JELLRAP Preview

Button Menu:
Begin by selecting which algorithm you would like to use to parse.

Grammar Window:
Next, you can either load a previous Grammar file or you can enter your new Grammar. Lambda is represented by an exclamation point that can be achieved using <CNTRL> 'l' or by typing an exclamation point like normal. You will also find many other useful shortcuts such as <SHIFT> '|' in case you wish to write: S->A | B | C

Data Windows:
Then you start entering data sets such as First Sets, First2 Sets (LL2 only), and you can even create a DFA (LR1 only), depending on which algorithm you selected at the beginning. JELLRAP will not let you advance to the next window until all your data sets are correct. Click Done when you think you have entered the correct data sets. If you have an error, JELLRAP will find it and won't let you continue until you fix it! If you are not sure how to fix it, click Show then Done.

Table:
Conflicts may be entered in the Table by separating entries with a space (just like entering first2 & follow2 data sets that have multiple elements). If the Table contains conflicts, you may not proceed to the StringTesterWindow unless you are using the LR1 parser.

String Testing (finally -- you can parse!):
The String Tester Window is where you enter input Strings to see if they can parse successfully according to the Grammar that you originally entered. JELLRAP even has a special Grammar Peek in case you forgot what your original grammar was by this point.

LR Parsing: You can view the derivation of your input String as an inverted/non-inverted tree or you can see the written derivation. Clicking on Return allows you to return either to the Table window (so you can change the order of a conflict) or the original Grammar. You can also view the state and symbol stack side by side and watch various table entries light up as the tester window animates the parsing of an input String

LL Parsing
You can view the derivation of your input String as a non-inverted tree or you can see the written derivation. Clicking on Return automatically sends you back to the original Grammar window.


Mail any bugs to Susan Rodger
Last modified: Sat Sep 27 12:00:03 EDT 1997