Last Update Time-stamp: "97/06/27 20:54:06 umrigar"
This page contains a java applet which demonstrates the operation of a recursive-descent parser for a simple language consisting of assignment statements and arithmetic expressions. An introduction to LL(1) parsing is also available.
The layout of the applet is as shown below. You can click on any of the yellow areas to get a fuller description in the frame to the left.
Please be patient: depending on the speed of your network connection, the applet may take a few minutes to load. Here it is...
If you find the size of the applet embedded above inconvenient, then you can another copy of the applet in a separate window which you may resize to your convenience (if permitted to do so by the security model used by your browser).
Any misbehavior of the applet may be due to known incompatiblities.
A parse tree node is constructed when a rule is predicted: i.e., a nonterminal is popped off the stack, the parse table is used to predict a rule for that nonterminal, and the subtree is constructed with the nonterminal as the root and the RHS grammar symbols of the predicted rule as children. The RHS grammar symbols are pushed onto the stack.
Feedback: Please email any feedback to zdu@acm.org.