What this article’s title alludes to is the fact that, once you have a complex language (or system) there are usually multiple equally valid ways to say something. Let’s consider the following typical case, a comma-separated list of some sort, something like: [1, 2, x, y, “Hello, World”] To describe the grammar for this in …
You say “Tomayto”, I say “Tomahto”. Exploring Syntax options in CongoCC. Read More »
Assertions, implemented in late 2021, are certainly an important feature in CongoCC — actually pretty much essential when writing grammars for very gnarly languages. However, as currently implemented, they are admittedly a somewhat strange hybrid construct. The main reason for this is that ASSERT has completely different semantics depending on whether you hit the assertion …
Revisiting Assertions, introducing the ENSURE keyword Read More »
I was trying to think back to when most students are introduced to basic algebra. A typical sort of exercise is simplifying unnecessarily complex expressions, so he can rewrite: (x + 1)y -y as: xy Well, regardless of the exact age when people first see such things, this is part of a typical middle school …
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 …
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 …
Revisiting LOOKAHEAD Redux Not so long ago, I had a sort of eureka moment when I realized that the legacy LOOKAHEAD construct was fundamentally half-baked or broken. Not only that, but I started narrowing in on how to definitely address the issue! Well, let’s get concrete. Suppose we have a production that looks kind of like this: FooBar : …
New Feature: The =>|| delimiter stands for “scan up to here” Read More »