StringScanner.substring, which returns a substring of the source string.Declare SpanScanner's exposed SourceSpans and SourceLocations to be FileSpans and FileLocations. They always were underneath, but callers may now rely on it.
Add SpanScanner.location, which returns the scanner's current SourceLocation.
Switch from source_maps' Span class to source_span's SourceSpan class.
new StringScanner()'s sourceUrl parameter is now named to make it clear that it can be safely null.
new StringScannerException() takes different arguments in a different order to match SpanFormatException.
StringScannerException.string has been renamed to StringScannerException.source to match the FormatException interface.
StringScannerException inherit from source_map's [SpanFormatException][].new StringScanner() now takes an optional sourceUrl argument that provides the URL of the source file. This is used for error reporting.
Add StringScanner.readChar() and StringScanner.peekChar() methods for doing character-by-character scanning.
Scanners now throw StringScannerExceptions which provide more detailed access to information about the errors that were thrown and can provide terminal-colored messages.
Add a LineScanner subclass of StringScanner that automatically tracks line and column information of the text being scanned.
Add a SpanScanner subclass of LineScanner that exposes matched ranges as [source map][] Span objects.