Add FeedIcon API call and update dependencies

vendor/github.com/tdewolff/parse/error.go

@@ -7,29 +7,43 @@ import (
 	"github.com/tdewolff/parse/buffer"
 )
 
+// Error is a parsing error returned by parser. It contains a message and an offset at which the error occurred.
 type Error struct {
 	Message string
-	Line    int
-	Col     int
-	Context string
+	r       io.Reader
+	Offset  int
+	line    int
+	column  int
+	context string
 }
 
+// NewError creates a new error
 func NewError(msg string, r io.Reader, offset int) *Error {
-	line, col, context, _ := Position(r, offset)
 	return &Error{
-		msg,
-		line,
-		col,
-		context,
+		Message: msg,
+		r:       r,
+		Offset:  offset,
 	}
 }
 
+// NewErrorLexer creates a new error from a *buffer.Lexer
 func NewErrorLexer(msg string, l *buffer.Lexer) *Error {
 	r := buffer.NewReader(l.Bytes())
 	offset := l.Offset()
 	return NewError(msg, r, offset)
 }
 
-func (e *Error) Error() string {
-	return fmt.Sprintf("parse error:%d:%d: %s\n%s", e.Line, e.Col, e.Message, e.Context)
+// Positions re-parses the file to determine the line, column, and context of the error.
+// Context is the entire line at which the error occurred.
+func (e *Error) Position() (int, int, string) {
+	if e.line == 0 {
+		e.line, e.column, e.context, _ = Position(e.r, e.Offset)
+	}
+	return e.line, e.column, e.context
+}
+
+// Error returns the error string, containing the context and line + column number.
+func (e *Error) Error() string {
+	line, column, context := e.Position()
+	return fmt.Sprintf("parse error:%d:%d: %s\n%s", line, column, e.Message, context)
 }