org.matheclipse.core.builtin.function

Class Position

java.lang.Object

org.matheclipse.core.eval.interfaces.AbstractCoreFunctionEvaluator

org.matheclipse.core.builtin.function.Position

All Implemented Interfaces:

ICoreFunctionEvaluator, IFunctionEvaluator, IEvaluator

public class Position
extends AbstractCoreFunctionEvaluator

Position(list, pattern) - return the positions where the pattern occurs in list.

Constructor Summary

Constructors

Constructor and Description
Position()

Method Summary

Modifier and Type	Method and Description
IExpr	evaluate(IAST ast, EvalEngine engine) Symbolic evaluation of a function.
static IAST	position(IAST list, IAST prototypeList, IAST resultCollection, LevelSpec level, java.util.function.Predicate<? super IExpr> matcher, IPositionConverter<? extends IExpr> positionConverter, int headOffset) Add the positions to the resultCollection where the matching expressions appear in list.
static IAST	position(IAST list, IExpr pattern, LevelSpec level)

Methods inherited from class org.matheclipse.core.eval.interfaces.AbstractCoreFunctionEvaluator

numericEval, setUp

Methods inherited from class java.lang.Object

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

Constructor Detail

Position

public Position()

Method Detail

evaluate

public IExpr evaluate(IAST ast,
                      EvalEngine engine)

Description copied from class: AbstractCoreFunctionEvaluator

Symbolic evaluation of a function. ast.get(0) (or alternatively ast.head()) contains the head (i.e. the function symbol) of this abstract syntax tree (AST).
From ast.arg1() to ast.get(n) the ast contains the first to n-th argument of the function (alternatively you get the first to fifth argument with the methods arg1(), arg2(),... arg5()).
If necessary use the methods from the Validate class to check the number or types of arguments in the evaluate method.
Note: if the symbolic evaluation isn't possible or no result is found the evaluate method returns with a null value without throwing an exception!

Specified by:

evaluate in interface IFunctionEvaluator

Specified by:

evaluate in class AbstractCoreFunctionEvaluator

Parameters:

ast - the abstract syntax tree (AST) which should be evaluated

engine - the users current evaluation engine

Returns:

the evaluated object or null, if evaluation isn't possible

See Also:

Validate, IExpr.head(), IAST.arg1(), IAST.arg2(), IAST.arg3()

position

public static IAST position(IAST list,
                            IAST prototypeList,
                            IAST resultCollection,
                            LevelSpec level,
                            java.util.function.Predicate<? super IExpr> matcher,
                            IPositionConverter<? extends IExpr> positionConverter,
                            int headOffset)

Add the positions to the resultCollection where the matching expressions appear in list. The positionConverter converts the int position into an object for the resultCollection.

Parameters:

list -

prototypeList -

resultCollection -

level -

matcher -

positionConverter -

headOffset -

position

public static IAST position(IAST list,
                            IExpr pattern,
                            LevelSpec level)