blt

README

goblt

A BLT file format parser in Go. Used for election data.

Background

6 3
-2 -6
28 1=2 3 0
26 2 1 3 0
3 3 0
2 4 0
1 5 0
0
"Alice"
"Bob"
"Chris"
"Don"
"Eric"
"Frank"
"My Election"

• The first line 6 3 indicates the number of candidates 6 and seats 3.

• The second line -2 -6 is optional and may be omitted. It contains negative candidate numbers indicating candidates 2 and 6 are withdrawn.

• The next lines contain vote data. 28 1=2 3 0 indicates there are 28 votes each containing candidate preferences 1=2 3. The end of a vote line is indicated by a 0. The preference 1=2 3 indicates 1 and 2 are tied for first preference, and 3 is second preference.

• A line with a single 0 indicates the end of all vote data.

• Next are quoted candidate names listed in a specific order matching the numbers for vote preferences.

• The last line is the title of the election.

Use

NewParser accepts an io.Reader and initializes a new parser.

parser := blt.NewParser(reader)

election, err := parser.Parse()

The resulting parsed election struct will look like this:

{
    "NumCandidates":6,
    "NumSeats":3,
    "Withdrawn":[2,6],
    "Ballots":[
        {
            "Count":28,
            "Preferences":[[1,2],[3]]
        },
        {
            "Count":26,
            "Preferences":[[2],[1],[3]]
        },
        {
            "Count":3,
            "Preferences":[[3]]
        },
        {
            "Count":2,
            "Preferences":[[4]]
        },
        {
            "Count":1,
            "Preferences":[[5]]
        }
    ],
    "Candidates": [
        "Alice",
        "Bob",
        "Chris",
        "Don",
        "Eric",
        "Frank"
    ],
    "Title":"Test"
}

Documentation

Index

• type Ballot
• type Election
  • func (e *Election) FlatNamedBallots() []FlatNamedBallot
  • func (e *Election) NamedBallots() []NamedBallot
  • func (e *Election) NamedWithdrawn() []string
• type FlatNamedBallot
• type NamedBallot
• type Parser
  • func NewParser(r io.Reader) *Parser
  • func (p *Parser) Parse() (*Election, error)

Types

type Ballot

type Ballot struct {
	Count       int
	Preferences [][]int
}

type Election

type Election struct {
	NumCandidates int
	NumSeats      int
	Withdrawn     []int
	Ballots       []Ballot
	Candidates    []string
	Title         string
}

func (*Election) FlatNamedBallots

func (e *Election) FlatNamedBallots() []FlatNamedBallot

FlatNamedBallots returns ballots with preferences flattened to a 1d slice and using candidate names.

func (*Election) NamedBallots

func (e *Election) NamedBallots() []NamedBallot

NamedBallots return ballots using candidate names.

func (*Election) NamedWithdrawn

func (e *Election) NamedWithdrawn() []string

NamedWithdrawn return withdrawn candidates by name.

type FlatNamedBallot

type FlatNamedBallot struct {
	Count       int
	Preferences []string
}

type NamedBallot

type NamedBallot struct {
	Count       int
	Preferences [][]string
}

type Parser

type Parser struct {
	// contains filtered or unexported fields
}

func NewParser

func NewParser(r io.Reader) *Parser

NewParser initializes a new Parser using the provided io.Reader.

func (*Parser) Parse

func (p *Parser) Parse() (*Election, error)

Parse reads BLT data and returns an Election.