@wener/miniquery/lib/ast/visit.js

SQL Where like **safe** filter expression for ORM.

export function visit(expr, fn) {
    if (fn(expr)) {
        return;
    }
    switch(expr.type){
        case 'logic':
            expr.exprs.forEach(function(e) {
                return visit(e, fn);
            });
            break;
        case 'binary':
            visit(expr.left, fn);
            visit(expr.right, fn);
            break;
        case 'compare':
            {
                visit(expr.left, fn);
                var arr = Array.isArray(expr.right) ? expr.right : [
                    expr.right
                ];
                arr.forEach(function(e) {
                    return visit(e, fn);
                });
                break;
            }
        case 'case':
            {
                expr.condition && visit(expr.condition, fn);
                expr.cases.forEach(function(c) {
                    visit(c.when, fn);
                    visit(c.then, fn);
                });
                expr.else && visit(expr.else, fn);
                break;
            }
        case 'unary':
            visit(expr.expr, fn);
            break;
        case 'func':
            expr.args.forEach(function(e) {
                return visit(e, fn);
            });
            break;
        case 'list':
            expr.items.forEach(function(e) {
                return visit(e, fn);
            });
            break;
    }
}