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moby--moby/pkg/dockerscript/dockerscript.go
Solomon Hykes bf51f36d8f Fix Go formatting in beam and dockerscript
Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
2014-04-22 16:16:29 -07:00

121 lines
2.6 KiB
Go

package dockerscript
import (
"fmt"
"github.com/dotcloud/docker/pkg/dockerscript/scanner"
"io"
"strings"
)
type Command struct {
Args []string
Children []*Command
Background bool
}
type Scanner struct {
scanner.Scanner
commentLine bool
}
func Parse(src io.Reader) ([]*Command, error) {
s := &Scanner{}
s.Init(src)
s.Whitespace = 1<<'\t' | 1<<' '
s.Mode = scanner.ScanStrings | scanner.ScanRawStrings | scanner.ScanIdents
expr, err := parse(s, "")
if err != nil {
return nil, fmt.Errorf("line %d:%d: %v\n", s.Pos().Line, s.Pos().Column, err)
}
return expr, nil
}
func (cmd *Command) subString(depth int) string {
var prefix string
for i := 0; i < depth; i++ {
prefix += " "
}
s := prefix + strings.Join(cmd.Args, ", ")
if len(cmd.Children) > 0 {
s += " {\n"
for _, subcmd := range cmd.Children {
s += subcmd.subString(depth + 1)
}
s += prefix + "}"
}
s += "\n"
return s
}
func (cmd *Command) String() string {
return cmd.subString(0)
}
func parseArgs(s *Scanner) ([]string, rune, error) {
var parseError error
// FIXME: we overwrite previously set error
s.Error = func(s *scanner.Scanner, msg string) {
parseError = fmt.Errorf(msg)
// parseError = fmt.Errorf("line %d:%d: %s\n", s.Pos().Line, s.Pos().Column, msg)
}
var args []string
tok := s.Scan()
for tok != scanner.EOF {
if parseError != nil {
return args, tok, parseError
}
text := s.TokenText()
// Toggle line comment
if strings.HasPrefix(text, "#") {
s.commentLine = true
} else if text == "\n" || text == "\r" {
s.commentLine = false
return args, tok, nil
}
if !s.commentLine {
if text == "{" || text == "}" || text == "\n" || text == "\r" || text == ";" || text == "&" {
return args, tok, nil
}
args = append(args, text)
}
tok = s.Scan()
}
return args, tok, nil
}
func parse(s *Scanner, opener string) (expr []*Command, err error) {
/*
defer func() {
fmt.Printf("parse() returned %d commands:\n", len(expr))
for _, c := range expr {
fmt.Printf("\t----> %s\n", c)
}
}()
*/
for {
args, tok, err := parseArgs(s)
if err != nil {
return nil, err
}
cmd := &Command{Args: args}
afterArgs := s.TokenText()
if afterArgs == "{" {
children, err := parse(s, "{")
if err != nil {
return nil, err
}
cmd.Children = children
} else if afterArgs == "}" && opener != "{" {
return nil, fmt.Errorf("unexpected end of block '}'")
} else if afterArgs == "&" {
cmd.Background = true
}
if len(cmd.Args) > 0 || len(cmd.Children) > 0 {
expr = append(expr, cmd)
}
if tok == scanner.EOF || afterArgs == "}" {
break
}
}
return expr, nil
}