new function expression syntax.

hartsantler · hartsantler · commit 4d5b4a882889 · 2014-07-23T07:07:01.000-07:00
diff --git a/README.md b/README.md
@@ -139,6 +139,11 @@ a = {}
 b = a['somekey'] except KeyError: 'my-default'
 ```
 
+. function expressions
+```
+F = function(x):
+	return x
+```
 
 Speed
 ---------------
diff --git a/pythonjs/python_to_pythonjs.py b/pythonjs/python_to_pythonjs.py
@@ -2592,6 +2592,7 @@ def visit_FunctionDef(self, node):
 		gpu_vectorize = False
 		gpu_method = False
 		local_typedefs = []
+		func_expr = None
 
 		## deprecated?
 		self._cached_property = None
@@ -2605,6 +2606,10 @@ def visit_FunctionDef(self, node):
 			if isinstance(decorator, Name) and decorator.id == 'gpu':
 				gpu = True
 
+			elif isinstance(decorator, Call) and decorator.func.id == 'expression':
+				assert len(decorator.args)==1
+				func_expr = self.visit(decorator.args[0])
+
 			elif isinstance(decorator, Call) and decorator.func.id == 'typedef':
 				c = decorator
 				assert len(c.args) == 0 and len(c.keywords)
@@ -2780,6 +2785,9 @@ def visit_FunctionDef(self, node):
 				if args_typedefs:
 					writer.write('@__typedef__(%s)' %','.join(args_typedefs))
 
+		if func_expr:
+			writer.write('@expression(%s)' %func_expr)
+
 
 		if not self._with_dart and not self._with_lua and not self._with_js and not javascript and not self._with_glsl:
 			writer.write('@__pyfunction__')
diff --git a/pythonjs/pythonjs.py b/pythonjs/pythonjs.py
@@ -38,7 +38,7 @@ def __init__(self, requirejs=True, insert_runtime=True, webworker=False, functio
 		self._exports = set()
 		self._inline_lambda = False
 
-		self.special_decorators = set(['__typedef__', '__glsl__', '__pyfunction__'])
+		self.special_decorators = set(['__typedef__', '__glsl__', '__pyfunction__', 'expression'])
 		self._glsl = False
 		self._has_glsl = False
 		self._typed_vars = dict()
@@ -242,8 +242,15 @@ def _visit_function(self, node):
 		gpu_vectorize = False
 		gpu_method = False
 		args_typedefs = {}
+		func_expr = False
+
 		for decor in node.decorator_list:
-			if isinstance(decor, ast.Name) and decor.id == '__pyfunction__':
+			if isinstance(decor, ast.Call) and isinstance(decor.func, ast.Name) and decor.func.id == 'expression':
+				assert len(decor.args)==1
+				func_expr = True
+				node.name = self.visit(decor.args[0])
+
+			elif isinstance(decor, ast.Name) and decor.id == '__pyfunction__':
 				is_pyfunc = True
 			elif isinstance(decor, ast.Name) and decor.id == '__glsl__':
 				glsl = True
@@ -473,10 +480,13 @@ def _visit_function(self, node):
 		elif len(self._function_stack) == 1:
 			## this style will not make function global to the eval context in NodeJS ##
 			#buffer = self.indent() + 'function %s(%s) {\n' % (node.name, ', '.join(args))
-			## this is required for eval to be able to work in NodeJS, note there is no var keyword.
 
-			if self._func_expressions:
-				buffer = self.indent() + '%s = function(%s) {\n' % (node.name, ', '.join(args))
+			## note if there is no var keyword and this function is at the global level,
+			## then it should be callable from eval in NodeJS - this is not correct.
+			## infact, var should always be used with function expressions.
+
+			if self._func_expressions or func_expr:
+				buffer = self.indent() + 'var %s = function(%s) {\n' % (node.name, ', '.join(args))
 			else:
 				buffer = self.indent() + 'function %s(%s) {\n' % (node.name, ', '.join(args))
 
@@ -485,7 +495,7 @@ def _visit_function(self, node):
 
 		else:
 
-			if self._func_expressions:
+			if self._func_expressions or func_expr:
 				buffer = self.indent() + 'var %s = function(%s) {\n' % (node.name, ', '.join(args))
 			else:
 				buffer = self.indent() + 'function %s(%s) {\n' % (node.name, ', '.join(args))
diff --git a/pythonjs/typedpython.py b/pythonjs/typedpython.py
@@ -65,7 +65,7 @@ def transform_source( source, strip=False ):
 		if '= function(' in c:
 			k = '= function('
 			a,b = c.split(k)
-			output.append( '@func_expression(%s)' %a.strip())
+			output.append( '@expression(%s)' %a.strip())
 			c = 'def __NAMELESS__(' + b
 
 		if ' except ' in c:  ## PEP 463 - exception expressions
diff --git a/regtests/calling/function_expression.py b/regtests/calling/function_expression.py
@@ -0,0 +1,8 @@
+"""func expr"""
+
+F = function( x,y ):
+	return x+y
+
+def main():
+	TestError( F(1,2) == 3 )
+
