Version bump for release 0.1.7 RC 3

This adds support for declaring predicates as placeholders through the
“#external” directive in the input language of clingo.

Placeholders are not subject to completion. This prevents predicates
that represent instance-specific facts from being assumed as universally
false by default negation when translating an encoding.

This stretches clingo’s usual syntax a bit in order to make the
implementation lightweight. In order to declare a predicate with a
specific arity as a placeholder, the following statement needs to be
added to the input program:

CHANGELOG.md

@@ -1,6 +1,6 @@
 # Change Log
 
-## 0.1.7 (2018-04-08)
+## 0.1.7 RC 3 (2018-04-07)
 
 ### Features
 

LICENSE.md

@@ -1,6 +1,6 @@
 # The MIT License (MIT)
 
-Copyright © 2016–2018 Patrick Lühne
+Copyright © 2016–2017 Patrick Lühne
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

app/main.cpp

@@ -70,7 +70,7 @@ int main(int argc, char **argv)
 
 	if (version)
 	{
-		std::cout << "anthem version 0.1.7" << std::endl;
+		std::cout << "anthem version 0.1.7-rc.3" << std::endl;
 		return EXIT_SUCCESS;
 	}
 

examples/graph-coloring.lp

@@ -1,9 +1,12 @@
-#external color(1).
+colored(V, red) :- vertex(V), not colored(V, green), not colored(V, blue).
-#external edge(2).
+colored(V, green) :- vertex(V), not colored(V, red), not colored(V, blue).
-#external vertex(1).
+colored(V, blue) :- vertex(V), not colored(V, red), not colored(V, green).
-#show color/2.
 
-{color(V,C)} :- vertex(V), color(C).
+:- edge(V1, V2), colored(V1, C), colored(V2, C).
-covered(V) :- color(V, _).
+
-:- vertex(V), not covered(V).
+vertex(a).
-:- color(V1,C), color(V2,C), edge(V1,V2).
+vertex(b).
+vertex(c).
+
+edge(a, b).
+edge(a, c).

src/anthem/ASTUtils.cpp

@@ -59,7 +59,7 @@ bool VariableStack::contains(const VariableDeclaration &variableDeclaration) con
 		};
 
 	const auto layerContainsVariableDeclaration =
-		[&variableDeclarationMatches](const auto &layer)
+		[&variableDeclaration, &variableDeclarationMatches](const auto &layer)
 		{
 			return (std::find_if(layer->cbegin(), layer->cend(), variableDeclarationMatches) != layer->cend());
 		};

tests/TestPlaceholders.cpp

@@ -1,62 +0,0 @@
-#include <catch.hpp>
-
-#include <sstream>
-
-#include <anthem/AST.h>
-#include <anthem/Context.h>
-#include <anthem/Translation.h>
-
-////////////////////////////////////////////////////////////////////////////////////////////////////
-
-TEST_CASE("[placeholders] Programs with placeholders are correctly completed", "[placeholders]")
-{
-	std::stringstream input;
-	std::stringstream output;
-	std::stringstream errors;
-
-	anthem::output::Logger logger(output, errors);
-	anthem::Context context(std::move(logger));
-	context.performSimplification = true;
-	context.performCompletion = true;
-
-	SECTION("no placeholders")
-	{
-		input <<
-			"colored(V, red) :- vertex(V), not colored(V, green), not colored(V, blue).";
-		anthem::translate("input", input, context);
-
-		CHECK(output.str() ==
-			"forall V1, V2 (colored(V1, V2) <-> (V2 = red and vertex(V1) and not colored(V1, green) and not colored(V1, blue)))\n"
-			"forall V3 not vertex(V3)\n");
-	}
-
-	SECTION("single placeholder")
-	{
-		input <<
-			"#external vertex(1).\n"
-			"colored(V, red) :- vertex(V), not colored(V, green), not colored(V, blue).";
-		anthem::translate("input", input, context);
-
-		CHECK(output.str() ==
-			"forall V1, V2 (colored(V1, V2) <-> (V2 = red and vertex(V1) and not colored(V1, green) and not colored(V1, blue)))\n");
-	}
-
-	SECTION("complex example: graph coloring")
-	{
-		input <<
-			"#external color(1).\n"
-			"#external edge(2).\n"
-			"#external vertex(1).\n"
-			"#show color/2.\n"
-			"{color(V, C)} :- vertex(V), color(C).\n"
-			"covered(V) :- color(V, _).\n"
-			":- vertex(V), not covered(V).\n"
-			":- color(V1, C), color(V2, C), edge(V1, V2).";
-		anthem::translate("input", input, context);
-
-		CHECK(output.str() ==
-			"forall V1, V2 (color(V1, V2) <-> (vertex(V1) and color(V2) and color(V1, V2)))\n"
-			"forall U1 not (vertex(U1) and not exists U2 color(U1, U2))\n"
-			"forall U3, U4, U5 not (color(U3, U4) and color(U5, U4) and edge(U3, U5))\n");
-	}
-}