This API is now deprecated in favor of gofunctional3.

Functional programming in go. The main data type, Stream, is similar to a python iterator or generator. The methods found in here are similar to the methods found in the python itertools module. This is version 2 of gofunctional.

This API is now stable. Any future changes will be backward compatible with existing code. However, any future function or data structure in "draft" mode may change in incompatible ways. Such function or data structure will be clearly marked as "draft" in the documentation.

import "github.com/keep94/gofunctional2/functional"
import "github.com/keep94/gofunctional2/consume"

go get github.com/keep94/gofunctional2/functional
go get github.com/keep94/gofunctional2/consume

Online documentation is available here.

Suppose there are names and phone numbers of people stored in a sqlite database. The table has a name and phone_number column.

The person class would look like:

type Person struct {
  Name string
  Phone string
}

func (p *Person) Ptrs() {
  return []interface{}{&p.Name, &p.Phone}
}

To get the 4th page of 25 people do:

package main

import (
  "code.google.com/p/gosqlite/sqlite"
  "github.com/keep94/gofunctional2/functional"
)

func main() {
  conn, _ := sqlite.Open("YourDataFilePath")
  stmt, _ := conn.Prepare("select * from People")
  s := functional.ReadRows(stmt)
  s = functional.Slice(s, 3 * 25, 4 * 25)
      var person Person
      err := s.Next(&person)
      for ; err == nil; err = s.Next(&person) {
        // Display person here
      }
      if err != functional.Done {
        // Do error handling here

        s.Close()
      }
    }

Like python iterators and generators, Stream types are lazily evaluated, so the above code will read only the first 100 names no matter how many people are in the database.

See tests and the included example for detailed usage.