//go:build generate // This program generates a property file in Go file from Unicode Character // Database auxiliary data files. The command line arguments are as follows: // // 1. The name of the Unicode data file (just the filename, without extension). // Can be "-" (to skip) if the emoji flag is included. // 2. The name of the locally generated Go file. // 3. The name of the slice mapping code points to properties. // 4. The name of the generator, for logging purposes. // 5. (Optional) Flags, comma-separated. The following flags are available: // - "emojis=<property>": include the specified emoji properties (e.g. // "Extended_Pictographic"). // - "gencat": include general category properties. // //go:generate go run gen_properties.go auxiliary/GraphemeBreakProperty graphemeproperties.go graphemeCodePoints graphemes emojis=Extended_Pictographic //go:generate go run gen_properties.go auxiliary/WordBreakProperty wordproperties.go workBreakCodePoints words emojis=Extended_Pictographic //go:generate go run gen_properties.go auxiliary/SentenceBreakProperty sentenceproperties.go sentenceBreakCodePoints sentences //go:generate go run gen_properties.go LineBreak lineproperties.go lineBreakCodePoints lines gencat //go:generate go run gen_properties.go EastAsianWidth eastasianwidth.go eastAsianWidth eastasianwidth //go:generate go run gen_properties.go - emojipresentation.go emojiPresentation emojipresentation emojis=Emoji_Presentation package main import ( "bufio" "bytes" "errors" "fmt" "go/format" "io/ioutil" "log" "net/http" "os" "regexp" "sort" "strconv" "strings" "time" ) // We want to test against a specific version rather than the latest. When the // package is upgraded to a new version, change these to generate new tests. const ( propertyURL = `https://www.unicode.org/Public/15.0.0/ucd/%s.txt` emojiURL = `https://unicode.org/Public/15.0.0/ucd/emoji/emoji-data.txt` ) // The regular expression for a line containing a code point range property. var propertyPattern = regexp.MustCompile(`^([0-9A-F]{4,6})(\.\.([0-9A-F]{4,6}))?\s*;\s*([A-Za-z0-9_]+)\s*#\s(.+)$`) func main() { if len(os.Args) < 5 { fmt.Println("Not enough arguments, see code for details") os.Exit(1) } log.SetPrefix("gen_properties (" + os.Args[4] + "): ") log.SetFlags(0) // Parse flags. flags := make(map[string]string) if len(os.Args) >= 6 { for _, flag := range strings.Split(os.Args[5], ",") { flagFields := strings.Split(flag, "=") if len(flagFields) == 1 { flags[flagFields[0]] = "yes" } else { flags[flagFields[0]] = flagFields[1] } } } // Parse the text file and generate Go source code from it. _, includeGeneralCategory := flags["gencat"] var mainURL string if os.Args[1] != "-" { mainURL = fmt.Sprintf(propertyURL, os.Args[1]) } src, err := parse(mainURL, flags["emojis"], includeGeneralCategory) if err != nil { log.Fatal(err) } // Format the Go code. formatted, err := format.Source([]byte(src)) if err != nil { log.Fatal("gofmt:", err) } // Save it to the (local) target file. log.Print("Writing to ", os.Args[2]) if err := ioutil.WriteFile(os.Args[2], formatted, 0644); err != nil { log.Fatal(err) } } // parse parses the Unicode Properties text files located at the given URLs and // returns their equivalent Go source code to be used in the uniseg package. If // "emojiProperty" is not an empty string, emoji code points for that emoji // property (e.g. "Extended_Pictographic") will be included. In those cases, you // may pass an empty "propertyURL" to skip parsing the main properties file. If // "includeGeneralCategory" is true, the Unicode General Category property will // be extracted from the comments and included in the output. func parse(propertyURL, emojiProperty string, includeGeneralCategory bool) (string, error) { if propertyURL == "" && emojiProperty == "" { return "", errors.New("no properties to parse") } // Temporary buffer to hold properties. var properties [][4]string // Open the first URL. if propertyURL != "" { log.Printf("Parsing %s", propertyURL) res, err := http.Get(propertyURL) if err != nil { return "", err } in1 := res.Body defer in1.Close() // Parse it. scanner := bufio.NewScanner(in1) num := 0 for scanner.Scan() { num++ line := strings.TrimSpace(scanner.Text()) // Skip comments and empty lines. if strings.HasPrefix(line, "#") || line == "" { continue } // Everything else must be a code point range, a property and a comment. from, to, property, comment, err := parseProperty(line) if err != nil { return "", fmt.Errorf("%s line %d: %v", os.Args[4], num, err) } properties = append(properties, [4]string{from, to, property, comment}) } if err := scanner.Err(); err != nil { return "", err } } // Open the second URL. if emojiProperty != "" { log.Printf("Parsing %s", emojiURL) res, err := http.Get(emojiURL) if err != nil { return "", err } in2 := res.Body defer in2.Close() // Parse it. scanner := bufio.NewScanner(in2) num := 0 for scanner.Scan() { num++ line := scanner.Text() // Skip comments, empty lines, and everything not containing // "Extended_Pictographic". if strings.HasPrefix(line, "#") || line == "" || !strings.Contains(line, emojiProperty) { continue } // Everything else must be a code point range, a property and a comment. from, to, property, comment, err := parseProperty(line) if err != nil { return "", fmt.Errorf("emojis line %d: %v", num, err) } properties = append(properties, [4]string{from, to, property, comment}) } if err := scanner.Err(); err != nil { return "", err } } // Avoid overflow during binary search. if len(properties) >= 1<<31 { return "", errors.New("too many properties") } // Sort properties. sort.Slice(properties, func(i, j int) bool { left, _ := strconv.ParseUint(properties[i][0], 16, 64) right, _ := strconv.ParseUint(properties[j][0], 16, 64) return left < right }) // Header. var ( buf bytes.Buffer emojiComment string ) columns := 3 if includeGeneralCategory { columns = 4 } if emojiURL != "" { emojiComment = ` // and // ` + emojiURL + ` // ("Extended_Pictographic" only)` } buf.WriteString(`// Code generated via go generate from gen_properties.go. DO NOT EDIT. package uniseg // ` + os.Args[3] + ` are taken from // ` + propertyURL + emojiComment + ` // on ` + time.Now().Format("January 2, 2006") + `. See https://www.unicode.org/license.html for the Unicode // license agreement. var ` + os.Args[3] + ` = [][` + strconv.Itoa(columns) + `]int{ `) // Properties. for _, prop := range properties { if includeGeneralCategory { generalCategory := "gc" + prop[3][:2] if generalCategory == "gcL&" { generalCategory = "gcLC" } prop[3] = prop[3][3:] fmt.Fprintf(&buf, "{0x%s,0x%s,%s,%s}, // %s\n", prop[0], prop[1], translateProperty("pr", prop[2]), generalCategory, prop[3]) } else { fmt.Fprintf(&buf, "{0x%s,0x%s,%s}, // %s\n", prop[0], prop[1], translateProperty("pr", prop[2]), prop[3]) } } // Tail. buf.WriteString("}") return buf.String(), nil } // parseProperty parses a line of the Unicode properties text file containing a // property for a code point range and returns it along with its comment. func parseProperty(line string) (from, to, property, comment string, err error) { fields := propertyPattern.FindStringSubmatch(line) if fields == nil { err = errors.New("no property found") return } from = fields[1] to = fields[3] if to == "" { to = from } property = fields[4] comment = fields[5] return } // translateProperty translates a property name as used in the Unicode data file // to a variable used in the Go code. func translateProperty(prefix, property string) string { return prefix + strings.ReplaceAll(property, "_", "") }