replace std.variant with std.sumtype

source/dub/commandline.d

@@ -35,7 +35,6 @@ import std.process;
 import std.stdio;
 import std.string;
 import std.typecons : Tuple, tuple;
-import std.variant;
 import std.path: setExtension;
 
 /** Retrieves a list of all available commands.
@@ -598,8 +597,10 @@ struct CommonOptions {
 */
 class CommandArgs {
 	struct Arg {
-		Variant defaultValue;
-		Variant value;
+		alias Value = SumType!(string[], string, bool, int, uint);
+
+		Value defaultValue;
+		Value value;
 		string names;
 		string[] helpText;
 		bool hidden;
@@ -658,23 +659,32 @@ class CommandArgs {
 
 	void getopt(T)(string names, T* var, void delegate(string, string) @safe parseValue, string[] help_text = null, bool hidden=false)
 	{
+		import std.traits : OriginalType;
+
 		foreach (ref arg; m_recognizedArgs)
 			if (names == arg.names) {
 				assert(help_text is null, format!("Duplicated argument '%s' must not change helptext, consider to remove the duplication")(names));
-				*var = arg.value.get!T;
+				*var = arg.value.match!(
+					(OriginalType!T v) => cast(T)v,
+					(_) {
+						if (false)
+							return T.init;
+						assert(false, "value from previous getopt has different type than the current getopt call");
+					}
+				);
 				return;
 			}
 		assert(help_text.length > 0);
 		Arg arg;
-		arg.defaultValue = *var;
+		arg.defaultValue = cast(OriginalType!T)*var;
 		arg.names = names;
 		arg.helpText = help_text;
 		arg.hidden = hidden;
 		if (parseValue is null)
 			m_args.getopt(config.passThrough, names, var);
 		else
 			m_args.getopt(config.passThrough, names, parseValue);
-		arg.value = *var;
+		arg.value = cast(OriginalType!T)*var;
 		m_recognizedArgs ~= arg;
 	}
 
@@ -2725,13 +2735,16 @@ private void writeOptions(CommandArgs args)
 		} else writeWS(longArgColumn);
 		size_t col = longArgColumn;
 		if (larg !is null) {
-			if (arg.defaultValue.peek!bool) {
-				writef("--%s", larg);
-				col += larg.length + 2;
-			} else {
-				writef("--%s=VALUE", larg);
-				col += larg.length + 8;
-			}
+			arg.defaultValue.match!(
+				(bool b) {
+					writef("--%s", larg);
+					col += larg.length + 2;
+				},
+				(_) {
+					writef("--%s=VALUE", larg);
+					col += larg.length + 8;
+				}
+			);
 		}
 		if (col < descColumn) {
 			writeWS(descColumn - col);

source/dub/internal/sdlang/ast.d

@@ -23,6 +23,8 @@ import dub.internal.sdlang.exception;
 import dub.internal.sdlang.token;
 import dub.internal.sdlang.util;
 
+import dub.internal.dyaml.stdsumtype;
+
 class Attribute
 {
 	Value    value;
@@ -1102,7 +1104,10 @@ class Tag
 
 		// Values
 		foreach(val; values)
-			buf.put("    (%s): %s\n".format(.toString(val.type), val));
+			buf.put("    (%s): %s\n".format(
+				val.match!(v => typeof(v).stringof),
+				val
+			));
 
 		// Attributes
 		foreach(attrNamespace; _attributes.keys.sort())
@@ -1116,7 +1121,9 @@ class Tag
 
 			buf.put(
 				"    %s%s(%s): %s\n".format(
-					namespaceStr, attr._name, .toString(attr.value.type), attr.value
+					namespaceStr, attr._name,
+					attr.value.match!(v => typeof(v).stringof),
+					attr.value
 				)
 			);
 		}

source/dub/internal/sdlang/parser.d

@@ -7,7 +7,6 @@ version (Have_sdlang_d) public import sdlang.parser;
 else:
 
 import std.file;
-import std.variant : Algebraic;
 
 import dub.internal.libInputVisitor;
 
@@ -18,6 +17,8 @@ import dub.internal.sdlang.symbol;
 import dub.internal.sdlang.token;
 import dub.internal.sdlang.util;
 
+import dub.internal.dyaml.stdsumtype;
+
 /// Returns root tag.
 Tag parseFile(string filename)
 {
@@ -119,7 +120,7 @@ auto pullParseSource(string source, string filename=null)
 }
 
 /// The element of the InputRange returned by pullParseFile and pullParseSource:
-alias ParserEvent = Algebraic!(
+alias ParserEvent = SumType!(
 	FileStartEvent,
 	FileEndEvent,
 	TagStartEvent,
@@ -483,41 +484,41 @@ private struct DOMParser
 		auto eventRange = inputVisitor!ParserEvent( parser );
 		foreach(event; eventRange)
 		{
-			if(auto e = event.peek!TagStartEvent())
-			{
-				auto newTag = new Tag(currTag, e.namespace, e.name);
-				newTag.location = e.location;
-
-				currTag = newTag;
-			}
-			else if(event.peek!TagEndEvent())
-			{
-				currTag = currTag.parent;
-
-				if(!currTag)
-					parser.error("Internal Error: Received an extra TagEndEvent");
-			}
-			else if(auto e = event.peek!ValueEvent())
-			{
-				currTag.add(e.value);
-			}
-			else if(auto e = event.peek!AttributeEvent())
-			{
-				auto attr = new Attribute(e.namespace, e.name, e.value, e.location);
-				currTag.add(attr);
-			}
-			else if(event.peek!FileStartEvent())
-			{
-				// Do nothing
-			}
-			else if(event.peek!FileEndEvent())
-			{
-				// There shouldn't be another parent.
-				if(currTag.parent)
-					parser.error("Internal Error: Unexpected end of file, not enough TagEndEvent");
-			}
-			else
-				parser.error("Internal Error: Received unknown parser event");
+			event.match!(
+				(TagStartEvent e)
+				{
+					auto newTag = new Tag(currTag, e.namespace, e.name);
+					newTag.location = e.location;
+
+					currTag = newTag;
+				},
+				(TagEndEvent _)
+				{
+					currTag = currTag.parent;
+
+					if(!currTag)
+						parser.error("Internal Error: Received an extra TagEndEvent");
+				},
+				(ValueEvent e)
+				{
+					currTag.add(e.value);
+				},
+				(AttributeEvent e)
+				{
+					auto attr = new Attribute(e.namespace, e.name, e.value, e.location);
+					currTag.add(attr);
+				},
+				(FileStartEvent _)
+				{
+					// Do nothing
+				},
+				(FileEndEvent _)
+				{
+					// There shouldn't be another parent.
+					if(currTag.parent)
+						parser.error("Internal Error: Unexpected end of file, not enough TagEndEvent");
+				}
+			);
 		}
 
 		return currTag;

source/dub/internal/sdlang/token.d

@@ -13,7 +13,8 @@ import std.datetime;
 import std.range;
 import std.string;
 import std.typetuple;
-import std.variant;
+
+import dub.internal.dyaml.stdsumtype;
 
 import dub.internal.sdlang.symbol;
 import dub.internal.sdlang.util;
@@ -80,16 +81,16 @@ Date Time (with a known timezone):    SysTime
 Date Time (with an unknown timezone): DateTimeFracUnknownZone
 +/
 alias TypeTuple!(
+	typeof(null),
 	bool,
 	string, dchar,
 	int, long,
 	float, double, real,
 	Date, DateTimeFrac, SysTime, DateTimeFracUnknownZone, Duration,
 	ubyte[],
-	typeof(null),
 ) ValueTypes;
 
-alias Algebraic!( ValueTypes ) Value; ///ditto
+alias SumType!ValueTypes Value; /// ditto
 
 template isSDLSink(T)
 {
@@ -124,16 +125,7 @@ string toSDLString(T)(T value) if(
 
 void toSDLString(Sink)(Value value, ref Sink sink) if(isOutputRange!(Sink,char))
 {
-	foreach(T; ValueTypes)
-	{
-		if(value.type == typeid(T))
-		{
-			toSDLString( value.get!T(), sink );
-			return;
-		}
-	}
-
-	throw new Exception("Internal SDLang-D error: Unhandled type of Value. Contains: "~value.toString());
+	value.match!(v => toSDLString(v, sink));
 }
 
 void toSDLString(Sink)(typeof(null) value, ref Sink sink) if(isOutputRange!(Sink,char))
@@ -362,7 +354,6 @@ struct Token
 	{
 		if(
 			this.symbol     != b.symbol     ||
-			this.value.type != b.value.type ||
 			this.value      != b.value
 		)
 			return false;