From 1f92e19f2bf9b0837d46d8599cac101971c372f0 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Fri, 21 Nov 2014 15:51:20 -0800
Subject: [PATCH] transforms/fold_constants: support decimal fractions

---
 artiq/transforms/fold_constants.py | 16 ++++++++++------
 test/full_stack.py                 | 17 ++++++++++++-----
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/artiq/transforms/fold_constants.py b/artiq/transforms/fold_constants.py
index ff9aac9ca..402fc243b 100644
--- a/artiq/transforms/fold_constants.py
+++ b/artiq/transforms/fold_constants.py
@@ -1,5 +1,6 @@
 import ast
 import operator
+from fractions import Fraction
 
 from artiq.transforms.tools import *
 from artiq.language.core import int64, round64
@@ -135,14 +136,17 @@ class _ConstantFolder(ast.NodeTransformer):
             "int": int,
             "int64": int64,
             "round": round,
-            "round64": round64
+            "round64": round64,
+            "Fraction": Fraction
         }
         if fn in constant_ops:
-            try:
-                arg = eval_constant(node.args[0])
-            except NotConstant:
-                return node
-            result = value_to_ast(constant_ops[fn](arg))
+            args = []
+            for arg in node.args:
+                try:
+                    args.append(eval_constant(arg))
+                except NotConstant:
+                    return node
+            result = value_to_ast(constant_ops[fn](*args))
             return ast.copy_location(result, node)
         else:
             return node
diff --git a/test/full_stack.py b/test/full_stack.py
index 73203b636..d8697b0b9 100644
--- a/test/full_stack.py
+++ b/test/full_stack.py
@@ -1,6 +1,7 @@
 import unittest
 from operator import itemgetter
 import os
+from fractions import Fraction
 
 from artiq import *
 from artiq.coredevice import comm_serial, core, runtime_exceptions, rtio
@@ -40,13 +41,16 @@ class _Primes(AutoContext):
                 self.output_list.append(x)
 
 
-class _Attributes(AutoContext):
+class _Misc(AutoContext):
     def build(self):
         self.input = 84
 
     @kernel
     def run(self):
-        self.result = self.input//2
+        self.half_input = self.input//2
+        decimal_fraction = Fraction("1.2")
+        self.decimal_fraction_n = int(decimal_fraction.numerator)
+        self.decimal_fraction_d = int(decimal_fraction.denominator)
 
 
 class _PulseLogger(AutoContext):
@@ -144,12 +148,15 @@ class ExecutionCase(unittest.TestCase):
         _run_on_host(_Primes, max=100, output_list=l_host)
         self.assertEqual(l_device, l_host)
 
-    def test_attributes(self):
+    def test_misc(self):
         with comm_serial.Comm() as comm:
             coredev = core.Core(comm)
-            uut = _Attributes(core=coredev)
+            uut = _Misc(core=coredev)
             uut.run()
-            self.assertEqual(uut.result, 42)
+            self.assertEqual(uut.half_input, 42)
+            self.assertEqual(Fraction(uut.decimal_fraction_n,
+                                      uut.decimal_fraction_d),
+                             Fraction("1.2"))
 
     def test_pulses(self):
         l_device, l_host = [], []