org.apache.poi.ss.formula.OperandClassTransformer Maven / Gradle / Ivy
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package org.apache.poi.ss.formula;
import org.apache.poi.ss.formula.ptg.AbstractFunctionPtg;
import org.apache.poi.ss.formula.ptg.AttrPtg;
import org.apache.poi.ss.formula.ptg.ControlPtg;
import org.apache.poi.ss.formula.ptg.FuncVarPtg;
import org.apache.poi.ss.formula.ptg.IntersectionPtg;
import org.apache.poi.ss.formula.ptg.MemAreaPtg;
import org.apache.poi.ss.formula.ptg.MemFuncPtg;
import org.apache.poi.ss.formula.ptg.Ptg;
import org.apache.poi.ss.formula.ptg.RangePtg;
import org.apache.poi.ss.formula.ptg.UnionPtg;
import org.apache.poi.ss.formula.ptg.ValueOperatorPtg;
/**
* This class performs 'operand class' transformation. Non-base tokens are classified into three
* operand classes:
*
* - reference
* - value
* - array
*
*
*
* The final operand class chosen for each token depends on the formula type and the token's place
* in the formula. If POI gets the operand class wrong, Excel may interpret the formula
* incorrectly. This condition is typically manifested as a formula cell that displays as '#VALUE!',
* but resolves correctly when the user presses F2, enter.
*
* The logic implemented here was partially inspired by the description in
* "OpenOffice.org's Documentation of the Microsoft Excel File Format". The model presented there
* seems to be inconsistent with observed Excel behaviour (These differences have not been fully
* investigated). The implementation in this class has been heavily modified in order to satisfy
* concrete examples of how Excel performs the same logic (see TestRVA).
*
* Hopefully, as additional important test cases are identified and added to the test suite,
* patterns might become more obvious in this code and allow for simplification.
*/
final class OperandClassTransformer {
private final FormulaType _formulaType;
public OperandClassTransformer(FormulaType formulaType) {
_formulaType = formulaType;
}
/**
* Traverses the supplied formula parse tree, calling {@code Ptg.setClass()} for each non-base
* token to set its operand class.
*/
public void transformFormula(ParseNode rootNode) {
byte rootNodeOperandClass;
switch (_formulaType) {
case CELL:
rootNodeOperandClass = Ptg.CLASS_VALUE;
break;
case ARRAY:
rootNodeOperandClass = Ptg.CLASS_ARRAY;
break;
case NAMEDRANGE:
case DATAVALIDATION_LIST:
rootNodeOperandClass = Ptg.CLASS_REF;
break;
default:
throw new RuntimeException("Incomplete code - formula type ("
+ _formulaType + ") not supported yet");
}
transformNode(rootNode, rootNodeOperandClass, false);
}
/**
* @param callerForceArrayFlag {@code true} if one of the current node's parents is a
* function Ptg which has been changed from default 'V' to 'A' type (due to requirements on
* the function return value).
*/
private void transformNode(ParseNode node, byte desiredOperandClass,
boolean callerForceArrayFlag) {
Ptg token = node.getToken();
ParseNode[] children = node.getChildren();
boolean isSimpleValueFunc = isSimpleValueFunction(token);
if (isSimpleValueFunc) {
boolean localForceArray = desiredOperandClass == Ptg.CLASS_ARRAY;
for (ParseNode child : children) {
transformNode(child, desiredOperandClass, localForceArray);
}
setSimpleValueFuncClass((AbstractFunctionPtg) token, desiredOperandClass, callerForceArrayFlag);
return;
}
if (isSingleArgSum(token)) {
// Need to process the argument of SUM with transformFunctionNode below
// so make a dummy FuncVarPtg for that call.
token = FuncVarPtg.SUM;
// Note - the tAttrSum token (node.getToken()) is a base
// token so does not need to have its operand class set
}
if (token instanceof ValueOperatorPtg || token instanceof ControlPtg
|| token instanceof MemFuncPtg
|| token instanceof MemAreaPtg
|| token instanceof UnionPtg
|| token instanceof IntersectionPtg) {
// Value Operator Ptgs and Control are base tokens, so token will be unchanged
// but any child nodes are processed according to desiredOperandClass and callerForceArrayFlag
// As per OOO documentation Sec 3.2.4 "Token Class Transformation", "Step 1"
// All direct operands of value operators that are initially 'R' type will
// be converted to 'V' type.
byte localDesiredOperandClass = desiredOperandClass == Ptg.CLASS_REF ? Ptg.CLASS_VALUE : desiredOperandClass;
for (ParseNode child : children) {
transformNode(child, localDesiredOperandClass, callerForceArrayFlag);
}
return;
}
if (token instanceof AbstractFunctionPtg) {
transformFunctionNode((AbstractFunctionPtg) token, children, desiredOperandClass, callerForceArrayFlag);
return;
}
if (children.length > 0) {
if (token == RangePtg.instance) {
// TODO is any token transformation required under the various ref operators?
return;
}
throw new IllegalStateException("Node should not have any children");
}
if (token.isBaseToken()) {
// nothing to do
return;
}
token.setClass(transformClass(token.getPtgClass(), desiredOperandClass, callerForceArrayFlag));
}
private static boolean isSingleArgSum(Ptg token) {
if (token instanceof AttrPtg) {
AttrPtg attrPtg = (AttrPtg) token;
return attrPtg.isSum();
}
return false;
}
private static boolean isSimpleValueFunction(Ptg token) {
if (token instanceof AbstractFunctionPtg) {
AbstractFunctionPtg aptg = (AbstractFunctionPtg) token;
if (aptg.getDefaultOperandClass() != Ptg.CLASS_VALUE) {
return false;
}
int numberOfOperands = aptg.getNumberOfOperands();
for (int i=numberOfOperands-1; i>=0; i--) {
if (aptg.getParameterClass(i) != Ptg.CLASS_VALUE) {
return false;
}
}
return true;
}
return false;
}
private byte transformClass(byte currentOperandClass, byte desiredOperandClass,
boolean callerForceArrayFlag) {
switch (desiredOperandClass) {
case Ptg.CLASS_VALUE:
if (!callerForceArrayFlag) {
return Ptg.CLASS_VALUE;
}
// else fall through
case Ptg.CLASS_ARRAY:
return Ptg.CLASS_ARRAY;
case Ptg.CLASS_REF:
if (!callerForceArrayFlag) {
return currentOperandClass;
}
return Ptg.CLASS_REF;
}
throw new IllegalStateException("Unexpected operand class (" + desiredOperandClass + ")");
}
private void transformFunctionNode(AbstractFunctionPtg afp, ParseNode[] children,
byte desiredOperandClass, boolean callerForceArrayFlag) {
boolean localForceArrayFlag;
byte defaultReturnOperandClass = afp.getDefaultOperandClass();
if (callerForceArrayFlag) {
switch (defaultReturnOperandClass) {
case Ptg.CLASS_REF:
if (desiredOperandClass == Ptg.CLASS_REF) {
afp.setClass(Ptg.CLASS_REF);
} else {
afp.setClass(Ptg.CLASS_ARRAY);
}
localForceArrayFlag = false;
break;
case Ptg.CLASS_ARRAY:
afp.setClass(Ptg.CLASS_ARRAY);
localForceArrayFlag = false;
break;
case Ptg.CLASS_VALUE:
afp.setClass(Ptg.CLASS_ARRAY);
localForceArrayFlag = true;
break;
default:
throw new IllegalStateException("Unexpected operand class ("
+ defaultReturnOperandClass + ")");
}
} else {
if (defaultReturnOperandClass == desiredOperandClass) {
localForceArrayFlag = false;
// an alternative would have been to for non-base Ptgs to set their operand class
// from their default, but this would require the call in many subclasses because
// the default OC is not known until the end of the constructor
afp.setClass(defaultReturnOperandClass);
} else {
switch (desiredOperandClass) {
case Ptg.CLASS_VALUE:
// always OK to set functions to return 'value'
afp.setClass(Ptg.CLASS_VALUE);
localForceArrayFlag = false;
break;
case Ptg.CLASS_ARRAY:
switch (defaultReturnOperandClass) {
case Ptg.CLASS_REF:
afp.setClass(Ptg.CLASS_REF);
// afp.setClass(Ptg.CLASS_ARRAY);
break;
case Ptg.CLASS_VALUE:
afp.setClass(Ptg.CLASS_ARRAY);
break;
default:
throw new IllegalStateException("Unexpected operand class ("
+ defaultReturnOperandClass + ")");
}
localForceArrayFlag = (defaultReturnOperandClass == Ptg.CLASS_VALUE);
break;
case Ptg.CLASS_REF:
switch (defaultReturnOperandClass) {
case Ptg.CLASS_ARRAY:
afp.setClass(Ptg.CLASS_ARRAY);
break;
case Ptg.CLASS_VALUE:
afp.setClass(Ptg.CLASS_VALUE);
break;
default:
throw new IllegalStateException("Unexpected operand class ("
+ defaultReturnOperandClass + ")");
}
localForceArrayFlag = false;
break;
default:
throw new IllegalStateException("Unexpected operand class ("
+ desiredOperandClass + ")");
}
}
}
for (int i = 0; i < children.length; i++) {
ParseNode child = children[i];
byte paramOperandClass = afp.getParameterClass(i);
transformNode(child, paramOperandClass, localForceArrayFlag);
}
}
private void setSimpleValueFuncClass(AbstractFunctionPtg afp,
byte desiredOperandClass, boolean callerForceArrayFlag) {
if (callerForceArrayFlag || desiredOperandClass == Ptg.CLASS_ARRAY) {
afp.setClass(Ptg.CLASS_ARRAY);
} else {
afp.setClass(Ptg.CLASS_VALUE);
}
}
}