diff options
Diffstat (limited to 'src/pkg/bignum/rational.go')
| -rw-r--r-- | src/pkg/bignum/rational.go | 82 |
1 files changed, 41 insertions, 41 deletions
diff --git a/src/pkg/bignum/rational.go b/src/pkg/bignum/rational.go index 9e9c3a8e0..378585e5f 100644 --- a/src/pkg/bignum/rational.go +++ b/src/pkg/bignum/rational.go @@ -12,31 +12,31 @@ import "fmt" // Rational represents a quotient a/b of arbitrary precision. // type Rational struct { - a *Integer; // numerator - b Natural; // denominator + a *Integer // numerator + b Natural // denominator } // MakeRat makes a rational number given a numerator a and a denominator b. // func MakeRat(a *Integer, b Natural) *Rational { - f := a.mant.Gcd(b); // f > 0 + f := a.mant.Gcd(b) // f > 0 if f.Cmp(Nat(1)) != 0 { - a = MakeInt(a.sign, a.mant.Div(f)); - b = b.Div(f); + a = MakeInt(a.sign, a.mant.Div(f)) + b = b.Div(f) } - return &Rational{a, b}; + return &Rational{a, b} } // Rat creates a small rational number with value a0/b0. // func Rat(a0 int64, b0 int64) *Rational { - a, b := Int(a0), Int(b0); + a, b := Int(a0), Int(b0) if b.sign { a = a.Neg() } - return MakeRat(a, b.mant); + return MakeRat(a, b.mant) } @@ -51,30 +51,30 @@ func (x *Rational) Value() (numerator *Integer, denominator Natural) { // IsZero returns true iff x == 0. // -func (x *Rational) IsZero() bool { return x.a.IsZero() } +func (x *Rational) IsZero() bool { return x.a.IsZero() } // IsNeg returns true iff x < 0. // -func (x *Rational) IsNeg() bool { return x.a.IsNeg() } +func (x *Rational) IsNeg() bool { return x.a.IsNeg() } // IsPos returns true iff x > 0. // -func (x *Rational) IsPos() bool { return x.a.IsPos() } +func (x *Rational) IsPos() bool { return x.a.IsPos() } // IsInt returns true iff x can be written with a denominator 1 // in the form x == x'/1; i.e., if x is an integer value. // -func (x *Rational) IsInt() bool { return x.b.Cmp(Nat(1)) == 0 } +func (x *Rational) IsInt() bool { return x.b.Cmp(Nat(1)) == 0 } // Operations // Neg returns the negated value of x. // -func (x *Rational) Neg() *Rational { return MakeRat(x.a.Neg(), x.b) } +func (x *Rational) Neg() *Rational { return MakeRat(x.a.Neg(), x.b) } // Add returns the sum x + y. @@ -93,19 +93,19 @@ func (x *Rational) Sub(y *Rational) *Rational { // Mul returns the product x * y. // -func (x *Rational) Mul(y *Rational) *Rational { return MakeRat(x.a.Mul(y.a), x.b.Mul(y.b)) } +func (x *Rational) Mul(y *Rational) *Rational { return MakeRat(x.a.Mul(y.a), x.b.Mul(y.b)) } // Quo returns the quotient x / y for y != 0. // If y == 0, a division-by-zero run-time error occurs. // func (x *Rational) Quo(y *Rational) *Rational { - a := x.a.MulNat(y.b); - b := y.a.MulNat(x.b); + a := x.a.MulNat(y.b) + b := y.a.MulNat(x.b) if b.IsNeg() { a = a.Neg() } - return MakeRat(a, b.mant); + return MakeRat(a, b.mant) } @@ -115,7 +115,7 @@ func (x *Rational) Quo(y *Rational) *Rational { // == 0 if x == y // > 0 if x > y // -func (x *Rational) Cmp(y *Rational) int { return (x.a.MulNat(y.b)).Cmp(y.a.MulNat(x.b)) } +func (x *Rational) Cmp(y *Rational) int { return (x.a.MulNat(y.b)).Cmp(y.a.MulNat(x.b)) } // ToString converts x to a string for a given base, with 2 <= base <= 16. @@ -123,24 +123,24 @@ func (x *Rational) Cmp(y *Rational) int { return (x.a.MulNat(y.b)).Cmp(y.a.MulNa // it is of form "n/d". // func (x *Rational) ToString(base uint) string { - s := x.a.ToString(base); + s := x.a.ToString(base) if !x.IsInt() { s += "/" + x.b.ToString(base) } - return s; + return s } // String converts x to its decimal string representation. // x.String() is the same as x.ToString(10). // -func (x *Rational) String() string { return x.ToString(10) } +func (x *Rational) String() string { return x.ToString(10) } // Format is a support routine for fmt.Formatter. It accepts // the formats 'b' (binary), 'o' (octal), and 'x' (hexadecimal). // -func (x *Rational) Format(h fmt.State, c int) { fmt.Fprintf(h, "%s", x.ToString(fmtbase(c))) } +func (x *Rational) Format(h fmt.State, c int) { fmt.Fprintf(h, "%s", x.ToString(fmtbase(c))) } // RatFromString returns the rational number corresponding to the @@ -164,35 +164,35 @@ func (x *Rational) Format(h fmt.State, c int) { fmt.Fprintf(h, "%s", x.ToString( // func RatFromString(s string, base uint) (*Rational, uint, int) { // read numerator - a, abase, alen := IntFromString(s, base); - b := Nat(1); + a, abase, alen := IntFromString(s, base) + b := Nat(1) // read denominator or fraction, if any - var blen int; + var blen int if alen < len(s) { - ch := s[alen]; + ch := s[alen] if ch == '/' { - alen++; - b, base, blen = NatFromString(s[alen:], base); + alen++ + b, base, blen = NatFromString(s[alen:], base) } else if ch == '.' { - alen++; - b, base, blen = NatFromString(s[alen:], abase); - assert(base == abase); - f := Nat(uint64(base)).Pow(uint(blen)); - a = MakeInt(a.sign, a.mant.Mul(f).Add(b)); - b = f; + alen++ + b, base, blen = NatFromString(s[alen:], abase) + assert(base == abase) + f := Nat(uint64(base)).Pow(uint(blen)) + a = MakeInt(a.sign, a.mant.Mul(f).Add(b)) + b = f } } // read exponent, if any - rlen := alen + blen; + rlen := alen + blen if rlen < len(s) { - ch := s[rlen]; + ch := s[rlen] if ch == 'e' || ch == 'E' { - rlen++; - e, _, elen := IntFromString(s[rlen:], 10); - rlen += elen; - m := Nat(10).Pow(uint(e.mant.Value())); + rlen++ + e, _, elen := IntFromString(s[rlen:], 10) + rlen += elen + m := Nat(10).Pow(uint(e.mant.Value())) if e.sign { b = b.Mul(m) } else { @@ -201,5 +201,5 @@ func RatFromString(s string, base uint) (*Rational, uint, int) { } } - return MakeRat(a, b), base, rlen; + return MakeRat(a, b), base, rlen } |