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package main
import (
"encoding/json"
"fmt"
"io"
"os"
"path/filepath"
verr "error"
"grammar"
spec "spec/grammar"
"spec/grammar/parser"
)
var compileFlags = struct {
output *string
}{}
/*
func init() {
cmd := &cobra.Command{
Use: "compile",
Short: "Compile grammar you defined into a parsing table",
Example: ` vartan compile grammar.vartan -o grammar.json`,
Args: cobra.MaximumNArgs(1),
RunE: runCompile,
}
compileFlags.output = cmd.Flags().StringP("output", "o", "", "output file path (default stdout)")
rootCmd.AddCommand(cmd)
}
*/
func runCompile(args []string) (retErr error) {
var tmpDirPath string
defer func() {
if tmpDirPath == "" {
return
}
os.RemoveAll(tmpDirPath)
}()
var grmPath string
if len(args) > 0 {
grmPath = args[0]
}
defer func() {
if retErr != nil {
specErrs, ok := retErr.(verr.SpecErrors)
if ok {
for _, err := range specErrs {
if len(args) > 0 {
err.FilePath = grmPath
err.SourceName = grmPath
} else {
err.FilePath = grmPath
err.SourceName = "stdin"
}
}
}
}
}()
if grmPath == "" {
var err error
tmpDirPath, err = os.MkdirTemp("", "vartan-compile-*")
if err != nil {
return err
}
src, err := io.ReadAll(os.Stdin)
if err != nil {
return err
}
grmPath = filepath.Join(tmpDirPath, "stdin.vartan")
err = os.WriteFile(grmPath, src, 0600)
if err != nil {
return err
}
}
gram, report, err := readGrammar(grmPath)
if err != nil {
return err
}
err = writeCompiledGrammarAndReport(gram, report, *compileFlags.output)
if err != nil {
return fmt.Errorf("Cannot write an output files: %w", err)
}
var implicitlyResolvedCount int
for _, s := range report.States {
for _, c := range s.SRConflict {
if c.ResolvedBy == grammar.ResolvedByShift.Int() {
implicitlyResolvedCount++
}
}
for _, c := range s.RRConflict {
if c.ResolvedBy == grammar.ResolvedByProdOrder.Int() {
implicitlyResolvedCount++
}
}
}
if implicitlyResolvedCount > 0 {
fmt.Fprintf(os.Stdout, "%v conflicts\n", implicitlyResolvedCount)
}
return nil
}
func readGrammar(path string) (*spec.CompiledGrammar, *spec.Report, error) {
f, err := os.Open(path)
if err != nil {
return nil, nil, fmt.Errorf("Cannot open the grammar file %s: %w", path, err)
}
defer f.Close()
ast, err := parser.Parse(f)
if err != nil {
return nil, nil, err
}
b := grammar.GrammarBuilder{
AST: ast,
}
return b.Build(grammar.EnableReporting())
}
// writeCompiledGrammarAndReport writes a compiled grammar and a report to a files located at a specified path.
// This function selects one of the following output methods depending on how the path is specified.
//
// 1. When the path is a directory path, this function writes the compiled grammar and the report to
// <path>/<grammar-name>.json and <path>/<grammar-name>-report.json files, respectively.
// <grammar-name>-report.json as the output files.
// 2. When the path is a file path or a non-exitent path, this function asumes that the path represents a file
// path for the compiled grammar. Then it also writes the report in the same directory as the compiled grammar.
// 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
}
{
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))
}
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
}
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