first = (this.last = '');
       this.compileSplatArguments = function(o) {
         return SplatNode.compileSplattedArray.call(this, this.args, o);
       };
@@ -479,30 +481,41 @@
       })());
     };
     CallNode.prototype.compileNode = function(o) {
-      var _b, _c, _d, _e, _f, _g, _h, arg, args, compilation;
+      var _b, _c, _d, _e, _f, _g, _h, _i, arg, args, compilation;
       if (!(o.chainRoot)) {
         o.chainRoot = this;
       }
-      _c = this.args;
+      if (this.exist) {
-      for (_b = 0, _d = _c.length; _b < _d; _b++) {
+        _b = this.variable.compileReference(o, {
-        arg = _c[_b];
+          precompile: true
+        });
+        this.first = _b[0];
+        this.meth = _b[1];
+        this.first = ("(typeof " + (this.first) + " === \"function\" ? ");
+        this.last = " : undefined)";
+      } else if (this.variable) {
+        this.meth = this.variable.compile(o);
+      }
+      _d = this.args;
+      for (_c = 0, _e = _d.length; _c < _e; _c++) {
+        arg = _d[_c];
         if (arg instanceof SplatNode) {
           compilation = this.compileSplat(o);
         }
       }
       if (!compilation) {
         args = (function() {
-          _e = []; _g = this.args;
+          _f = []; _h = this.args;
-          for (_f = 0, _h = _g.length; _f < _h; _f++) {
+          for (_g = 0, _i = _h.length; _g < _i; _g++) {
-            arg = _g[_f];
+            arg = _h[_g];
-            _e.push((function() {
+            _f.push((function() {
               arg.parenthetical = true;
               return arg.compile(o);
             })());
           }
-          return _e;
+          return _f;
         }).call(this);
-        compilation = this.isSuper ? this.compileSuper(args.join(', '), o) : ("" + (this.prefix()) + (this.variable.compile(o)) + "(" + (args.join(', ')) + ")");
+        compilation = this.isSuper ? this.compileSuper(args.join(', '), o) : ("" + (this.first) + (this.prefix()) + (this.meth) + "(" + (args.join(', ')) + ")" + (this.last));
       }
       return compilation;
     };
@@ -511,7 +524,7 @@
     };
     CallNode.prototype.compileSplat = function(o) {
       var meth, obj, temp;
-      meth = this.variable ? this.variable.compile(o) : this.superReference(o);
+      meth = this.meth || this.superReference(o);
       obj = this.variable && this.variable.source || 'this';
       if (obj.match(/\(/)) {
         temp = o.scope.freeVariable();
@@ -520,9 +533,9 @@
       }
       if (this.isNew) {
         utility('extends');
-        return "(function() {\n" + (this.idt(1)) + "var ctor = function(){};\n" + (this.idt(1)) + "__extends(ctor, " + (meth) + ");\n" + (this.idt(1)) + "return " + (meth) + ".apply(new ctor, " + (this.compileSplatArguments(o)) + ");\n" + (this.tab) + "}).call(this)";
+        return "" + (this.first) + "(function() {\n" + (this.idt(1)) + "var ctor = function(){};\n" + (this.idt(1)) + "__extends(ctor, " + (meth) + ");\n" + (this.idt(1)) + "return " + (meth) + ".apply(new ctor, " + (this.compileSplatArguments(o)) + ");\n" + (this.tab) + "}).call(this)" + (this.last);
       } else {
-        return "" + (this.prefix()) + (meth) + ".apply(" + (obj) + ", " + (this.compileSplatArguments(o)) + ")";
+        return "" + (this.first) + (this.prefix()) + (meth) + ".apply(" + (obj) + ", " + (this.compileSplatArguments(o)) + ")" + (this.last);
       }
     };
     return CallNode;

lib/rewriter.js

@@ -197,7 +197,10 @@
         if (include(LINEBREAKS, token[0])) {
           classLine = false;
         }
-        if (prev && (prev.spaced && include(IMPLICIT_FUNC, prev[0]) && include(IMPLICIT_CALL, token[0]) && !(token[0] === 'UNARY' && (('IN' === (_c = this.tag(i + 1)) || 'OF' === _c || 'INSTANCEOF' === _c)))) || callObject) {
+        if (prev && !prev.spaced && token[0] === '?') {
+          token.call = true;
+        }
+        if (prev && (prev.spaced && (include(IMPLICIT_FUNC, prev[0]) || prev.call) && include(IMPLICIT_CALL, token[0]) && !(token[0] === 'UNARY' && (('IN' === (_c = this.tag(i + 1)) || 'OF' === _c || 'INSTANCEOF' === _c)))) || callObject) {
           this.tokens.splice(i, 0, ['CALL_START', '(', token[2]]);
           condition = function(token, i) {
             return (!token.generated && this.tokens[i - 1][0] !== ',' && include(IMPLICIT_END, token[0]) && !(token[0] === 'INDENT' && (include(IMPLICIT_BLOCK, this.tag(i - 1)) || this.tag(i - 2) === 'CLASS'))) || token[0] === 'PROPERTY_ACCESS' && this.tag(i - 1) === 'OUTDENT';
@@ -207,6 +210,9 @@
             return this.tokens.splice(idx, 0, ['CALL_END', ')', token[2]]);
           };
           this.detectEnd(i + idx, condition, action);
+          if (prev[0] === '?') {
+            prev[0] = 'FUNC_EXIST';
+          }
           return 2;
         }
         return 1;

src/grammar.coffee

@@ -313,8 +313,14 @@ grammar =
 
   # Ordinary function invocation, or a chained series of calls.
   Invocation: [
-    o "Value Arguments",                        -> new CallNode $1, $2
+    o "Value OptFuncExist Arguments",           -> new CallNode $1, $3, $2
-    o "Invocation Arguments",                   -> new CallNode $1, $2
+    o "Invocation OptFuncExist Arguments",      -> new CallNode $1, $3, $2
+  ]
+
+  # An optional existence check on a function.
+  OptFuncExist: [
+    o "",                                       -> no
+    o "FUNC_EXIST",                             -> yes
   ]
 
   # The list of arguments to a function call.

src/lexer.coffee

@@ -272,12 +272,12 @@ exports.Lexer = class Lexer
     @tagParameters() if value and value.match CODE
     value or= @chunk.substr 0, 1
     @i += value.length
-    spaced = @prev() and @prev().spaced
+    spaced = (prev = @prev()) and prev.spaced
     tag = value
     if value is '='
       @assignmentError() if include JS_FORBIDDEN, @value()
       if @value() in ['or', 'and']
-        @tokens.splice(@tokens.length - 1, 1, ['COMPOUND_ASSIGN', CONVERSIONS[@value()] + '=', @prev()[2]])
+        @tokens.splice(@tokens.length - 1, 1, ['COMPOUND_ASSIGN', CONVERSIONS[@value()] + '=', prev[2]])
         return true
     if value is ';'                         then tag = 'TERMINATOR'
     else if include(LOGIC, value)           then tag = 'LOGIC'
@@ -288,6 +288,7 @@ exports.Lexer = class Lexer
     else if include(SHIFT, value)           then tag = 'SHIFT'
     else if include(CALLABLE, @tag()) and not spaced
       if value is '('
+        prev[0] = 'FUNC_EXIST' if prev[0] is '?'
         tag = 'CALL_START'
       else if value is '['
         tag = 'INDEX_START'

src/nodes.coffee

@@ -410,12 +410,13 @@ exports.CallNode = class CallNode extends BaseNode
   class:     'CallNode'
   children: ['variable', 'args']
 
-  constructor: (variable, @args) ->
+  constructor: (variable, @args, @exist) ->
     super()
     @isNew    = false
     @isSuper  = variable is 'super'
     @variable = if @isSuper then null else variable
     @args     or= []
+    @first = @last = ''
     @compileSplatArguments = (o) ->
       SplatNode.compileSplattedArray.call(this, @args, o)
 
@@ -439,6 +440,11 @@ exports.CallNode = class CallNode extends BaseNode
   # Compile a vanilla function call.
   compileNode: (o) ->
     o.chainRoot = this unless o.chainRoot
+    if @exist
+      [@first, @meth] = @variable.compileReference o, precompile: yes
+      @first = "(typeof #{@first} === \"function\" ? "
+      @last  = " : undefined)"
+    else if @variable then @meth = @variable.compile o
     for arg in @args when arg instanceof SplatNode
       compilation = @compileSplat(o)
     if not compilation
@@ -448,7 +454,7 @@ exports.CallNode = class CallNode extends BaseNode
       compilation = if @isSuper
         @compileSuper(args.join(', '), o)
       else
-        "#{@prefix()}#{@variable.compile(o)}(#{ args.join(', ') })"
+        "#{@first}#{@prefix()}#{@meth}(#{ args.join(', ') })#{@last}"
     compilation
 
   # `super()` is converted into a call against the superclass's implementation
@@ -461,7 +467,7 @@ exports.CallNode = class CallNode extends BaseNode
   # If it's a constructor, then things get real tricky. We have to inject an
   # inner constructor in order to be able to pass the varargs.
   compileSplat: (o) ->
-    meth = if @variable then @variable.compile(o) else @superReference(o)
+    meth = @meth or @superReference(o)
     obj  = @variable and @variable.source or 'this'
     if obj.match(/\(/)
       temp = o.scope.freeVariable()
@@ -470,14 +476,14 @@ exports.CallNode = class CallNode extends BaseNode
     if @isNew
       utility 'extends'
       """
-      (function() {
+      #{@first}(function() {
       #{@idt(1)}var ctor = function(){};
       #{@idt(1)}__extends(ctor, #{meth});
       #{@idt(1)}return #{meth}.apply(new ctor, #{ @compileSplatArguments(o) });
-      #{@tab}}).call(this)
+      #{@tab}}).call(this)#{@last}
       """
     else
-      "#{@prefix()}#{meth}.apply(#{obj}, #{ @compileSplatArguments(o) })"
+      "#{@first}#{@prefix()}#{meth}.apply(#{obj}, #{ @compileSplatArguments(o) })#{@last}"
 
 #### ExtendsNode
 

src/rewriter.coffee

@@ -148,7 +148,6 @@ exports.Rewriter = class Rewriter
         return 2
       return 1
 
-
   # Methods may be optionally called without parentheses, for simple cases.
   # Insert the implicit parentheses here, so that the parser doesn't have to
   # deal with them.
@@ -162,7 +161,8 @@ exports.Rewriter = class Rewriter
       callObject = not classLine and token[0] is 'INDENT' and next and next.generated and next[0] is '{' and prev and include(IMPLICIT_FUNC, prev[0])
       idx        = 2 if callObject
       classLine  = no  if include(LINEBREAKS, token[0])
-      if prev and (prev.spaced and include(IMPLICIT_FUNC, prev[0]) and include(IMPLICIT_CALL, token[0]) and
+      token.call = yes if prev and not prev.spaced and token[0] is '?'
+      if prev and (prev.spaced and (include(IMPLICIT_FUNC, prev[0]) or prev.call) and include(IMPLICIT_CALL, token[0]) and
           not (token[0] is 'UNARY' and (@tag(i + 1) in ['IN', 'OF', 'INSTANCEOF']))) or callObject
         @tokens.splice i, 0, ['CALL_START', '(', token[2]]
         condition = (token, i) ->
@@ -173,6 +173,7 @@ exports.Rewriter = class Rewriter
           idx = if token[0] is 'OUTDENT' then i + 1 else i
           @tokens.splice idx, 0, ['CALL_END', ')', token[2]]
         @detectEnd i + idx, condition, action
+        prev[0] = 'FUNC_EXIST' if prev[0] is '?'
         return 2
       return 1
 

test/test_existence.coffee

@@ -109,3 +109,20 @@ ok x is - 1
 # Things that compile to ternaries should force parentheses, like operators do.
 duration = if options?.animated then 150 else 0
 ok duration is 0
+
+
+# function soak
+plus1 = (x) -> x + 1
+
+ok plus1?(41) is 42
+ok (plus1? 41) is 42
+ok plus2?(41) is undefined
+ok (plus2? 41) is undefined
+
+maybe_close = (f, arg) -> if typeof f is 'function' then () -> f(arg) else -1
+
+ok maybe_close(plus1, 41)?() is 42
+ok (maybe_close plus1, 41)?() is 42
+ok (maybe_close 'string', 41)?() is undefined
+
+ok 2?(3) is undefined