net.sf.saxon.expr

Class RoleLocator

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.

Field Summary
static int	BINARY_EXPR
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
void	setErrorCode(String code) Set the error code to be produced if a type error is detected

Field Detail

BINARY_EXPR

public static final int BINARY_EXPR

FUNCTION

public static final int FUNCTION

FUNCTION_RESULT

public static final int FUNCTION_RESULT

GROUPING_KEY

public static final int GROUPING_KEY

INSTRUCTION

public static final int INSTRUCTION

ORDER_BY

public static final int ORDER_BY

PARAM

public static final int PARAM

TEMPLATE_RESULT

public static final int TEMPLATE_RESULT

TYPE_OP

public static final int TYPE_OP

UNARY_EXPR

public static final int UNARY_EXPR

UPDATING_EXPR

public static final int UPDATING_EXPR

VARIABLE

public static final int VARIABLE

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

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"

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"

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

setErrorCode

public void setErrorCode(String code)

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

Parameters: code The error code