Initial commit

vendor/github.com/hyperhq/hypercli/builder/dockerfile/parser/utils.go

@@ -0,0 +1,176 @@
+package parser
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"unicode"
+)
+
+// Dump dumps the AST defined by `node` as a list of sexps.
+// Returns a string suitable for printing.
+func (node *Node) Dump() string {
+	str := ""
+	str += node.Value
+
+	if len(node.Flags) > 0 {
+		str += fmt.Sprintf(" %q", node.Flags)
+	}
+
+	for _, n := range node.Children {
+		str += "(" + n.Dump() + ")\n"
+	}
+
+	if node.Next != nil {
+		for n := node.Next; n != nil; n = n.Next {
+			if len(n.Children) > 0 {
+				str += " " + n.Dump()
+			} else {
+				str += " " + strconv.Quote(n.Value)
+			}
+		}
+	}
+
+	return strings.TrimSpace(str)
+}
+
+// performs the dispatch based on the two primal strings, cmd and args. Please
+// look at the dispatch table in parser.go to see how these dispatchers work.
+func fullDispatch(cmd, args string) (*Node, map[string]bool, error) {
+	fn := dispatch[cmd]
+
+	// Ignore invalid Dockerfile instructions
+	if fn == nil {
+		fn = parseIgnore
+	}
+
+	sexp, attrs, err := fn(args)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return sexp, attrs, nil
+}
+
+// splitCommand takes a single line of text and parses out the cmd and args,
+// which are used for dispatching to more exact parsing functions.
+func splitCommand(line string) (string, []string, string, error) {
+	var args string
+	var flags []string
+
+	// Make sure we get the same results irrespective of leading/trailing spaces
+	cmdline := tokenWhitespace.Split(strings.TrimSpace(line), 2)
+	cmd := strings.ToLower(cmdline[0])
+
+	if len(cmdline) == 2 {
+		var err error
+		args, flags, err = extractBuilderFlags(cmdline[1])
+		if err != nil {
+			return "", nil, "", err
+		}
+	}
+
+	return cmd, flags, strings.TrimSpace(args), nil
+}
+
+// covers comments and empty lines. Lines should be trimmed before passing to
+// this function.
+func stripComments(line string) string {
+	// string is already trimmed at this point
+	if tokenComment.MatchString(line) {
+		return tokenComment.ReplaceAllString(line, "")
+	}
+
+	return line
+}
+
+func extractBuilderFlags(line string) (string, []string, error) {
+	// Parses the BuilderFlags and returns the remaining part of the line
+
+	const (
+		inSpaces = iota // looking for start of a word
+		inWord
+		inQuote
+	)
+
+	words := []string{}
+	phase := inSpaces
+	word := ""
+	quote := '\000'
+	blankOK := false
+	var ch rune
+
+	for pos := 0; pos <= len(line); pos++ {
+		if pos != len(line) {
+			ch = rune(line[pos])
+		}
+
+		if phase == inSpaces { // Looking for start of word
+			if pos == len(line) { // end of input
+				break
+			}
+			if unicode.IsSpace(ch) { // skip spaces
+				continue
+			}
+
+			// Only keep going if the next word starts with --
+			if ch != '-' || pos+1 == len(line) || rune(line[pos+1]) != '-' {
+				return line[pos:], words, nil
+			}
+
+			phase = inWord // found someting with "--", fall thru
+		}
+		if (phase == inWord || phase == inQuote) && (pos == len(line)) {
+			if word != "--" && (blankOK || len(word) > 0) {
+				words = append(words, word)
+			}
+			break
+		}
+		if phase == inWord {
+			if unicode.IsSpace(ch) {
+				phase = inSpaces
+				if word == "--" {
+					return line[pos:], words, nil
+				}
+				if blankOK || len(word) > 0 {
+					words = append(words, word)
+				}
+				word = ""
+				blankOK = false
+				continue
+			}
+			if ch == '\'' || ch == '"' {
+				quote = ch
+				blankOK = true
+				phase = inQuote
+				continue
+			}
+			if ch == '\\' {
+				if pos+1 == len(line) {
+					continue // just skip \ at end
+				}
+				pos++
+				ch = rune(line[pos])
+			}
+			word += string(ch)
+			continue
+		}
+		if phase == inQuote {
+			if ch == quote {
+				phase = inWord
+				continue
+			}
+			if ch == '\\' {
+				if pos+1 == len(line) {
+					phase = inWord
+					continue // just skip \ at end
+				}
+				pos++
+				ch = rune(line[pos])
+			}
+			word += string(ch)
+		}
+	}
+
+	return "", words, nil
+}