Description of the Java design pattern interpreter pattern (interpreter mode) _java

Interpreter definition: Defines the grammar of a language and creates an interpreter to interpret the sentences in that language.

Interpreter does not seem to have a wide range of facets, it describes how a language interpreter is constructed, and in practical applications we may rarely construct a language grammar. Let's just take a quick look.

The first step is to create an interface to describe the common operation.

Copy Code code as follows:

Public interface Abstractexpression {
void interpret (context context);
}

And look at some global information outside of the interpreter.

Copy Code code as follows:

Public interface Context {}

The concrete implementations of abstractexpression are divided into two types: non-terminal expressions and non-terminal expressions.
public class Terminalexpression implements Abstractexpression {
public void Interpret {}
}

No non-terminal expression is required for a rule in the grammar:
public class Nonterminalexpression implements Abstractexpression {
Private Abstractexpression successor;
　　
public void Setsuccessor (Abstractexpression successor) {
This.successor = successor;
}

Public Abstractexpression Getsuccessor () {
return successor;
}

public void Interpret {}
}