From 7d62b9cc12239da40ecb77d1b814799cd65873ac Mon Sep 17 00:00:00 2001
From: Mark Dufour <mark.dufour@stcorp.nl>
Date: Thu, 30 Nov 2023 10:24:12 +0100
Subject: [PATCH] support named function parameters

this allows for syntax like:

OData.CSC.Intersects(area=geography'SRID=4326;Point(1 2)')

-add NamedParam ast Node (with name, param attrs)
-add '=' literal
-add list_named_parameters grammar (similar to list_expr)
-only check args for functions with namespace () or ('geo',)
-in django_q visitor, passed NamedParams as keyword args

externally, we can now use the following to support above query:

class AstToDjangoQVisitorCSC(AstToDjangoQVisitor):
    def djangofunc_odata__csc__intersects(self, area):
        return super().djangofunc_geo__intersects(ast.Identifier('footprint'), area)
---
 odata_query/ast.py             |  5 +++
 odata_query/django/django_q.py | 10 +++++-
 odata_query/grammar.py         | 64 ++++++++++++++++++++++++----------
 3 files changed, 60 insertions(+), 19 deletions(-)

diff --git a/odata_query/ast.py b/odata_query/ast.py
index 90e0716..1189aaf 100644
--- a/odata_query/ast.py
+++ b/odata_query/ast.py
@@ -320,6 +320,11 @@ class UnaryOp(_Node):
 ###############################################################################
 # Function calls
 ###############################################################################
+@dataclass(frozen=True)
+class NamedParam(_Node):
+    name: Identifier
+    param: _Node
+
 @dataclass(frozen=True)
 class Call(_Node):
     func: Identifier
diff --git a/odata_query/django/django_q.py b/odata_query/django/django_q.py
index af8730e..4a5259e 100644
--- a/odata_query/django/django_q.py
+++ b/odata_query/django/django_q.py
@@ -265,7 +265,15 @@ def visit_Call(self, node: ast.Call) -> Union[Expression, Q]:
         except AttributeError:
             raise ex.UnsupportedFunctionException(func_name)
 
-        res = q_gen(*node.args)
+        args = []
+        kwargs = {}
+        for arg in node.args:
+            if isinstance(arg, ast.NamedParam):
+                kwargs[arg.name.name] = arg.param
+            else:
+                args.append(arg)
+
+        res = q_gen(*args, **kwargs)
         return res
 
     def visit_CollectionLambda(self, node: ast.CollectionLambda) -> Q:
diff --git a/odata_query/grammar.py b/odata_query/grammar.py
index 697a190..70e8d6d 100644
--- a/odata_query/grammar.py
+++ b/odata_query/grammar.py
@@ -96,7 +96,7 @@ class ODataLexer(Lexer):
         "ALL",
         "WS",
     }
-    literals = {"(", ")", ",", "/", ":"}
+    literals = {"(", ")", ",", "/", ":", "="}
     reflags = re.I
 
     # Ensure MyPy doesn't lose its mind:
@@ -563,23 +563,24 @@ def _function_call(self, func: ast.Identifier, args: List[ast._Node]):
 
         func_name = func.full_name()
 
-        try:
-            n_args_exp = ODATA_FUNCTIONS[func_name]
-        except KeyError:
-            raise exceptions.UnknownFunctionException(func_name)
-
-        n_args_given = len(args)
-        if isinstance(n_args_exp, int) and n_args_given != n_args_exp:
-            raise exceptions.ArgumentCountException(
-                func_name, n_args_exp, n_args_exp, n_args_given
-            )
-
-        if isinstance(n_args_exp, tuple) and (
-            n_args_given < n_args_exp[0] or n_args_given > n_args_exp[1]
-        ):
-            raise exceptions.ArgumentCountException(
-                func_name, n_args_exp[0], n_args_exp[1], n_args_given
-            )
+        if func.namespace in ((), ('geo',)):
+            try:
+                n_args_exp = ODATA_FUNCTIONS[func_name]
+            except KeyError:
+                raise exceptions.UnknownFunctionException(func_name)
+
+            n_args_given = len(args)
+            if isinstance(n_args_exp, int) and n_args_given != n_args_exp:
+                raise exceptions.ArgumentCountException(
+                    func_name, n_args_exp, n_args_exp, n_args_given
+                )
+
+            if isinstance(n_args_exp, tuple) and (
+                n_args_given < n_args_exp[0] or n_args_given > n_args_exp[1]
+            ):
+                raise exceptions.ArgumentCountException(
+                    func_name, n_args_exp[0], n_args_exp[1], n_args_given
+                )
 
         return ast.Call(func, args)
 
@@ -601,6 +602,33 @@ def common_expr(self, p):
         args = p[1].val
         return self._function_call(p[0], args)
 
+    @_('ODATA_IDENTIFIER "=" common_expr')  # type:ignore[no-redef]
+    def named_param(self, p):
+        ":meta private:"
+        return ast.NamedParam(p[0], p.common_expr)
+
+    @_('named_param BWS "," BWS named_param')
+    def list_named_param(self, p):
+        ":meta private:"
+        return [p[0], p[4]]
+
+    @_('list_named_param BWS "," BWS named_param')  # type:ignore[no-redef]
+    def list_named_param(self, p):
+        ":meta private:"
+        return p.list_items + [p.named_param]
+
+    @_('ODATA_IDENTIFIER "(" BWS named_param BWS ")"')  # type:ignore[no-redef]
+    def common_expr(self, p):
+        ":meta private:"
+        args = [p.named_param]
+        return self._function_call(p[0], args)
+
+    @_('ODATA_IDENTIFIER "(" BWS list_named_param BWS ")"')  # type:ignore[no-redef]
+    def common_expr(self, p):
+        ":meta private:"
+        args = p.list_named_param
+        return self._function_call(p[0], args)
+
     ####################################################################################
     # Misc
     ####################################################################################