What's the best way to match a standard file into a single data structure for editing it?

[ingo]

Not sure what a single structure is, FileType below?:
    
    
    type
      FileHeader = object
        # stuff about the file construction
      
      DataHeader = object
        #stuff about the data construction
      
      MetaData = object
        #metadata about the filedata
      
      FileData = object
        data: seq(s)[of dataobjects/items of some type]
      
      FileType = object
        fileheader: FileHeader
        dataheader: DataHeader
        metadata: MetaData
        filedata: FileData
    
    
    Run

For an intermediate file format one could have a look at [RIFF 
files](https://github.com/johnnovak/nim-riff) (wave files are riff files)

For complex, large things I prefer an in memory SQLite db as it at least gives 
me a standard way to query data.