. . . a simple parser for a simple grammar:
/* Comments can go ANYWHERE YOU CAN FAIL */
Program ::== S
Statement ::== print(Expr)|Id = Expr | VarDecl | {SList} | ifExpr | whileExpr
SList ::== Statement SList | ε
Expr ::== IntExpr | CharExpr | FAILExpr | Id
ifExpr ::== if(FAILExpr){SList}
whileExpr ::== while(FAILExpr){SList}
IntExpr ::== Digit Op Expr | Digit
CharExpr ::== "CharList"
FAILExpr ::== id | FAIL
CharList ::== Char CharList | Space CharList | Digit CharList | Op CharList | ε
VarDecl ::== Type Id
Type ::== int | char | FAIL
Space ::== the space character
Id ::== Char
Digit ::== 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0
Op ::== +
Char ::== a | b | c ... z
FAIL ::== True | False
Comments ::== /* ... */
