* Implemented the ==' and !=' operators. These now use a deep

equality test, so they also work for (finite) attribute sets and
  lists.
This commit is contained in:
Eelco Dolstra 2010-03-26 13:27:26 +00:00
parent 8da118e4d0
commit cad8726b2c

View file

@ -26,6 +26,7 @@ struct Env
typedef enum {
tInt = 1,
tBool,
tAttrs,
tList,
tThunk,
@ -41,6 +42,7 @@ struct Value
union
{
int integer;
bool boolean;
Bindings * attrs;
struct {
unsigned int length;
@ -66,6 +68,9 @@ std::ostream & operator << (std::ostream & str, Value & v)
case tInt:
str << v.integer;
break;
case tBool:
str << (v.boolean ? "true" : "false");
break;
case tAttrs:
str << "{ ";
foreach (Bindings::iterator, i, *v.attrs)
@ -152,6 +157,45 @@ static Value * lookupVar(Env * env, Sym name)
}
static void setBoolValue(Value & v, bool b)
{
v.type = tBool;
v.boolean = b;
}
static bool eqValues(Value & v1, Value & v2)
{
forceValue(v1);
forceValue(v2);
switch (v1.type) {
case tInt:
return v2.type == tInt && v1.integer == v2.integer;
case tBool:
return v2.type == tBool && v1.boolean == v2.boolean;
case tList:
if (v2.type != tList || v1.list.length != v2.list.length) return false;
for (unsigned int n = 0; n < v1.list.length; ++n)
if (!eqValues(v1.list.elems[n], v2.list.elems[n])) return false;
return true;
case tAttrs: {
if (v2.type != tAttrs || v1.attrs->size() != v2.attrs->size()) return false;
Bindings::iterator i, j;
for (i = v1.attrs->begin(), j = v2.attrs->begin(); i != v1.attrs->end(); ++i, ++j)
if (!eqValues(i->second, j->second)) return false;
return true;
}
default:
throw Error("cannot compare given values");
}
}
unsigned long nrValues = 0, nrEnvs = 0;
static Env * allocEnv()
@ -337,6 +381,20 @@ static void eval(Env * env, Expr e, Value & v)
return;
}
if (matchOpEq(e, e1, e2)) {
Value v1; eval(env, e1, v1);
Value v2; eval(env, e2, v2);
setBoolValue(v, eqValues(v1, v2));
return;
}
if (matchOpNEq(e, e1, e2)) {
Value v1; eval(env, e1, v1);
Value v2; eval(env, e2, v2);
setBoolValue(v, !eqValues(v1, v2));
return;
}
if (matchOpConcat(e, e1, e2)) {
Value v1; eval(env, e1, v1);
if (v1.type != tList) throw TypeError("list expected");
@ -411,6 +469,15 @@ void run(Strings args)
doTest("with { x = 1; }; with { x = 2; }; x"); // => 1
doTest("[ 1 2 3 ]");
doTest("[ 1 2 ] ++ [ 3 4 5 ]");
doTest("123 == 123");
doTest("123 == 456");
doTest("let id = x: x; in [1 2] == [(id 1) (id 2)]");
doTest("let id = x: x; in [1 2] == [(id 1) (id 3)]");
doTest("[1 2] == [3 (let x = x; in x)]");
doTest("{ x = 1; y.z = 2; } == { y = { z = 2; }; x = 1; }");
doTest("{ x = 1; y = 2; } == { x = 2; }");
doTest("{ x = [ 1 2 ]; } == { x = [ 1 ] ++ [ 2 ]; }");
doTest("1 != 1");
printMsg(lvlError, format("alloced %1% values") % nrValues);
printMsg(lvlError, format("alloced %1% environments") % nrEnvs);