protected void declarePragma()

in src/main/java/org/apache/commons/jexl3/parser/JexlParser.java [412:455]
42 lines of code
12 McCabe index (conditional complexity)

    protected void declarePragma(final String key, final Object value) {
        final JexlFeatures features = getFeatures();
        if (!features.supportsPragma()) {
            throwFeatureException(JexlFeatures.PRAGMA, getToken(0));
        }
        if (PRAGMA_IMPORT.equals(key) && !features.supportsImportPragma()) {
            throwFeatureException(JexlFeatures.IMPORT_PRAGMA, getToken(0));
        }
        if (pragmas == null) {
            pragmas = new TreeMap<>();
        }
        // declaring a namespace or module
        final String[] nsprefixes = { PRAGMA_JEXLNS, PRAGMA_MODULE };
        for(final String nsprefix : nsprefixes) {
            if (key.startsWith(nsprefix)) {
                if (!features.supportsNamespacePragma()) {
                    throwFeatureException(JexlFeatures.NS_PRAGMA, getToken(0));
                }
                final String nsname = key.substring(nsprefix.length());
                if (!nsname.isEmpty()) {
                    if (namespaces == null) {
                        namespaces = new HashSet<>();
                    }
                    namespaces.add(nsname);
                }
                break;
            }
        }
        // merge new value into a set created on the fly if key is already mapped
        if (value == null) {
            pragmas.putIfAbsent(key, null);
        } else {
            pragmas.merge(key, value, (previous, newValue) -> {
                if (previous instanceof Set<?>) {
                    ((Set<Object>) previous).add(newValue);
                    return previous;
                }
                final Set<Object> values = new LinkedHashSet<>();
                values.add(previous);
                values.add(newValue);
                return values;
            });
        }
    }