Add ecosystem-specific version handling

Author: andrew

README.md

@@ -66,6 +66,11 @@ r, _ = vers.ParseNative(">> 1.0", "deb")
 
 // RPM
 r, _ = vers.ParseNative(">= 1.0", "rpm")
+
+// Conan, OpenSSL, and Nginx
+r, _ = vers.ParseNative("^1.2", "conan")
+r, _ = vers.ParseNative("1.1.1w, 3.0.0", "openssl")
+r, _ = vers.ParseNative("0.8.40+", "nginx")
 ```
 
 ### Check Version Satisfaction
@@ -89,6 +94,10 @@ vers.Compare("1.0.0", "1.0.0")  // 0  (equal)
 
 // Prerelease versions sort before stable
 vers.Compare("1.0.0", "1.0.0-alpha")  // 1 (stable > prerelease)
+
+// Use ecosystem-specific ordering where versions are not SemVer
+vers.CompareWithScheme("1.0~rc1", "1.0", "deb")  // -1
+vers.CompareWithScheme("1.0.beta1", "1.0", "gem") // -1
 ```
 
 ### Version Validation and Normalization
@@ -100,6 +109,9 @@ vers.Valid("invalid")      // false
 v, _ := vers.Normalize("1")      // "1.0.0"
 v, _ = vers.Normalize("1.2")     // "1.2.0"
 v, _ = vers.Normalize("1.2.3")   // "1.2.3"
+
+vers.ValidWithScheme("1:2.3.4-1", "deb") // true
+v, _ = vers.NormalizeWithScheme("01!02.0RC1", "pypi") // "1!2.0rc1"
 ```
 
 ### Create Ranges Programmatically
@@ -150,8 +162,15 @@ uri = vers.ToVersString(r, "npm")
 | NuGet | `nuget` | Same as Maven |
 | Cargo | `cargo` | Same as npm |
 | Go | `go`, `golang` | `>=1.0.0,<2.0.0` |
+| Hex | `hex`, `elixir` | `~> 1.2`, `>= 1.0 and < 2.0` |
 | Debian | `deb`, `debian` | `>> 1.0`, `<< 2.0`, `>= 1.0` |
 | RPM | `rpm` | `>= 1.0`, `<= 2.0` |
+| Conan | `conan` | `^1.2`, `~1.2`, `>1 <2`, `||` |
+| OpenSSL | `openssl` | `1.1.1w`, `1.1.1w, 3.0.0` |
+| Nginx | `nginx` | `0.8.40+`, `0.7.52-0.8.39` |
+
+Version comparison additionally supports `semver`, `apk`/`alpine`, `alpm`,
+`gentoo`, `intdot`, `lexicographic`, and `datetime`.
 
 ## Development
 

conformance_test.go

@@ -34,6 +34,10 @@ type versionCmpInput struct {
 	Versions    []string `json:"versions"`
 }
 
+type roundtripInput struct {
+	Vers string `json:"vers"`
+}
+
 func loadTestFile(t *testing.T, filename string) *versTestFile {
 	t.Helper()
 	path := filepath.Join("testdata", "vers-spec", "tests", filename)
@@ -50,8 +54,12 @@ func loadTestFile(t *testing.T, filename string) *versTestFile {
 
 func TestConformance_FromNative(t *testing.T) {
 	files := []string{
+		"conan_range_from_native_basic_test.json",
+		"conan_range_from_native_test.json",
 		"gem_range_from_native_test.json",
+		"nginx_range_from_native_test.json",
 		"npm_range_from_native_test.json",
+		"openssl_range_from_native_test.json",
 		"pypi_range_from_native_test.json",
 		"nuget_range_from_native_test.json",
 	}
@@ -136,11 +144,45 @@ func TestConformance_Containment(t *testing.T) {
 	}
 }
 
+func TestConformance_RoundTrip(t *testing.T) {
+	tf := loadTestFile(t, "pypi_range_roundtrip_test.json")
+	for _, tc := range tf.Tests {
+		if tc.TestType != "roundtrip" {
+			continue
+		}
+		var input roundtripInput
+		if err := json.Unmarshal(tc.Input, &input); err != nil {
+			t.Errorf("failed to parse input: %v", err)
+			continue
+		}
+		var expected string
+		if err := json.Unmarshal(tc.ExpectedOutput, &expected); err != nil {
+			t.Errorf("failed to parse expected output: %v", err)
+			continue
+		}
+		t.Run(input.Vers, func(t *testing.T) {
+			r, err := Parse(input.Vers)
+			if err != nil {
+				t.Fatalf("Parse(%q) error: %v", input.Vers, err)
+			}
+			if got := ToVersString(r, r.Scheme); got != expected {
+				t.Errorf("round trip = %q, want %q", got, expected)
+			}
+		})
+	}
+}
+
 //nolint:gocognit
 func TestConformance_VersionComparison(t *testing.T) {
 	files := []string{
+		"alpine_version_cmp_test.json",
+		"alpm_version_cmp_test.json",
+		"conan_version_cmp_test.json",
+		"gentoo_version_cmp_test.json",
+		"lexicographic-test.json",
 		"nuget_version_cmp_test.json",
 		"maven_version_cmp_test.json",
+		"openssl_version_cmp_test.json",
 	}
 
 	for _, file := range files {

constraint.go

@@ -16,13 +16,19 @@ var operatorRegex = regexp.MustCompile(`^(!=|>=|<=|[<>=])`)
 type Constraint struct {
 	Operator string
 	Version  string
+	Scheme   string
 }
 
 // ParseConstraint parses a constraint string into a Constraint.
 func ParseConstraint(s string) (*Constraint, error) {
 	return parseConstraintWithScheme(s, "")
 }
 
+// ParseConstraintWithScheme parses a constraint using scheme-specific comparison rules.
+func ParseConstraintWithScheme(s, scheme string) (*Constraint, error) {
+	return parseConstraintWithScheme(s, scheme)
+}
+
 // parseConstraintWithScheme parses a constraint with scheme-specific handling.
 // For Go/golang schemes, the v prefix is preserved.
 func parseConstraintWithScheme(s, scheme string) (*Constraint, error) {
@@ -47,7 +53,7 @@ func parseConstraintWithScheme(s, scheme string) (*Constraint, error) {
 		if !preserveVPrefix {
 			version = stripVPrefix(version)
 		}
-		return &Constraint{Operator: operator, Version: version}, nil
+		return &Constraint{Operator: operator, Version: version, Scheme: scheme}, nil
 	}
 
 	// No operator found, treat as exact match
@@ -56,9 +62,9 @@ func parseConstraintWithScheme(s, scheme string) (*Constraint, error) {
 		version = decoded
 	}
 	if !preserveVPrefix {
-		version = stripVPrefix(s)
+		version = stripVPrefix(version)
 	}
-	return &Constraint{Operator: "=", Version: version}, nil
+	return &Constraint{Operator: "=", Version: version, Scheme: scheme}, nil
 }
 
 // stripVPrefix removes a leading 'v' or 'V' from version strings.
@@ -98,7 +104,16 @@ func (c *Constraint) IsExclusion() bool {
 
 // Satisfies checks if a version satisfies this constraint.
 func (c *Constraint) Satisfies(version string) bool {
-	cmp := CompareVersions(version, c.Version)
+	return c.satisfiesCmp(version, compareFuncFor(c.Scheme))
+}
+
+// SatisfiesWithScheme checks the constraint using the specified version scheme.
+func (c *Constraint) SatisfiesWithScheme(version, scheme string) bool {
+	return c.satisfiesCmp(version, compareFuncFor(scheme))
+}
+
+func (c *Constraint) satisfiesCmp(version string, compare func(a, b string) int) bool {
+	cmp := compare(version, c.Version)
 
 	switch c.Operator {
 	case "=":

constraint_test.go

@@ -16,6 +16,7 @@ func TestParseConstraint(t *testing.T) {
 		{"=1.0.0", "=", "1.0.0", false},
 		{"!=1.5.0", "!=", "1.5.0", false},
 		{"1.0.0", "=", "1.0.0", false}, // No operator defaults to =
+		{"1.0%2Bmeta", "=", "1.0+meta", false},
 		{"", "", "", true},
 		{">=", "", "", true}, // Missing version
 	}