The langtools package supports PHP language and package versions (#7)

Changes.md

@@ -1,13 +1,20 @@
+## v0.0.7 2021-05-11
+
+* Add support for parsing PHP versions.
+
+
 ## v0.0.6 2021-05-11
 
 * Fix bug in remove trailing zeros change when the version is all zeros.
 
+
 ## v0.0.5 2021-05-10
 
 * Remove trailing zeros from parsed package versions because version comparison
   func `version.Compare` does not need trailing zeros to compare versions
   correctly.
 
+
 ## v0.0.4  2020-12-14
 
 * Added support for parsing Ruby package versions, based on the [rubygems

pkg/version/php.go

@@ -0,0 +1,204 @@
+package version
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+var (
+	phpAliasRegex = regexp.MustCompile(
+		`^([^,\s]+) +as +([^,\s]+)$`,
+	)
+	phpAtStabilitiesRegex = regexp.MustCompile(
+		`(?i)@(?:stable|RC|beta|alpha|dev)$`,
+	)
+	phpBuildRegex = regexp.MustCompile(
+		`^([^,\s+]+)\+[^\s]+$`,
+	)
+	phpClassicalRegex = regexp.MustCompile(
+		`(?i)^v?(\d{1,5})(\.\d+)?(\.\d+)?(\.\d+)?[._-]?(?:(stable|beta|b|RC|alpha|a|patch|pl|p)((?:[.-]?\d+)*)?)?([.-]?dev)?$`,
+	)
+	phpDatetimeRegex = regexp.MustCompile(
+		`(?i)^v?(\d{4}(?:[.:-]?\d{2}){1,6}(?:[.:-]?\d{1,3})?)[._-]?(?:(stable|beta|b|RC|alpha|a|patch|pl|p)((?:[.-]?\d+)*)?)?([.-]?dev)?$`,
+	)
+	phpNondigitRegex = regexp.MustCompile(
+		`\D`,
+	)
+	phpDigitWordRegex = regexp.MustCompile(
+		`(\d)([a-zA-Z])`,
+	)
+	phpWordDigitRegex = regexp.MustCompile(
+		`([a-zA-Z])(\d)`,
+	)
+)
+
+// ParsePHP attempts to parse a version according to the same rules used by
+// composer (https://github.com/composer/semver)
+func ParsePHP(version string) (*Version, error) {
+	original := version
+
+	version, err := normalizePHP(version)
+	if err != nil {
+		return nil, err
+	}
+
+	version = strings.ReplaceAll(version, "_", ".")
+	version = strings.ReplaceAll(version, "-", ".")
+	version = strings.ReplaceAll(version, "+", ".")
+
+	version = phpDigitWordRegex.ReplaceAllString(version, "$1.$2")
+	version = phpWordDigitRegex.ReplaceAllString(version, "$1.$2")
+
+	segments := strings.Split(version, ".")
+	numericSegments := convertPHPSegments(segments)
+	return fromStringSlice(PHP, original, numericSegments)
+}
+
+func convertPHPSegments(segments []string) []string {
+	results := []string{}
+	leadingSegmentCount := 0
+	hasSpecial := false
+	lastIsSpecial := false
+	for _, segment := range segments {
+		switch segment {
+		case "dev":
+			segment = "-4"
+			hasSpecial = true
+			lastIsSpecial = true
+		case "alpha":
+			segment = "-3"
+			hasSpecial = true
+			lastIsSpecial = true
+		case "beta":
+			segment = "-2"
+			hasSpecial = true
+			lastIsSpecial = true
+		case "RC":
+			segment = "-1"
+			hasSpecial = true
+			lastIsSpecial = true
+		case "patch":
+			segment = "0.5"
+			hasSpecial = true
+			lastIsSpecial = true
+		default:
+			if !hasSpecial {
+				leadingSegmentCount++
+			}
+			lastIsSpecial = false
+		}
+		results = append(results, segment)
+	}
+
+	// Special asinine "datetime" version handling. This is probably a bug
+	// in the semver PHP library that we are doing our best to reproduce...
+	if leadingSegmentCount < 4 {
+		var value string
+		if len(results) > leadingSegmentCount && results[leadingSegmentCount] == "0.5" {
+			value = "1000000000"
+		} else {
+			value = "-0.5"
+		}
+		results = append(
+			results[:leadingSegmentCount],
+			append([]string{value}, results[leadingSegmentCount:]...)...,
+		)
+	}
+
+	// Ensure that "1.0.patch" < "1.0.patch.0".
+	if lastIsSpecial {
+		results = append(results, "-0.5")
+	}
+
+	return results
+}
+
+func expandPHPStability(stability string) string {
+	switch strings.ToLower(stability) {
+	case "a":
+		return "alpha"
+	case "b":
+		return "beta"
+	case "p":
+		return "patch"
+	case "pl":
+		return "patch"
+	case "rc":
+		return "RC"
+	default:
+		return stability
+	}
+}
+
+func normalizePHP(version string) (string, error) {
+	original := version
+
+	// Extra whitespace is tolerated
+	version = strings.TrimSpace(version)
+
+	// Remove aliasing
+	matches := phpAliasRegex.FindStringSubmatch(version)
+	if len(matches) > 1 {
+		version = matches[1]
+	}
+
+	// Remove stability suffix
+	loc := phpAtStabilitiesRegex.FindStringIndex(version)
+	if loc != nil {
+		version = version[:loc[0]]
+	}
+
+	// Remove build metadata
+	matches = phpBuildRegex.FindStringSubmatch(version)
+	if len(matches) > 1 {
+		version = matches[1]
+	}
+
+	// Try normal matching first
+	index := 0
+	matches = phpClassicalRegex.FindStringSubmatch(version)
+	if len(matches) > 4 {
+		if matches[2] == "" {
+			matches[2] = ".0"
+		}
+		if matches[3] == "" {
+			matches[3] = ".0"
+		}
+		if matches[4] == "" {
+			matches[4] = ".0"
+		}
+		version = matches[1] + matches[2] + matches[3] + matches[4]
+		index = 5
+	}
+	if len(matches) == 0 {
+		// Then try datetime matching
+		matches = phpDatetimeRegex.FindStringSubmatch(version)
+		if len(matches) > 1 {
+			version = phpNondigitRegex.ReplaceAllLiteralString(matches[1], ".")
+			index = 2
+		}
+	}
+
+	// Add version modifiers
+	if index != 0 {
+		if matches[index] != "" {
+			if matches[index] == "stable" {
+				return version, nil
+			}
+			version = version + "-"
+			version = version + expandPHPStability(matches[index])
+			if matches[index+1] != "" {
+				version = version + strings.TrimLeft(matches[index+1], ".-")
+			}
+		}
+
+		if matches[index+2] != "" {
+			version = version + "-dev"
+		}
+
+		return version, nil
+	}
+
+	return "", fmt.Errorf("invalid php version: %v", original)
+}