Sha256: f9aa1387bfd176f93ab786b3a72b640ce59e325dcad42ebf6ed0de9d9fc4421f
Contents?: true
Size: 1.37 KB
Versions: 121
Compression:
Stored size: 1.37 KB
Contents
package cipher
import "strings"
func NewCaesar() Cipher { return NewShift(3) }
type shift int
func NewShift(s int) Cipher {
c := shift(s)
switch {
case c > 0 && c < 26:
return c
case c > -26 && c < 0:
c += 26
return c
}
return nil
}
func (c shift) Encode(s string) string {
return strings.Map(
func(r rune) rune { return enc(r, int(c)) },
s)
}
func (c shift) Decode(ct string) string {
return strings.Map(
func(r rune) rune { return dec(r, int(c)) },
ct)
}
func enc(r rune, sa int) rune {
switch {
case r >= 'a' && r <= 'z':
return (r-'a'+rune(sa))%26 + 'a'
case r >= 'A' && r <= 'Z':
return (r-'A'+rune(sa))%26 + 'a'
}
return -1
}
func dec(r rune, sa int) rune {
if r >= 'a' && r <= 'z' {
return (r-'a'+rune(26-sa))%26 + 'a'
}
return -1
}
type vigenere string
func NewVigenere(key string) Cipher {
ok := false
for _, r := range key {
switch {
case r < 'a' || r > 'z':
return nil
case r > 'a':
ok = true
}
}
if !ok {
return nil
}
return vigenere(key)
}
func (v vigenere) Encode(s string) string {
x := 0
return strings.Map(
func(r rune) rune {
if r = enc(r, int(v[x]-'a')); r >= 0 {
x = (x + 1) % len(v)
}
return r
},
s)
}
func (v vigenere) Decode(ct string) string {
x := 0
return strings.Map(
func(r rune) rune {
if r = dec(r, int(v[x]-'a')); r >= 0 {
x = (x + 1) % len(v)
}
return r
},
ct)
}
Version data entries
121 entries across 121 versions & 1 rubygems