I'm working on a simple editor for the C programming language (without using an AST), and I need to implement a code folding feature.
When the user opens a file, an initial parse is performed, and all {} code blocks are easily detected. I store these blocks in a tree structure, where nested blocks are children of their enclosing block.
The challenge arises when the user makes edits. For each edit, I have the following information:
- startLineIndex (the index of the first affected line),
- endLineIndex (the index of the last affected line),
- addedLineCount,
- removedLineCount.
At this point, I need to update the folding model in the most efficient way possible — ideally by re-parsing only a minimal portion of the code.
Can someone suggest which algorithms or techniques could be used to efficiently update the folding block model after user edits?
