chore: vendor

vendor/github.com/google/shlex/shlex.go

@@ -0,0 +1,415 @@
+/*
+Copyright 2012 Google Inc. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/*
+Package shlex implements a simple lexer which splits input in to tokens using
+shell-style rules for quoting and commenting.
+
+The basic use case uses the default ASCII lexer to split a string into sub-strings:
+
+	shlex.Split("one \"two three\" four") -> []string{"one", "two three", "four"}
+
+To process a stream of strings:
+
+	l := NewLexer(os.Stdin)
+	for ; token, err := l.Next(); err != nil {
+		// process token
+	}
+
+To access the raw token stream (which includes tokens for comments):
+
+	  t := NewTokenizer(os.Stdin)
+	  for ; token, err := t.Next(); err != nil {
+		// process token
+	  }
+*/
+package shlex
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"strings"
+)
+
+// TokenType is a top-level token classification: A word, space, comment, unknown.
+type TokenType int
+
+// runeTokenClass is the type of a UTF-8 character classification: A quote, space, escape.
+type runeTokenClass int
+
+// the internal state used by the lexer state machine
+type lexerState int
+
+// Token is a (type, value) pair representing a lexographical token.
+type Token struct {
+	tokenType TokenType
+	value     string
+}
+
+// Equal reports whether tokens a, and b, are equal.
+// Two tokens are equal if both their types and values are equal. A nil token can
+// never be equal to another token.
+func (a *Token) Equal(b *Token) bool {
+	if a == nil || b == nil {
+		return false
+	}
+	if a.tokenType != b.tokenType {
+		return false
+	}
+	return a.value == b.value
+}
+
+// Named classes of UTF-8 runes
+const (
+	spaceRunes            = " \t\r\n"
+	escapingQuoteRunes    = `"`
+	nonEscapingQuoteRunes = "'"
+	escapeRunes           = `\`
+	commentRunes          = "#"
+)
+
+// Classes of rune token
+const (
+	unknownRuneClass runeTokenClass = iota
+	spaceRuneClass
+	escapingQuoteRuneClass
+	nonEscapingQuoteRuneClass
+	escapeRuneClass
+	commentRuneClass
+	eofRuneClass
+)
+
+// Classes of lexographic token
+const (
+	UnknownToken TokenType = iota
+	WordToken
+	SpaceToken
+	CommentToken
+)
+
+// Lexer state machine states
+const (
+	startState           lexerState = iota // no runes have been seen
+	inWordState                            // processing regular runes in a word
+	escapingState                          // we have just consumed an escape rune; the next rune is literal
+	escapingQuotedState                    // we have just consumed an escape rune within a quoted string
+	quotingEscapingState                   // we are within a quoted string that supports escaping ("...")
+	quotingState                           // we are within a string that does not support escaping ('...')
+	commentState                           // we are within a comment (everything following an unquoted or unescaped #
+)
+
+// tokenClassifier is used for classifying rune characters.
+type tokenClassifier map[rune]runeTokenClass
+
+func (typeMap tokenClassifier) addRuneClass(runes string, tokenType runeTokenClass) {
+	for _, runeChar := range runes {
+		typeMap[runeChar] = tokenType
+	}
+}
+
+// newDefaultClassifier creates a new classifier for ASCII characters.
+func newDefaultClassifier() tokenClassifier {
+	t := tokenClassifier{}
+	t.addRuneClass(spaceRunes, spaceRuneClass)
+	t.addRuneClass(escapingQuoteRunes, escapingQuoteRuneClass)
+	t.addRuneClass(nonEscapingQuoteRunes, nonEscapingQuoteRuneClass)
+	t.addRuneClass(escapeRunes, escapeRuneClass)
+	t.addRuneClass(commentRunes, commentRuneClass)
+	return t
+}
+
+// ClassifyRune classifiees a rune
+func (t tokenClassifier) ClassifyRune(runeVal rune) runeTokenClass {
+	return t[runeVal]
+}
+
+// Lexer turns an input stream into a sequence of tokens. Whitespace and comments are skipped.
+type Lexer Tokenizer
+
+// NewLexer creates a new lexer from an input stream.
+func NewLexer(r io.Reader) *Lexer {
+
+	return (*Lexer)(NewTokenizer(r))
+}
+
+// Next returns the next word, or an error. If there are no more words,
+// the error will be io.EOF.
+func (l *Lexer) Next() (string, error) {
+	for {
+		token, err := (*Tokenizer)(l).Next()
+		if err != nil {
+			return "", err
+		}
+		switch token.tokenType {
+		case WordToken:
+			return token.value, nil
+		case CommentToken:
+			// skip comments
+		default:
+			return "", fmt.Errorf("Unknown token type: %v", token.tokenType)
+		}
+	}
+}
+
+// Tokenizer turns an input stream into a sequence of typed tokens
+type Tokenizer struct {
+	input      bufio.Reader
+	classifier tokenClassifier
+}
+
+// NewTokenizer creates a new tokenizer from an input stream.
+func NewTokenizer(r io.Reader) *Tokenizer {
+	input := bufio.NewReader(r)
+	classifier := newDefaultClassifier()
+	return &Tokenizer{
+		input:      *input,
+		classifier: classifier}
+}
+
+// scanStream scans the stream for the next token using the internal state machine.
+// It will panic if it encounters a rune which it does not know how to handle.
+func (t *Tokenizer) scanStream() (*Token, error) {
+	state := startState
+	var tokenType TokenType
+	var value []rune
+	var nextRune rune
+	var nextRuneType runeTokenClass
+	var err error
+
+	for {
+		nextRune, _, err = t.input.ReadRune()
+		nextRuneType = t.classifier.ClassifyRune(nextRune)
+
+		if err == io.EOF {
+			nextRuneType = eofRuneClass
+			err = nil
+		} else if err != nil {
+			return nil, err
+		}
+
+		switch state {
+		case startState: // no runes read yet
+			{
+				switch nextRuneType {
+				case eofRuneClass:
+					{
+						return nil, io.EOF
+					}
+				case spaceRuneClass:
+					{
+					}
+				case escapingQuoteRuneClass:
+					{
+						tokenType = WordToken
+						state = quotingEscapingState
+					}
+				case nonEscapingQuoteRuneClass:
+					{
+						tokenType = WordToken
+						state = quotingState
+					}
+				case escapeRuneClass:
+					{
+						tokenType = WordToken
+						state = escapingState
+					}
+				case commentRuneClass:
+					{
+						tokenType = CommentToken
+						state = commentState
+					}
+				default:
+					{
+						tokenType = WordToken
+						value = append(value, nextRune)
+						state = inWordState
+					}
+				}
+			}
+		case inWordState: // in a regular word
+			{
+				switch nextRuneType {
+				case eofRuneClass:
+					{
+						token := &Token{
+							tokenType: tokenType,
+							value:     string(value)}
+						return token, err
+					}
+				case spaceRuneClass:
+					{
+						token := &Token{
+							tokenType: tokenType,
+							value:     string(value)}
+						return token, err
+					}
+				case escapingQuoteRuneClass:
+					{
+						state = quotingEscapingState
+					}
+				case nonEscapingQuoteRuneClass:
+					{
+						state = quotingState
+					}
+				case escapeRuneClass:
+					{
+						state = escapingState
+					}
+				default:
+					{
+						value = append(value, nextRune)
+					}
+				}
+			}
+		case escapingState: // the rune after an escape character
+			{
+				switch nextRuneType {
+				case eofRuneClass:
+					{
+						err = fmt.Errorf("EOF found after escape character")
+						token := &Token{
+							tokenType: tokenType,
+							value:     string(value)}
+						return token, err
+					}
+				default:
+					{
+						state = inWordState
+						value = append(value, nextRune)
+					}
+				}
+			}
+		case escapingQuotedState: // the next rune after an escape character, in double quotes
+			{
+				switch nextRuneType {
+				case eofRuneClass:
+					{
+						err = fmt.Errorf("EOF found after escape character")
+						token := &Token{
+							tokenType: tokenType,
+							value:     string(value)}
+						return token, err
+					}
+				default:
+					{
+						state = quotingEscapingState
+						value = append(value, nextRune)
+					}
+				}
+			}
+		case quotingEscapingState: // in escaping double quotes
+			{
+				switch nextRuneType {
+				case eofRuneClass:
+					{
+						err = fmt.Errorf("EOF found when expecting closing quote")
+						token := &Token{
+							tokenType: tokenType,
+							value:     string(value)}
+						return token, err
+					}
+				case escapingQuoteRuneClass:
+					{
+						state = inWordState
+					}
+				case escapeRuneClass:
+					{
+						state = escapingQuotedState
+					}
+				default:
+					{
+						value = append(value, nextRune)
+					}
+				}
+			}
+		case quotingState: // in non-escaping single quotes
+			{
+				switch nextRuneType {
+				case eofRuneClass:
+					{
+						err = fmt.Errorf("EOF found when expecting closing quote")
+						token := &Token{
+							tokenType: tokenType,
+							value:     string(value)}
+						return token, err
+					}
+				case nonEscapingQuoteRuneClass:
+					{
+						state = inWordState
+					}
+				default:
+					{
+						value = append(value, nextRune)
+					}
+				}
+			}
+		case commentState: // in a comment
+			{
+				switch nextRuneType {
+				case eofRuneClass:
+					{
+						token := &Token{
+							tokenType: tokenType,
+							value:     string(value)}
+						return token, err
+					}
+				case spaceRuneClass:
+					{
+						if nextRune == '\n' {
+							state = startState
+							token := &Token{
+								tokenType: tokenType,
+								value:     string(value)}
+							return token, err
+						} else {
+							value = append(value, nextRune)
+						}
+					}
+				default:
+					{
+						value = append(value, nextRune)
+					}
+				}
+			}
+		default:
+			{
+				return nil, fmt.Errorf("Unexpected state: %v", state)
+			}
+		}
+	}
+}
+
+// Next returns the next token in the stream.
+func (t *Tokenizer) Next() (*Token, error) {
+	return t.scanStream()
+}
+
+// Split partitions a string into a slice of strings.
+func Split(s string) ([]string, error) {
+	l := NewLexer(strings.NewReader(s))
+	subStrings := make([]string, 0)
+	for {
+		word, err := l.Next()
+		if err != nil {
+			if err == io.EOF {
+				return subStrings, nil
+			}
+			return subStrings, err
+		}
+		subStrings = append(subStrings, word)
+	}
+}