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 Detail

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 Detail

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.