Module java.base

Package java.lang.classfile.attribute^PREVIEW

Interface CharacterRangeInfo

public sealed interface CharacterRangeInfo

CharacterRangeInfo is a preview API of the Java platform.

Programs can only use CharacterRangeInfo when preview features are enabled.

Preview features may be removed in a future release, or upgraded to permanent features of the Java platform.

Models a single character range in the CharacterRangeTableAttribute^PREVIEW.

Since:

22

Method Summary

Modifier and Type	Method	Description
int	characterRangeEnd()	Returns the encoded end of the character range region (exclusive).
int	characterRangeStart()	Returns the encoded start of the character range region (inclusive).
int	endPc()	Returns the end of the character range region (exclusive).
int	flags()	The value of the flags item describes the kind of range.
static CharacterRangeInfoPREVIEW	of(int startPc, int endPc, int characterRangeStart, int characterRangeEnd, int flags)	Returns a character range description.
int	startPc()	Returns the start of the character range region (inclusive).

Method Details

startPc

int startPc()

Returns the start of the character range region (inclusive). This is the index into the code array at which the code for this character range begins.

Returns:

the start of the character range region (inclusive)

endPc

int endPc()

Returns the end of the character range region (exclusive). This is the index into the code array after which the code for this character range ends.

Returns:

the end of the character range region (exclusive)

characterRangeStart

int characterRangeStart()

Returns the encoded start of the character range region (inclusive). The value is constructed from the line_number/column_number pair as given by line_number << 10 + column_number, where the source file is viewed as an array of (possibly multi-byte) characters.

Returns:

the encoded start of the character range region (inclusive)

characterRangeEnd

int characterRangeEnd()

Returns the encoded end of the character range region (exclusive).. The value is constructed from the line_number/column_number pair as given by line_number << 10 + column_number, where the source file is viewed as an array of (possibly multi-byte) characters.

Returns:

the encoded end of the character range region (exclusive)

flags

int flags()

The value of the flags item describes the kind of range. Multiple flags may be set within flags.

• ClassFile.CRT_STATEMENT^PREVIEW Range is a Statement (except ExpressionStatement), StatementExpression 14.8, as well as each VariableDeclaratorId = VariableInitializer of LocalVariableDeclarationStatement 14.4 or FieldDeclaration 8.3 in the grammar.
• ClassFile.CRT_BLOCK^PREVIEW Range is a Block in the grammar.
• ClassFile.CRT_ASSIGNMENT^PREVIEW Range is an assignment expression - Expression1 AssignmentOperator Expression1 in the grammar as well as increment and decrement expressions (both prefix and postfix).
• ClassFile.CRT_FLOW_CONTROLLER^PREVIEW An expression whose value will effect control flow. Flowcon in the following:

   if ( Flowcon ) Statement [else Statement]
   for ( ForInitOpt ; [Flowcon] ; ForUpdateOpt ) Statement
   while ( Flowcon ) Statement
   do Statement while ( Flowcon ) ;
   switch ( Flowcon ) { SwitchBlockStatementGroups }
   Flowcon || Expression3
   Flowcon && Expression3
   Flowcon ? Expression : Expression1
   

• ClassFile.CRT_FLOW_TARGET^PREVIEW Statement or expression effected by a CRT_FLOW_CONTROLLER. Flowtarg in the following:

   if ( Flowcon ) Flowtarg [else Flowtarg]
   for ( ForInitOpt ; [Flowcon] ; ForUpdateOpt ) Flowtarg
   while ( Flowcon ) Flowtarg
   do Flowtarg while ( Flowcon ) ;
   Flowcon || Flowtarg
   Flowcon && Flowtarg
   Flowcon ? Flowtarg : Flowtarg
   

• ClassFile.CRT_INVOKE^PREVIEW Method invocation. For example: Identifier Arguments.
• ClassFile.CRT_CREATE^PREVIEW New object creation. For example: new Creator.
• ClassFile.CRT_BRANCH_TRUE^PREVIEW A condition encoded in the branch instruction immediately contained in the code range for this item is not inverted towards the corresponding branch condition in the source code. I.e. actual jump occurs if and only if the the source code branch condition evaluates to true. Entries of this type are produced only for conditions that are listed in the description of CRT_FLOW_CONTROLLER flag. The source range for the entry contains flow controlling expression. start_pc field for an entry of this type must point to a branch instruction: if_acmp<cond>, if_icmp<cond>, if<cond>, ifnonull, ifnull or goto. CRT_BRANCH_TRUE and CRT_BRANCH_FALSE are special kinds of entries that can be used to determine what branch of a condition was chosen during the runtime.
• ClassFile.CRT_BRANCH_FALSE^PREVIEW A condition encoded in the branch instruction immediately contained in the code range for this item is inverted towards the corresponding branch condition in the source code. I.e. actual jump occurs if and only if the the source code branch condition evaluates to false. Entries of this type are produced only for conditions that are listed in the description of CRT_FLOW_CONTROLLER flag. The source range for the entry contains flow controlling expression. start_pc field for an entry of this type must point to a branch instruction: if_acmp<cond>, if_icmp<cond>, if<cond>, ifnonull, ifnull or goto.

All bits of the flags item not assigned above are reserved for future use. They should be set to zero in generated class files and should be ignored by Java virtual machine implementations.

Returns:

the flags

of

static CharacterRangeInfoPREVIEW of(int startPc,
 int endPc,
 int characterRangeStart,
 int characterRangeEnd,
 int flags)

Returns a character range description.

Parameters:

startPc - the start of the bytecode range, inclusive

endPc - the end of the bytecode range, exclusive

characterRangeStart - the start of the character range, inclusive, encoded as line_number << 10 + column_number

characterRangeEnd - the end of the character range, exclusive, encoded as line_number << 10 + column_number

flags - the range flags

Returns:

a character range description