8 files changed, 134 insertions, 213 deletions

diff --git a/cpp/sca/modules/eval/Makefile.am b/cpp/sca/modules/eval/Makefile.am
index 9b09d912d9..e1add383f4 100644
--- a/cpp/sca/modules/eval/Makefile.am
+++ b/cpp/sca/modules/eval/Makefile.am
@@ -22,11 +22,6 @@ nobase_data_DATA = *.xsd
 
 INCLUDES = -I. -I$(top_builddir)/kernel -I${LIBXML2_INCLUDE}
 
-#libdir=$(prefix)/modules/eval/lib
-#lib_LTLIBRARIES = libtuscany_eval.la
-#libtuscany_eval_la_SOURCES = eval.cpp
-#libtuscany_eval_la_LIBADD = -L${TUSCANY_SCACPP}/lib -ltuscany_sca -lpthread
-
 eval_test_SOURCES = eval-test.cpp
 eval_test_LDADD = -lpthread -L${LIBXML2_LIB} -lxml2
 
diff --git a/cpp/sca/modules/eval/driver.hpp b/cpp/sca/modules/eval/driver.hpp
index c1b2e1e96f..582f4f1b08 100644
--- a/cpp/sca/modules/eval/driver.hpp
+++ b/cpp/sca/modules/eval/driver.hpp
@@ -33,16 +33,16 @@
 namespace tuscany
 {
 
-const std::string evalOutputPrompt(";;; Eval value: ");
-const std::string evalInputPrompt(";;; Eval input: ");
+const std::string evalOutputPrompt("; ");
+const std::string evalInputPrompt("=> ");
 
 const bool promptForInput(std::ostream& out, const std::string str) {
-    out << "\n\n" << str << "\n";
+    out << "\n\n" << str;
     return true;
 }
 
 const bool announceOutput(std::ostream& out, const std::string str) {
-    out << "\n" << str << "\n";
+    out << "\n" << str;
     return true;
 }
 
diff --git a/cpp/sca/modules/eval/environment.hpp b/cpp/sca/modules/eval/environment.hpp
index 4ee27df552..46c1716cd8 100644
--- a/cpp/sca/modules/eval/environment.hpp
+++ b/cpp/sca/modules/eval/environment.hpp
@@ -29,6 +29,7 @@
 #include <string>
 #include "list.hpp"
 #include "value.hpp"
+#include "primitive.hpp"
 
 namespace tuscany
 {
@@ -40,6 +41,7 @@ const value trueSymbol = value("true");
 const value falseSymbol = value("false");
 const value defineSymbol = value("define");
 const value setSymbol = value("set!");
+const value dotSymbol = value(".");
 
 const Env theEmptyEnvironment() {
     return list<value>();
@@ -73,8 +75,35 @@ list<value> frameValues(const Frame& frame) {
     return cdr((list<value> )frame);
 }
 
+const bool isDotVariable(const value& var) {
+    return var == dotSymbol;
+}
+
+const Frame makeBinding(const Frame& frameSoFar, const list<value>& variables, const list<value> values) {
+    if (variables == list<value>()) {
+        if (values != list<value>())
+            std::cout << "Too many arguments supplied " << values << "\n";
+        return frameSoFar;
+    }
+    if (isDotVariable(car(variables)))
+        return makeBinding(frameSoFar, cdr(variables), makeList(value(values)));
+
+    if (values == list<value>()) {
+        if (variables != list<value>())
+            std::cout << "Too few arguments supplied " << variables << "\n";
+        return frameSoFar;
+    }
+
+    const list<value> vars = cons(car(variables), frameVariables(frameSoFar));
+    const list<value> vals = cons(car(values), frameValues(frameSoFar));
+    const Frame newFrame = value(cons(value(vars), vals));
+
+    return makeBinding(newFrame, cdr(variables), cdr(values));
+}
+
 const Frame makeFrame(const list<value>& variables, const list<value> values) {
-    return value(cons((value)variables, values));
+    const Frame emptyFrame = value(cons((value)list<value>(), list<value>()));
+    return makeBinding(emptyFrame, variables, values);
 }
 
 const value definitionVariable(const value& exp) {
@@ -110,13 +139,13 @@ const Env defineVariable(const value& var, const value& val, Env& env) {
 }
 
 const Env extendEnvironment(const list<value>& vars, const list<value>& vals, const Env& baseEnv) {
-    if(length(vars) == length(vals))
-        return cons(makeFrame(vars, vals), baseEnv);
-    else if(length(vars) < length(vals))
-        std::cout << "Too many arguments supplied " << vars << " " << vals << "\n";
-    else
-        std::cout << "Too few arguments supplied " << vars << " " << vals << "\n";
-    return baseEnv;
+//    if(length(vars) == length(vals))
+//    else if(length(vars) < length(vals))
+//        std::cout << "Too many arguments supplied " << vars << " " << vals << "\n";
+//    else
+//        std::cout << "Too few arguments supplied " << vars << " " << vals << "\n";
+//    return baseEnv;
+    return cons(makeFrame(vars, vals), baseEnv);
 }
 
 const Env setupEnvironment() {
diff --git a/cpp/sca/modules/eval/eval-test b/cpp/sca/modules/eval/eval-test
index 9e9b36ddbb..ff394153d1 100755
--- a/cpp/sca/modules/eval/eval-test
+++ b/cpp/sca/modules/eval/eval-test
diff --git a/cpp/sca/modules/eval/eval-test.cpp b/cpp/sca/modules/eval/eval-test.cpp
index e75485a2d5..c8c86a1666 100644
--- a/cpp/sca/modules/eval/eval-test.cpp
+++ b/cpp/sca/modules/eval/eval-test.cpp
@@ -41,13 +41,16 @@ bool testEnv() {
 }
 
 bool testEnvGC() {
-    resetValueCounters();
     resetLambdaCounters();
-    resetlistCounters();
+    resetListCounters();
+    resetValueCounters();
     testEnv();
     assert(countValues == 0);
     assert(countLambdas == 0);
     assert(countlists == 0);
+    printLambdaCounters();
+    printListCounters();
+    printValueCounters();
     return true;
 }
 
@@ -138,13 +141,16 @@ bool testEvalExpr() {
 }
 
 bool testEvalGC() {
-    resetValueCounters();
     resetLambdaCounters();
-    resetlistCounters();
+    resetListCounters();
+    resetValueCounters();
     testEval();
     assert(countValues == 0);
     assert(countLambdas == 0);
     assert(countlists == 0);
+    printLambdaCounters();
+    printListCounters();
+    printValueCounters();
     return true;
 }
 
diff --git a/cpp/sca/modules/eval/eval.hpp b/cpp/sca/modules/eval/eval.hpp
index 23e9554aa8..28e1d01ffc 100644
--- a/cpp/sca/modules/eval/eval.hpp
+++ b/cpp/sca/modules/eval/eval.hpp
@@ -23,10 +23,10 @@
 #define tuscany_eval_eval_hpp
 
 /**
- * Script evaluator core evaluation logic.
+ * Core script evaluation logic.
  */
 
-#include <string>
+#include <string.h>
 #include "list.hpp"
 #include "value.hpp"
 #include "primitive.hpp"
@@ -36,8 +36,11 @@
 namespace tuscany
 {
 
+const value eval(const value& exp, Env& env);
+
 const value compoundProcedureSymbol("compound-procedure");
 const value procedureSymbol("procedure");
+const value applySymbol("apply");
 const value beginSymbol("begin");
 const value condSymbol("cond");
 const value elseSymbol("else");
@@ -67,6 +70,10 @@ const value makeProcedure(const list<value>& parameters, const value& body, cons
     return value(makeList(procedureSymbol, value(parameters), body, value(env)));
 }
 
+const bool isApply(const value& exp) {
+    return isTaggedList(exp, applySymbol);
+}
+
 const bool isApplication(const value& exp) {
     return isList(exp);
 }
@@ -79,6 +86,20 @@ const list<value> operands(const value& exp) {
     return cdr((list<value> )exp);
 }
 
+const list<value> listOfValues(const list<value> exps, Env& env) {
+    if(exps == list<value> ())
+        return list<value> ();
+    return cons(eval(car(exps), env), listOfValues(cdr(exps), env));
+}
+
+const value applyOperat(const value& exp) {
+    return cadr((list<value> )exp);
+}
+
+const value applyOperand(const value& exp) {
+    return caddr((list<value> )exp);
+}
+
 const bool isCompoundProcedure(const value& procedure) {
     return isTaggedList(procedure, procedureSymbol);
 }
@@ -103,10 +124,32 @@ const value firstExp(const list<value>& seq) {
     return car(seq);
 }
 
+const list<value> restExp(const list<value>& seq) {
+    return cdr(seq);
+}
+
 const value makeBegin(const list<value> seq) {
     return value(cons(beginSymbol, seq));
 }
 
+const value evalSequence(const list<value>& exps, Env& env) {
+    if(isLastExp(exps))
+        return eval(firstExp(exps), env);
+    eval(firstExp(exps), env);
+    return evalSequence(restExp(exps), env);
+}
+
+const value applyProcedure(const value& procedure, list<value>& arguments) {
+    if(isPrimitiveProcedure(procedure))
+        return applyPrimitiveProcedure(procedure, arguments);
+    if(isCompoundProcedure(procedure)) {
+        Env env = extendEnvironment(procedureParameters(procedure), arguments, procedureEnvironment(procedure));
+        return evalSequence(procedureBody(procedure), env);
+    }
+    std::cout << "Unknown procedure type " << procedure << "\n";
+    return value();
+}
+
 const value sequenceToExp(const list<value> exps) {
     if(exps == list<value> ())
         return value(list<value>());
@@ -175,208 +218,44 @@ value condToIf(const value& exp) {
     return expandClauses(condClauses(exp));
 }
 
-const lambda<value(Env&)> analyze(const value exp);
-
-struct evalUndefinedLambda {
-    evalUndefinedLambda() {
-    }
-
-    const value operator()(Env& env) const {
-        return value();
-    }
-};
-
-struct evalSelfEvaluatingLambda {
-    const value exp;
-    evalSelfEvaluatingLambda(const value& exp) : exp(exp) {
-    }
-    const value operator()(Env& env) const {
-        return exp;
-    }
-};
-
-const lambda<value(Env&)> analyzeSelfEvaluating(value exp) {
-    return lambda<value(Env&)>(evalSelfEvaluatingLambda(exp));
-}
-
-struct evalQuotedLambda {
-    const value qval;
-    evalQuotedLambda(const value& qval) : qval(qval) {
-    }
-    const value operator()(Env& env) const {
-        return qval;
-    }
-};
-
-const lambda<value(Env&)> analyzeQuoted(const value& exp) {
-    return lambda<value(Env&)>(evalQuotedLambda(textOfQuotation(exp)));
-}
-
-struct evalVariableLambda {
-    const value var;
-    evalVariableLambda(const value& var) : var(var) {
-    }
-    const value operator()(Env& env) const {
-        return lookupVariableValue(var, env);
-    }
-};
-
-const lambda<value(Env&)> analyzeVariable(const value& exp) {
-    return lambda<value(Env&)>(evalVariableLambda(exp));
-}
-
-struct evalDefinitionLambda {
-    const value var;
-    const lambda<value(Env&)> vproc;
-    evalDefinitionLambda(const value& var, const lambda<value(Env&)>& vproc) : var(var), vproc(vproc) {
-    }
-    const value operator()(Env& env) const {
-        env = defineVariable(var, vproc(env), env);
-        return var;
-    }
-};
-
-const lambda<value(Env&)> analyzeDefinition(const value& exp) {
-    return lambda<value(Env&)>(evalDefinitionLambda(definitionVariable(exp), analyze(definitionValue(exp))));
+value evalIf(const value& exp, Env& env) {
+    if(isTrue(eval(ifPredicate(exp), env)))
+        return eval(ifConsequent(exp), env);
+    return eval(ifAlternative(exp), env);
 }
 
-struct evalIfLambda {
-    const lambda<value(Env&)> pproc;
-    const lambda<value(Env&)> cproc;
-    const lambda<value(Env&)> aproc;
-    evalIfLambda(const lambda<value(Env&)> pproc, const lambda<value(Env&)>& cproc, const lambda<value(Env&)>& aproc) :
-        pproc(pproc), cproc(cproc), aproc(aproc) {
-    }
-    const value operator()(Env& env) const {
-        if(pproc(env))
-            return cproc(env);
-        return aproc(env);
-    }
-};
-
-const lambda<value(Env&)> analyzeIf(const value& exp) {
-    const lambda<value(Env&)> pproc = analyze(ifPredicate(exp));
-    const lambda<value(Env&)> cproc = analyze(ifConsequent(exp));
-    const lambda<value(Env&)> aproc = analyze(ifAlternative(exp));
-    return lambda<value(Env&)>(evalIfLambda(pproc, cproc, aproc));
-}
-
-struct evalSequenceLambda {
-    const lambda<value(Env&)> proc1;
-    const lambda<value(Env&)> proc2;
-    evalSequenceLambda(const lambda<value(Env&)>& proc1, const lambda<value(Env&)>& proc2) :
-        proc1(proc1), proc2(proc2) {
-    }
-    const value operator()(Env& env) const {
-        proc1(env);
-        return proc2(env);
-    }
-};
-
-const lambda<value(Env&)> analyzeSequenceSequentially(const lambda<value(Env&)>& proc1, const lambda<value(Env&)>& proc2) {
-    return lambda<value(Env&)>(evalSequenceLambda(proc1, proc2));
+const value evalDefinition(const value& exp, Env& env) {
+    env = defineVariable(definitionVariable(exp), eval(definitionValue(exp), env), env);
+    return definitionVariable(exp);
 }
 
-const lambda<value(Env&)> analyzeSequenceLoop(const lambda<value(Env&)>& firstProc, const list<lambda<value(Env&)> >& restProcs) {
-    if(restProcs == list<lambda<value(Env&)> >())
-        return firstProc;
-    return analyzeSequenceLoop(analyzeSequenceSequentially(firstProc, car(restProcs)), cdr(restProcs));
-}
-
-const lambda<value(Env&)> analyzeSequence(const list<value>& exps) {
-    lambda<lambda<value(Env&)>(value exp)> a(analyze);
-    const list<lambda<value(Env&)> > procs = map(a, exps);
-    if(procs == list<lambda<value(Env&)> >()) {
-        std::cout << "Empty sequence" << "\n";
-        return lambda<value(Env&)>(evalUndefinedLambda());
-    }
-    return analyzeSequenceLoop(car(procs), cdr(procs));
-}
-
-struct lambdaLambda {
-    const list<value> vars;
-    const lambda<value(Env&)> bproc;
-    lambdaLambda(const list<value> vars, const lambda<value(Env&)>& bproc)
-        : vars(vars), bproc(bproc) {
-    }
-
-    const value operator()(Env& env) const {
-        return makeProcedure(vars, value(bproc), env);
-    }
-};
-
-const lambda<value(Env&)> analyzeLambda(const value& exp) {
-    const list<value> vars = lambdaParameters(exp);
-    const lambda<value(Env&)> bproc = analyzeSequence(lambdaBody(exp));
-    return lambda<value(Env&)>(lambdaLambda(vars, bproc));
-}
-
-const value executeApplication(const value& proc, const list<value>& args) {
-    if(isPrimitiveProcedure(proc)) {
-        list<value> ncargs = args;
-        return applyPrimitiveProcedure(proc, ncargs);
-    }
-    if(isCompoundProcedure(proc)) {
-        lambda<value(Env&) > bproc(procedureBody(proc));
-        Env env = extendEnvironment(procedureParameters(proc), args, procedureEnvironment(proc));
-        return bproc(env);
-    }
-    std::cout << "Unknown procedure type " << proc << "\n";
-    return value();
-}
-
-struct evalApplicationArgLambda {
-    Env& env;
-    evalApplicationArgLambda(Env& env) : env(env) {
-    }
-    const value operator()(const lambda<value(Env&)>& aproc) const {
-        return aproc(env);
-    }
-};
-
-struct evalApplicationLambda {
-    const lambda<value(Env&)> fproc;
-    const list<lambda<value(Env&)> > aprocs;
-    evalApplicationLambda(const lambda<value(Env&)>& fproc, const list<lambda<value(Env&)> >& aprocs) :
-        fproc(fproc), aprocs(aprocs) {
-    }
-    const value operator()(Env& env) const {
-        return executeApplication(fproc(env), map(lambda<value(lambda<value(Env&)>)>(evalApplicationArgLambda(env)), aprocs));
-    }
-};
-
-const lambda<value(Env&)> analyzeApplication(const value& exp) {
-    const lambda<value(Env&)> fproc = analyze(operat(exp));
-    lambda<lambda<value(Env&)>(value exp)> a(analyze);
-    const list<lambda<value(Env&)> > aprocs = map(a, operands(exp));
-    return lambda<value(Env&)>(evalApplicationLambda(fproc, aprocs));
-}
-
-const lambda<value(Env&)> analyze(const value exp) {
+const value eval(const value& exp, Env& env) {
     if(isSelfEvaluating(exp))
-        return analyzeSelfEvaluating(exp);
+        return exp;
     if(isQuoted(exp))
-        return analyzeQuoted(exp);
+        return textOfQuotation(exp);
     if(isDefinition(exp))
-        return analyzeDefinition(exp);
+        return evalDefinition(exp, env);
     if(isIf(exp))
-        return analyzeIf(exp);
+        return evalIf(exp, env);
     if(isBegin(exp))
-        return analyzeSequence(beginActions(exp));
+        return evalSequence(beginActions(exp), env);
     if(isCond(exp))
-        return analyze(condToIf(exp));
+        return eval(condToIf(exp), env);
     if(isLambda(exp))
-        return analyzeLambda(exp);
+        return makeProcedure(lambdaParameters(exp), value(lambdaBody(exp)), env);
     if(isVariable(exp))
-        return analyzeVariable(exp);
-    if(isApplication(exp))
-        return analyzeApplication(exp);
+        return lookupVariableValue(exp, env);
+    if(isApply(exp)) {
+        list<value> applyOperandValues = eval(applyOperand(exp), env);
+        return applyProcedure(eval(applyOperat(exp), env), applyOperandValues);
+    }
+    if(isApplication(exp)) {
+        list<value> operandValues = listOfValues(operands(exp), env);
+        return applyProcedure(eval(operat(exp), env), operandValues);
+    }
     std::cout << "Unknown expression type " << exp << "\n";
-    return lambda<value(Env&)>(evalUndefinedLambda());
-}
-
-    const value eval(const value& exp, Env& env) {
-    return analyze(exp)(env);
+    return value();
 }
 
 }
diff --git a/cpp/sca/modules/eval/primitive.hpp b/cpp/sca/modules/eval/primitive.hpp
index 881f669317..04e26178f4 100644
--- a/cpp/sca/modules/eval/primitive.hpp
+++ b/cpp/sca/modules/eval/primitive.hpp
@@ -57,6 +57,10 @@ const value valueCons(list<value>& args) {
     return value(cons(car(args), (list<value> )cadr(args)));
 }
 
+const value valueList(list<value>& args) {
+    return value(args);
+}
+
 const value valueNul(list<value>& args) {
     return value((bool)isNil(car(args)));
 }
@@ -66,10 +70,14 @@ const value valueEqual(list<value>& args) {
 }
 
 const value valueAdd(list<value>& args) {
+    if (cdr(args) == list<value>())
+        return value((double)car(args));
     return value((double)car(args) + (double)cadr(args));
 }
 
 const value valueSub(list<value>& args) {
+    if (cdr(args) == list<value>())
+        return value(0 - (double)car(args));
     return value((double)car(args) - (double)cadr(args));
 }
 
@@ -126,12 +134,14 @@ const list<value> primitiveProcedureNames() {
     list<value> l = makeList(value("car"));
     l = cons(value("cdr"), l);
     l = cons(value("cons"), l);
+    l = cons(value("list"), l);
     l = cons(value("nul"), l);
     l = cons(value("="), l);
     l = cons(value("+"), l);
     l = cons(value("-"), l);
     l = cons(value("*"), l);
     l = cons(value("/"), l);
+    l = cons(value("equal?"), l);
     l = cons(value("display"), l);
     return l;
 }
@@ -140,12 +150,14 @@ const list<value> primitiveProcedureObjects() {
     list<value> l = makeList(primitiveProcedure(valueCar));
     l = cons(primitiveProcedure(valueCdr), l);
     l = cons(primitiveProcedure(valueCons), l);
+    l = cons(primitiveProcedure(valueList), l);
     l = cons(primitiveProcedure(valueNul), l);
     l = cons(primitiveProcedure(valueEqual), l);
     l = cons(primitiveProcedure(valueAdd), l);
     l = cons(primitiveProcedure(valueSub), l);
     l = cons(primitiveProcedure(valueMul), l);
     l = cons(primitiveProcedure(valueDiv), l);
+    l = cons(primitiveProcedure(valueEqual), l);
     l = cons(primitiveProcedure(valueDisplay), l);
     return l;
 }
diff --git a/cpp/sca/modules/eval/read.hpp b/cpp/sca/modules/eval/read.hpp
index 8ede2189a6..cd9068c017 100644
--- a/cpp/sca/modules/eval/read.hpp
+++ b/cpp/sca/modules/eval/read.hpp
@@ -61,7 +61,7 @@ const bool isIdentifierPart(const char ch) {
 }
 
 const bool isDigit(const char ch) {
-    return isdigit(ch);
+    return isdigit(ch) || ch == '.';
 }
 
 const bool isLeftParenthesis(const value& token) {