.vimrc Folding Based on Class and Function

; You’ve configured Vim to use expression-based folding (foldmethod=expr) with two custom functions:
; 	•	ClassFoldExpr() → decides where folds start and end (fold structure).
; 	•	ClassFoldText() → decides how folded text is displayed (fold summary).
; 
; This lets Vim fold your custom language in a hierarchical way:
; 	•	Level 1 → folds whole classes (classname { ... })
; 	•	Level 2 → folds functions inside classes (functionname { ... })


set foldmethod=expr
set foldexpr=ClassFoldExpr()
set foldtext=ClassFoldText()

function! ClassFoldExpr()
    let l:line = getline(v:lnum)

    " Top-level class (level 1)
    if l:line =~ '^[A-Za-z0-9_]\+\s*{'
        return '>1'
    endif

    " Function inside class (indented, level 2)
    if l:line =~ '^\s\+\w\+\s*{'
        return '>2'
    endif

    " Closing braces
    if l:line =~ '^}'
        return '<1'   " closes a class
    endif
    if l:line =~ '^\s\+}'
        return '<2'   " closes a function
    endif

    return '='
endfunction

function! ClassFoldText()
    " First and last lines
    let l:first = getline(v:foldstart)
    let l:last  = getline(v:foldend)

    " Folded line count
    let l:count = v:foldend - v:foldstart - 1

    " Build summary: show opening line, placeholder, closing brace
    return l:first . '  +-- ' . l:count . ' lines: -----  ' . l:last
endfunction