IParse VS pp

Nice library with many features. But I do not always understand the focus on memory usage. I guess that the reason behind this is that less memory allocations, have a positive effect on execution times. In a parser, where you often have to compare identifiers, it is a good idea to put all strings for identifiers into a unique pointer with the help of a hash table.

In my interpreting parser [1] I use a hexa hash tree [2] for storing identifiers. It is not very memory efficient, but very fast. It turns every string (from the input buffer) into a unique pointer for that string pointing to a copy of the string. In this way comparing string (identifiers) is equivalent to comparing pointers.

The idea of the hexa hash tree is that is a tree where each node has sixteen child nodes. Which node is selected is based on a step wise evaluated hash function that first takes the lower four bytes of the string, and after reaching the end of the string, the higher four bytes of the string. The nodes often taken up more memory space than the strings themselves.

[1] https://github.com/FransFaase/IParse/

[2] https://github.com/FransFaase/IParse/blob/master/software/Id...

I wrote a tool that can process a number of MarkDown files with fragments of C code and put all those fragments in the right order to produce a file that can be compiled. It is grammar based and works with manipulating Abstract Syntax Trees, so I guess, it could be adapted for different programming languages. See: https://github.com/FransFaase/IParse#markdownc

Interesting. I have not looked into the code, but I wonder whether it is a compiler, or just an interpreter, e.g. it converts the grammar into some internal representation that is executed by an interpreter or virtual machine. I started worked on an interpreting parser in C many years ago. And later also made Java, C++ and JavaScript version of it. For the JavaScript implementation, see: https://fransfaase.github.io/ParserWorkshop/Online_inter_par... For the C++ version, see: https://github.com/FransFaase/IParse

I implemented an unparse function in IParse, which is not a parser generator, but a parser that interprets a grammar. See for example https://github.com/FransFaase/IParse/blob/master/software/c_... where symbols starting with a back slash are a kind of white space terminals during the unparse. For example, \inc stands for incrementing the indentation where \dec decrements it. The \s is used to indicate that at given location a space should be included.

Talking about the downsides of Markdown: it's not that you can't use Markdown without tables. Since there is not just one Markdown flavor, there are variants such as this one which do define table support and more. This introduces other difficulties to users of Markdown. For example, you need to know what kind of Markdown is supported with your current tool-set. In my business life, we do use a tool-chain to generate documents via Markdown, pandoc and pp (I'm not sure if the correct link is this or that). Using that, I may use even two different kinds of Markdown tables with different syntax and different features for formatting. I guess I don't need to explain much more on that to emphasize that this is a complicated thing to write and maintain since editing tools do not seem to support Markdown tables at all or they only support only one kind of Markdown table and not all of them. It's a big mess that the original authors or Markdown could not foresee and later, nobody could fix it so far although there is CommonMark which tried to fix it but it didn't stick much.