Introduce option groups

src/CommandLine/Core/OptionSpecification.cs

@@ -1,4 +1,4 @@
-// Copyright 2005-2015 Giacomo Stelluti Scala & Contributors. All rights reserved. See License.md in the project root for license information.
+// Copyright 2005-2015 Giacomo Stelluti Scala & Contributors. All rights reserved. See License.md in the project root for license information.
 
 using System;
 using System.Collections.Generic;
@@ -13,16 +13,19 @@ sealed class OptionSpecification : Specification
         private readonly string longName;
         private readonly char separator;
         private readonly string setName;
+        private readonly string group;
 
         public OptionSpecification(string shortName, string longName, bool required, string setName, Maybe<int> min, Maybe<int> max,
             char separator, Maybe<object> defaultValue, string helpText, string metaValue, IEnumerable<string> enumValues,
-            Type conversionType, TargetType targetType, bool hidden = false)
-            : base(SpecificationType.Option, required, min, max, defaultValue, helpText, metaValue, enumValues, conversionType, targetType, hidden)
+            Type conversionType, TargetType targetType, string group, bool hidden = false)
+            : base(SpecificationType.Option,
+                 required, min, max, defaultValue, helpText, metaValue, enumValues, conversionType, targetType, hidden)
         {
             this.shortName = shortName;
             this.longName = longName;
             this.separator = separator;
             this.setName = setName;
+            this.group = group;
         }
 
         public static OptionSpecification FromAttribute(OptionAttribute attribute, Type conversionType, IEnumerable<string> enumValues)
@@ -41,13 +44,14 @@ public static OptionSpecification FromAttribute(OptionAttribute attribute, Type
                 enumValues,
                 conversionType,
                 conversionType.ToTargetType(),
+                attribute.Group,
                 attribute.Hidden);
         }
 
         public static OptionSpecification NewSwitch(string shortName, string longName, bool required, string helpText, string metaValue, bool hidden = false)
         {
             return new OptionSpecification(shortName, longName, required, string.Empty, Maybe.Nothing<int>(), Maybe.Nothing<int>(),
-                '\0', Maybe.Nothing<object>(), helpText, metaValue, Enumerable.Empty<string>(), typeof(bool), TargetType.Switch, hidden);
+                '\0', Maybe.Nothing<object>(), helpText, metaValue, Enumerable.Empty<string>(), typeof(bool), TargetType.Switch, string.Empty, hidden);
         }
 
         public string ShortName
@@ -69,5 +73,10 @@ public string SetName
         {
             get { return setName; }
         }
+
+        public string Group
+        {
+            get { return group; }
+        }
     }
-}
+}

src/CommandLine/Core/SpecificationExtensions.cs

@@ -34,6 +34,7 @@ public static OptionSpecification WithLongName(this OptionSpecification specific
                 specification.EnumValues,
                 specification.ConversionType,
                 specification.TargetType,
+                specification.Group,
                 specification.Hidden);
         }
 

src/CommandLine/Core/SpecificationPropertyRules.cs

@@ -1,9 +1,10 @@
-// Copyright 2005-2015 Giacomo Stelluti Scala & Contributors. All rights reserved. See License.md in the project root for license information.
+// Copyright 2005-2015 Giacomo Stelluti Scala & Contributors. All rights reserved. See License.md in the project root for license information.
+
+using CSharpx;
 
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using CSharpx;
 
 namespace CommandLine.Core
 {
@@ -16,12 +17,43 @@ public static IEnumerable<Func<IEnumerable<SpecificationProperty>, IEnumerable<E
             return new List<Func<IEnumerable<SpecificationProperty>, IEnumerable<Error>>>
                 {
                     EnforceMutuallyExclusiveSet(),
+                    EnforceGroup(),
                     EnforceRequired(),
                     EnforceRange(),
                     EnforceSingle(tokens)
                 };
         }
 
+        private static Func<IEnumerable<SpecificationProperty>, IEnumerable<Error>> EnforceGroup()
+        {
+            return specProps =>
+            {
+                var optionsValues =
+                    from sp in specProps
+                    where sp.Specification.IsOption()
+                    let o = (OptionSpecification)sp.Specification
+                    where o.Group.Length > 0
+                    select new
+                    {
+                        Option = o,
+                        Value = sp.Value
+                    };
+
+                var groups = from o in optionsValues
+                             group o by o.Option.Group into g
+                             select g;
+
+                var errorGroups = groups.Where(gr => gr.All(g => g.Value.IsNothing()));
+
+                if (errorGroups.Any())
+                {
+                    return errorGroups.Select(gr => new MissingGroupOptionError(gr.Key, gr.Select(g => new NameInfo(g.Option.ShortName, g.Option.LongName))));
+                }
+
+                return Enumerable.Empty<Error>();
+            };
+        }
+
         private static Func<IEnumerable<SpecificationProperty>, IEnumerable<Error>> EnforceMutuallyExclusiveSet()
         {
             return specProps =>
@@ -51,26 +83,27 @@ private static Func<IEnumerable<SpecificationProperty>, IEnumerable<Error>> Enfo
             return specProps =>
             {
                 var requiredWithValue = from sp in specProps
-                    where sp.Specification.IsOption()
-                    where sp.Specification.Required
-                    where sp.Value.IsJust()
-                    let o = (OptionSpecification)sp.Specification
-                    where o.SetName.Length > 0
-                    select sp.Specification;
+                                        where sp.Specification.IsOption()
+                                        where sp.Specification.Required
+                                        where sp.Value.IsJust()
+                                        let o = (OptionSpecification)sp.Specification
+                                        where o.SetName.Length > 0
+                                        select sp.Specification;
                 var setWithRequiredValue = (
                     from s in requiredWithValue
                     let o = (OptionSpecification)s
                     where o.SetName.Length > 0
                     select o.SetName)
                         .Distinct();
                 var requiredWithoutValue = from sp in specProps
-                    where sp.Specification.IsOption()
-                    where sp.Specification.Required
-                    where sp.Value.IsNothing()
-                    let o = (OptionSpecification)sp.Specification
-                    where o.SetName.Length > 0
-                    where setWithRequiredValue.ContainsIfNotEmpty(o.SetName)
-                    select sp.Specification;
+                                           where sp.Specification.IsOption()
+                                           where sp.Specification.Required
+                                           where sp.Value.IsNothing()
+                                           let o = (OptionSpecification)sp.Specification
+                                           where o.SetName.Length > 0
+                                           where o.Group.Length == 0
+                                           where setWithRequiredValue.ContainsIfNotEmpty(o.SetName)
+                                           select sp.Specification;
                 var missing =
                     requiredWithoutValue
                         .Except(requiredWithValue)
@@ -81,6 +114,7 @@ where sp.Specification.Required
                             where sp.Value.IsNothing()
                             let o = (OptionSpecification)sp.Specification
                             where o.SetName.Length == 0
+                            where o.Group.Length == 0
                             select sp.Specification)
                         .Concat(
                             from sp in specProps
@@ -130,11 +164,11 @@ from o in to.DefaultIfEmpty()
                                        where o != null
                                        select new { o.ShortName, o.LongName };
                     var longOptions = from t in tokens
-                                       where t.IsName()
-                                       join o in specs on t.Text equals o.LongName into to
-                                       from o in to.DefaultIfEmpty()
-                                       where o != null
-                                       select new { o.ShortName, o.LongName };
+                                      where t.IsName()
+                                      join o in specs on t.Text equals o.LongName into to
+                                      from o in to.DefaultIfEmpty()
+                                      where o != null
+                                      select new { o.ShortName, o.LongName };
                     var groups = from x in shortOptions.Concat(longOptions)
                                  group x by x into g
                                  let count = g.Count()
@@ -155,4 +189,4 @@ private static bool ContainsIfNotEmpty<T>(this IEnumerable<T> sequence, T value)
             return true;
         }
     }
-}
+}

src/CommandLine/Error.cs

@@ -1,6 +1,7 @@
 // Copyright 2005-2015 Giacomo Stelluti Scala & Contributors. All rights reserved. See License.md in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 
 namespace CommandLine
 {
@@ -69,7 +70,11 @@ public enum ErrorType
         /// <summary>
         /// Value of <see cref="CommandLine.InvalidAttributeConfigurationError"/> type.
         /// </summary>
-        InvalidAttributeConfigurationError
+        InvalidAttributeConfigurationError,
+        /// <summary>
+        /// Value of <see cref="CommandLine.MissingGroupOptionError"/> type.
+        /// </summary>
+        MissingGroupOptionError
 
     }
 
@@ -210,7 +215,7 @@ public override bool Equals(object obj)
         /// <remarks>A hash code for the current <see cref="System.Object"/>.</remarks>
         public override int GetHashCode()
         {
-            return new {Tag, StopsProcessing, Token}.GetHashCode();
+            return new { Tag, StopsProcessing, Token }.GetHashCode();
         }
 
         /// <summary>
@@ -289,7 +294,7 @@ public override bool Equals(object obj)
         /// <remarks>A hash code for the current <see cref="System.Object"/>.</remarks>
         public override int GetHashCode()
         {
-            return new {Tag, StopsProcessing, NameInfo}.GetHashCode();
+            return new { Tag, StopsProcessing, NameInfo }.GetHashCode();
         }
 
         /// <summary>
@@ -526,4 +531,29 @@ internal InvalidAttributeConfigurationError()
         {
         }
     }
+
+    public sealed class MissingGroupOptionError : Error
+    {
+        public const string ErrorMessage = "At least one option in a group must have value.";
+
+        private readonly string group;
+        private readonly IEnumerable<NameInfo> names;
+
+        internal MissingGroupOptionError(string group, IEnumerable<NameInfo> names)
+            : base(ErrorType.MissingGroupOptionError)
+        {
+            this.group = group;
+            this.names = names;
+        }
+
+        public string Group
+        {
+            get { return group; }
+        }
+
+        public IEnumerable<NameInfo> Names
+        {
+            get { return names; }
+        }
+    }
 }

src/CommandLine/OptionAttribute.cs

@@ -1,8 +1,9 @@
 // Copyright 2005-2015 Giacomo Stelluti Scala & Contributors. All rights reserved. See License.md in the project root for license information.
 
-using System;
 using CommandLine.Infrastructure;
 
+using System;
+
 namespace CommandLine
 {
     /// <summary>
@@ -15,6 +16,7 @@ public sealed class OptionAttribute : BaseAttribute
         private readonly string shortName;
         private string setName;
         private char separator;
+        private string group=string.Empty;
 
         private OptionAttribute(string shortName, string longName) : base()
         {
@@ -100,8 +102,17 @@ public string SetName
         /// </summary>
         public char Separator
         {
-            get { return separator ; }
+            get { return separator; }
             set { separator = value; }
         }
+
+        /// <summary>
+        /// Gets or sets the option group name. When one or more options are grouped, at least one of them should have value. Required rules are ignored.
+        /// </summary>
+        public string Group
+        {
+            get { return group; }
+            set { group = value; }
+        }
     }
-}
+}