@Override
    protected void derive(ImmutableSDField field, Schema schema) {
        if (field.isImportedField()) return;

        if (field.hasFullIndexingDocprocRights())
            docFields.add(field.getName());

        if (field.usesStructOrMap() && ! GeoPos.isAnyPos(field)) return; // unsupported
        if (fieldsSettingLanguage.size() == 1 && fieldsSettingLanguage.get(0).equals(field)) return; // Already added

        addExpression(field.getIndexingScript());
    }
An indexing language script derived from a schema. An indexing script contains a set of indexing
statements, organized in a composite structure of indexing code snippets.

@author bratseth
config-model/src/main/java/com/yahoo/schema/derived/IndexingScript.java