Package org.apache.xpath.compiler
Class OpMap
java.lang.Object
org.apache.xpath.compiler.OpMap
- Direct Known Subclasses:
Compiler
This class represents the data structure basics of the XPath
object.
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final int
The length is always the opcode position + 1. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
Tell the user of an error, and probably throw an exception.int
getArgLength
(int opPos) Get the length of an operation.int
getArgLengthOfStep
(int opPos) Given a location step, get the length of that step.static int
getFirstChildPos
(int opPos) Go to the first child of a given operation.static int
getFirstChildPosOfStep
(int opPos) Get the first child position of a given location step.int
getFirstPredicateOpPos
(int opPos) Given an FROM_stepType position, return the position of the first predicate, if there is one, or else this will point to the end of the FROM_stepType.int
getNextOpPos
(int opPos) Given an operation position, return the end position, i.e. the beginning of the next operation.static int
getNextOpPos
(int[] opMap, int opPos) Given an operation position, return the end position, i.e. the beginning of the next operation.int
getNextStepPos
(int opPos) Given a location step position, return the end position, i.e. the beginning of the next step.int
getOp
(int opPos) Given an operation position, return the current op.getOpMap()
Get the opcode list that describes the XPath operations.Return the expression as a string for diagnostics.getStepLocalName
(int opPosOfStep) Get the local name of the step.getStepNS
(int opPosOfStep) Get the namespace of the step.int
getStepTestType
(int opPosOfStep) Get the test type of the step, i.e.getToken
(int pos) Get the XPath as a list of tokens.Get the XPath as a list of tokens.int
Get size of the token queue.void
setOp
(int opPos, int value) Set the op at index to the given int.toString()
Return the expression as a string for diagnostics.
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Field Details
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MAPINDEX_LENGTH
public static final int MAPINDEX_LENGTHThe length is always the opcode position + 1. Length is always expressed as the opcode+length bytes, so it is always 2 or greater.- See Also:
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Constructor Details
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OpMap
public OpMap()
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Method Details
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toString
Return the expression as a string for diagnostics. -
getPatternString
Return the expression as a string for diagnostics.- Returns:
- The expression string.
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getTokenQueue
Get the XPath as a list of tokens.- Returns:
- ObjectVector of tokens.
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getToken
Get the XPath as a list of tokens.- Parameters:
pos
- index into token queue.- Returns:
- The token, normally a string.
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getTokenQueueSize
public int getTokenQueueSize()Get size of the token queue.- Returns:
- The size of the token queue.
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getOpMap
Get the opcode list that describes the XPath operations. It contains operations codes and indexes into the m_tokenQueue. I use an array instead of a full parse tree in order to cut down on the number of objects created.- Returns:
- An IntVector that is the opcode list that describes the XPath operations.
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getOp
public int getOp(int opPos) Given an operation position, return the current op.- Parameters:
opPos
- index into op map.- Returns:
- the op that corresponds to the opPos argument.
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setOp
public void setOp(int opPos, int value) Set the op at index to the given int.- Parameters:
opPos
- index into op map.value
- Value to set
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getNextOpPos
public int getNextOpPos(int opPos) Given an operation position, return the end position, i.e. the beginning of the next operation.- Parameters:
opPos
- An op position of an operation for which there is a size entry following.- Returns:
- position of next operation in m_opMap.
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getNextStepPos
public int getNextStepPos(int opPos) Given a location step position, return the end position, i.e. the beginning of the next step.- Parameters:
opPos
- the position of a location step.- Returns:
- the position of the next location step.
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getNextOpPos
public static int getNextOpPos(int[] opMap, int opPos) Given an operation position, return the end position, i.e. the beginning of the next operation.- Parameters:
opMap
- The operations map.opPos
- index to operation, for which there is a size entry following.- Returns:
- position of next operation in m_opMap.
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getFirstPredicateOpPos
Given an FROM_stepType position, return the position of the first predicate, if there is one, or else this will point to the end of the FROM_stepType. Example: int posOfPredicate = xpath.getNextOpPos(stepPos); boolean hasPredicates = OpCodes.OP_PREDICATE == xpath.getOp(posOfPredicate);- Parameters:
opPos
- position of FROM_stepType op.- Returns:
- position of predicate in FROM_stepType structure.
- Throws:
TransformerException
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error
Tell the user of an error, and probably throw an exception.- Parameters:
msg
- An error msgkey that corresponds to one of the constants found inXPATHErrorResources
, which is a key for a format string.args
- An array of arguments represented in the format string, which may be null.
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getFirstChildPos
public static int getFirstChildPos(int opPos) Go to the first child of a given operation.- Parameters:
opPos
- position of operation.- Returns:
- The position of the first child of the operation.
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getArgLength
public int getArgLength(int opPos) Get the length of an operation.- Parameters:
opPos
- The position of the operation in the op map.- Returns:
- The size of the operation.
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getArgLengthOfStep
public int getArgLengthOfStep(int opPos) Given a location step, get the length of that step.- Parameters:
opPos
- Position of location step in op map.- Returns:
- The length of the step.
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getFirstChildPosOfStep
public static int getFirstChildPosOfStep(int opPos) Get the first child position of a given location step.- Parameters:
opPos
- Position of location step in the location map.- Returns:
- The first child position of the step.
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getStepTestType
public int getStepTestType(int opPosOfStep) Get the test type of the step, i.e. NODETYPE_XXX value.- Parameters:
opPosOfStep
- The position of the FROM_XXX step.- Returns:
- NODETYPE_XXX value.
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getStepNS
Get the namespace of the step.- Parameters:
opPosOfStep
- The position of the FROM_XXX step.- Returns:
- The step's namespace, NodeTest.WILD, or null for null namespace.
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getStepLocalName
Get the local name of the step.- Parameters:
opPosOfStep
- The position of the FROM_XXX step.- Returns:
- OpCodes.EMPTY, OpCodes.ELEMWILDCARD, or the local name.
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