org.scijava.script

Interface ScriptInterpreter

All Known Implementing Classes:

DefaultScriptInterpreter

public interface ScriptInterpreter

The contract for script interpreters.

Author:

Johannes Schindelin, Curtis Rueden

Field Summary

Fields

Modifier and Type	Field and Description
static Object	MORE_INPUT_PENDING A special object returned by interpret(String) when the interpreter is expecting additional input before finishing the evaluation.

Method Summary

Modifier and Type	Method and Description
Object	eval(String command) Evaluates a command.
Bindings	getBindings() Returns the Bindings of the associated ScriptEngine at ScriptContext.ENGINE_SCOPE scope.
ScriptEngine	getEngine() Returns the associated ScriptEngine.
ScriptLanguage	getLanguage() Returns the associated ScriptLanguage.
Object	interpret(String line) Interprets the given line of code, which might be part of a multi-line statement.
boolean	isExpectingMoreInput()
boolean	isReady()
void	readHistory() Reads the persisted history of the current script interpreter.
void	reset() Clears the buffer of not-yet-evaluated lines of code, accumulated from previous calls to interpret(java.lang.String).
String	walkHistory(String currentCommand, boolean forward) Obtains the next/previous command in the command history.
void	writeHistory() Persists the history of the current script interpreter.

Field Detail

MORE_INPUT_PENDING

static final Object MORE_INPUT_PENDING

A special object returned by interpret(String) when the interpreter is expecting additional input before finishing the evaluation.

Method Detail

readHistory

void readHistory()

Reads the persisted history of the current script interpreter.

writeHistory

void writeHistory()

Persists the history of the current script interpreter.

walkHistory

String walkHistory(String currentCommand,
                   boolean forward)

Obtains the next/previous command in the command history.

Parameters:

currentCommand - the current command (will be stored in the history)

forward - if true, the next history entry is returned (more recent), if false, the previous one

Returns:

the next/previous command

eval

Object eval(String command)
     throws ScriptException

Evaluates a command.

Parameters:

command - the command to evaluate

Returns:

result of the evaluation

Throws:

ScriptException

interpret

Object interpret(String line)
          throws ScriptException

Interprets the given line of code, which might be part of a multi-line statement.

Parameters:

line - line of code to interpret

Returns:

value of the line, or MORE_INPUT_PENDING if there is still pending input

Throws:

ScriptException - in case of an exception

reset

void reset()

Clears the buffer of not-yet-evaluated lines of code, accumulated from previous calls to interpret(java.lang.String). In other words: start over with a new (potentially multi-line) statement, discarding the current partial one.

See Also:

interpret(java.lang.String)

getLanguage

ScriptLanguage getLanguage()

Returns the associated ScriptLanguage.

getEngine

ScriptEngine getEngine()

Returns the associated ScriptEngine.

Returns:

the script engine

getBindings

Bindings getBindings()

Returns the Bindings of the associated ScriptEngine at ScriptContext.ENGINE_SCOPE scope.

isReady

boolean isReady()

Returns:

whether the interpreter is ready for a brand new statement.

See Also:

interpret(String)

isExpectingMoreInput

boolean isExpectingMoreInput()

Returns:

whether the interpreter expects more input. A true value means there is definitely more input needed. A false value means no more input is needed, but it may not yet be appropriate to evaluate all the pending lines. (there's some ambiguity depending on the language)

See Also:

interpret(String)