Class OperandResolver
- Author:
- Josh Micich, Brendan Nolan
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Method Summary
Modifier and TypeMethodDescriptionstatic ValueEval
chooseSingleElementFromArea
(AreaEval ae, int srcCellRow, int srcCellCol) Implements (some perhaps not well known) Excel functionality to select a single cell from an area depending on the coordinates of the calling cell.static Boolean
coerceValueToBoolean
(ValueEval ve, boolean stringsAreBlanks) static double
Applies some conversion rules if the supplied value is not already a number.static int
Applies some conversion rules if the supplied value is not already an integer.
Value is first coerced to a double ( See coerceValueToDouble() ).static String
static ValueEval
getElementFromArray
(AreaEval ae, EvaluationCell cell) Retrieves a single value from an area evaluation utilizing the 2D indices of the cell within its own area reference to index the value in the area evaluation.static ValueEval
getSingleValue
(ValueEval arg, int srcCellRow, int srcCellCol) Retrieves a single value from a variety of different argument types according to standard Excel rules.static Double
parseDouble
(String pText) Converts a string to a double using standard rules that Excel would use.
Tolerates leading and trailing spaces,
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Method Details
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getSingleValue
public static ValueEval getSingleValue(ValueEval arg, int srcCellRow, int srcCellCol) throws EvaluationException Retrieves a single value from a variety of different argument types according to standard Excel rules. Does not perform any type conversion.- Parameters:
arg
- the evaluated argument as passed to the function or operator.srcCellRow
- used when arg is a single column AreaRefsrcCellCol
- used when arg is a single row AreaRef- Returns:
- a NumberEval, StringEval, BoolEval or BlankEval.
Never
null
or ErrorEval. - Throws:
EvaluationException
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getElementFromArray
Retrieves a single value from an area evaluation utilizing the 2D indices of the cell within its own area reference to index the value in the area evaluation.- Parameters:
ae
- area reference after evaluationcell
- the source cell of the formula that contains its 2D indices- Returns:
- a NumberEval, StringEval, BoolEval or BlankEval. or ErrorEval
Never
null
.
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chooseSingleElementFromArea
public static ValueEval chooseSingleElementFromArea(AreaEval ae, int srcCellRow, int srcCellCol) throws EvaluationException Implements (some perhaps not well known) Excel functionality to select a single cell from an area depending on the coordinates of the calling cell. Here is an example demonstrating both selection from a single row area and a single column area in the same formula.A B C D 1 15 20 25 2 200 3 300 3 400 A B C D 1 15 20 25 2 1215 1220 #VALUE! 200 3 1315 1320 #VALUE! 300 4 #VALUE! #VALUE! #VALUE! 400 The same concept is extended to references across sheets, such that even multi-row, multi-column areas can be useful.
Of course with carefully (or carelessly) chosen parameters, cyclic references can occur and hence this method can throw a 'circular reference' EvaluationException. Note that this method does not attempt to detect cycles. Every cell in the specified Area ae has already been evaluated prior to this method call. Any cell (or cells) part of ae that would incur a cyclic reference error if selected by this method, will already have the value
ErrorEval.CIRCULAR_REF_ERROR upon entry to this method. It is assumed logic exists elsewhere to produce this behaviour. - Returns:
- whatever the selected cell's evaluated value is. Never
null
. Never ErrorEval. - Throws:
EvaluationException
- if there is a problem with indexing into the area, or if the evaluated cell has an error.
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coerceValueToInt
Applies some conversion rules if the supplied value is not already an integer.
Value is first coerced to a double ( See coerceValueToDouble() ). Note - BlankEval is converted to0
.Excel typically converts doubles to integers by truncating toward negative infinity.
The equivalent java code is:
return (int)Math.floor(d);
not:
return (int)d; // wrong - rounds toward zero
- Throws:
EvaluationException
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coerceValueToDouble
Applies some conversion rules if the supplied value is not already a number. Note - BlankEval is converted toNumberEval.ZERO
.- Parameters:
ev
- must be aNumberEval
,StringEval
,BoolEval
orBlankEval
- Returns:
- actual, parsed or interpreted double value (respectively).
- Throws:
RuntimeException
- if the supplied parameter is notNumberEval
,StringEval
,BoolEval
orBlankEval
EvaluationException
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parseDouble
Converts a string to a double using standard rules that Excel would use.
Tolerates leading and trailing spaces,Doesn't support currency prefixes, commas, percentage signs or arithmetic operations strings. Some examples:
" 123 " -> 123.0
".123" -> 0.123
"1E4" -> 1000
"-123" -> -123.0
These not supported yet:
" $ 1,000.00 " -> 1000.0
"$1.25E4" -> 12500.0
"5**2" -> 500
"250%" -> 2.5- Returns:
null
if the specified text cannot be parsed as a number
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coerceValueToString
- Parameters:
ve
- must be a NumberEval, StringEval, BoolEval, or BlankEval- Returns:
- the converted string value. never
null
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coerceValueToBoolean
public static Boolean coerceValueToBoolean(ValueEval ve, boolean stringsAreBlanks) throws EvaluationException - Returns:
null
to represent blank values- Throws:
EvaluationException
- if ve is an ErrorEval, or if a string value cannot be converted
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