README
¶
Combinatoric 
Combinatoric is a simple Go port of the "combinatoric" parts of Python's
itertools--specifically, combinations, permutations, and product.
See godocs for more.
Installation
$ go get https://github.com/ecooper/combinatoric
Quickstart
package main
import (
"fmt"
"github.com/ecooper/combinatoric"
)
func main() {
src := []interface{}{"A", "B", "C", "D"}
// Create a new CombinationIterator of 2 elements using src
iter, _ := combinatoric.Combinations(src, 2)
// Print the length of the iterator
fmt.Printf("Expecting %d combinations:\n", iter.Len())
// Set c to the next combination until Next returns a nil slice.
for c := iter.First(); c != nil; c = iter.Next() {
fmt.Printf("%s\n", c)
}
// Restore the CombinationsIterator to its original state
iter.Reset()
}
Usage
See godocs for more documentation and usage examples.
Documentation
¶
Overview ¶
Package combinatoric is a simple Go port of the "combinatoric" parts of Python's itertools--specifically, combinations, permutations, and product.
None of the iterators are threadsafe. Implement mutexes as required. Additionally, it should be assumed the return values for First and Next always share the same memory address. If return values must be persisted between iterations, copy them into another slice.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type CombinationIterator ¶
type CombinationIterator struct {
// contains filtered or unexported fields
}
CombinationIterator implements an Iterator to generate unique combinations of a given slice.
CombinationIterator is not threadsafe, and should always be initialized through Combinations. Return values from First and Next share the same memory address. Use copy if the value must persist between iterations.
func Combinations ¶
func Combinations(pool []interface{}, r int) (*CombinationIterator, error)
Combinations creates a new CombinationIterator for a given slice and desired output size.
func (*CombinationIterator) First ¶
func (iter *CombinationIterator) First() []interface{}
First resets the iterator to its starting state and returns the first combination.
func (*CombinationIterator) HasNext ¶
func (iter *CombinationIterator) HasNext() bool
HasNext returns true if the iterator is not yet exhausted.
func (*CombinationIterator) Len ¶
func (iter *CombinationIterator) Len() uint64
Len returns the maximum iterations.
func (*CombinationIterator) Next ¶
func (iter *CombinationIterator) Next() []interface{}
Next returns the next value in the iterator or returns nil.
func (*CombinationIterator) Reset ¶
func (iter *CombinationIterator) Reset()
Reset returns the iterator to its starting state.
type Iterator ¶
type Iterator interface {
First() []interface{}
Next() []interface{}
HasNext() bool
Len() uint64
Reset()
}
Iterator is the interface that wraps a basic iterator.
Iterators are expected to track state and be able to calculate the number of iterations for a given implementation.
First and Next should return nil when a result slice is not available.
type PermutationIterator ¶
type PermutationIterator struct {
// contains filtered or unexported fields
}
PermutationIterator implements an Iterator to generate all permutations of a given slice.
PermutationIterator is not threadsafe, and should always be initialized through Permutations. Return values from First and Next share the same memory address. Use copy if the value must persist between iterations.
func Permutations ¶
func Permutations(pool []interface{}, r int) (*PermutationIterator, error)
Permutations creates a new PermutationIterator for a given slice and desired output size.
func (*PermutationIterator) First ¶
func (iter *PermutationIterator) First() []interface{}
First resets the iterator to its starting state and returns the first permutation.
func (*PermutationIterator) HasNext ¶
func (iter *PermutationIterator) HasNext() bool
HasNext returns true if the iterator is not yet exhausted.
func (*PermutationIterator) Len ¶
func (iter *PermutationIterator) Len() uint64
Len returns the maximum iterations.
func (*PermutationIterator) Next ¶
func (iter *PermutationIterator) Next() []interface{}
Next returns the next value in the iterator or returns nil.
func (*PermutationIterator) Reset ¶
func (iter *PermutationIterator) Reset()
Reset returns the iterator to its starting state.
type ProductIterator ¶
type ProductIterator struct {
// contains filtered or unexported fields
}
ProductIterator implements an Iterator to generate the Cartesian product of a slice of slices.
ProductIterator is not threadsafe, and should always be initialized through Products. Return values from First and Next share the same memory address. Use copy if the value must persist between iterations.
func Product ¶
func Product(pools [][]interface{}) (*ProductIterator, error)
Product creates a new ProductIterator for a given slice and desired output size.
func (*ProductIterator) First ¶
func (iter *ProductIterator) First() []interface{}
First resets the iterator to its starting state and returns the first product.
func (*ProductIterator) HasNext ¶
func (iter *ProductIterator) HasNext() bool
HasNext returns true if the iterator is not yet exhausted.
func (*ProductIterator) Len ¶
func (iter *ProductIterator) Len() uint64
Len returns the maximum iterations.
func (*ProductIterator) Next ¶
func (iter *ProductIterator) Next() []interface{}
Next returns the next value in the iterator or returns nil.
func (*ProductIterator) Reset ¶
func (iter *ProductIterator) Reset()
Reset returns the iterator to its starting state.
Source Files