Allow whitespace before CallArguments (fixes #124)

This is picking up the tests for projectfluent/fluent#281,
and adjusts the parser to pass those tests.

Author: Pike

fluent.syntax/fluent/syntax/parser.py

@@ -564,17 +564,21 @@ def get_inline_expression(self, ps):
                 ps.next()
                 attribute = self.get_identifier(ps)
             arguments = None
-            if ps.current_char == '(':
+            ps.peek_blank()
+            if ps.current_peek == '(':
+                ps.skip_to_peek()
                 arguments = self.get_call_arguments(ps)
             return ast.TermReference(id, attribute, arguments)
 
         if ps.is_identifier_start():
             id = self.get_identifier(ps)
+            ps.peek_blank()
 
-            if ps.current_char == '(':
+            if ps.current_peek == '(':
                 # It's a Function. Ensure it's all upper-case.
                 if not re.match('^[A-Z][A-Z0-9_-]*$', id.name):
                     raise ParseError('E0008')
+                ps.skip_to_peek()
                 args = self.get_call_arguments(ps)
                 return ast.FunctionReference(id, args)
 

fluent.syntax/tests/syntax/fixtures_reference/call_expressions.ftl

@@ -29,14 +29,15 @@ duplicate-named-args = {FUN(x: 1, x: "X")}
 
 ## Whitespace around arguments
 
-sparse-inline-call = {FUN(  "a"  , msg,   x: 1   )}
+sparse-inline-call = {FUN     (  "a"  , msg,   x: 1   )}
 empty-inline-call = {FUN(  )}
 multiline-call = {FUN(
         "a",
         msg,
         x: 1
     )}
-sparse-multiline-call = {FUN(
+sparse-multiline-call = {FUN
+    (
 
         "a"    ,
         msg

fluent.syntax/tests/syntax/fixtures_reference/term_parameters.ftl

@@ -3,6 +3,6 @@
 }
 
 key01 = { -term }
-key02 = { -term() }
+key02 = { -term () }
 key03 = { -term(arg: 1) }
 key04 = { -term("positional", narg1: 1, narg2: 2) }