In computer science, Thompson's construction algorithm, also called the McNaughton–Yamada–Thompson algorithm, [1] is a method of transforming a regular expression into an equivalent nondeterministic finite automaton (NFA). [2]

tuent subexpressions. The rules for constructing an NFA consist of basis rules for handling subexpressions with no operators, and inductive rules for constructing larger NFA's from the NFA's for the immediate subexpressions . lly, suppose r = (s). Then L(r) = L(s), and we can use .

May 23, 2020 · We have successfully converted a regular expression to postfix notation with the Shunting-Yard Algorithm, and then build its respective NFA diagram with Thompson’s Construction Algorithm.

The McNaughton-Yamada-Thompson algorithm (also known as Thompson algorithm) is designed to transform a regular expression into a Non-Deterministic Finite Automaton (NDFA) that recognizes the language represented by the regular expression.

We can use Thompson's Construction to find out a Finite Automaton from a Regular Expression. We will reduce the regular expression into smallest regular expressions and converting these to NFA and finally to DFA.

Visualize the Thompson-McNaughton-Yamada construction NFA for a given regular expression. The subset construction algorithm is also applied to the resultant NFA, resulting in a language-equivalent deterministic finite-state automata (DFA).

To construct a NFA from this, use Thompson’s construction. This method constructs a regular expression from its components using ε-transitions. The ε transitions act as “glue or mortar” for the subcomponent NFA’s.

It provides a construction rule for each of the core RE operations: concatenation (e.g. AB), kleene star (e.g. A*), alternation/or (e.g. A|B) e.g. For the (0|1)*1 example all we need are two states as shown below.

A trivial implementation of Thompson's Construction Algorithm to kick off my lecture on compiler construction.

Thompson’s Construction Steps 1. Parse (break down) r into its constituent subexpressions 2. Using rules (1),(2) construct NFAs for each of the basic symbols in r • If a symbol occurs …