diff options
Diffstat (limited to 'calc.go')
| -rw-r--r-- | calc.go | 70 |
1 files changed, 70 insertions, 0 deletions
@@ -288,6 +288,8 @@ var tokenPriority = map[string]int{ // ISO.CEILING // KURT // LCM +// LEFT +// LEFTB // LEN // LENB // LN @@ -321,6 +323,8 @@ var tokenPriority = map[string]int{ // RAND // RANDBETWEEN // REPT +// RIGHT +// RIGHTB // ROMAN // ROUND // ROUNDDOWN @@ -4635,6 +4639,54 @@ func (fn *formulaFuncs) EXACT(argsList *list.List) formulaArg { return newBoolFormulaArg(text1 == text2) } +// LEFT function returns a specified number of characters from the start of a +// supplied text string. The syntax of the function is: +// +// LEFT(text,[num_chars]) +// +func (fn *formulaFuncs) LEFT(argsList *list.List) formulaArg { + return fn.leftRight("LEFT", argsList) +} + +// LEFTB returns the first character or characters in a text string, based on +// the number of bytes you specify. The syntax of the function is: +// +// LEFTB(text,[num_bytes]) +// +func (fn *formulaFuncs) LEFTB(argsList *list.List) formulaArg { + return fn.leftRight("LEFTB", argsList) +} + +// leftRight is an implementation of the formula function LEFT, LEFTB, RIGHT, +// RIGHTB. TODO: support DBCS include Japanese, Chinese (Simplified), Chinese +// (Traditional), and Korean. +func (fn *formulaFuncs) leftRight(name string, argsList *list.List) formulaArg { + if argsList.Len() < 1 { + return newErrorFormulaArg(formulaErrorVALUE, fmt.Sprintf("%s requires at least 1 argument", name)) + } + if argsList.Len() > 2 { + return newErrorFormulaArg(formulaErrorVALUE, fmt.Sprintf("%s allows at most 2 arguments", name)) + } + text, numChars := argsList.Front().Value.(formulaArg).Value(), 1 + if argsList.Len() == 2 { + numArg := argsList.Back().Value.(formulaArg).ToNumber() + if numArg.Type != ArgNumber { + return numArg + } + if numArg.Number < 0 { + return newErrorFormulaArg(formulaErrorVALUE, formulaErrorVALUE) + } + numChars = int(numArg.Number) + } + if len(text) > numChars { + if name == "LEFT" || name == "LEFTB" { + return newStringFormulaArg(text[:numChars]) + } + return newStringFormulaArg(text[len(text)-numChars:]) + } + return newStringFormulaArg(text) +} + // LEN returns the length of a supplied text string. The syntax of the // function is: // @@ -4742,6 +4794,24 @@ func (fn *formulaFuncs) REPT(argsList *list.List) formulaArg { return newStringFormulaArg(buf.String()) } +// RIGHT function returns a specified number of characters from the end of a +// supplied text string. The syntax of the function is: +// +// RIGHT(text,[num_chars]) +// +func (fn *formulaFuncs) RIGHT(argsList *list.List) formulaArg { + return fn.leftRight("RIGHT", argsList) +} + +// RIGHTB returns the last character or characters in a text string, based on +// the number of bytes you specify. The syntax of the function is: +// +// RIGHTB(text,[num_bytes]) +// +func (fn *formulaFuncs) RIGHTB(argsList *list.List) formulaArg { + return fn.leftRight("RIGHTB", argsList) +} + // UPPER converts all characters in a supplied text string to upper case. The // syntax of the function is: // |