private static MNode lexInput(MInputStream input)
{
ByteAutomata ba = new ByteAutomata();
automata = ba;
defineTransitions(ba);
ba.next((byte)1); // set first state
root = new MNode(null, 0, "<ROOT>");
currentExpr = root;
currentBlock = null;
currentToken = null;
lastStart = 0;
ba.run(input);
ba.step((byte)' '); // ended cleanly: last white space
if (currentBlock != null)
{
MeanCS.print("closing parenthesis missing at the end");
ba.ok = false;
}
if (!ba.ok)
{
ba.printError();
root = null;
return(null);
}
MeanCS.verbose("\nFINISHED!");
return(root);
}
private static void defineTransitions(ByteAutomata ba)
{
stateSpace = ba.addState("space");
stateName = ba.addState("name");
stateNumber = ba.addState("number");
ba.transition(stateSpace, whiteSpace, null);
ba.transition(stateSpace, letters, () => { next(stateName); });
ba.transition(stateSpace, numbers, () => { next(stateNumber); });
ba.transition(stateSpace, expressionBreak, () => { exprBreak(); });
ba.transition(stateSpace, blockStart, () => { addBlock(); });
ba.transition(stateSpace, blockEnd, () => { endBlock(); });
ba.transition(stateName, letters, null);
ba.transition(stateName, whiteSpace, () => { addToken(NODE_TEXT); next(stateSpace); });
ba.transition(stateName, blockStart, () => { addToken(NODE_TEXT); stay(); next(stateSpace); });
ba.transition(stateName, blockEnd, () => { addToken(NODE_TEXT); stay(); next(stateSpace); });
ba.transition(stateName, expressionBreak, () => { addToken(NODE_TEXT); exprBreak(); next(stateSpace); });
ba.transition(stateNumber, numbers, null);
ba.transition(stateNumber, whiteSpace, () => { addToken(NODE_NUMBER); next(stateSpace); });
ba.transition(stateNumber, blockStart, () => { addToken(NODE_NUMBER); stay(); next(stateSpace); });
ba.transition(stateNumber, blockEnd, () => { addToken(NODE_NUMBER); stay(); next(stateSpace); });
ba.transition(stateNumber, expressionBreak, () => { addToken(NODE_NUMBER); exprBreak(); next(stateSpace); });
}