Replace Option with Nullable

source/tanya/algorithm/iteration.d

@@ -21,11 +21,11 @@
 module tanya.algorithm.iteration;
 
 import std.algorithm.comparison;
+import std.typecons;
 import tanya.memory.lifetime;
 import tanya.meta.trait;
 import tanya.meta.transform;
 import tanya.range;
-import tanya.typecons;
 
 // These predicates are used to help preserve `const` and `inout` for
 // ranges built on other ranges.
@@ -570,7 +570,7 @@ if (isBidirectionalRange!Range)
 
 private struct SingletonByValue(E)
 {
-    private Option!E element;
+    private Nullable!E element;
 
     @disable this();
 
@@ -581,9 +581,9 @@ private struct SingletonByValue(E)
     }
 
     private this(U)(ref U element)
-    if (is(Unqual!U == Option!(Unqual!E)) || is(Unqual!U == Option!(const E)))
+    if (is(Unqual!U == Nullable!(Unqual!E)) || is(Unqual!U == Nullable!(const E)))
     {
-        if (!element.isNothing)
+        if (!element.isNull)
         {
             this.element = element.get;
         }
@@ -600,19 +600,19 @@ private struct SingletonByValue(E)
     void popFront()
     in (!empty)
     {
-        this.element.reset();
+        this.element.nullify();
     }
 
     alias popBack = popFront;
 
     @property bool empty() const
     {
-        return this.element.isNothing;
+        return this.element.isNull;
     }
 
     @property size_t length() const
     {
-        return !this.element.isNothing;
+        return !this.element.isNull;
     }
 
     auto save()
@@ -620,11 +620,6 @@ private struct SingletonByValue(E)
         return SingletonByValue!E(this.element);
     }
 
-    auto save() const
-    {
-        return SingletonByValue!(const E)(this.element);
-    }
-
     ref inout(E) opIndex(size_t i) inout
     in (!empty)
     in (i == 0)
@@ -675,11 +670,6 @@ private struct SingletonByRef(E)
         return typeof(this)(*this.element);
     }
 
-    auto save() const return
-    {
-        return SingletonByRef!(const E)(*this.element);
-    }
-
     ref inout(E) opIndex(size_t i) inout return
     in (!empty)
     in (i == 0)

source/tanya/math/random.d

@@ -14,6 +14,7 @@
  */
 module tanya.math.random;
 
+import std.typecons;
 import tanya.memory.allocator;
 import tanya.typecons;
 
@@ -90,8 +91,8 @@ abstract class EntropySource
      * Postcondition: Returned length is less than or equal to
      *                $(D_PARAM output) length.
      */
-    Option!ubyte poll(out ubyte[maxGather] output) @nogc
+    Nullable!ubyte poll(out ubyte[maxGather] output) @nogc
-    out (length; length.isNothing || length.get <= maxGather);
+    out (length; length.isNull || length.get <= maxGather);
 }
 
 version (CRuntime_Bionic)
@@ -151,12 +152,12 @@ version (linux)
          * Returns: Number of bytes that were copied to the $(D_PARAM output)
          *          or nothing on error.
          */
-        override Option!ubyte poll(out ubyte[maxGather] output) @nogc nothrow
+        override Nullable!ubyte poll(out ubyte[maxGather] output) @nogc nothrow
         {
             // int getrandom(void *buf, size_t buflen, unsigned int flags);
             import mir.linux._asm.unistd : NR_getrandom;
             auto length = syscall(NR_getrandom, output.ptr, output.length, 0);
-            Option!ubyte ret;
+            Nullable!ubyte ret;
 
             if (length >= 0)
             {
@@ -202,11 +203,11 @@ else version (SecureARC4Random)
          * Returns: Number of bytes that were copied to the $(D_PARAM output)
          *          or nothing on error.
          */
-        override Option!ubyte poll(out ubyte[maxGather] output)
+        override Nullable!ubyte poll(out ubyte[maxGather] output)
         @nogc nothrow @safe
         {
             (() @trusted => arc4random_buf(output.ptr, output.length))();
-            return Option!ubyte(cast(ubyte) (output.length));
+            return Nullable!ubyte(cast(ubyte) (output.length));
         }
     }
 }
@@ -310,10 +311,10 @@ else version (Windows)
          * Returns: Number of bytes that were copied to the $(D_PARAM output)
          *          or nothing on error.
          */
-        override Option!ubyte poll(out ubyte[maxGather] output)
+        override Nullable!ubyte poll(out ubyte[maxGather] output)
         @nogc nothrow @safe
         {
-            Option!ubyte ret;
+            Nullable!ubyte ret;
 
             assert(hProvider > 0, "hProvider not properly initialized");
             if ((() @trusted => CryptGenRandom(hProvider, output.length, cast(PBYTE) output.ptr))())

source/tanya/net/ip.d

@@ -15,6 +15,7 @@
 module tanya.net.ip;
 
 import std.algorithm.comparison;
+import std.typecons;
 import tanya.algorithm.iteration;
 import tanya.algorithm.mutation;
 import tanya.container.string;
@@ -242,7 +243,7 @@ struct Address4
      *
      * Returns: $(D_PARAM output).
      */
-    OR toString(OR)(OR output) const @nogc nothrow pure @safe
+    OR toString(OR)(OR output) const
     if (isOutputRange!(OR, const(char)[]))
     {
         const octets = (() @trusted => (cast(ubyte*) &this.address)[0 .. 4])();
@@ -324,10 +325,10 @@ struct Address4
  *  R     = Input range type.
  *  range = Stringish range containing the address.
  *
- * Returns: $(D_PSYMBOL Option) containing the address if the parsing was
+ * Returns: $(D_PSYMBOL Nullable) containing the address if the parsing was
  *          successful, or nothing otherwise.
  */
-Option!Address4 address4(R)(R range)
+Nullable!Address4 address4(R)(R range)
 if (isForwardRange!R && is(Unqual!(ElementType!R) == char) && hasLength!R)
 {
     Address4 result;
@@ -370,10 +371,10 @@ if (isForwardRange!R && is(Unqual!(ElementType!R) == char) && hasLength!R)
  *  R     = Input range type.
  *  range = $(D_KEYWORD ubyte) range containing the address.
  *
- * Returns: $(D_PSYMBOL Option) containing the address if the $(D_PARAM range)
+ * Returns: $(D_PSYMBOL Nullable) containing the address if the $(D_PARAM range)
  *          contains exactly 4 bytes, or nothing otherwise.
  */
-Option!Address4 address4(R)(R range)
+Nullable!Address4 address4(R)(R range)
 if (isInputRange!R && is(Unqual!(ElementType!R) == ubyte))
 {
     Address4 result;
@@ -407,11 +408,11 @@ if (isInputRange!R && is(Unqual!(ElementType!R) == ubyte))
     }
     {
         ubyte[3] actual = [127, 0, 0];
-        assert(address4(actual[]).isNothing);
+        assert(address4(actual[]).isNull);
     }
     {
         ubyte[5] actual = [127, 0, 0, 0, 1];
-        assert(address4(actual[]).isNothing);
+        assert(address4(actual[]).isNull);
     }
 }
 
@@ -795,10 +796,10 @@ in (digit < 16)
  *  R     = Input range type.
  *  range = Stringish range containing the address.
  *
- * Returns: $(D_PSYMBOL Option) containing the address if the parsing was
+ * Returns: $(D_PSYMBOL Nullable) containing the address if the parsing was
  *          successful, or nothing otherwise.
  */
-Option!Address6 address6(R)(R range)
+Nullable!Address6 address6(R)(R range)
 if (isForwardRange!R && is(Unqual!(ElementType!R) == char) && hasLength!R)
 {
     if (range.empty)
@@ -1006,10 +1007,10 @@ CopyTail:
  *  range   = $(D_KEYWORD ubyte) range containing the address.
  *  scopeID = Scope ID.
  *
- * Returns: $(D_PSYMBOL Option) containing the address if the $(D_PARAM range)
+ * Returns: $(D_PSYMBOL Nullable) containing the address if the $(D_PARAM range)
  *          contains exactly 16 bytes, or nothing otherwise.
  */
-Option!Address6 address6(R)(R range, uint scopeID = 0)
+Nullable!Address6 address6(R)(R range, uint scopeID = 0)
 if (isInputRange!R && is(Unqual!(ElementType!R) == ubyte))
 {
     Address6 result;
@@ -1030,20 +1031,20 @@ if (isInputRange!R && is(Unqual!(ElementType!R) == ubyte))
     {
         ubyte[16] actual = [ 1, 2, 3, 4, 5, 6, 7, 8,
                              9, 10, 11, 12, 13, 14, 15, 16 ];
-        assert(!address6(actual[]).isNothing);
+        assert(!address6(actual[]).isNull);
     }
     {
         ubyte[15] actual = [ 1, 2, 3, 4, 5, 6, 7, 8,
                              9, 10, 11, 12, 13, 14, 15 ];
-        assert(address6(actual[]).isNothing);
+        assert(address6(actual[]).isNull);
     }
     {
         ubyte[17] actual = [ 1, 2, 3, 4, 5, 6, 7, 8, 9,
                              10, 11, 12, 13, 14, 15, 16, 17 ];
-        assert(address6(actual[]).isNothing);
+        assert(address6(actual[]).isNull);
     }
     {
-        assert(address6(cast(ubyte[]) []).isNothing);
+        assert(address6(cast(ubyte[]) []).isNull);
     }
 }
 

source/tanya/typecons.d

@@ -153,274 +153,6 @@ template tuple(Names...)
     assert(t.two == 5);
 }
 
-/**
- * $(D_PSYMBOL Option) is a type that contains an optional value.
- *
- * Params:
- *  T = Type of the encapsulated value.
- *
- * See_Also: $(D_PSYMBOL option).
- */
-struct Option(T)
-{
-    private bool isNothing_ = true;
-    private T value = void;
-
-    /**
-     * Constructs a new option with $(D_PARAM value).
-     *
-     * Params:
-     *  value = Encapsulated value.
-     */
-    this()(ref T value)
-    {
-        this.value = value;
-        this.isNothing_ = false;
-    }
-
-    /// ditto
-    this()(T value) @trusted
-    {
-        moveEmplace(value, this.value);
-        this.isNothing_ = false;
-    }
-
-    /**
-     * Tells if the option is just a value or nothing.
-     *
-     * Returns: $(D_KEYWORD true) if this $(D_PSYMBOL Option) contains a nothing,
-     *          $(D_KEYWORD false) if it contains a value.
-     */
-    @property bool isNothing() const
-    {
-        return this.isNothing_;
-    }
-
-    /**
-     * Returns the encapsulated value.
-     *
-     * Returns: Value encapsulated in this $(D_PSYMBOL Option).
-     *
-     * See_Also: $(D_PSYMBOL or).
-     *
-     * Precondition: `!isNothing`.
-     */
-    @property ref inout(T) get() inout
-    in (!isNothing, "Option is nothing")
-    {
-        return this.value;
-    }
-
-    /**
-     * Returns the encapsulated value if available or a default value
-     * otherwise.
-     *
-     * Note that the contained value can be returned by reference only if the
-     * default value is passed by reference as well.
-     *
-     * Params:
-     *  U            = Type of the default value.
-     *  defaultValue = Default value.
-     *
-     * Returns: The value of this $(D_PSYMBOL Option) if available,
-     *          $(D_PARAM defaultValue) otherwise.
-     *
-     * See_Also: $(D_PSYMBOL isNothing), $(D_PSYMBOL get).
-     */
-    @property U or(U)(U defaultValue) inout
-    if (is(U == T) && isCopyable!T)
-    {
-        return isNothing ? defaultValue : this.value;
-    }
-
-    /// ditto
-    @property ref inout(T) or(ref inout(T) defaultValue) inout
-    {
-        return isNothing ? defaultValue : this.value;
-    }
-
-    /**
-     * Casts this $(D_PSYMBOL Option) to $(D_KEYWORD bool).
-     *
-     * An $(D_PSYMBOL Option) is $(D_KEYWORD true) if it contains a value,
-     * ($D_KEYWORD false) if it contains nothing.
-     *
-     * Returns: $(D_KEYWORD true) if this $(D_PSYMBOL Option) contains a value,
-     *          ($D_KEYWORD false) if it contains nothing.
-     */
-    bool opCast(U : bool)()
-    {
-        return !isNothing;
-    }
-
-    /**
-     * Compares this $(D_PSYMBOL Option) with $(D_PARAM that).
-     *
-     * If both objects are options of the same type and they don't contain a
-     * value, they are considered equal. If only one of them contains a value,
-     * they aren't equal. Otherwise, the encapsulated values are compared for
-     * equality.
-     *
-     * If $(D_PARAM U) is a type comparable with the type encapsulated by this
-     * $(D_PSYMBOL Option), the value of this $(D_PSYMBOL Option) is compared
-     * with $(D_PARAM that), this $(D_PSYMBOL Option) must have a value then.
-     *
-     * Params:
-     *  U    = Type of the object to compare with.
-     *  that = Object to compare with.
-     *
-     * Returns: $(D_KEYWORD true) if this $(D_PSYMBOL Option) and
-     *          $(D_PARAM that) are equal, $(D_KEYWORD false) if not.
-     *
-     * Precondition: `!isNothing` if $(D_PARAM U) is equality comparable with
-     *               $(D_PARAM T).
-     */
-    bool opEquals(U)(auto ref const U that) const
-    if (is(U == Option))
-    {
-        if (!isNothing && !that.isNothing)
-        {
-            return this.value == that.value;
-        }
-        return isNothing == that.isNothing;
-    }
-
-    /// ditto
-    bool opEquals(U)(auto ref const U that) const
-    if (ifTestable!(U, a => a == T.init) && !is(U == Option))
-    in (!isNothing)
-    {
-        return get == that;
-    }
-
-    /**
-     * Resets this $(D_PSYMBOL Option) and destroys the contained value.
-     *
-     * $(D_PSYMBOL reset) can be safely called on an $(D_PSYMBOL Option) that
-     * doesn't contain any value.
-     */
-    void reset()
-    {
-        static if (hasElaborateDestructor!T)
-        {
-            destroy(this.value);
-        }
-        this.isNothing_ = true;
-    }
-
-    /**
-     * Assigns a new value.
-     *
-     * Params:
-     *  U    = Type of the new value.
-     *  that = New value.
-     *
-     * Returns: $(D_KEYWORD this).
-     */
-    ref typeof(this) opAssign(U)(ref U that)
-    if (is(U : T) && !is(U == Option))
-    {
-        this.value = that;
-        this.isNothing_ = false;
-        return this;
-    }
-
-    /// ditto
-    ref typeof(this) opAssign(U)(U that)
-    if (is(U == T))
-    {
-        move(that, this.value);
-        this.isNothing_ = false;
-        return this;
-    }
-
-    /// ditto
-    ref typeof(this) opAssign(U)(ref U that)
-    if (is(U == Option))
-    {
-        if (that.isNothing)
-        {
-            reset();
-        }
-        else
-        {
-            this.value = that.get;
-            this.isNothing_ = false;
-        }
-        return this;
-    }
-
-    /// ditto
-    ref typeof(this) opAssign(U)(U that)
-    if (is(U == Option))
-    {
-        move(that.value, this.value);
-        this.isNothing_ = that.isNothing_;
-        return this;
-    }
-
-    version (D_Ddoc)
-    {
-        /**
-         * If $(D_PARAM T) has a `toHash()` method, $(D_PSYMBOL Option) defines
-         * `toHash()` which returns `T.toHash()` if it is set or 0 otherwise.
-         *
-         * Returns: Hash value.
-         */
-        size_t toHash() const;
-    }
-    else static if (is(typeof(T.init.toHash()) == size_t))
-    {
-        size_t toHash() const
-        {
-            return isNothing ? 0U : this.value.toHash();
-        }
-    }
-}
-
-///
-@nogc nothrow pure @safe unittest
-{
-    Option!int option;
-    assert(option.isNothing);
-    assert(option.or(8) == 8);
-    
-    option = 5;
-    assert(!option.isNothing);
-    assert(option.get == 5);
-    assert(option.or(8) == 5);
-
-    option.reset();
-    assert(option.isNothing);
-}
-
-/**
- * Creates a new $(D_PSYMBOL Option).
- *
- * Params:
- *  T     = Option type.
- *  value = Initial value.
- *
- * See_Also: $(D_PSYMBOL Option).
- */
-Option!T option(T)(auto ref T value)
-{
-    return Option!T(forward!value);
-}
-
-/// ditto
-Option!T option(T)()
-{
-    return Option!T();
-}
-
-///
-@nogc nothrow pure @safe unittest
-{
-    assert(option!int().isNothing);
-    assert(option(5) == 5);
-}
-
 /**
  * Type that can hold one of the types listed as its template parameters.
  *

tests/tanya/net/tests/ip.d

@@ -9,17 +9,17 @@ import tanya.range;
 // Rejects malformed addresses
 @nogc nothrow pure @safe unittest
 {
-    assert(address4("256.0.0.1").isNothing);
+    assert(address4("256.0.0.1").isNull);
-    assert(address4(".0.0.1").isNothing);
+    assert(address4(".0.0.1").isNull);
-    assert(address4("0..0.1").isNothing);
+    assert(address4("0..0.1").isNull);
-    assert(address4("0.0.0.").isNothing);
+    assert(address4("0.0.0.").isNull);
-    assert(address4("0.0.").isNothing);
+    assert(address4("0.0.").isNull);
-    assert(address4("").isNothing);
+    assert(address4("").isNull);
 }
 
 @nogc nothrow pure @safe unittest
 {
-    assert(address4(cast(ubyte[]) []).isNothing);
+    assert(address4(cast(ubyte[]) []).isNull);
 }
 
 // Assignment and comparison works
@@ -106,12 +106,12 @@ import tanya.range;
 // Rejects malformed addresses
 @nogc nothrow @safe unittest
 {
-    assert(address6("").isNothing);
+    assert(address6("").isNull);
-    assert(address6(":").isNothing);
+    assert(address6(":").isNull);
-    assert(address6(":a").isNothing);
+    assert(address6(":a").isNull);
-    assert(address6("a:").isNothing);
+    assert(address6("a:").isNull);
-    assert(address6("1:2:3:4::6:").isNothing);
+    assert(address6("1:2:3:4::6:").isNull);
-    assert(address6("fe80:2:3:4::6:7:8%").isNothing);
+    assert(address6("fe80:2:3:4::6:7:8%").isNull);
 }
 
 // Parses embedded IPv4 address
@@ -138,9 +138,9 @@ import tanya.range;
 
 @nogc nothrow @safe unittest
 {
-    assert(address6("0:0:0:0:0:0:1.2.3.").isNothing);
+    assert(address6("0:0:0:0:0:0:1.2.3.").isNull);
-    assert(address6("0:0:0:0:0:0:1.2:3.4").isNothing);
+    assert(address6("0:0:0:0:0:0:1.2:3.4").isNull);
-    assert(address6("0:0:0:0:0:0:1.2.3.4.").isNothing);
+    assert(address6("0:0:0:0:0:0:1.2.3.4.").isNull);
     assert(address6("fe80:0:0:0:0:0:1.2.3.4%1").get.scopeID == 1);
 }
 

tests/tanya/tests/typecons.d

@@ -22,120 +22,6 @@ import tanya.typecons;
     static assert(!is(Tuple!(int, "first", double, "second", char, "third")));
 }
 
-// Assigns a new value
-@nogc nothrow pure @safe unittest
-{
-    Option!int option = 5;
-    option = 8;
-    assert(!option.isNothing);
-    assert(option == 8);
-}
-
-@nogc nothrow pure @safe unittest
-{
-    Option!int option;
-    const int newValue = 8;
-    assert(option.isNothing);
-    option = newValue;
-    assert(!option.isNothing);
-    assert(option == newValue);
-}
-
-@nogc nothrow pure @safe unittest
-{
-    Option!int option1;
-    Option!int option2 = 5;
-    assert(option1.isNothing);
-    option1 = option2;
-    assert(!option1.isNothing);
-    assert(option1.get == 5);
-}
-
-// Constructs with a value passed by reference
-@nogc nothrow pure @safe unittest
-{
-    int i = 5;
-    assert(Option!int(i).get == 5);
-}
-
-// Moving
-@nogc nothrow pure @safe unittest
-{
-    static assert(is(typeof(Option!NonCopyable(NonCopyable()))));
-    // The value cannot be returned by reference because the default value
-    // isn't passed by reference
-    static assert(!is(typeof(Option!DisabledPostblit().or(NonCopyable()))));
-}
-
-@nogc nothrow pure @safe unittest
-{
-    NonCopyable notCopyable;
-    static assert(is(typeof(Option!NonCopyable().or(notCopyable))));
-}
-
-@nogc nothrow pure @safe unittest
-{
-    Option!NonCopyable option;
-    assert(option.isNothing);
-    option = NonCopyable();
-    assert(!option.isNothing);
-}
-
-@nogc nothrow pure @safe unittest
-{
-    Option!NonCopyable option;
-    assert(option.isNothing);
-    option = Option!NonCopyable(NonCopyable());
-    assert(!option.isNothing);
-}
-
-// Cast to bool is done before touching the encapsulated value
-@nogc nothrow pure @safe unittest
-{
-    assert(Option!bool(false));
-}
-
-// Option can be const
-@nogc nothrow pure @safe unittest
-{
-    assert((const Option!int(5)).get == 5);
-    assert((const Option!int()).or(5) == 5);
-}
-
-// Equality
-@nogc nothrow pure @safe unittest
-{
-    assert(Option!int() == Option!int());
-    assert(Option!int(0) != Option!int());
-    assert(Option!int(5) == Option!int(5));
-    assert(Option!int(5) == 5);
-    assert(Option!int(5) == cast(ubyte) 5);
-}
-
-// Returns default value
-@nogc nothrow pure @safe unittest
-{
-    int i = 5;
-    assert(((ref e) => e)(Option!int().or(i)) == 5);
-}
-
-// Implements toHash() for nothing
-@nogc nothrow pure @safe unittest
-{
-    alias OptionT = Option!Hashable;
-    assert(OptionT().toHash() == 0U);
-    assert(OptionT(Hashable(1U)).toHash() == 1U);
-}
-
-// Can assign Option that is nothing
-@nogc nothrow pure @safe unittest
-{
-    auto option1 = Option!int(5);
-    Option!int option2;
-    option1 = option2;
-    assert(option1.isNothing);
-}
-
 @nogc nothrow pure @safe unittest
 {
     Variant!(int, double) variant;