parsepre_op_white

    pub fn parsepre_op_white(p: *Parser) Error!bool {
        const def_index = @backingInt(Def.defpre_op_white);
        if (p.depths[def_index] > max_depth) return error.MaxDepth;
        p.depths[def_index] += 1;
        defer p.depths[def_index] -= 1;
        return blk_0: {
            const pos_0 = p.i;
            if (blk_1: {
                var match_1 = false;
                var i_1: usize = 0;
                while (blk_3: {
                    const pos_3 = p.i;
                    if ((p.i < p.source.len and switch (p.source[p.i]) {
                        ' '...' ',
                        '\n'...'\n',
                        '\t'...'\t',
                        '\r'...'\r',
                        => blk_4: {
                            p.i += 1;
                            break :blk_4 true;
                        },
                        else => false,
                    })) break :blk_3 true;
                    p.i = pos_3;
                    if (try p.parseline_comment()) break :blk_3 true;
                    p.i = pos_3;
                    break :blk_3 false;
                }) {
                    match_1 = true;
                    if (i_1 > max_depth) return error.MaxDepth;
                    i_1 += 1;
                }
                break :blk_1 match_1;
            }) break :blk_0 true;
            p.i = pos_0;
            break :blk_0 false;
        };
    }