public void setMatchingAlgorithm(MatchAlgorithm algorithm) {
        this.getMatching().setAlgorithm(algorithm);
        for (SDField structField : getStructFields()) {
            structField.getMatching().setAlgorithm(algorithm);
        }
    }
Set matching algorithm for this field and all subfields.
config-model/src/main/java/com/yahoo/schema/document/SDField.java