Double Metaphone

DoubleMetaphone returns two codes for a word. Two words sounds similar when either non-empty code of one word matches either of the other word's codes. Producing codes for the words in a word list and matching them with the codes for an attempted spelling allows a spell checker program to suggest correct spellings.

Example use:

import "github.com/charltoncr/metaphone"
// ...
m, m2 := metaphone.DoubleMetaphone("knewmoanya", 4)
n, n2 := metaphone.DoubleMetaphone("pneumonia", 4)
if m == n || m == n2 || m2 == n || len(m2) > 0 && m2 == n2 {
    // match
}
// m is "NMN", as is n, so the two spellings match.
// The maximum allowed length for each of m, m2,
// n and n2 is 4 in this case.

Double Metaphone Convenience Functions

The Double Metaphone convenience functions ease the use of DoubleMetaphone. Two function calls are sufficient to read all words in a file, create a map of words that have the same metaphone return values, and find all words in the map that match a given word/misspelling. See the example below.

• func NewMetaphMap(wordlist []string, maxLen int) *MetaphMap
• func NewMetaphMapFromFile(fileName string, maxLen int) (*MetaphMap, error)
• func (metaph *MetaphMap) MatchWord(word string) (output []string)
• func (metaph *MetaphMap) Len() int

NewMetaphMap returns a MetaphMap made from a wordlist and a maximum length for the DoubleMetaphone return values.

NewMetaphMapFromFile returns a MetaphMap made from a word list file and a maximum length for the DoubleMetaphone return values.

MatchWord returns all words in metaph that sound like word. Case in word is ignored.

Len returns the number of sounds-alike keys in the metaph map.

Example use:

package main

import (
    "fmt"
    "github.com/charltoncr/metaphone"
)
func main() {
    // The file specified by fileName should contain a comprehesive word
    // list with one word per line.  (Error check is omitted for brevity.)
    fileName := "spellCheckerWords.txt" // (could be a *.txt.gz file)
    metaphMap, _ := metaphone.NewMetaphMapFromFile(fileName, 4)
    matches := metaphMap.MatchWord("knewmoanya")
    for _, word := range matches {
        fmt.Println(word)
    }
}

Ron Charlton