In conjunction with New Year 2021 (a landmark year for JavaCC 21 for sure!) I decided to scratch some longstanding itches — even at the expense of introducing some (minor) backward incompatibilities. The various option settings can only be set in the grammar file. There was a longstanding setup in legacy JavaCC (carried forward in …
Happy New Year! Some Backward-Incompatible API Changes! Read More »
One of my longstanding interests is language learning — I mean, human languages like Russian or Chinese, not computer languages. One striking thing about language learning is the extreme variability in people’s results. One observes that certain people, frequently very capable in other fields, will have some ongoing project of learning a language, Spanish for …
Since I started my work on resuscitating the JavaCC project, at least a couple of people have asked me how I can do this work if I have no theoretical background in computer science, specifically all this theory behind grammars and parsers. My response has typically amounted to saying: Watch me! I don’t know about …
Is All this Parsing theory just bullshit or what? Read More »
It was at the 1972 Olympic Games in Munich that 22-year-old German student Norbert Südhaus had his Warholian 15 minutes of fame — or infamy, rather. As a prank, he snuck into the stadium (security was much more lax back then) just before the winner of the marathon, the American Frank Shorter, was set to …
Thomas Hobbes famously said that in humankind’s natural state, a man’s life tends be "nasty, brutish, and short". I suppose the natural corollary of this is that in technologically advanced societies, life is comparatively "pleasant, peaceful, and long". Of those three things, it is the last one that can be measured most objectively; we see, …
When I say "fully supported", I mean all the new features that are categorized as "stable". In fact, the only new language feature that has been promoted to stable in JDK 14 is the new syntax for the Switch statement. This also allows a Switch statement to be used as an expression. In fact, the …
(N.B. Note added 13 June 2021: This article is useful in terms of understanding how to add token hooks to code. However, in terms of solving the specific problem outlined, the article is obsolete. See here for the updated solution.) Since I picked up my work on the JavaCC codebase at the end of 2019, …
“You can’t get there from here!” — The Problem of Context-Sensitive Tokenization Read More »
About half a year ago, I wrote a post about ripping out so-called JAVACODE productions. I have to admit that I had almost forgotten about that whole issue (or maybe ersatz issue…) but just now Jan Monterrubio of the JSQLParser project asked me about this and I figured it would be better to answer the …
In the beginning there was… CommonTokenAction Legacy JavaCC had (and still has) a means of applying whatever adjustments (a.k.a. kludges) to a Token just before it is handed off to the parser machinery. You could define a method called CommonTokenAction in your Lexer TokenManager class and this method is invoked when you get another Token …
Not too long ago, I implemented a new syntactical element in JavaCC, that I call the up-to-here marker. To recap: Suppose you have a production like this: FooBar : “foo” “bar” Baz; NB. I am moving towards always just using the newer streamlined syntax in any examples and documentation. For the record, if you really …