pschyska · July 23, 2012 12:54
diff --git a/soundex.go b/soundex.go
 // Copyright © 2010-12 Qtrac Ltd.
 // 
 // This program or package and any associated files are licensed under the
 // Apache License, Version 2.0 (the "License"); you may not use these files
 // except in compliance with the License. You can get a copy of the License
 // at: http://www.apache.org/licenses/LICENSE-2.0.
 // 
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package main

 import (
    "fmt"
    "html"
    "io/ioutil"
    "log"
    "net/http"
    "sort"
    "strings"
 )

 const (
    pageTop    = `<!DOCTYPE HTML><html><head>
 <style>.error{color:#FF0000;}</style></head>
 <title>Soundex</title><body><h3>Soundex</h3>
 <p>Compute soundex codes for a list of names.</p>`
    form       = `<form action="/" method="POST">
 <label for="names">Names (comma or space-separated):</label><br />
 <input type="text" name="names" size="30"><br />
 <input type="submit" name="compute" value="Compute">
 </form>`
    pageBottom = `</body></html>`
    error      = `<p class="error">%s</p>`
 )

 var digitForLetter = []rune{
    0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5,
    // A  B  C  D  E  F  G  H  I  J  K  L  M
    5, 0, 1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2}
    // N  O  P  Q  R  S  T  U  V  W  X  Y  Z

 var testCases map[string]string

 func main() {
    http.HandleFunc("/", homePage)
    var ok bool
    if testCases, ok = populateTestCases("soundex-test-data.txt"); ok {
        http.HandleFunc("/test", testPage)
    }
    if err := http.ListenAndServe(":9001", nil); err != nil {
        log.Fatal("failed to start server", err)
    }
 }

 func populateTestCases(filename string) (map[string]string, bool) {
    testCases := make(map[string]string)
    if lines, err := ioutil.ReadFile(filename); err != nil {
        log.Println(err)
        return testCases, false
    } else {
        for _, line := range strings.Split(string(lines), "\n") {
            if fields := strings.Fields(line); len(fields) == 2 {
                testCases[fields[1]] = fields[0]
            }
        }
    }
    return testCases, true
 }

 func homePage(writer http.ResponseWriter, request *http.Request) {
    err := request.ParseForm() // Must be called before writing response
    fmt.Fprint(writer, pageTop, form)
    if err != nil {
        fmt.Fprintf(writer, error, err)
    } else {
        if names := processRequest(request); len(names) > 0 {
            soundexes := make([]string, len(names))
            for i, name := range names {
                soundexes[i] = soundex(name)
            }
            fmt.Fprint(writer, formatResults(names, soundexes))
        }
    }
    fmt.Fprint(writer, pageBottom)
 }

 func processRequest(request *http.Request) (names []string) {
    if slice, found := request.Form["names"]; found && len(slice) > 0 {
        text := strings.Replace(slice[0], ",", " ", -1)
        names = strings.Fields(text)
    }
    return names
 }

 // "c - 'A'" produces a 0-based index, so 'A' -> 0, 'B' -> 1, etc.
 // "'0' + digitForLetter[index]" converts a one digit integer into the
 // equivalent Unicode character, i.e., 0 -> "0", 1 -> "1", etc.
 func soundex(name string) string {
    name = strings.ToUpper(name)
    chars := []rune(name)
    var codes []rune
    codes = append(codes, chars[0])
    for i := 1; i < len(chars); i++ {
        char := chars[i]
        if i > 0 && char == chars[i-1] {
            continue
        }
        if index := char - 'A'; 0 <= index &&
            index < int32(len(digitForLetter)) &&
            digitForLetter[index] != 0 {
            codes = append(codes, '0'+digitForLetter[index])
        }
    }
    for len(codes) < 4 {
        codes = append(codes, '0')
    }
    return string(codes[:4])
 }

 func formatResults(names, soundexes []string) string {
    text := `<table border="1"><tr><th>Name</th><th>Soundex</th></tr>`
    for i := range names {
        text += "<tr><td>" + html.EscapeString(names[i]) + "</td><td>" +
            html.EscapeString(soundexes[i]) + "</td></tr>"
    }
    return text + "</table>"
 }

 func testPage(writer http.ResponseWriter, request *http.Request) {
    fmt.Fprint(writer, `<html><head><title>Soundex Test</title>
 <style>.fail{color:#F00;} .pass{color:#0F0;}</style></head><body>
 <table border="1"><tr><th>Name</th><th>Soundex</th>
 <th>Expected</th><th>Test</th></tr>`)
    var names []string
    for name := range testCases {
        names = append(names, name)
    }
    sort.Strings(names)
    for _, name := range names {
        actual := soundex(name)
        expected := testCases[name]
        test := `<span class="fail">FAIL</span>`
        if actual == expected {
            test = `<span class="pass">PASS</span>`
        }
        fmt.Fprintf(writer, `<tr><td>%s</td><td>%s</td><td>%s</td>
 <td>%s</td></tr>`, name, actual, expected, test)
    }
    fmt.Fprint(writer, "</table></body></html>")
 }
	// Copyright © 2010-12 Qtrac Ltd.
	//
	// This program or package and any associated files are licensed under the
	// Apache License, Version 2.0 (the "License"); you may not use these files
	// except in compliance with the License. You can get a copy of the License
	// at: http://www.apache.org/licenses/LICENSE-2.0.
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package main

	import (
	"fmt"
	"html"
	"io/ioutil"
	"log"
	"net/http"
	"sort"
	"strings"
	)

	const (
	pageTop = `<!DOCTYPE HTML><html><head>
	<style>.error{color:#FF0000;}</style></head>
	<title>Soundex</title><body><h3>Soundex</h3>
	<p>Compute soundex codes for a list of names.</p>`
	form = `<form action="/" method="POST">
	<label for="names">Names (comma or space-separated):</label><br />
	<input type="text" name="names" size="30"><br />
	<input type="submit" name="compute" value="Compute">
	</form>`
	pageBottom = `</body></html>`
	error = `<p class="error">%s</p>`
	)

	var digitForLetter = []rune{
	0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5,
	// A B C D E F G H I J K L M
	5, 0, 1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2}
	// N O P Q R S T U V W X Y Z

	var testCases map[string]string

	func main() {
	http.HandleFunc("/", homePage)
	var ok bool
	if testCases, ok = populateTestCases("soundex-test-data.txt"); ok {
	http.HandleFunc("/test", testPage)
	}
	if err := http.ListenAndServe(":9001", nil); err != nil {
	log.Fatal("failed to start server", err)
	}
	}

	func populateTestCases(filename string) (map[string]string, bool) {
	testCases := make(map[string]string)
	if lines, err := ioutil.ReadFile(filename); err != nil {
	log.Println(err)
	return testCases, false
	} else {
	for _, line := range strings.Split(string(lines), "\n") {
	if fields := strings.Fields(line); len(fields) == 2 {
	testCases[fields[1]] = fields[0]
	}
	}
	}
	return testCases, true
	}

	func homePage(writer http.ResponseWriter, request *http.Request) {
	err := request.ParseForm() // Must be called before writing response
	fmt.Fprint(writer, pageTop, form)
	if err != nil {
	fmt.Fprintf(writer, error, err)
	} else {
	if names := processRequest(request); len(names) > 0 {
	soundexes := make([]string, len(names))
	for i, name := range names {
	soundexes[i] = soundex(name)
	}
	fmt.Fprint(writer, formatResults(names, soundexes))
	}
	}
	fmt.Fprint(writer, pageBottom)
	}

	func processRequest(request *http.Request) (names []string) {
	if slice, found := request.Form["names"]; found && len(slice) > 0 {
	text := strings.Replace(slice[0], ",", " ", -1)
	names = strings.Fields(text)
	}
	return names
	}

	// "c - 'A'" produces a 0-based index, so 'A' -> 0, 'B' -> 1, etc.
	// "'0' + digitForLetter[index]" converts a one digit integer into the
	// equivalent Unicode character, i.e., 0 -> "0", 1 -> "1", etc.
	func soundex(name string) string {
	name = strings.ToUpper(name)
	chars := []rune(name)
	var codes []rune
	codes = append(codes, chars[0])
	for i := 1; i < len(chars); i++ {
	char := chars[i]
	if i > 0 && char == chars[i-1] {
	continue
	}
	if index := char - 'A'; 0 <= index &&
	index < int32(len(digitForLetter)) &&
	digitForLetter[index] != 0 {
	codes = append(codes, '0'+digitForLetter[index])
	}
	}
	for len(codes) < 4 {
	codes = append(codes, '0')
	}
	return string(codes[:4])
	}

	func formatResults(names, soundexes []string) string {
	text := `<table border="1"><tr><th>Name</th><th>Soundex</th></tr>`
	for i := range names {
	text += "<tr><td>" + html.EscapeString(names[i]) + "</td><td>" +
	html.EscapeString(soundexes[i]) + "</td></tr>"
	}
	return text + "</table>"
	}

	func testPage(writer http.ResponseWriter, request *http.Request) {
	fmt.Fprint(writer, `<html><head><title>Soundex Test</title>
	<style>.fail{color:#F00;} .pass{color:#0F0;}</style></head><body>
	<table border="1"><tr><th>Name</th><th>Soundex</th>
	<th>Expected</th><th>Test</th></tr>`)
	var names []string
	for name := range testCases {
	names = append(names, name)
	}
	sort.Strings(names)
	for _, name := range names {
	actual := soundex(name)
	expected := testCases[name]
	test := `<span class="fail">FAIL</span>`
	if actual == expected {
	test = `<span class="pass">PASS</span>`
	}
	fmt.Fprintf(writer, `<tr><td>%s</td><td>%s</td><td>%s</td>
	<td>%s</td></tr>`, name, actual, expected, test)
	}
	fmt.Fprint(writer, "</table></body></html>")
	}