Support exponential notation in RatFromString.
R=gri
APPROVED=gri
DELTA=30 (25 added, 0 deleted, 5 changed)
OCL=31796
CL=31799
diff --git a/src/pkg/bignum/bignum.go b/src/pkg/bignum/bignum.go
index 4fe6d04..4cd520f 100755
--- a/src/pkg/bignum/bignum.go
+++ b/src/pkg/bignum/bignum.go
@@ -1527,5 +1527,24 @@
}
}
- return MakeRat(a, b), base, alen + blen;
+ // read exponent, if any
+ var elen int;
+ mlen := alen + blen;
+ if mlen < len(s) {
+ ch := s[mlen];
+ if ch == 'e' || ch == 'E' {
+ var e *Integer;
+ e, base, elen = IntFromString(s[mlen + 1 : len(s)], abase);
+ elen++;
+ assert(base == abase);
+ m := Nat(10).Pow(uint(e.mant.Value()));
+ if e.sign {
+ b = b.Mul(m);
+ } else {
+ a = a.MulNat(m);
+ }
+ }
+ }
+
+ return MakeRat(a, b), base, alen + blen + elen;
}
diff --git a/src/pkg/bignum/bignum_test.go b/src/pkg/bignum/bignum_test.go
index 4f6f3f6..88bdf56 100644
--- a/src/pkg/bignum/bignum_test.go
+++ b/src/pkg/bignum/bignum_test.go
@@ -213,9 +213,15 @@
test(4, slen == 7);
rat_eq(5, ratFromString("0.", 0, nil), rat_zero);
rat_eq(6, ratFromString("0.001f", 10, nil), bignum.Rat(1, 1000));
- rat_eq(7, ratFromString("10101.0101", 2, nil), bignum.Rat(0x155, 1<<4));
- rat_eq(8, ratFromString("-0003.145926", 10, &slen), bignum.Rat(-3145926, 1000000));
- test(9, slen == 12);
+ rat_eq(7, ratFromString(".1", 0, nil), bignum.Rat(1, 10));
+ rat_eq(8, ratFromString("10101.0101", 2, nil), bignum.Rat(0x155, 1<<4));
+ rat_eq(9, ratFromString("-0003.145926", 10, &slen), bignum.Rat(-3145926, 1000000));
+ test(10, slen == 12);
+ rat_eq(11, ratFromString("1e2", 0, nil), bignum.Rat(100, 1));
+ rat_eq(12, ratFromString("1e-2", 0, nil), bignum.Rat(1, 100));
+ rat_eq(13, ratFromString("1.1e2", 0, nil), bignum.Rat(110, 1));
+ rat_eq(14, ratFromString(".1e2x", 0, &slen), bignum.Rat(10, 1));
+ test(15, slen == 4);
}
