Lexan

An university task whose goal is to create a Deterministic Finite Automaton.

Input Files

Input files may have tokens as-is or Regular Grammars, but each must follow the rules:

Tokens

Tokens should be separated by lines. To create a DFA to tokens if, else and end you must have a file:

if
else
end

None of the following will generate the desired DFA:

if else
e
n
d

Regular Grammars

Grammars are defined by state-definition pairs, separated by ::= as it follows:

<S> ::= a<A> | b<B>
<A> ::= b<S> | a<A>
<B> ::= b<B> | <>

Where:

• <_> is a nonterminal symbol and _ is any single-byte character
• <> is aknowledged as "Epsilon"
• Any single-byte character is a terminal symbol, except: :, =, , <, > and |
• The left side of ::= is the state and the right side are its transitions
• A state may have multiple transitions and them are separated by |
• Each transition must be defined as a<A> or <>, where a is any terminal symbol and <A> is any nonterminal symbol.

You may have multiple grammars defined as:

<S> ::= a<A> | b<B>                  <-- S State: Here begins a grammar
<A> ::= b<S> | a<A>
<S> ::= a<A> | e<A> | i<A>           <-- S State: Here begins another grammar
<A> ::= a<A> | e<A> | i<A> | <>