- implemented String() and Format functionality in Bignum

- added a test

R=r
OCL=18687
CL=18687

src/lib/bignum.go

@@ -11,6 +11,7 @@ package Bignum
 // - Integer	signed integer numbers
 // - Rational	rational numbers
 
+import Fmt "fmt"
 
 // ----------------------------------------------------------------------------
 // Internal representation
@@ -675,7 +676,7 @@ func DivMod1(x *Natural, d Digit) (*Natural, Digit) {
 }
 
 
-func (x *Natural) String(base uint) string {
+func (x *Natural) ToString(base uint) string {
 	if len(x) == 0 {
 		return "0";
 	}
@@ -702,6 +703,27 @@ func (x *Natural) String(base uint) string {
 }
 
 
+func (x *Natural) String() string {
+	return x.ToString(10);
+}
+
+
+func FmtBase(c int) uint {
+	switch c {
+	case 'b': return 2;
+	case 'o': return 8;
+	case 'x': return 16;
+	}
+	return 10;
+}
+
+
+func (x *Natural) Format(h Fmt.Formatter, c int) {
+	t := x.ToString(FmtBase(c));  // BUG in 6g
+	Fmt.fprintf(h, "%s", t);
+}
+
+
 func HexValue(ch byte) uint {
 	d := uint(1 << LogH);
 	switch {
@@ -1092,7 +1114,7 @@ func (x *Integer) Cmp(y *Integer) int {
 }
 
 
-func (x *Integer) String(base uint) string {
+func (x *Integer) ToString(base uint) string {
 	if x.mant.IsZero() {
 		return "0";
 	}
@@ -1100,7 +1122,18 @@ func (x *Integer) String(base uint) string {
 	if x.sign {
 		s = "-";
 	}
-	return s + x.mant.String(base);
+	return s + x.mant.ToString(base);
+}
+
+	
+func (x *Integer) String() string {
+	return x.ToString(10);
+}
+
+
+func (x *Integer) Format(h Fmt.Formatter, c int) {
+	t := x.ToString(FmtBase(c));  // BUG in 6g
+	Fmt.fprintf(h, "%s", t);
 }
 
 
@@ -1215,15 +1248,26 @@ func (x *Rational) Cmp(y *Rational) int {
 }
 
 
-func (x *Rational) String(base uint) string {
-	s := x.a.String(base);
+func (x *Rational) ToString(base uint) string {
+	s := x.a.ToString(base);
 	if !x.IsInt() {
-		s += "/" + x.b.String(base);
+		s += "/" + x.b.ToString(base);
 	}
 	return s;
 }
 
 
+func (x *Rational) String() string {
+	return x.ToString(10);
+}
+
+
+func (x *Rational) Format(h Fmt.Formatter, c int) {
+	t := x.ToString(FmtBase(c));  // BUG in 6g
+	Fmt.fprintf(h, "%s", t);
+}
+
+
 // Determines base (octal, decimal, hexadecimal) if base == 0.
 // Returns the number and base of the nominator.
 export func RatFromString(s string, base uint, slen *int) (*Rational, uint) {

test/bignum_test.go

@@ -7,6 +7,7 @@
 package main
 
 import Big "bignum"
+import Fmt "fmt"
 
 const (
 	sa = "991";
@@ -71,8 +72,8 @@ func TEST(n uint, b bool) {
 func NAT_EQ(n uint, x, y *Big.Natural) {
 	if x.Cmp(y) != 0 {
 		println("TEST failed:", test_msg, "(", n, ")");
-		println("x =", x.String(10));
-		println("y =", y.String(10));
+		println("x =", x.String());
+		println("y =", y.String());
 		panic();
 	}
 }
@@ -81,8 +82,8 @@ func NAT_EQ(n uint, x, y *Big.Natural) {
 func INT_EQ(n uint, x, y *Big.Integer) {
 	if x.Cmp(y) != 0 {
 		println("TEST failed:", test_msg, "(", n, ")");
-		println("x =", x.String(10));
-		println("y =", y.String(10));
+		println("x =", x.String());
+		println("y =", y.String());
 		panic();
 	}
 }
@@ -91,8 +92,8 @@ func INT_EQ(n uint, x, y *Big.Integer) {
 func RAT_EQ(n uint, x, y *Big.Rational) {
 	if x.Cmp(y) != 0 {
 		println("TEST failed:", test_msg, "(", n, ")");
-		println("x =", x.String(10));
-		println("y =", y.String(10));
+		println("x =", x.String());
+		println("y =", y.String());
 		panic();
 	}
 }
@@ -103,9 +104,9 @@ func NatConv() {
 	NAT_EQ(0, a, Big.Nat(991));
 	NAT_EQ(1, b, Big.Fact(20));
 	NAT_EQ(2, c, Big.Fact(100));
-	TEST(3, a.String(10) == sa);
-	TEST(4, b.String(10) == sb);
-	TEST(5, c.String(10) == sc);
+	TEST(3, a.String() == sa);
+	TEST(4, b.String() == sb);
+	TEST(5, c.String() == sc);
 
 	test_msg = "NatConvB";
 	var slen int;
@@ -119,8 +120,13 @@ func NatConv() {
 	test_msg = "NatConvC";
 	t := c.Mul(c);
 	for base := uint(2); base <= 16; base++ {
-		NAT_EQ(base, NatFromString(t.String(base), base, nil), t);
+		NAT_EQ(base, NatFromString(t.ToString(base), base, nil), t);
 	}
+
+	test_msg = "NatConvD";
+	x := Big.Nat(100);
+	y, b := Big.NatFromString(Fmt.sprintf("%b", x), 2, nil);
+	NAT_EQ(0, y, x);
 }
 
 
@@ -162,8 +168,8 @@ func Add(x, y *Big.Natural) *Big.Natural {
 	z2 := y.Add(x);
 	if z1.Cmp(z2) != 0 {
 		println("addition not symmetric");
-		println("x =", x.String(10));
-		println("y =", y.String(10));
+		println("x =", x.String());
+		println("y =", y.String());
 		panic();
 	}
 	return z1;
@@ -197,20 +203,20 @@ func Mul(x, y *Big.Natural) *Big.Natural {
 	z2 := y.Mul(x);
 	if z1.Cmp(z2) != 0 {
 		println("multiplication not symmetric");
-		println("x =", x.String(10));
-		println("y =", y.String(10));
+		println("x =", x.String());
+		println("y =", y.String());
 		panic();
 	}
 	if !x.IsZero() && z1.Div(x).Cmp(y) != 0 {
 		println("multiplication/division not inverse (A)");
-		println("x =", x.String(10));
-		println("y =", y.String(10));
+		println("x =", x.String());
+		println("y =", y.String());
 		panic();
 	}
 	if !y.IsZero() && z1.Div(y).Cmp(x) != 0 {
 		println("multiplication/division not inverse (B)");
-		println("x =", x.String(10));
-		println("y =", y.String(10));
+		println("x =", x.String());
+		println("y =", y.String());
 		panic();
 	}
 	return z1;