This closes #1160, and added 4 new formula functions

* Fix show sheet tabs issue
* Ref #65, new formula functions: ERROR.TYPE, HOUR, SECOND TIMEVALUE

3 files changed, 208 insertions, 22 deletions

diff --git a/calc.go b/calc.go
index a4c45fb..d4828be 100644
--- a/calc.go
+++ b/calc.go
@@ -401,6 +401,7 @@ type formulaFuncs struct {
 //    ERF.PRECISE
 //    ERFC
 //    ERFC.PRECISE
+//    ERROR.TYPE
 //    EVEN
 //    EXACT
 //    EXP
@@ -427,6 +428,7 @@ type formulaFuncs struct {
 //    HEX2DEC
 //    HEX2OCT
 //    HLOOKUP
+//    HOUR
 //    IF
 //    IFERROR
 //    IFNA
@@ -574,6 +576,7 @@ type formulaFuncs struct {
 //    RRI
 //    SEC
 //    SECH
+//    SECOND
 //    SHEET
 //    SHEETS
 //    SIGN
@@ -604,6 +607,7 @@ type formulaFuncs struct {
 //    TBILLYIELD
 //    TEXTJOIN
 //    TIME
+//    TIMEVALUE
 //    TODAY
 //    TRANSPOSE
 //    TRIM
@@ -852,7 +856,9 @@ func (f *File) evalInfixExpFunc(sheet, cell string, token, nextToken efp.Token,
 		// calculate trigger
 		topOpt := opftStack.Peek().(efp.Token)
 		if err := calculate(opfdStack, topOpt); err != nil {
-			return err
+			argsStack.Peek().(*list.List).PushBack(newErrorFormulaArg(err.Error(), err.Error()))
+			opftStack.Pop()
+			continue
 		}
 		opftStack.Pop()
 	}
@@ -874,7 +880,11 @@ func (f *File) evalInfixExpFunc(sheet, cell string, token, nextToken efp.Token,
 	if opfStack.Len() > 0 { // still in function stack
 		if nextToken.TType == efp.TokenTypeOperatorInfix || (opftStack.Len() > 1 && opfdStack.Len() > 0) {
 			// mathematics calculate in formula function
-			opfdStack.Push(efp.Token{TValue: arg.Value(), TType: efp.TokenTypeOperand, TSubType: efp.TokenSubTypeNumber})
+			if arg.Type == ArgError {
+				opfdStack.Push(efp.Token{TValue: arg.Value(), TType: efp.TokenTypeOperand, TSubType: efp.TokenSubTypeError})
+			} else {
+				opfdStack.Push(efp.Token{TValue: arg.Value(), TType: efp.TokenTypeOperand, TSubType: efp.TokenSubTypeNumber})
+			}
 		} else {
 			argsStack.Peek().(*list.List).PushBack(arg)
 		}
@@ -1096,11 +1106,19 @@ func calculate(opdStack *Stack, opt efp.Token) error {
 	fn, ok := tokenCalcFunc[opt.TValue]
 	if ok {
 		if opdStack.Len() < 2 {
+			if opdStack.Len() == 1 {
+				rOpd := opdStack.Pop().(efp.Token)
+				if rOpd.TSubType == efp.TokenSubTypeError {
+					return errors.New(rOpd.TValue)
+				}
+			}
 			return ErrInvalidFormula
 		}
 		rOpd := opdStack.Pop().(efp.Token)
 		lOpd := opdStack.Pop().(efp.Token)
-
+		if lOpd.TSubType == efp.TokenSubTypeError {
+			return errors.New(lOpd.TValue)
+		}
 		if err := fn(rOpd, lOpd, opdStack); err != nil {
 			return err
 		}
@@ -4797,8 +4815,8 @@ func (fn *formulaFuncs) SUM(argsList *list.List) formulaArg {
 	for arg := argsList.Front(); arg != nil; arg = arg.Next() {
 		token := arg.Value.(formulaArg)
 		switch token.Type {
-		case ArgUnknown:
-			continue
+		case ArgError:
+			return token
 		case ArgString:
 			if num := token.ToNumber(); num.Type == ArgNumber {
 				sum += num.Number
@@ -6787,6 +6805,29 @@ func (fn *formulaFuncs) ZTEST(argsList *list.List) formulaArg {
 
 // Information Functions
 
+// ERRORdotTYPE function receives an error value and returns an integer, that
+// tells you the type of the supplied error. The syntax of the function is:
+//
+//    ERROR.TYPE(error_val)
+//
+func (fn *formulaFuncs) ERRORdotTYPE(argsList *list.List) formulaArg {
+	if argsList.Len() != 1 {
+		return newErrorFormulaArg(formulaErrorVALUE, "ERROR.TYPE requires 1 argument")
+	}
+	token := argsList.Front().Value.(formulaArg)
+	if token.Type == ArgError {
+		for i, errType := range []string{
+			formulaErrorNULL, formulaErrorDIV, formulaErrorVALUE, formulaErrorREF,
+			formulaErrorNAME, formulaErrorNUM, formulaErrorNA,
+		} {
+			if errType == token.String {
+				return newNumberFormulaArg(float64(i) + 1)
+			}
+		}
+	}
+	return newErrorFormulaArg(formulaErrorNA, formulaErrorNA)
+}
+
 // ISBLANK function tests if a specified cell is blank (empty) and if so,
 // returns TRUE; Otherwise the function returns FALSE. The syntax of the
 // function is:
@@ -7884,6 +7925,40 @@ func (fn *formulaFuncs) ISOWEEKNUM(argsList *list.List) formulaArg {
 	return newNumberFormulaArg(float64(weeknum))
 }
 
+// HOUR function returns an integer representing the hour component of a
+// supplied Excel time. The syntax of the function is:
+//
+//    HOUR(serial_number)
+//
+func (fn *formulaFuncs) HOUR(argsList *list.List) formulaArg {
+	if argsList.Len() != 1 {
+		return newErrorFormulaArg(formulaErrorVALUE, "HOUR requires exactly 1 argument")
+	}
+	date := argsList.Front().Value.(formulaArg)
+	num := date.ToNumber()
+	if num.Type != ArgNumber {
+		timeString := strings.ToLower(date.Value())
+		if !isTimeOnlyFmt(timeString) {
+			_, _, _, _, err := strToDate(timeString)
+			if err.Type == ArgError {
+				return err
+			}
+		}
+		h, _, _, pm, _, err := strToTime(timeString)
+		if err.Type == ArgError {
+			return err
+		}
+		if pm {
+			h += 12
+		}
+		return newNumberFormulaArg(float64(h))
+	}
+	if num.Number < 0 {
+		return newErrorFormulaArg(formulaErrorNUM, "HOUR only accepts positive argument")
+	}
+	return newNumberFormulaArg(float64(timeFromExcelTime(num.Number, false).Hour()))
+}
+
 // MINUTE function returns an integer representing the minute component of a
 // supplied Excel time. The syntax of the function is:
 //
@@ -8131,6 +8206,37 @@ func (fn *formulaFuncs) NOW(argsList *list.List) formulaArg {
 	return newNumberFormulaArg(25569.0 + float64(now.Unix()+int64(offset))/86400)
 }
 
+// SECOND function returns an integer representing the second component of a
+// supplied Excel time. The syntax of the function is:
+//
+//    SECOND(serial_number)
+//
+func (fn *formulaFuncs) SECOND(argsList *list.List) formulaArg {
+	if argsList.Len() != 1 {
+		return newErrorFormulaArg(formulaErrorVALUE, "SECOND requires exactly 1 argument")
+	}
+	date := argsList.Front().Value.(formulaArg)
+	num := date.ToNumber()
+	if num.Type != ArgNumber {
+		timeString := strings.ToLower(date.Value())
+		if !isTimeOnlyFmt(timeString) {
+			_, _, _, _, err := strToDate(timeString)
+			if err.Type == ArgError {
+				return err
+			}
+		}
+		_, _, s, _, _, err := strToTime(timeString)
+		if err.Type == ArgError {
+			return err
+		}
+		return newNumberFormulaArg(float64(int(s) % 60))
+	}
+	if num.Number < 0 {
+		return newErrorFormulaArg(formulaErrorNUM, "SECOND only accepts positive argument")
+	}
+	return newNumberFormulaArg(float64(timeFromExcelTime(num.Number, false).Second()))
+}
+
 // TIME function accepts three integer arguments representing hours, minutes
 // and seconds, and returns an Excel time. I.e. the function returns the
 // decimal value that represents the time in Excel. The syntax of the Time
@@ -8155,6 +8261,37 @@ func (fn *formulaFuncs) TIME(argsList *list.List) formulaArg {
 	return newNumberFormulaArg(t)
 }
 
+// TIMEVALUE function converts a text representation of a time, into an Excel
+// time. The syntax of the Timevalue function is:
+//
+//    TIMEVALUE(time_text)
+//
+func (fn *formulaFuncs) TIMEVALUE(argsList *list.List) formulaArg {
+	if argsList.Len() != 1 {
+		return newErrorFormulaArg(formulaErrorVALUE, "TIMEVALUE requires exactly 1 argument")
+	}
+	date := argsList.Front().Value.(formulaArg)
+	timeString := strings.ToLower(date.Value())
+	if !isTimeOnlyFmt(timeString) {
+		_, _, _, _, err := strToDate(timeString)
+		if err.Type == ArgError {
+			return err
+		}
+	}
+	h, m, s, pm, _, err := strToTime(timeString)
+	if err.Type == ArgError {
+		return err
+	}
+	if pm {
+		h += 12
+	}
+	args := list.New()
+	args.PushBack(newNumberFormulaArg(float64(h)))
+	args.PushBack(newNumberFormulaArg(float64(m)))
+	args.PushBack(newNumberFormulaArg(s))
+	return fn.TIME(args)
+}
+
 // TODAY function returns the current date. The function has no arguments and
 // therefore. The syntax of the function is:
 //
diff --git a/calc_test.go b/calc_test.go
index c3be308..e49b29e 100644
--- a/calc_test.go
+++ b/calc_test.go
@@ -990,6 +990,12 @@ func TestCalcCellValue(t *testing.T) {
 		"=WEIBULL.DIST(1,3,1,FALSE)":  "1.103638323514327",
 		"=WEIBULL.DIST(2,5,1.5,TRUE)": "0.985212776817482",
 		// Information Functions
+		// ERROR.TYPE
+		"=ERROR.TYPE(1/0)":           "2",
+		"=ERROR.TYPE(COT(0))":        "2",
+		"=ERROR.TYPE(XOR(\"text\"))": "3",
+		"=ERROR.TYPE(HEX2BIN(2,1))":  "6",
+		"=ERROR.TYPE(NA())":          "7",
 		// ISBLANK
 		"=ISBLANK(A1)": "FALSE",
 		"=ISBLANK(A5)": "TRUE",
@@ -1139,6 +1145,13 @@ func TestCalcCellValue(t *testing.T) {
 		"=DAYS(2,1)":                           "1",
 		"=DAYS(INT(2),INT(1))":                 "1",
 		"=DAYS(\"02/02/2015\",\"01/01/2015\")": "32",
+		// HOUR
+		"=HOUR(1)":                    "0",
+		"=HOUR(43543.5032060185)":     "12",
+		"=HOUR(\"43543.5032060185\")": "12",
+		"=HOUR(\"13:00:55\")":         "13",
+		"=HOUR(\"1:00 PM\")":          "13",
+		"=HOUR(\"12/09/2015 08:55\")": "8",
 		// ISOWEEKNUM
 		"=ISOWEEKNUM(42370)":          "53",
 		"=ISOWEEKNUM(\"42370\")":      "53",
@@ -1183,10 +1196,26 @@ func TestCalcCellValue(t *testing.T) {
 		"=YEARFRAC(\"02/29/2000\", \"01/29/2001\",1)": "0.915300546448087",
 		"=YEARFRAC(\"02/29/2000\", \"03/29/2000\",1)": "0.0792349726775956",
 		"=YEARFRAC(\"01/31/2000\", \"03/29/2000\",4)": "0.163888888888889",
+		// SECOND
+		"=SECOND(\"13:35:55\")":            "55",
+		"=SECOND(\"13:10:60\")":            "0",
+		"=SECOND(\"13:10:61\")":            "1",
+		"=SECOND(\"08:17:00\")":            "0",
+		"=SECOND(\"12/09/2015 08:55\")":    "0",
+		"=SECOND(\"12/09/2011 08:17:23\")": "23",
+		"=SECOND(\"43543.5032060185\")":    "37",
+		"=SECOND(43543.5032060185)":        "37",
 		// TIME
 		"=TIME(5,44,32)":             "0.239259259259259",
 		"=TIME(\"5\",\"44\",\"32\")": "0.239259259259259",
 		"=TIME(0,0,73)":              "0.000844907407407407",
+		// TIMEVALUE
+		"=TIMEVALUE(\"2:23\")":             "0.0993055555555556",
+		"=TIMEVALUE(\"2:23 am\")":          "0.0993055555555556",
+		"=TIMEVALUE(\"2:23 PM\")":          "0.599305555555555",
+		"=TIMEVALUE(\"14:23:00\")":         "0.599305555555555",
+		"=TIMEVALUE(\"00:02:23\")":         "0.00165509259259259",
+		"=TIMEVALUE(\"01/01/2011 02:23\")": "0.0993055555555556",
 		// WEEKDAY
 		"=WEEKDAY(0)":                 "7",
 		"=WEEKDAY(47119)":             "2",
@@ -2167,12 +2196,14 @@ func TestCalcCellValue(t *testing.T) {
 		"=POISSON(0,0,\"\")":     "strconv.ParseBool: parsing \"\": invalid syntax",
 		"=POISSON(0,-1,TRUE)":    "#N/A",
 		// SUM
-		"=SUM((":   ErrInvalidFormula.Error(),
-		"=SUM(-)":  ErrInvalidFormula.Error(),
-		"=SUM(1+)": ErrInvalidFormula.Error(),
-		"=SUM(1-)": ErrInvalidFormula.Error(),
-		"=SUM(1*)": ErrInvalidFormula.Error(),
-		"=SUM(1/)": ErrInvalidFormula.Error(),
+		"=SUM((":             ErrInvalidFormula.Error(),
+		"=SUM(-)":            ErrInvalidFormula.Error(),
+		"=SUM(1+)":           ErrInvalidFormula.Error(),
+		"=SUM(1-)":           ErrInvalidFormula.Error(),
+		"=SUM(1*)":           ErrInvalidFormula.Error(),
+		"=SUM(1/)":           ErrInvalidFormula.Error(),
+		"=SUM(1*SUM(1/0))":   "#DIV/0!",
+		"=SUM(1*SUM(1/0)*1)": "#DIV/0!",
 		// SUMIF
 		"=SUMIF()": "SUMIF requires at least 2 arguments",
 		// SUMSQ
@@ -2453,6 +2484,9 @@ func TestCalcCellValue(t *testing.T) {
 		"=ZTEST(A1,1)":      "#DIV/0!",
 		"=ZTEST(A1,1,\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",
 		// Information Functions
+		// ERROR.TYPE
+		"=ERROR.TYPE()":  "ERROR.TYPE requires 1 argument",
+		"=ERROR.TYPE(1)": "#N/A",
 		// ISBLANK
 		"=ISBLANK(A1,A2)": "ISBLANK requires 1 argument",
 		// ISERR
@@ -2582,6 +2616,11 @@ func TestCalcCellValue(t *testing.T) {
 		"=DAYS(0,\"\")": "#VALUE!",
 		"=DAYS(NA(),0)": "#VALUE!",
 		"=DAYS(0,NA())": "#VALUE!",
+		// HOUR
+		"=HOUR()":             "HOUR requires exactly 1 argument",
+		"=HOUR(-1)":           "HOUR only accepts positive argument",
+		"=HOUR(\"\")":         "#VALUE!",
+		"=HOUR(\"25:10:55\")": "#VALUE!",
 		// ISOWEEKNUM
 		"=ISOWEEKNUM()":                    "ISOWEEKNUM requires 1 argument",
 		"=ISOWEEKNUM(\"\")":                "#VALUE!",
@@ -2612,10 +2651,20 @@ func TestCalcCellValue(t *testing.T) {
 		"=YEARFRAC(42005,42094,\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",
 		// NOW
 		"=NOW(A1)": "NOW accepts no arguments",
+		// SECOND
+		"=SECOND()":          "SECOND requires exactly 1 argument",
+		"=SECOND(-1)":        "SECOND only accepts positive argument",
+		"=SECOND(\"\")":      "#VALUE!",
+		"=SECOND(\"25:55\")": "#VALUE!",
 		// TIME
 		"=TIME()":         "TIME requires 3 number arguments",
 		"=TIME(\"\",0,0)": "TIME requires 3 number arguments",
 		"=TIME(0,0,-1)":   "#NUM!",
+		// TIMEVALUE
+		"=TIMEVALUE()":          "TIMEVALUE requires exactly 1 argument",
+		"=TIMEVALUE(1)":         "#VALUE!",
+		"=TIMEVALUE(-1)":        "#VALUE!",
+		"=TIMEVALUE(\"25:55\")": "#VALUE!",
 		// TODAY
 		"=TODAY(A1)": "TODAY accepts no arguments",
 		// WEEKDAY
@@ -3354,7 +3403,7 @@ func TestCalcCellValue(t *testing.T) {
 		f := prepareCalcData(cellData)
 		assert.NoError(t, f.SetCellFormula("Sheet1", "C1", formula))
 		result, err := f.CalcCellValue("Sheet1", "C1")
-		assert.EqualError(t, err, expected)
+		assert.EqualError(t, err, expected, formula)
 		assert.Equal(t, "", result, formula)
 	}
 
diff --git a/xmlWorkbook.go b/xmlWorkbook.go
index f014bee..2bb417c 100644
--- a/xmlWorkbook.go
+++ b/xmlWorkbook.go
@@ -139,19 +139,19 @@ type xlsxBookViews struct {
 // http://schemas.openxmlformats.org/spreadsheetml/2006/main This element
 // specifies a single Workbook view.
 type xlsxWorkBookView struct {
-	ActiveTab              int    `xml:"activeTab,attr,omitempty"`
-	AutoFilterDateGrouping bool   `xml:"autoFilterDateGrouping,attr,omitempty"`
-	FirstSheet             int    `xml:"firstSheet,attr,omitempty"`
-	Minimized              bool   `xml:"minimized,attr,omitempty"`
-	ShowHorizontalScroll   bool   `xml:"showHorizontalScroll,attr,omitempty"`
-	ShowSheetTabs          bool   `xml:"showSheetTabs,attr,omitempty"`
-	ShowVerticalScroll     bool   `xml:"showVerticalScroll,attr,omitempty"`
-	TabRatio               int    `xml:"tabRatio,attr,omitempty"`
 	Visibility             string `xml:"visibility,attr,omitempty"`
-	WindowHeight           int    `xml:"windowHeight,attr,omitempty"`
-	WindowWidth            int    `xml:"windowWidth,attr,omitempty"`
+	Minimized              bool   `xml:"minimized,attr,omitempty"`
+	ShowHorizontalScroll   *bool  `xml:"showHorizontalScroll,attr"`
+	ShowVerticalScroll     *bool  `xml:"showVerticalScroll,attr"`
+	ShowSheetTabs          *bool  `xml:"showSheetTabs,attr"`
 	XWindow                string `xml:"xWindow,attr,omitempty"`
 	YWindow                string `xml:"yWindow,attr,omitempty"`
+	WindowWidth            int    `xml:"windowWidth,attr,omitempty"`
+	WindowHeight           int    `xml:"windowHeight,attr,omitempty"`
+	TabRatio               int    `xml:"tabRatio,attr,omitempty"`
+	FirstSheet             int    `xml:"firstSheet,attr,omitempty"`
+	ActiveTab              int    `xml:"activeTab,attr,omitempty"`
+	AutoFilterDateGrouping *bool  `xml:"autoFilterDateGrouping,attr"`
 }
 
 // xlsxSheets directly maps the sheets element from the namespace