Module string_modification 

StringModification

Often, you want to modify a string before using it.

For example you may want to get a URL’s query then

1. Split it on / and keep only the third segment.

2. Remove the first character.

3. Base64 decode it using the default URL safe alphabet.

4. Split it on , and keep only the last segment.

5. Replace the URL being cleaned with that segment.

While this seems like and is a bizarre example, this exact process is used to clean the links cnn sends you in emails.

To express the above operations, we would write a StringSource::Modified as follows:

{"SetWhole": {"Modified": {
  "value": {"Part": "Query"},
  "modification": {"All": [
    {"KeepNthSegment": {"split": "/", "index": 2}},
    {"RemoveChar": 0},
    "Base64Decode",
    {"KeepNthSegment": {"split": ",", "index": -1}}
  ]}
}}}