From 05c90b17793f299ba9dfafe720f7e00fc6d3e1fd Mon Sep 17 00:00:00 2001
From: Paul Beckingham <paul@beckingham.net>
Date: Sat, 12 Apr 2014 12:28:48 -0400
Subject: [PATCH] Bug

- Fixed bug in named entity lookup.
- Removed obsolete failing test.
---
 src/Eval.cpp    | 21 ++++++++++++++++++++-
 test/eval.t.cpp | 28 ++++++++++++++++++++--------
 2 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/src/Eval.cpp b/src/Eval.cpp
index bc0b8ef3e..5855fd6b4 100644
--- a/src/Eval.cpp
+++ b/src/Eval.cpp
@@ -28,6 +28,7 @@
 #include <time.h>
 #include <Eval.h>
 
+////////////////////////////////////////////////////////////////////////////////
 // Supported operators, borrowed from C++, particularly the precedence.
 // Note: table is sorted by length of operator string, so searches match
 //       longest first.
@@ -78,11 +79,25 @@ static struct
 
 #define NUM_OPERATORS (sizeof (operators) / sizeof (operators[0]))
 
+////////////////////////////////////////////////////////////////////////////////
+// Built-in support for some named constants.
+static bool namedConstants (const std::string& name, Variant& value)
+{
+       if (name == "true")  value = Variant (true);
+  else if (name == "false") value = Variant (false);
+  else if (name == "pi")    value = Variant (3.14159165);
+  else
+    return false;
+
+  return true;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 Eval::Eval ()
 : _ambiguity (true)
 , _debug (false)
 {
+  addSource (namedConstants);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -233,6 +248,8 @@ void Eval::evaluatePostfixStack (
 
       values.push_back (left);
     }
+
+    // Literals and identifiers.
     else
     {
       Variant v (token->first);
@@ -253,6 +270,7 @@ void Eval::evaluatePostfixStack (
 
       case Lexer::typeIdentifier:
         {
+          bool found = false;
           std::vector <bool (*)(const std::string&, Variant&)>::const_iterator source;
           for (source = _sources.begin (); source != _sources.end (); ++source)
           {
@@ -260,12 +278,13 @@ void Eval::evaluatePostfixStack (
             {
               if (_debug)
                 std::cout << "# [" << values.size () << "] eval source '" << token->first << "' --> '" << (std::string) v << "'\n";
+              found = true;
               break;
             }
           }
 
           // An identifier that fails lookup is a string.
-          if (source == _sources.end ())
+          if (!found)
           {
             v.cast (Variant::type_string);
             if (_debug)
diff --git a/test/eval.t.cpp b/test/eval.t.cpp
index 0cf7a74c7..e0fa43849 100644
--- a/test/eval.t.cpp
+++ b/test/eval.t.cpp
@@ -35,16 +35,18 @@ Context context;
 // A few hard-coded symbols.
 bool get (const std::string& name, Variant& value)
 {
-       if (name == "pi") {value = Variant (3.14159165); return true;}
-  else if (name == "x")  {value = Variant (true);       return true;}
+  if (name == "x")
+    value = Variant (true);
+  else
+    return false;
 
-  return false;
+  return true;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 int main (int argc, char** argv)
 {
-  UnitTest t (43);
+  UnitTest t (46);
 
   // Test the source independently.
   Variant v;
@@ -54,10 +56,6 @@ int main (int argc, char** argv)
   t.is (v.type (), Variant::type_boolean,  "get(x) --> boolean");
   t.is (v.get_bool (), true,               "get(x) --> true");
 
-  t.ok (get ("pi", v),                     "true <-- get(pi)");
-  t.is (v.type (), Variant::type_real,     "get(pi) --> real");
-  t.is (v.get_real (), 3.141592, 0.00001,  "get(pi) --> 3.14159265");
-
   Eval e;
   e.addSource (get);
   Variant result;
@@ -138,6 +136,20 @@ int main (int argc, char** argv)
   t.is (result.type (), Variant::type_integer, "infix '2*3+1' --> integer");
   t.is (result.get_integer (), 7,              "infix '2*3+1' --> 7");
 
+  // TW-1254 - Unary minus support.
+  e.evaluateInfixExpression ("2--3", result);
+  t.is (result.type (), Variant::type_integer, "infix '2--3' --> integer");
+  t.is (result.get_integer (), 5,              "infix '2--3' --> 5");
+
+  //e.debug ();
+  e.evaluateInfixExpression ("!false", result);
+  t.is (result.type (), Variant::type_boolean, "infix '!false' --> boolean");
+  t.is (result.get_bool (), true,              "infix '!false' --> true");
+
+  e.evaluateInfixExpression ("!true", result);
+  t.is (result.type (), Variant::type_boolean, "infix '!true' --> boolean");
+  t.is (result.get_bool (), false,             "infix '!true' --> false");
+
   return 0;
 }