Combine "CompiledGrammar" and "Report" payloads

Instead of one JSON file for each output, a single file with both
outputs combined, each under its own key.  The beauty of maps.

Also instead of using a flag to determine where to put the data, just
print to stdout and be done with it.

4 files changed, 26 insertions, 66 deletions

diff --git a/src/urubu/cmd/vartan/compile.go b/src/urubu/cmd/vartan/compile.go
index 79fa9ef..7b67a97 100644
--- a/src/urubu/cmd/vartan/compile.go
+++ b/src/urubu/cmd/vartan/compile.go
@@ -69,7 +69,7 @@ func runCompile(args []string) (retErr error) {
 		return err
 	}
 
-	err = writeCompiledGrammarAndReport(gram, report, "")
+	err = writeCompiledGrammarAndReport(gram, report, os.Stdout)
 	if err != nil {
 		return fmt.Errorf("Cannot write an output files: %w", err)
 	}
@@ -123,68 +123,21 @@ func readGrammar(path string) (*spec.CompiledGrammar, *spec.Report, error) {
 //     The report file is named <grammar-name>.json.
 //  3. When the path is an empty string, this function writes the compiled grammar to the stdout and writes
 //     the report to a file named <current-directory>/<grammar-name>-report.json.
-func writeCompiledGrammarAndReport(cgram *spec.CompiledGrammar, report *spec.Report, path string) error {
-	cgramPath, reportPath, err := makeOutputFilePaths(cgram.Name, path)
-	if err != nil {
-		return err
+func writeCompiledGrammarAndReport(
+	cgram *spec.CompiledGrammar,
+	report *spec.Report,
+	w io.Writer,
+) error {
+	out := map[string]interface{}{
+		"grammar": cgram,
+		"report":  report,
 	}
 
-	{
-		var cgramW io.Writer
-		if cgramPath != "" {
-			cgramFile, err := os.OpenFile(cgramPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
-			if err != nil {
-				return err
-			}
-			defer cgramFile.Close()
-			cgramW = cgramFile
-		} else {
-			cgramW = os.Stdout
-		}
-
-		b, err := json.Marshal(cgram)
-		if err != nil {
-			return err
-		}
-		fmt.Fprintf(cgramW, "%v\n", string(b))
-	}
-
-	{
-		reportFile, err := os.OpenFile(reportPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
-		if err != nil {
-			return err
-		}
-		defer reportFile.Close()
-
-		b, err := json.Marshal(report)
-		if err != nil {
-			return err
-		}
-		fmt.Fprintf(reportFile, "%v\n", string(b))
+	b, err := json.Marshal(out)
+	if err != nil {
+		return err
 	}
+	fmt.Fprintf(w, "%v\n", string(b))
 
 	return nil
 }
-
-func makeOutputFilePaths(gramName string, path string) (string, string, error) {
-	reportFileName := gramName + "-report.json"
-
-	if path == "" {
-		wd, err := os.Getwd()
-		if err != nil {
-			return "", "", err
-		}
-		return "", filepath.Join(wd, reportFileName), nil
-	}
-
-	fi, err := os.Stat(path)
-	if err != nil && !os.IsNotExist(err) {
-		return "", "", err
-	}
-	if os.IsNotExist(err) || !fi.IsDir() {
-		dir, _ := filepath.Split(path)
-		return path, filepath.Join(dir, reportFileName), nil
-	}
-
-	return filepath.Join(path, gramName+".json"), filepath.Join(path, reportFileName), nil
-}
diff --git a/src/urubu/cmd/vartan/parse.go b/src/urubu/cmd/vartan/parse.go
index 9c5fd9c..41b8723 100644
--- a/src/urubu/cmd/vartan/parse.go
+++ b/src/urubu/cmd/vartan/parse.go
@@ -78,12 +78,14 @@ func readCompiledGrammar(path string) (*spec.CompiledGrammar, error) {
 	if err != nil {
 		return nil, err
 	}
-	cg := &spec.CompiledGrammar{}
-	err = json.Unmarshal(data, cg)
+
+	output := &spec.Output{}
+	err = json.Unmarshal(data, output)
 	if err != nil {
 		return nil, err
 	}
-	return cg, nil
+
+	return &output.Grammar, nil
 }
 
 func writeSyntaxErrorMessage(b *strings.Builder, cgram *spec.CompiledGrammar, synErr *driver.SyntaxError) {
diff --git a/src/urubu/cmd/vartan/show.go b/src/urubu/cmd/vartan/show.go
index cab63a0..a7a8be9 100644
--- a/src/urubu/cmd/vartan/show.go
+++ b/src/urubu/cmd/vartan/show.go
@@ -40,13 +40,13 @@ func readReport(path string) (*spec.Report, error) {
 		return nil, err
 	}
 
-	report := &spec.Report{}
-	err = json.Unmarshal(d, report)
+	output := &spec.Output{}
+	err = json.Unmarshal(d, output)
 	if err != nil {
 		return nil, err
 	}
 
-	return report, nil
+	return &output.Report, nil
 }
 
 const reportTemplate = `# Conflicts
diff --git a/src/urubu/spec/grammar.go b/src/urubu/spec/grammar.go
index c2708d8..1c2bdf2 100644
--- a/src/urubu/spec/grammar.go
+++ b/src/urubu/spec/grammar.go
@@ -82,6 +82,11 @@ type CompiledGrammar struct {
 	ASTAction *ASTAction     `json:"ast_action"`
 }
 
+type Output struct{
+	Grammar CompiledGrammar `json:"grammar"`
+	Report  Report          `json:"report"`
+}
+
 // StateID represents an ID of a state of a transition table.
 type StateID int