#Lighttable add syntax highlighting how to#
#Lighttable add syntax highlighting code#
#Lighttable add syntax highlighting windows#

When vim and emacs need to draw the end of a big file, they start parsing the text a few lines behind first visible line, but not from the beginning. But if I try to jump to the end of huge file - the interface just freezes. This approach works fine if the file is opened in the beginning. The parsing is lazy - a file is parsed from the beginning to the last line visible on the screen.

#Lighttable add syntax highlighting code#

Katepart parses code in the main GUI thread. 300K LOC file is parsed slower than the user would like to wait, so the parsing should be asynchronous. It doesn’t matter how cool the parsing algorithm developer is or how quick the CPU is. The majority of source files are quite small. With the parser in C and pcre the performance has became much better. I had to add the first (and only one) external Qutepart dependency - the pcre regular expression library. These calls took 90% of the parsing time. Standard C library doesn’t support them, so I tried to call the Python re module from the C extension. katepart highlighting algorithms use regular expressions. When the accelerated parser was ready, I measured the performance and discovered that it was just a little bit faster than pure Python code.

#Lighttable add syntax highlighting how to#

I started googling how to write Python extensions in C. Further code optimisation would have made the parser just a bit quicker but much more complicated.

I discovered that my parser was really slow.Īfter few hours of profiling, the parser became ten times quicker. All 59 files in various languages from the katepart collection looked pretty and opened quickly. When finished writing the parser, my joy knew no bounds. An interpreter which parses any code using Highlight Definition in the majority of cases works slower than a parser for a concrete programming language. The only disadvantage is the performance. This is probably why katepart supports more than 2 hundred languages and formats. The Highlight Definition XML file format is very well documented. The highlighting system is universal and powerful. The context “string” highlights symbols in red and contains a rule if “ symbol found - return to previous context. A context “code” includes a rule if symbol “ was found - switch to context “string”. All contexts are saved in the stack, so the machine may return to previous state.Įxample: C++. The machine moves over the code and changes its state - “Context”. Highlight Definition describes something similar to a finite state machine. So I decided to use the existing syntax base from katepart.įor every highlighting language katepart supports there is Highlight Definition - an XML file which describes syntax and highlighting rules. I’d like to highlight as many languages as possible. Code parsingĮnki is not designed for some concrete languages and technologies. So, I decided to create my own component.

#Lighttable add syntax highlighting windows#

It is not convenient, especially for Windows and MacOS. Katepart is really cool, but depends on KDE libraries. Initially I used the QScintilla text editor component, but it has some limitations which are not compatible with my goals. But, with a bit more intuitive and modern GUI. I’m developing Enki - a universal, cross platform, extensible text editor inspired by Vim and Emacs. The article is not about UI, but about the architecture. This article explains how syntax highlighting in Qutepart (and katepart) works. It doesn’t matter how many buttons or menus or IDE or editor has, the core is a code editor component.

If you are a programmer, you spend a significant amount of your time coding. I finally found the time to translate it to English