ALADIN: A Scanner Generator for Incremental Programming Environments

A large number of scanner generators have been developed. Since they are restricted to the longestmatch rule, they are unsuitable for an incremental environment. We present the ALADIN system, which is able to deliver more than a single token if required. Thus, an ambiguity may be passed to the calling instance. Beyond this ‘incremental feature’, ALADIN is a well-structured and easy-to-understand language. In contrast to existing systems, the desired behaviour of the generated scanners is completely specified explicitly. Thus, the specifications are more abstract than in other systems. A prototype implementation has shown that ALADIN-generated scanners have about the same performance as those generated by Lex.