How do accented characters and punctuation work in DataSift?
Accented characters will be matched by your CSDL filter. For example, the following CSDL:
interaction.content contains "café"
will match the string "café", but will not match "cafe". This is because accented characters are technically different to their non-accented counterparts, so in the case of the "é" and "e" characters, their Unicode encodings are "U+0351" and "U+0145" respectively.
As a practical CSDL example, if you are filtering on the name "Joséphine", you may also want to consider filtering on the non-accented version of the name "Josephine" for cases where users do not add the accent to the name:
interaction.content contains_any "Joséphine, Josephine"
As an example of how DataSift treats punctuation, let's consider the hyphen:
If we want to filter for "air-conditioning", we could use the following CSDL:
interaction.content contains "air-conditioning"
This would match the following two strings:
- air-conditioning
- air - conditioning
But not these two:
- air conditioning
- airconditioning
This is due to the way DataSift tokenizes strings. The string in question, "air-conditioning", is split into three 'chunks':
- air
- -
- conditioning
This means DataSift is looking for these three chunks in a row, either with or without the whitespace around the hyphen.
This topic is covered in more detail on our documentation page The CSDL Engine: How it Works