@Override
	public long getValue(ParserWalker walker) throws MemoryAccessException {
		OperandSymbol sym = ct.getOperand(index);
		PatternExpression patexp = sym.getDefiningExpression();
		if (patexp == null) {
			TripleSymbol defSym = sym.getDefiningSymbol();
			if (defSym != null) {
				patexp = defSym.getPatternExpression();
			}
			if (patexp == null) {
				return 0;
			}
		}
		ConstructState tempstate = new ConstructState(null);
		ParserWalker newwalker = new ParserWalker(walker.getParserContext());
		newwalker.setOutOfBandState(ct, index, tempstate, walker);
		long res = patexp.getValue(newwalker);
		return res;
	}
An Expression representing the value of a Constructor operand
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/processors/sleigh/expression/OperandValue.java