Expand Gotlin language and tooling

cmd/gotlinc/main.go

@@ -42,13 +42,13 @@ func runBuild(args []string) {
 	if err := fs.Parse(normalizedArgs); err != nil {
 		fail(err)
 	}
-	if fs.NArg() != 1 {
+	if fs.NArg() < 1 {
 		fs.Usage()
 		os.Exit(2)
 	}
 
 	inputPath := fs.Arg(0)
-	goSrc := compileFile(inputPath, !*srcOnly)
+	goSrc := compileFiles(fs.Args(), !*srcOnly)
 
 	if *srcOnly {
 		if *outPath == "" {
@@ -113,17 +113,42 @@ func runRun(args []string) {
 }
 
 func compileFile(inputPath string, forceMain bool) string {
-	src, err := os.ReadFile(inputPath)
-	if err != nil {
-		fail(err)
-	}
+	return compileFiles([]string{inputPath}, forceMain)
+}
 
-	program, err := lang.Parse(string(src))
-	if err != nil {
-		fail(err)
-	}
+func compileFiles(inputPaths []string, forceMain bool) string {
+	program := &lang.Program{}
+	var firstSource string
+	for _, inputPath := range inputPaths {
+		src, err := os.ReadFile(inputPath)
+		if err != nil {
+			fail(err)
+		}
 
+		parsed, err := lang.Parse(string(src))
+		if err != nil {
+			fail(err)
+		}
+
+		if program.PackagePath == "" {
+			program.PackagePath = parsed.PackagePath
+		}
+		if parsed.PackagePath != program.PackagePath {
+			fail(fmt.Errorf("Gotlin files must use the same package"))
+		}
+		program.Imports = append(program.Imports, parsed.Imports...)
+		program.Interfaces = append(program.Interfaces, parsed.Interfaces...)
+		program.Enums = append(program.Enums, parsed.Enums...)
+		program.Classes = append(program.Classes, parsed.Classes...)
+		program.Workers = append(program.Workers, parsed.Workers...)
+		program.Functions = append(program.Functions, parsed.Functions...)
+		program.Embeds = append(program.Embeds, parsed.Embeds...)
+		if firstSource == "" {
+			firstSource = string(src)
+		}
+	}
 	var goSrc []byte
+	var err error
 	if forceMain {
 		goSrc, err = lang.GenerateGoMain(program)
 	} else {
@@ -133,7 +158,7 @@ func compileFile(inputPath string, forceMain bool) string {
 		fail(err)
 	}
 	if forceMain {
-		return addBestEffortLineDirectives(string(goSrc), inputPath, string(src))
+		return addBestEffortLineDirectives(string(goSrc), inputPaths[0], firstSource)
 	}
 	return string(goSrc)
 }