net.sf.saxon.expr
Class RoleLocator

java.lang.Object
  net.sf.saxon.expr.RoleLocator

All Implemented Interfaces:

Serializable

public class RoleLocator
extends Object
implements Serializable

A RoleLocator identifies the role in which an expression is used, for example as the third argument of the concat() function. This information is stored in an ItemChecker or CardinalityChecker so that good diagnostics can be achieved when run-time type errors are detected.

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Serialized Form

Field Summary

static int	BINARY_EXPR
static int	EVALUATE_RESULT
static int	FUNCTION
static int	FUNCTION_RESULT
static int	GROUPING_KEY
static int	INSTRUCTION
static int	ORDER_BY
static int	PARAM
static int	TEMPLATE_RESULT
static int	TYPE_OP
static int	UNARY_EXPR
static int	UPDATING_EXPR
static int	VARIABLE

Constructor Summary

RoleLocator(int kind, Serializable operation, int operand)
Create information about the role of a subexpression within its parent expression

Method Summary

String	composeErrorMessage(ItemType requiredItemType, ItemType suppliedItemType, NamePool pool) Construct a full error message
String	composeRequiredMessage(ItemType requiredItemType, NamePool pool) Construct the part of the message giving the required item type
String	getErrorCode() Get the error code to be produced if a type error is detected
String	getMessage() Construct and return the error message indicating a type error
static String	ordinal(int n) Get the ordinal representation of a number (used to identify which argument of a function is in error)
void	setErrorCode(String code) Set the error code to be produced if a type error is detected

Methods inherited from class java.lang.Object

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

Field Detail

FUNCTION

public static final int FUNCTION

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Constant Field Values

BINARY_EXPR

public static final int BINARY_EXPR

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Constant Field Values

TYPE_OP

public static final int TYPE_OP

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Constant Field Values

VARIABLE

public static final int VARIABLE

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Constant Field Values

INSTRUCTION

public static final int INSTRUCTION

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Constant Field Values

FUNCTION_RESULT

public static final int FUNCTION_RESULT

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Constant Field Values

ORDER_BY

public static final int ORDER_BY

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Constant Field Values

TEMPLATE_RESULT

public static final int TEMPLATE_RESULT

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Constant Field Values

PARAM

public static final int PARAM

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Constant Field Values

UNARY_EXPR

public static final int UNARY_EXPR

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Constant Field Values

UPDATING_EXPR

public static final int UPDATING_EXPR

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Constant Field Values

GROUPING_KEY

public static final int GROUPING_KEY

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Constant Field Values

EVALUATE_RESULT

public static final int EVALUATE_RESULT

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Constant Field Values

Constructor Detail

RoleLocator

public RoleLocator(int kind,
                   Serializable operation,
                   int operand)

Create information about the role of a subexpression within its parent expression

Parameters:

kind - the kind of parent expression, e.g. a function call or a variable reference

operation - the name of the object in the parent expression, e.g. a function name or instruction name. May be expressed either as a String or as a StructuredQName. For a string, the special format element/attribute is recognized, for example xsl:for-each/select, to identify the role of an XPath expression in a stylesheet.

operand - Ordinal position of this subexpression, e.g. the position of an argument in a function call

Method Detail

setErrorCode

public void setErrorCode(String code)

Set the error code to be produced if a type error is detected

Parameters:

code - The error code

getErrorCode

public String getErrorCode()

Get the error code to be produced if a type error is detected

Returns:

code The error code

getMessage

public String getMessage()

Construct and return the error message indicating a type error

Returns:

the constructed error message

composeRequiredMessage

public String composeRequiredMessage(ItemType requiredItemType,
                                     NamePool pool)

Construct the part of the message giving the required item type

Parameters:

requiredItemType - the item type required by the context of a particular expression

pool - the name pool

Returns:

a message of the form "Required item type of X is Y"

composeErrorMessage

public String composeErrorMessage(ItemType requiredItemType,
                                  ItemType suppliedItemType,
                                  NamePool pool)

Construct a full error message

Parameters:

requiredItemType - the item type required by the context of a particular expression

suppliedItemType - the item type inferred by static analysis of an expression

pool - the name pool

Returns:

a message of the form "Required item type of A is R; supplied value has item type S"

ordinal

public static String ordinal(int n)

Get the ordinal representation of a number (used to identify which argument of a function is in error)

Parameters:

n - the cardinal number

Returns:

the ordinal representation