1 files changed, 409 insertions, 0 deletions
diff --git a/vendor/github.com/aymerick/douceur/parser/parser.go b/vendor/github.com/aymerick/douceur/parser/parser.go
new file mode 100644
index 0000000000..6c4917ccf9
--- /dev/null
+++ b/vendor/github.com/aymerick/douceur/parser/parser.go
@@ -0,0 +1,409 @@
+package parser
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/gorilla/css/scanner"
+
+	"github.com/aymerick/douceur/css"
+)
+
+const (
+	importantSuffixRegexp = `(?i)\s*!important\s*$`
+)
+
+var (
+	importantRegexp *regexp.Regexp
+)
+
+// Parser represents a CSS parser
+type Parser struct {
+	scan *scanner.Scanner // Tokenizer
+
+	// Tokens parsed but not consumed yet
+	tokens []*scanner.Token
+
+	// Rule embedding level
+	embedLevel int
+}
+
+func init() {
+	importantRegexp = regexp.MustCompile(importantSuffixRegexp)
+}
+
+// NewParser instanciates a new parser
+func NewParser(txt string) *Parser {
+	return &Parser{
+		scan: scanner.New(txt),
+	}
+}
+
+// Parse parses a whole stylesheet
+func Parse(text string) (*css.Stylesheet, error) {
+	result, err := NewParser(text).ParseStylesheet()
+	if err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}
+
+// ParseDeclarations parses CSS declarations
+func ParseDeclarations(text string) ([]*css.Declaration, error) {
+	result, err := NewParser(text).ParseDeclarations()
+	if err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}
+
+// ParseStylesheet parses a stylesheet
+func (parser *Parser) ParseStylesheet() (*css.Stylesheet, error) {
+	result := css.NewStylesheet()
+
+	// Parse BOM
+	if _, err := parser.parseBOM(); err != nil {
+		return result, err
+	}
+
+	// Parse list of rules
+	rules, err := parser.ParseRules()
+	if err != nil {
+		return result, err
+	}
+
+	result.Rules = rules
+
+	return result, nil
+}
+
+// ParseRules parses a list of rules
+func (parser *Parser) ParseRules() ([]*css.Rule, error) {
+	result := []*css.Rule{}
+
+	inBlock := false
+	if parser.tokenChar("{") {
+		// parsing a block of rules
+		inBlock = true
+		parser.embedLevel++
+
+		parser.shiftToken()
+	}
+
+	for parser.tokenParsable() {
+		if parser.tokenIgnorable() {
+			parser.shiftToken()
+		} else if parser.tokenChar("}") {
+			if !inBlock {
+				errMsg := fmt.Sprintf("Unexpected } character: %s", parser.nextToken().String())
+				return result, errors.New(errMsg)
+			}
+
+			parser.shiftToken()
+			parser.embedLevel--
+
+			// finished
+			break
+		} else {
+			rule, err := parser.ParseRule()
+			if err != nil {
+				return result, err
+			}
+
+			rule.EmbedLevel = parser.embedLevel
+			result = append(result, rule)
+		}
+	}
+
+	return result, parser.err()
+}
+
+// ParseRule parses a rule
+func (parser *Parser) ParseRule() (*css.Rule, error) {
+	if parser.tokenAtKeyword() {
+		return parser.parseAtRule()
+	}
+
+	return parser.parseQualifiedRule()
+}
+
+// ParseDeclarations parses a list of declarations
+func (parser *Parser) ParseDeclarations() ([]*css.Declaration, error) {
+	result := []*css.Declaration{}
+
+	if parser.tokenChar("{") {
+		parser.shiftToken()
+	}
+
+	for parser.tokenParsable() {
+		if parser.tokenIgnorable() {
+			parser.shiftToken()
+		} else if parser.tokenChar("}") {
+			// end of block
+			parser.shiftToken()
+			break
+		} else {
+			declaration, err := parser.ParseDeclaration()
+			if err != nil {
+				return result, err
+			}
+
+			result = append(result, declaration)
+		}
+	}
+
+	return result, parser.err()
+}
+
+// ParseDeclaration parses a declaration
+func (parser *Parser) ParseDeclaration() (*css.Declaration, error) {
+	result := css.NewDeclaration()
+	curValue := ""
+
+	for parser.tokenParsable() {
+		if parser.tokenChar(":") {
+			result.Property = strings.TrimSpace(curValue)
+			curValue = ""
+
+			parser.shiftToken()
+		} else if parser.tokenChar(";") || parser.tokenChar("}") {
+			if result.Property == "" {
+				errMsg := fmt.Sprintf("Unexpected ; character: %s", parser.nextToken().String())
+				return result, errors.New(errMsg)
+			}
+
+			if importantRegexp.MatchString(curValue) {
+				result.Important = true
+				curValue = importantRegexp.ReplaceAllString(curValue, "")
+			}
+
+			result.Value = strings.TrimSpace(curValue)
+
+			if parser.tokenChar(";") {
+				parser.shiftToken()
+			}
+
+			// finished
+			break
+		} else {
+			token := parser.shiftToken()
+			curValue += token.Value
+		}
+	}
+
+	// log.Printf("[parsed] Declaration: %s", result.String())
+
+	return result, parser.err()
+}
+
+// Parse an At Rule
+func (parser *Parser) parseAtRule() (*css.Rule, error) {
+	// parse rule name (eg: "@import")
+	token := parser.shiftToken()
+
+	result := css.NewRule(css.AtRule)
+	result.Name = token.Value
+
+	for parser.tokenParsable() {
+		if parser.tokenChar(";") {
+			parser.shiftToken()
+
+			// finished
+			break
+		} else if parser.tokenChar("{") {
+			if result.EmbedsRules() {
+				// parse rules block
+				rules, err := parser.ParseRules()
+				if err != nil {
+					return result, err
+				}
+
+				result.Rules = rules
+			} else {
+				// parse declarations block
+				declarations, err := parser.ParseDeclarations()
+				if err != nil {
+					return result, err
+				}
+
+				result.Declarations = declarations
+			}
+
+			// finished
+			break
+		} else {
+			// parse prelude
+			prelude, err := parser.parsePrelude()
+			if err != nil {
+				return result, err
+			}
+
+			result.Prelude = prelude
+		}
+	}
+
+	// log.Printf("[parsed] Rule: %s", result.String())
+
+	return result, parser.err()
+}
+
+// Parse a Qualified Rule
+func (parser *Parser) parseQualifiedRule() (*css.Rule, error) {
+	result := css.NewRule(css.QualifiedRule)
+
+	for parser.tokenParsable() {
+		if parser.tokenChar("{") {
+			if result.Prelude == "" {
+				errMsg := fmt.Sprintf("Unexpected { character: %s", parser.nextToken().String())
+				return result, errors.New(errMsg)
+			}
+
+			// parse declarations block
+			declarations, err := parser.ParseDeclarations()
+			if err != nil {
+				return result, err
+			}
+
+			result.Declarations = declarations
+
+			// finished
+			break
+		} else {
+			// parse prelude
+			prelude, err := parser.parsePrelude()
+			if err != nil {
+				return result, err
+			}
+
+			result.Prelude = prelude
+		}
+	}
+
+	result.Selectors = strings.Split(result.Prelude, ",")
+	for i, sel := range result.Selectors {
+		result.Selectors[i] = strings.TrimSpace(sel)
+	}
+
+	// log.Printf("[parsed] Rule: %s", result.String())
+
+	return result, parser.err()
+}
+
+// Parse Rule prelude
+func (parser *Parser) parsePrelude() (string, error) {
+	result := ""
+
+	for parser.tokenParsable() && !parser.tokenEndOfPrelude() {
+		token := parser.shiftToken()
+		result += token.Value
+	}
+
+	result = strings.TrimSpace(result)
+
+	// log.Printf("[parsed] prelude: %s", result)
+
+	return result, parser.err()
+}
+
+// Parse BOM
+func (parser *Parser) parseBOM() (bool, error) {
+	if parser.nextToken().Type == scanner.TokenBOM {
+		parser.shiftToken()
+		return true, nil
+	}
+
+	return false, parser.err()
+}
+
+// Returns next token without removing it from tokens buffer
+func (parser *Parser) nextToken() *scanner.Token {
+	if len(parser.tokens) == 0 {
+		// fetch next token
+		nextToken := parser.scan.Next()
+
+		// log.Printf("[token] %s => %v", nextToken.Type.String(), nextToken.Value)
+
+		// queue it
+		parser.tokens = append(parser.tokens, nextToken)
+	}
+
+	return parser.tokens[0]
+}
+
+// Returns next token and remove it from the tokens buffer
+func (parser *Parser) shiftToken() *scanner.Token {
+	var result *scanner.Token
+
+	result, parser.tokens = parser.tokens[0], parser.tokens[1:]
+	return result
+}
+
+// Returns tokenizer error, or nil if no error
+func (parser *Parser) err() error {
+	if parser.tokenError() {
+		token := parser.nextToken()
+		return fmt.Errorf("Tokenizer error: %s", token.String())
+	}
+
+	return nil
+}
+
+// Returns true if next token is Error
+func (parser *Parser) tokenError() bool {
+	return parser.nextToken().Type == scanner.TokenError
+}
+
+// Returns true if next token is EOF
+func (parser *Parser) tokenEOF() bool {
+	return parser.nextToken().Type == scanner.TokenEOF
+}
+
+// Returns true if next token is a whitespace
+func (parser *Parser) tokenWS() bool {
+	return parser.nextToken().Type == scanner.TokenS
+}
+
+// Returns true if next token is a comment
+func (parser *Parser) tokenComment() bool {
+	return parser.nextToken().Type == scanner.TokenComment
+}
+
+// Returns true if next token is a CDO or a CDC
+func (parser *Parser) tokenCDOorCDC() bool {
+	switch parser.nextToken().Type {
+	case scanner.TokenCDO, scanner.TokenCDC:
+		return true
+	default:
+		return false
+	}
+}
+
+// Returns true if next token is ignorable
+func (parser *Parser) tokenIgnorable() bool {
+	return parser.tokenWS() || parser.tokenComment() || parser.tokenCDOorCDC()
+}
+
+// Returns true if next token is parsable
+func (parser *Parser) tokenParsable() bool {
+	return !parser.tokenEOF() && !parser.tokenError()
+}
+
+// Returns true if next token is an At Rule keyword
+func (parser *Parser) tokenAtKeyword() bool {
+	return parser.nextToken().Type == scanner.TokenAtKeyword
+}
+
+// Returns true if next token is given character
+func (parser *Parser) tokenChar(value string) bool {
+	token := parser.nextToken()
+	return (token.Type == scanner.TokenChar) && (token.Value == value)
+}
+
+// Returns true if next token marks the end of a prelude
+func (parser *Parser) tokenEndOfPrelude() bool {
+	return parser.tokenChar(";") || parser.tokenChar("{")
+}