Package net.sourceforge.plantuml.jasic

Class Jasic

java.lang.Object
net.sourceforge.plantuml.jasic.Jasic
public class Jasic extends Object

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    class 
    Jasic.AssignStatement
    An assignment statement evaluates an expression and stores the result in a variable.
    static interface 
    Jasic.Expression
    Base interface for an expression.
    class 
    Jasic.GotoStatement
    A "goto" statement jumps execution to another place in the program.
    class 
    Jasic.IfThenStatement
    An if then statement jumps execution to another place in the program, but only if an expression evaluates to something other than 0.
    class 
    Jasic.InputStatement
    An "input" statement reads input from the user and stores it in a variable.
    class 
    Jasic.NumberValue
    A numeric value.
    class 
    Jasic.OperatorExpression
    An operator expression evaluates two expressions and then performs some arithmetic operation on the results.
    class 
    Jasic.PrintStatement
    A "print" statement evaluates an expression, converts the result to a string, and displays it to the user.
    static interface 
    Jasic.Statement
    Base interface for a Jasic statement.
    class 
    Jasic.StringValue
    A string value.
    static interface 
    Jasic.Value
    This is the base interface for a value.
    class 
    Jasic.VariableExpression
    A variable expression evaluates to the current value stored in that variable.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Jasic()
    Constructs a new Jasic instance.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    interpret(String source)
    This is where the magic happens.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Jasic

      public Jasic()
      Constructs a new Jasic instance. The instance stores the global state of the interpreter such as the values of all of the variables and the current statement.

  • Method Details

    • interpret

      public void interpret(String source)
      This is where the magic happens. This runs the code through the parsing pipeline to generate the AST. Then it executes each statement. It keeps track of the current line in a member variable that the statement objects have access to. This lets "goto" and "if then" do flow control by simply setting the index of the current statement. In an interpreter that didn't mix the interpretation logic in with the AST node classes, this would be doing a lot more work.
      Parameters:
      source - A string containing the source code of a .jas script to interpret.