diff options
Diffstat (limited to 'src/pkg/big/nat.go')
| -rwxr-xr-x | src/pkg/big/nat.go | 37 |
1 files changed, 20 insertions, 17 deletions
diff --git a/src/pkg/big/nat.go b/src/pkg/big/nat.go index f752ce647..56f3c444e 100755 --- a/src/pkg/big/nat.go +++ b/src/pkg/big/nat.go @@ -69,7 +69,7 @@ func (z nat) make(n int) nat { } -func (z nat) new(x uint64) nat { +func (z nat) setUint64(x uint64) nat { if x == 0 { return z.make(0) } @@ -194,7 +194,7 @@ func (x nat) cmp(y nat) (r int) { func (z nat) mulAddWW(x nat, y, r Word) nat { m := len(x) if m == 0 || y == 0 { - return z.new(uint64(r)) // result is r + return z.setUint64(uint64(r)) // result is r } // m > 0 @@ -456,13 +456,13 @@ func (z nat) mulRange(a, b uint64) nat { switch { case a == 0: // cut long ranges short (optimization) - return z.new(0) + return z.setUint64(0) case a > b: - return z.new(1) + return z.setUint64(1) case a == b: - return z.new(a) + return z.setUint64(a) case a+1 == b: - return z.mul(nat(nil).new(a), nat(nil).new(b)) + return z.mul(nat(nil).setUint64(a), nat(nil).setUint64(b)) } m := (a + b) / 2 return z.mul(nat(nil).mulRange(a, m), nat(nil).mulRange(m+1, b)) @@ -621,7 +621,8 @@ func hexValue(ch byte) int { // // If the base argument is 0, the string prefix determines the actual // conversion base. A prefix of ``0x'' or ``0X'' selects base 16; the -// ``0'' prefix selects base 8. Otherwise the selected base is 10. +// ``0'' prefix selects base 8, and a ``0b'' or ``0B'' prefix selects +// base 2. Otherwise the selected base is 10. // func (z nat) scan(s string, base int) (nat, int, int) { // determine base if necessary @@ -629,23 +630,25 @@ func (z nat) scan(s string, base int) (nat, int, int) { if base == 0 { base = 10 if n > 0 && s[0] == '0' { - if n > 1 && (s[1] == 'x' || s[1] == 'X') { - if n == 2 { - // Reject a string which is just '0x' as nonsense. - return nil, 0, 0 + base, i = 8, 1 + if n > 1 { + switch s[1] { + case 'x', 'X': + base, i = 16, 2 + case 'b', 'B': + base, i = 2, 2 } - base, i = 16, 2 - } else { - base, i = 8, 1 } } } - if base < 2 || 16 < base { - panic("illegal base") + + // reject illegal bases or strings consisting only of prefix + if base < 2 || 16 < base || (base != 8 && i >= n) { + return nil, 0, 0 } // convert string - z = z[0:0] + z = z.make(0) for ; i < n; i++ { d := hexValue(s[i]) if 0 <= d && d < base { |