Method invoke

src/jvm/clojure/lang/LispReader.java:945–987

(Object reader, Object caret, Object opts, Object pendingForms)

public static class MetaReader extends AFn{
	public Object invoke(Object reader, Object caret, Object opts, Object pendingForms) {
		PushbackReader r = (PushbackReader) reader;
		int line = -1;
		int column = -1;
		if(r instanceof LineNumberingPushbackReader)
			{
			line = ((LineNumberingPushbackReader) r).getLineNumber();
			column = ((LineNumberingPushbackReader) r).getColumnNumber()-1;
			}
		pendingForms = ensurePending(pendingForms);
		Object meta = read(r, true, null, true, opts, pendingForms);
		if(meta instanceof Symbol || meta instanceof String)
			meta = RT.map(RT.TAG_KEY, meta);
		else if (meta instanceof Keyword)
			meta = RT.map(meta, RT.T);
		else if (meta instanceof IPersistentVector)
			meta = RT.map(RT.PARAM_TAGS_KEY, meta);
		else if(!(meta instanceof IPersistentMap))
			throw new IllegalArgumentException("Metadata must be Symbol,Keyword,String,Vector or Map");

		Object o = read(r, true, null, true, opts, pendingForms);
		if(o instanceof IMeta)
			{
			if(line != -1 && o instanceof ISeq)
				{
				meta = RT.assoc(meta, RT.LINE_KEY, RT.get(meta, RT.LINE_KEY, line));
				meta = RT.assoc(meta, RT.COLUMN_KEY, RT.get(meta,RT.COLUMN_KEY, column));
				}
			if(o instanceof IReference)
				{
				((IReference)o).resetMeta((IPersistentMap) meta);
				return o;
				}
			Object ometa = RT.meta(o);
			for(ISeq s = RT.seq(meta); s != null; s = s.next()) {
			IMapEntry kv = (IMapEntry) s.first();
			ometa = RT.assoc(ometa, kv.getKey(), kv.getValue());
			}
			return ((IObj) o).withMeta((IPersistentMap) ometa);
			}
		else
			throw new IllegalArgumentException("Metadata can only be applied to IMetas");
	}

}