Past versions of ZPE have often contained flawed features such as the LAMP evaluator or minor things like performance glitches. This is often the case with any project. But any project will have flaws in it somewhere. ZPE is no different.
However, the stability of ZPE has got to the point where I believe that most of the flaws and errors that stop it being usable have been ironed out.
Over the last few months, ZPE 1.8.x has been removing old code and has cut down over 10,000 lines of code from both the runtime and compiler to make it more streamlined but also to improve stability. Further to this, features from very early versions have been revisited and revised to ensure much better performance and reliability - writing a programming language, compiler and runtime is quite tricky you know! Most of the issues actually come from the runtime, since I spent a lot of time in 2016 improving the compiler whereas the runtime just got a small bit of TLC.
Another major issue that often occurs is when new compiler features are added that actually could interfere with another feature. Now I spend a lot of time drawing up the ideas so don't get me wrong, I actually do plan. But sometimes it's difficult to see these potential collisions from the offset. For example, the move to the fat arrow syntax for lambda functions caused all sorts of issues until I decided to merge functions with lambda functions (that in itself caused further issues). More recently I discovered after going through the compiler that the generate_parameters function would allow values to be added in a function declaration's parameters: e.g. function foo ($x, 10) { print($x) } because the generate_parameters function was designed for both formal parameters and actual parameters. This has been fixed by separating these into generate_parameters and generate_arguments.
If you are writing programs using ZPE and compiling them, make sure to recompile them with the latest versions as soon as they are available as byte codes are constantly changing and being added. A new feature I'm adding into the runtime is to check which version compiled the program before attempting to run it since old versions may have different byte codes.
Since ZPE 1.8.8 was released as a fix for a bug in ZPE 1.8.7, ZPE 1.8.9 will be released on 05/08/2020.
