allow new -> syntax to auto bind method's this.

hartsantler · hartsantler · commit e46b9ab1667b · 2014-07-20T23:24:27.000-07:00
diff --git a/README.md b/README.md
@@ -99,6 +99,13 @@ def setup_my_jquery_class( $ ):
 	$.fn.someclass = myclass_init
 ```
 
+6. `->` can be used to as a special attribute operator for passing methods that will automatically bind
+the method's `this` calling context.  This enables you to pass methods as callbacks to other objects,
+and not have to write `a.some_method.bind(a)`
+```
+	b.set_callback( a->some_method )
+```
+
 Speed
 ---------------
 PythonJS gives you the option to optimize your program for speed with a new syntax for static typing, in some cases this results in code that is 20X faster.
@@ -349,6 +356,7 @@ pythonjs.configure(
 Gotchas
 ---------
 1. The calling context of `this` must be taken into account when using fast javascript mode, code that comes after: `pythonjs.configure(javascript=True)` or is inside a `with javascript:` block.  When in javascript mode, passing a method as a callback, or setting it as an attribute on another object, requires you call `f.bind(self)` to ensure that `self` within the method points to the class instance.  This is not required when using classes defined normal mode, because the `this` calling context is automatically managed.
+Note: you can use the special `->` syntax in place of the attribute operator `.` to call `bind` automatically.
 
 ```
 class A:
@@ -365,10 +373,12 @@ with javascript:
 	b = B()
 	a.b_method1 = b.method
 	a.b_method2 = b.method.bind(b)
+	a.b_method3 = b->method
 
 	a.method()     ## OK: prints a
 	a.b_method1()  ## FAILS: prints a, should have printed b
 	a.b_method2()  ## OK: prints b
+	a.b_method3()  ## OK: prints b
 
 	b.a_method = a.method
 	b.a_method()   ## OK: prints a
diff --git a/pythonjs/typedpython.py b/pythonjs/typedpython.py
@@ -91,6 +91,12 @@ def transform_source( source, strip=False ):
 			c += ')' * c.count(' new ')
 			c = c.replace(' new ', ' new(')
 
+		if '->' in c:
+			a,b = c.split('->')
+			this_name = a.split()[-1].split('=')[-1].split(':')[-1].split(',')[-1]
+			method_name = b.split()[0].split('(')[0]
+			c = c.replace('->'+method_name, '.'+method_name+'.bind(%s)'%this_name)
+
 		## jquery ##
 		## TODO ensure this is not inside quoted text
 		if '$(' in c:
@@ -117,6 +123,11 @@ def transform_source( source, strip=False ):
 if True:
 	float* def Y():
 		pass
+
+A.callback = B->method
+A.do_something( x,y,z, B->method )
+A.do_something( x,y,z, callback=B->method )
+
 '''
 
 if __name__ == '__main__':
