Rule basics

Recoding rule schemes can be written in a yaml file. A very simple rule scheme would be to recode the CMU dictionary label AH0 to a schwa-like character, @. Here’s the contents of a just-schwa.yml file.

yaml

# just-schwa.yml
- rule: schwa
  conditions:
    - attribute: label
      relation: ==
      set: AH0
  return: "@"

Anatomy of a rule scheme

Every rule scheme file is a list of rules, which indicated by each line starting a new rule beginning with -.

yaml

# rule skeleton
- rule: ...
  ...
- rule: ...
  ...

The Rule Name

Each rule has a rule name, which is indicated by the text following rule:.

The Rule Conditions

Each rule also has a list of conditions which can result in true or a false. The schwa rule has just one condition.

yaml

attribute: label
relation: ==
set: AH0

• attribute refers to properties of a TextGrid interval. Read more here.
• relation refers to how the specified attribute relates to the set. Read more here.
• set is some reference value or set of values.

This condition will return true with a TextGrid interval’s label is equal to (==) the string AH0.

The Rule Outcome

The label of a TextGrid interval is replaced with the value in return.