feat: publish the Sandwich Hime source preview

Signed-off-by: Cole Speelman <gamertan@noreply.localhost>

internal/version/version.go

@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+// Package version contains build identifiers shared by the compiler and CLI.
+package version
+
+import (
+	"regexp"
+	"runtime/debug"
+	"strings"
+)
+
+const developmentCompilerVersion = "0.1.0-dev"
+
+// Compiler may be replaced in release binaries with
+// `-X gamertan.com/sandwich-hime/internal/version.Compiler=vX.Y.Z`.
+// A versioned `go install module/package@vX.Y.Z` instead supplies the main
+// module version through Go build information; init adopts that version when
+// no explicit linker value was provided.
+var Compiler = developmentCompilerVersion
+
+var (
+	taggedCompilerVersionPattern = regexp.MustCompile(`^v(?:0|[1-9][0-9]*)\.(?:0|[1-9][0-9]*)\.(?:0|[1-9][0-9]*)(?:-([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?$`)
+	pseudoVersionSuffixPattern   = regexp.MustCompile(`(?:^|[.-])(?:0\.)?[0-9]{14}-[0-9a-f]{12,}$`)
+)
+
+func init() {
+	if information, ok := debug.ReadBuildInfo(); ok {
+		Compiler = selectCompilerVersion(Compiler, information.Main.Version)
+	}
+}
+
+func selectCompilerVersion(linkerValue, moduleVersion string) string {
+	if linkerValue != developmentCompilerVersion {
+		return linkerValue
+	}
+	moduleVersion = strings.TrimSpace(moduleVersion)
+	if !isTaggedCompilerVersion(moduleVersion) {
+		return linkerValue
+	}
+	return moduleVersion
+}
+
+func isTaggedCompilerVersion(value string) bool {
+	matches := taggedCompilerVersionPattern.FindStringSubmatch(value)
+	if matches == nil {
+		// Build metadata is deliberately excluded. In particular, local VCS
+		// builds can carry +dirty and must remain development builds.
+		return false
+	}
+	prerelease := matches[1]
+	if pseudoVersionSuffixPattern.MatchString(prerelease) {
+		// Go synthesizes valid-semver pseudo-versions for local VCS builds. They
+		// identify source, but they are not signed/tagged Hime-san releases.
+		return false
+	}
+	for _, identifier := range strings.Split(prerelease, ".") {
+		if len(identifier) > 1 && identifier[0] == '0' && allDecimal(identifier) {
+			return false
+		}
+	}
+	return true
+}
+
+func allDecimal(value string) bool {
+	if value == "" {
+		return false
+	}
+	for _, character := range value {
+		if character < '0' || character > '9' {
+			return false
+		}
+	}
+	return true
+}
+
+const (
+	// RuntimeABI identifies the generated-code/runtime contract.
+	RuntimeABI = "sando.v1"
+
+	// ConfigSchema is the supported himesan.json schema version.
+	ConfigSchema = 1
+)