Attribute lookup on a Value object which is a Scope now searches the scope.

Makefile.am

@@ -196,6 +196,7 @@ libledger_python_la_SOURCES =			\
 	python/py_chain.cc			\
 	python/py_commodity.cc			\
 	python/py_entry.cc			\
+	python/py_expr.cc			\
 	python/py_flags.cc			\
 	python/py_format.cc			\
 	python/py_global.cc			\

python/py_expr.cc

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2003-2009, John Wiegley.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of New Artisans LLC nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "pyinterp.h"
+#include "pyutils.h"
+#include "expr.h"
+
+namespace ledger {
+
+using namespace boost::python;
+
+namespace {
+  value_t py_expr_call(expr_t& expr)
+  {
+    return expr.calc();
+  }
+}
+
+void export_expr()
+{
+  class_< expr_t > ("Expr")
+    .def(init<string>())
+
+    .def("__nonzero__", &expr_t::operator bool)
+    .def("text", &expr_t::text)
+    .def("set_text", &expr_t::set_text)
+
+    //.def("parse", &expr_t::parse)
+
+    .def("__call__", py_expr_call)
+    .def("compile", &expr_t::compile)
+    //.def("calc", &expr_t::calc)
+
+    .def("is_constant", &expr_t::is_constant)
+
+    //.def("constant_value", &expr_t::constant_value)
+    ;
+}
+
+} // namespace ledger

python/py_scope.cc

@@ -37,36 +37,42 @@ namespace ledger {
 
 using namespace boost::python;
 
-#define EXC_TRANSLATOR(type)				\
-  void exc_translate_ ## type(const type& err) {	\
-    PyErr_SetString(PyExc_ArithmeticError, err.what());	\
+namespace {
+  void py_scope_define(scope_t& scope, const string& name, expr_t& def)
+  {
+    return scope.define(name, def.get_op());
   }
 
-//EXC_TRANSLATOR(scope_error)
+  expr_t py_scope_lookup(scope_t& scope, const string& name)
+  {
+    return scope.lookup(name);
+  }
+
+  expr_t py_scope_getattr(scope_t& scope, const string& name)
+  {
+    return scope.lookup(name);
+  }
+
+  struct scope_wrapper : public scope_t
+  {
+    PyObject * self;
+
+    scope_wrapper(PyObject * self_) : self(self_) {}
+
+    virtual expr_t::ptr_op_t lookup(const string& name) {
+      return NULL;
+    }    
+  };
+}
 
 void export_scope()
 {
-#if 0
-  class_< scope_t > ("Scope")
+  class_< scope_t, scope_wrapper, boost::noncopyable > ("Scope", no_init)
+    .def("define", py_scope_define)
+    .def("lookup", py_scope_lookup)
+    .def("resolve", &scope_t::resolve)
+    .def("__getattr__", py_scope_getattr)
     ;
-  class_< child_scope_t > ("ChildScope")
-    ;
-  class_< symbol_scope_t > ("SymbolScope")
-    ;
-  class_< call_scope_t > ("CallScope")
-    ;
-  class_< bind_scope_t > ("BindScope")
-    ;
-#endif
-
-  //register_optional_to_python<amount_t>();
-
-  //implicitly_convertible<string, amount_t>();
-
-#define EXC_TRANSLATE(type)					\
-  register_exception_translator<type>(&exc_translate_ ## type);
-
-  //EXC_TRANSLATE(scope_error);
 }
 
 } // namespace ledger

python/py_value.cc

@@ -39,28 +39,40 @@ using namespace boost::python;
 
 BOOST_PYTHON_MEMBER_FUNCTION_OVERLOADS(value_overloads, value, 0, 2)
 
-string py_dump(const value_t& value) {
-  std::ostringstream buf;
-  value.dump(buf);
-  return buf.str();
-}
+namespace {
+  expr_t py_value_getattr(value_t& value, const string& name)
+  {
+    if (value.is_pointer()) {
+      if (scope_t * scope = value.as_pointer_lval<scope_t>())
+	return expr_t(scope->lookup(name), scope);
+    }
+    throw_(value_error, "Cannot lookup attributes in " << value.label());
+    return expr_t();
+  }
 
-string py_dump_relaxed(const value_t& value) {
-  std::ostringstream buf;
-  value.dump(buf, true);
-  return buf.str();
-}
+  string py_dump(const value_t& value) {
+    std::ostringstream buf;
+    value.dump(buf);
+    return buf.str();
+  }
 
-void py_set_string(value_t& amount, const string& str) {
-  return amount.set_string(str);
-}
+  string py_dump_relaxed(const value_t& value) {
+    std::ostringstream buf;
+    value.dump(buf, true);
+    return buf.str();
+  }
+
+  void py_set_string(value_t& amount, const string& str) {
+    return amount.set_string(str);
+  }
 
 #define EXC_TRANSLATOR(type)				\
   void exc_translate_ ## type(const type& err) {	\
     PyErr_SetString(PyExc_ArithmeticError, err.what());	\
   }
 
-EXC_TRANSLATOR(value_error)
+  EXC_TRANSLATOR(value_error)
+}
 
 void export_value()
 {
@@ -262,6 +274,8 @@ void export_value()
     .def("print", &value_t::print)
 
     .def("valid", &value_t::valid)
+
+    .def("__getattr__", py_value_getattr)
     ;
 
   enum_< value_t::type_t >("ValueType")

tools/sample.py

@@ -1,7 +1,5 @@
 import ledger
 
-def myvalue(incoming):
-    x = ledger.Amount("$123.12")
-    print x
-    print x * 1
-    return x * 1
+def get_amount(item):
+    print "I found an amount:", item.amount()
+    return 123