package gcfg import ( "fmt" "io" "io/ioutil" "os" "strings" "github.com/src-d/gcfg/scanner" "github.com/src-d/gcfg/token" "gopkg.in/warnings.v0" ) var unescape = map[rune]rune{'\\': '\\', '"': '"', 'n': '\n', 't': '\t'} // no error: invalid literals should be caught by scanner func unquote(s string) string { u, q, esc := make([]rune, 0, len(s)), false, false for _, c := range s { if esc { uc, ok := unescape[c] switch { case ok: u = append(u, uc) fallthrough case !q && c == '\n': esc = false continue } panic("invalid escape sequence") } switch c { case '"': q = !q case '\\': esc = true default: u = append(u, c) } } if q { panic("missing end quote") } if esc { panic("invalid escape sequence") } return string(u) } func read(c *warnings.Collector, callback func(string,string,string,string,bool)error, fset *token.FileSet, file *token.File, src []byte) error { // var s scanner.Scanner var errs scanner.ErrorList s.Init(file, src, func(p token.Position, m string) { errs.Add(p, m) }, 0) sect, sectsub := "", "" pos, tok, lit := s.Scan() errfn := func(msg string) error { return fmt.Errorf("%s: %s", fset.Position(pos), msg) } for { if errs.Len() > 0 { if err := c.Collect(errs.Err()); err != nil { return err } } switch tok { case token.EOF: return nil case token.EOL, token.COMMENT: pos, tok, lit = s.Scan() case token.LBRACK: pos, tok, lit = s.Scan() if errs.Len() > 0 { if err := c.Collect(errs.Err()); err != nil { return err } } if tok != token.IDENT { if err := c.Collect(errfn("expected section name")); err != nil { return err } } sect, sectsub = lit, "" pos, tok, lit = s.Scan() if errs.Len() > 0 { if err := c.Collect(errs.Err()); err != nil { return err } } if tok == token.STRING { sectsub = unquote(lit) if sectsub == "" { if err := c.Collect(errfn("empty subsection name")); err != nil { return err } } pos, tok, lit = s.Scan() if errs.Len() > 0 { if err := c.Collect(errs.Err()); err != nil { return err } } } if tok != token.RBRACK { if sectsub == "" { if err := c.Collect(errfn("expected subsection name or right bracket")); err != nil { return err } } if err := c.Collect(errfn("expected right bracket")); err != nil { return err } } pos, tok, lit = s.Scan() if tok != token.EOL && tok != token.EOF && tok != token.COMMENT { if err := c.Collect(errfn("expected EOL, EOF, or comment")); err != nil { return err } } // If a section/subsection header was found, ensure a // container object is created, even if there are no // variables further down. err := c.Collect(callback(sect, sectsub, "", "", true)) if err != nil { return err } case token.IDENT: if sect == "" { if err := c.Collect(errfn("expected section header")); err != nil { return err } } n := lit pos, tok, lit = s.Scan() if errs.Len() > 0 { return errs.Err() } blank, v := tok == token.EOF || tok == token.EOL || tok == token.COMMENT, "" if !blank { if tok != token.ASSIGN { if err := c.Collect(errfn("expected '='")); err != nil { return err } } pos, tok, lit = s.Scan() if errs.Len() > 0 { if err := c.Collect(errs.Err()); err != nil { return err } } if tok != token.STRING { if err := c.Collect(errfn("expected value")); err != nil { return err } } v = unquote(lit) pos, tok, lit = s.Scan() if errs.Len() > 0 { if err := c.Collect(errs.Err()); err != nil { return err } } if tok != token.EOL && tok != token.EOF && tok != token.COMMENT { if err := c.Collect(errfn("expected EOL, EOF, or comment")); err != nil { return err } } } err := c.Collect(callback(sect, sectsub, n, v, blank)) if err != nil { return err } default: if sect == "" { if err := c.Collect(errfn("expected section header")); err != nil { return err } } if err := c.Collect(errfn("expected section header or variable declaration")); err != nil { return err } } } panic("never reached") } func readInto(config interface{}, fset *token.FileSet, file *token.File, src []byte) error { // c := warnings.NewCollector(isFatal) firstPassCallback := func(s string, ss string, k string, v string, bv bool) error { return set(c, config, s, ss, k, v, bv, false) } err := read(c, firstPassCallback, fset, file, src) if err != nil { return err } secondPassCallback := func(s string, ss string, k string, v string, bv bool) error { return set(c, config, s, ss, k, v, bv, true) } err = read(c, secondPassCallback, fset, file, src) if err != nil { return err } return c.Done() } // ReadWithCallback reads gcfg formatted data from reader and calls // callback with each section and option found. // // Callback is called with section, subsection, option key, option value // and blank value flag as arguments. // // When a section is found, callback is called with nil subsection, option key // and option value. // // When a subsection is found, callback is called with nil option key and // option value. // // If blank value flag is true, it means that the value was not set for an option // (as opposed to set to empty string). // // If callback returns an error, ReadWithCallback terminates with an error too. func ReadWithCallback(reader io.Reader, callback func(string,string,string,string,bool)error) error { src, err := ioutil.ReadAll(reader) if err != nil { return err } fset := token.NewFileSet() file := fset.AddFile("", fset.Base(), len(src)) c := warnings.NewCollector(isFatal) return read(c, callback, fset, file, src) } // ReadInto reads gcfg formatted data from reader and sets the values into the // corresponding fields in config. func ReadInto(config interface{}, reader io.Reader) error { src, err := ioutil.ReadAll(reader) if err != nil { return err } fset := token.NewFileSet() file := fset.AddFile("", fset.Base(), len(src)) return readInto(config, fset, file, src) } // ReadStringInto reads gcfg formatted data from str and sets the values into // the corresponding fields in config. func ReadStringInto(config interface{}, str string) error { r := strings.NewReader(str) return ReadInto(config, r) } // ReadFileInto reads gcfg formatted data from the file filename and sets the // values into the corresponding fields in config. func ReadFileInto(config interface{}, filename string) error { f, err := os.Open(filename) if err != nil { return err } defer f.Close() src, err := ioutil.ReadAll(f) if err != nil { return err } fset := token.NewFileSet() file := fset.AddFile(filename, fset.Base(), len(src)) return readInto(config, fset, file, src) }