dotnet · BillWagner · Mar 17, 2022 · Mar 16, 2022
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+open System
+
+// <Snippet1>
+let longValue = -130L
+
+if longValue <= int64 SByte.MaxValue && longValue >= int64 SByte.MinValue then
+    let byteValue = int8 longValue
+    printfn $"Converted long integer value to {byteValue}."
+else
+    let rangeLimit, relationship =
+        if longValue > int64 SByte.MaxValue then
+            SByte.MaxValue, "greater"
+        else
+            SByte.MinValue, "less"
+
+    printfn $"Conversion failure: {longValue:n0} is {relationship} than {rangeLimit}."
+// </Snippet1>
@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="MaxValue1.fs" />
+  </ItemGroup>
+</Project>
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="parseex1.fs" />
+    <Compile Include="parseex2.fs" />
+    <Compile Include="parseex3.fs" />
+    <Compile Include="parse_1.fs" />
+  </ItemGroup>
+</Project>
@@ -0,0 +1,74 @@
+module parse_1
+
+// <Snippet2>
+open System
+open System.Globalization
+
+let provider = NumberFormatInfo.CurrentInfo
+
+let callParseOperation stringValue (style: NumberStyles) =
+    if stringValue = null then
+        printfn "Cannot parse a null string..."
+    else
+        try
+            let number = SByte.Parse(stringValue, style)
+            printfn $"SByte.Parse('{stringValue}', {style})) = {number}" 
+        with
+        | :? FormatException ->
+            printfn $"'{stringValue}' and {style} throw a FormatException"
+        | :? OverflowException ->
+            printfn $"'{stringValue}' is outside the range of a signed byte"
+
+[<EntryPoint>]
+let main _ =
+    let stringValue = "   123   "
+    let style = NumberStyles.None     
+    callParseOperation stringValue style
+
+    let stringValue = "000,000,123"
+    let style = NumberStyles.Integer ||| NumberStyles.AllowThousands
+    callParseOperation stringValue style
+
+    let stringValue = "-100"
+    let style = NumberStyles.AllowLeadingSign
+    callParseOperation stringValue style
+
+    let stringValue = "100-"
+    let style = NumberStyles.AllowLeadingSign
+    callParseOperation stringValue style
+
+    let stringValue = "100-"
+    let style = NumberStyles.AllowTrailingSign
+    callParseOperation stringValue style
+
+    let stringValue = "$100"
+    let style = NumberStyles.AllowCurrencySymbol
+    callParseOperation stringValue style
+
+    let style = NumberStyles.Integer
+    callParseOperation stringValue style
+
+    let style = NumberStyles.AllowDecimalPoint
+    callParseOperation "100.0" style
+
+    let stringValue = "1e02"
+    let style = NumberStyles.AllowExponent
+    callParseOperation stringValue style
+
+    let stringValue = "(100)"
+    let style = NumberStyles.AllowParentheses
+    callParseOperation stringValue style
+    0
+
+// The example displays the following information to the console:
+//       '   123   ' and None throw a FormatException
+//       SByte.Parse('000,000,123', Integer, AllowThousands)) = 123
+//       SByte.Parse('-100', AllowLeadingSign)) = -100
+//       '100-' and AllowLeadingSign throw a FormatException
+//       SByte.Parse('100-', AllowTrailingSign)) = -100
+//       SByte.Parse('$100', AllowCurrencySymbol)) = 100
+//       '$100' and Integer throw a FormatException
+//       SByte.Parse('100.0', AllowDecimalPoint)) = 100
+//       SByte.Parse('1e02', AllowExponent)) = 100
+//       SByte.Parse('(100)', AllowParentheses)) = -100
+// </Snippet2>
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+module parseex1
+
+// <Snippet1>
+open System
+
+// Define an array of numeric strings.
+let values = 
+    [| "-16"; "  -3"; "+ 12"; " +12 "; "  12  "
+       "+120"; "(103)"; "192"; "-160" |]
+
+// Parse each string and display the result.
+for value in values do
+    try
+        printfn $"Converted '{value}' to the SByte value {SByte.Parse value}."
+    with
+    | :? FormatException ->
+        printfn $"'{value}' cannot be parsed successfully by SByte type."
+    | :? OverflowException ->
+        printfn $"'{value}' is out of range of the SByte type."
+
+// The example displays the following output:
+//       Converted '-16' to the SByte value -16.
+//       Converted '  -3' to the SByte value -3.
+//       '+ 12' cannot be parsed successfully by SByte type.
+//       Converted ' +12 ' to the SByte value 12.
+//       Converted '  12  ' to the SByte value 12.
+//       Converted '+120' to the SByte value 120.
+//       '(103)' cannot be parsed successfully by SByte type.
+//       '192' is out of range of the SByte type.
+//       '-160' is out of range of the SByte type.
+// </Snippet1>
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+module parseex2
+
+// <Snippet2>
+open System
+open System.Globalization
+
+// Parse value with no styles allowed.
+let values1 = [| " 121 "; "121"; "-121" |]
+let style = NumberStyles.None
+printfn $"Styles: {style}"
+for value in values1 do
+    try
+        let number = SByte.Parse(value, style)
+        printfn $"   Converted '{value}' to {number}."
+    with :? FormatException ->
+        printfn $"   Unable to parse '{value}'."
+printfn ""
+
+// Parse value with trailing sign.
+let style2 = NumberStyles.Integer ||| NumberStyles.AllowTrailingSign
+let values2 = [| " 103+"; " 103 +"; "+103"; "(103)"; "   +103  " |]
+printfn $"Styles: {style2}"
+for value in values2 do
+    try
+        let number = SByte.Parse(value, style2)
+        printfn $"   Converted '{value}' to {number}."
+    with 
+    | :? FormatException ->
+        printfn $"   Unable to parse '{value}'."
+    | :? OverflowException ->
+        printfn $"   '{value}' is out of range of the SByte type."         
+printfn ""
+// The example displays the following output:
+//       Styles: None
+//          Unable to parse ' 121 '.
+//          Converted '121' to 121.
+//          Unable to parse '-121'.
+//       
+//       Styles: Integer, AllowTrailingSign
+//          Converted ' 103+' to 103.
+//          Converted ' 103 +' to 103.
+//          Converted '+103' to 103.
+//          Unable to parse '(103)'.
+//          Converted '   +103  ' to 103.
+// </Snippet2>
@@ -0,0 +1,37 @@
+module parseex3
+
+// <Snippet3>
+open System
+open System.Globalization
+
+let nf = NumberFormatInfo()
+nf.NegativeSign <- "~" 
+
+let values = [| "-103"; "+12"; "~16"; "  1"; "~255" |]
+let providers: IFormatProvider[] = [| nf; CultureInfo.InvariantCulture |]
+
+for provider in providers do
+    printfn $"Conversions using {(box provider).GetType().Name}:"
+    for value in values do
+        try
+            printfn $"   Converted '{value}' to {SByte.Parse(value, provider)}."
+        with
+        | :? FormatException ->
+            printfn $"   Unable to parse '{value}'."
+        | :? OverflowException ->
+            printfn $"   '{value}' is out of range of the SByte type."
+
+// The example displays the following output:
+//       Conversions using NumberFormatInfo:
+//          Unable to parse '-103'.
+//          Converted '+12' to 12.
+//          Converted '~16' to -16.
+//          Converted '  1' to 1.
+//          '~255' is out of range of the SByte type.
+//       Conversions using CultureInfo:
+//          Converted '-103' to -103.
+//          Converted '+12' to 12.
+//          Unable to parse '~16'.
+//          Converted '  1' to 1.
+//          Unable to parse '~255'.
+// </Snippet3>
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="tostring2.fs" />
+    <Compile Include="tostring3.fs" />
+    <Compile Include="tostring4.fs" />
+    <Compile Include="tostring5.fs" />
+  </ItemGroup>
+</Project>
@@ -0,0 +1,14 @@
+module tostring2
+
+// <Snippet2>
+let value = -123y
+// Display value using default ToString method.
+printfn $"{value.ToString()}"               // Displays -123
+// Display value using some standard format specifiers.
+printfn $"""{value.ToString "G"}"""         // Displays -123
+printfn $"""{value.ToString "C"}"""         // Displays ($-123.00)
+printfn $"""{value.ToString "D"}"""         // Displays -123
+printfn $"""{value.ToString "F"}"""         // Displays -123.00
+printfn $"""{value.ToString "N"}"""         // Displays -123.00
+printfn $"""{value.ToString "X"}"""         // Displays 85
+// </Snippet2>
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+module tostring3
+
+// <Snippet3>
+open System.Globalization
+
+// Define a custom NumberFormatInfo object with "~" as its negative sign.
+let nfi = NumberFormatInfo(NegativeSign = "~")
+
+// Initialize an array of SByte values.
+let bytes = [| -122y; 17y; 124y |]
+
+// Display the formatted result using the custom provider.
+printfn "Using the custom NumberFormatInfo object:"
+for value in bytes do
+    printfn $"{value.ToString nfi}"
+
+printfn ""
+
+// Display the formatted result using the invariant culture.
+printfn "Using the invariant culture:"
+for value in bytes do
+   printfn $"{value.ToString NumberFormatInfo.InvariantInfo}"
+// The example displays the following output:
+//       Using the custom NumberFormatInfo object:
+//       ~122
+//       17
+//       124
+//       
+//       Using the invariant culture:
+//       -122
+//       17
+//       124
+// </Snippet3>
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+module tostring4
+
+// <Snippet4>
+let values = [| -124y; 0y; 118y |]
+let specifiers = 
+    [| "G"; "C"; "D3"; "E2"; "e3"; "F" 
+       "N"; "P"; "X"; "00.0"; "#.0" 
+       "000(0)**Zero**" |]
+
+for value in values do
+    for specifier in specifiers do
+        printfn $"{specifier}: {value.ToString specifier}"
+    printfn ""
+// The example displays the following output:
+//       G: -124
+//       C: ($124.00)
+//       D3: -124
+//       E2: -1.24E+002
+//       e3: -1.240e+002
+//       F: -124.00
+//       N: -124.00
+//       P: -12,400.00 %
+//       X: 84
+//       00.0: -124.0
+//       #.0: -124.0
+//       000(0)**Zero**: (124)
+//       
+//       G: 0
+//       C: $0.00
+//       D3: 000
+//       E2: 0.00E+000
+//       e3: 0.000e+000
+//       F: 0.00
+//       N: 0.00
+//       P: 0.00 %
+//       X: 0
+//       00.0: 00.0
+//       #.0: .0
+//       000(0)**Zero**: **Zero**
+//       
+//       G: 118
+//       C: $118.00
+//       D3: 118
+//       E2: 1.18E+002
+//       e3: 1.180e+002
+//       F: 118.00
+//       N: 118.00
+//       P: 11,800.00 %
+//       X: 76
+//       00.0: 118.0
+//       #.0: 118.0
+//       000(0)**Zero**: 118
+// </Snippet4>