Refactoring: Decouple API implementation from config structures

.gitattributes

@@ -16,4 +16,4 @@
 *.gpg  filter=lfs diff=lfs merge=lfs binary
 *.bin  filter=lfs diff=lfs merge=lfs binary
 
-alpha-core/benchmarks/** linguist-vendored
+alpha-solver/benchmarks/** linguist-vendored

.gitignore

@@ -107,3 +107,4 @@ gradle-app.setting
 /.dbeaver
 /Scripts
 /.vscode/
+*.code-workspace

alpha-api/src/main/java/at/ac/tuwien/kr/alpha/api/Alpha.java

@@ -8,7 +8,7 @@
 
 import at.ac.tuwien.kr.alpha.api.common.fixedinterpretations.PredicateInterpretation;
 import at.ac.tuwien.kr.alpha.api.config.InputConfig;
-import at.ac.tuwien.kr.alpha.api.programs.ASPCore2Program;
+import at.ac.tuwien.kr.alpha.api.programs.InputProgram;
 import at.ac.tuwien.kr.alpha.api.programs.NormalProgram;
 import at.ac.tuwien.kr.alpha.api.programs.Predicate;
 
@@ -27,7 +27,7 @@ public interface Alpha {
 	 * @return an {@link ASPCore2Program} representing the parsed ASP code from all sources referenced in the given {@link InputConfig}
 	 * @throws IOException in case one or more program sources (e.g. files) cannot be read, or parsing fails
 	 */
-	ASPCore2Program readProgram(InputConfig cfg) throws IOException;
+	InputProgram readProgram(InputConfig cfg) throws IOException;
 
 	/**
 	 * Reads and parses an {@link ASPCore2Program} from a list of {@link String}s representing paths.
@@ -38,12 +38,12 @@ public interface Alpha {
 	 * @return an {@link ASPCore2Program} representing the parsed ASP code from all given path strings
 	 * @throws IOException in case one or more program sources cannot be read, or parsing fails
 	 */
-	ASPCore2Program readProgramFiles(boolean literate, Map<String, PredicateInterpretation> externals, List<String> paths) throws IOException;
+	InputProgram readProgramFiles(boolean literate, Map<String, PredicateInterpretation> externals, List<String> paths) throws IOException;
 
 	/**
 	 * see {@link Alpha#readProgramFiles(boolean, Map, List)}
 	 */
-	ASPCore2Program readProgramFiles(boolean literate, Map<String, PredicateInterpretation> externals, Path... paths) throws IOException;
+	InputProgram readProgramFiles(boolean literate, Map<String, PredicateInterpretation> externals, Path... paths) throws IOException;
 
 	/**
 	 * Parses a given String into an {@link ASPCore2Program}, using a map of custom {@link PredicateInterpretation}s to resolve external atoms
@@ -53,19 +53,19 @@ public interface Alpha {
 	 * @param externals a map of custom {@link PredicateInterpretation}s against which external atoms in the given code are resolved
 	 * @return an {@link ASPCore2Program} representing the parsed ASP code
 	 */
-	ASPCore2Program readProgramString(String aspString, Map<String, PredicateInterpretation> externals);
+	InputProgram readProgramString(String aspString, Map<String, PredicateInterpretation> externals);
 
 	/**
 	 * Convenience method to parse ASP strings not containing any user-defined external atoms, see {@link Alpha#readProgramString(String, Map)}.
 	 */
-	ASPCore2Program readProgramString(String aspString);
+	InputProgram readProgramString(String aspString);
 
 	/**
 	 * Prepares a {@link DebugSolvingContext} for the given {@link ASPCore2Program} to debug program preprocessing.
 	 * 
 	 * @return a {@link DebugSolvingContext} holding debug information for the given program
 	 */
-	DebugSolvingContext prepareDebugSolve(final ASPCore2Program program);
+	DebugSolvingContext prepareDebugSolve(final InputProgram program);
 
 	/**
 	 * Prepares a {@link DebugSolvingContext} for the given {@link NormalProgram} to debug program preprocessing.
@@ -80,7 +80,7 @@ public interface Alpha {
 	 * @param filter a {@link java.util.function.Predicate} against which {@link Predicate}s of answer sets are tested.
 	 * @return a {@link DebugSolvingContext} holding debug information for the given program
 	 */
-	DebugSolvingContext prepareDebugSolve(final ASPCore2Program program, java.util.function.Predicate<Predicate> filter);
+	DebugSolvingContext prepareDebugSolve(final InputProgram program, java.util.function.Predicate<Predicate> filter);
 
 	/**
 	 * Prepares a {@link DebugSolvingContext} for the given {@link NormalProgram} to debug program preprocessing.
@@ -95,15 +95,15 @@ public interface Alpha {
 	 * @param program an input program
 	 * @return a {@link Stream} of {@link AnswerSet}s of the given program
 	 */
-	Stream<AnswerSet> solve(ASPCore2Program program);
+	Stream<AnswerSet> solve(InputProgram program);
 
 	/**
 	 * Solves the given {@link ASPCore2Program}.
 	 * @param program an input program
 	 * @param filter a {@link java.util.function.Predicate} against which {@link Predicate}s of answer sets are tested.
 	 * @return a {@link Stream} of {@link AnswerSet}s of the given program
 	 */
-	Stream<AnswerSet> solve(ASPCore2Program program, java.util.function.Predicate<Predicate> filter);
+	Stream<AnswerSet> solve(InputProgram program, java.util.function.Predicate<Predicate> filter);
 
 	/**
 	 * Solves the given {@link NormalProgram}.
@@ -126,7 +126,7 @@ public interface Alpha {
 	 * @param program An {@link ASPCore2Program} to normalize
 	 * @return a {@link NormalProgram} that is a semantic equivalent to the given input program
 	 */
-	NormalProgram normalizeProgram(ASPCore2Program program);
+	NormalProgram normalizeProgram(InputProgram program);
 
 	/**
 	 * Constructs a @{link Solver} pre-loaded with the given {@link ASPCore2Program} from which {@link AnswerSet}s can be obtained via {@link Solver#stream()}.
@@ -135,7 +135,7 @@ public interface Alpha {
 	 * @param filter a {@link java.util.function.Predicate} against which {@link Predicate}s of answer sets are tested.
 	 * @return a {@link Solver} pre-loaded withthe given program
 	 */
-	Solver prepareSolverFor(ASPCore2Program program, java.util.function.Predicate<Predicate> filter);
+	Solver prepareSolverFor(InputProgram program, java.util.function.Predicate<Predicate> filter);
 
 	/**
 	 * Constructs a @{link Solver} pre-loaded with the given {@link NormalProgram} from which {@link AnswerSet}s can be obtained via {@link Solver#stream()}.

alpha-api/src/main/java/at/ac/tuwien/kr/alpha/api/ComparisonOperator.java

@@ -1,11 +1,11 @@
 package at.ac.tuwien.kr.alpha.api;
 
-import at.ac.tuwien.kr.alpha.api.programs.ASPCore2Program;
+import at.ac.tuwien.kr.alpha.api.programs.InputProgram;
 import at.ac.tuwien.kr.alpha.api.programs.Predicate;
 import at.ac.tuwien.kr.alpha.api.terms.Term;
 
 /**
- * A comparison operator that can be used in {@link ASPCore2Program}s.
+ * A comparison operator that can be used in {@link InputProgram}s.
  * 
  * Copyright (c) 2021, the Alpha Team.
  */

alpha-api/src/main/java/at/ac/tuwien/kr/alpha/api/DebugSolvingContext.java

@@ -1,6 +1,6 @@
 package at.ac.tuwien.kr.alpha.api;
 
-import at.ac.tuwien.kr.alpha.api.programs.ASPCore2Program;
+import at.ac.tuwien.kr.alpha.api.programs.InputProgram;
 import at.ac.tuwien.kr.alpha.api.programs.NormalProgram;
 import at.ac.tuwien.kr.alpha.api.programs.analysis.ComponentGraph;
 import at.ac.tuwien.kr.alpha.api.programs.analysis.DependencyGraph;
@@ -13,13 +13,13 @@
 public interface DebugSolvingContext {
 
 	/**
-	 * The normalized version of the {@link ASPCore2Program} that is being solved.
-	 * See {@link Alpha#normalizeProgram(ASPCore2Program)}.
+	 * The normalized version of the {@link InputProgram} that is being solved.
+	 * See {@link Alpha#normalizeProgram(InputProgram)}.
 	 */
 	NormalProgram getNormalizedProgram();
 
 	/**
-	 * The fully preprocessed version of the {@link ASPCore2Program} that is being solved.
+	 * The fully preprocessed version of the {@link InputProgram} that is being solved.
 	 * This differs from the value of {@link DebugSolvingContext#getNormalizedProgram()} in the stratified part of the normalized program may
 	 * already be evaluated depending on the respective configuration of {@link Alpha}.
 	 */

alpha-api/src/main/java/at/ac/tuwien/kr/alpha/api/config/SystemConfig.java

@@ -44,13 +44,11 @@ public class SystemConfig {
 	// initializing from those values in order to have the values accessible in
 	// contexts where no AlphaConfig instance exists (e.g. argument parsing from
 	// command line)
-	public static final String DEFAULT_GROUNDER_NAME = "naive";
 	public static final String DEFAULT_SOLVER_NAME = "default";
 	public static final String DEFAULT_NOGOOD_STORE_NAME = "alphaRoaming";
 	public static final Heuristic DEFAULT_BRANCHING_HEURISTIC = Heuristic.VSIDS;
 	public static final BinaryNoGoodPropagationEstimationStrategy DEFAULT_MOMS_STRATEGY = BinaryNoGoodPropagationEstimationStrategy.CountBinaryWatches;
 	public static final long DEFAULT_SEED = System.nanoTime();
-	public static final boolean DEFAULT_DETERMINISTIC = false;
 	public static final boolean DEFAULT_PRINT_STATS = false;
 	public static final boolean DEFAULT_QUIET = false;
 	public static final boolean DEFAULT_DISABLE_JUSTIFICATION_SEARCH = false;
@@ -65,10 +63,8 @@ public class SystemConfig {
 	public static final String DEFAULT_ATOM_SEPARATOR = ", ";
 	public static final AggregateRewritingConfig DEFAULT_AGGREGATE_REWRITING_CONFIG = new AggregateRewritingConfig();
 
-	private String grounderName = DEFAULT_GROUNDER_NAME;
 	private String solverName = DEFAULT_SOLVER_NAME;
 	private String nogoodStoreName = DEFAULT_NOGOOD_STORE_NAME;
-	private boolean deterministic = DEFAULT_DETERMINISTIC;
 	private long seed = DEFAULT_SEED;
 	private boolean debugInternalChecks = DEFAULT_DEBUG_INTERNAL_CHECKS;
 	private Heuristic branchingHeuristic = DEFAULT_BRANCHING_HEURISTIC;
@@ -86,17 +82,6 @@ public class SystemConfig {
 	private String atomSeparator = DEFAULT_ATOM_SEPARATOR;
 	private AggregateRewritingConfig aggregateRewritingConfig = DEFAULT_AGGREGATE_REWRITING_CONFIG;
 
-	public String getGrounderName() {
-		return this.grounderName;
-	}
-
-	/**
-	 * Sets the name of the grounder implementation to use.
-	 */
-	public void setGrounderName(String grounderName) {
-		this.grounderName = grounderName;
-	}
-
 	public String getSolverName() {
 		return this.solverName;
 	}
@@ -119,18 +104,6 @@ public void setNogoodStoreName(String nogoodStoreName) {
 		this.nogoodStoreName = nogoodStoreName;
 	}
 
-	public boolean isDeterministic() {
-		return this.deterministic;
-	}
-
-	/**
-	 * If set, 0 will be used as random seed for solver-internal branching heuristics, resulting in answer sets of the same program being found
-	 * in a fixed sequence.
-	 */
-	public void setDeterministic(boolean deterministic) {
-		this.deterministic = deterministic;
-	}
-
 	public long getSeed() {
 		return this.seed;
 	}

alpha-api/src/main/java/at/ac/tuwien/kr/alpha/api/programs/InputProgram.java

@@ -0,0 +1,9 @@
+package at.ac.tuwien.kr.alpha.api.programs;
+
+import at.ac.tuwien.kr.alpha.api.rules.Rule;
+import at.ac.tuwien.kr.alpha.api.rules.heads.Head;
+
+// TODO javadoc
+public interface InputProgram extends Program<Rule<Head>> {
+
+}

alpha-api/src/main/java/at/ac/tuwien/kr/alpha/api/programs/ProgramParser.java

@@ -9,40 +9,40 @@
 import at.ac.tuwien.kr.alpha.api.common.fixedinterpretations.PredicateInterpretation;
 
 /**
- * A parser for {@link ASPCore2Program}s.
+ * A parser for {@link InputProgram}s.
  * 
  * Copyright (c) 2021, the Alpha Team.
  */
 public interface ProgramParser {
 
-	default ASPCore2Program parse(String programString) {
+	default InputProgram parse(String programString) {
 		return parse(programString, Collections.emptyMap());
 	}
 
-	default ASPCore2Program parse(InputStream programSource) throws IOException {
+	default InputProgram parse(InputStream programSource) throws IOException {
 		return parse(programSource, Collections.emptyMap());
 	}
 
-	default ASPCore2Program parse(Path programPath) throws IOException {
+	default InputProgram parse(Path programPath) throws IOException {
 		return parse(programPath, Collections.emptyMap());
 	}
 
-	default ASPCore2Program parse(Path... programSources) throws IOException {
+	default InputProgram parse(Path... programSources) throws IOException {
 		return parse(Collections.emptyMap(), programSources);
 	}
 
-	default ASPCore2Program parse(Iterable<Path> programSources) throws IOException {
+	default InputProgram parse(Iterable<Path> programSources) throws IOException {
 		return parse(programSources, Collections.emptyMap());
 	}
 
-	ASPCore2Program parse(String programString, Map<String, PredicateInterpretation> externalPredicateDefinitions);
+	InputProgram parse(String programString, Map<String, PredicateInterpretation> externalPredicateDefinitions);
 
-	ASPCore2Program parse(InputStream programSource, Map<String, PredicateInterpretation> externalPredicateDefinitions) throws IOException;
+	InputProgram parse(InputStream programSource, Map<String, PredicateInterpretation> externalPredicateDefinitions) throws IOException;
 
-	ASPCore2Program parse(Path programPath, Map<String, PredicateInterpretation> externalPredicateDefinitions) throws IOException;
+	InputProgram parse(Path programPath, Map<String, PredicateInterpretation> externalPredicateDefinitions) throws IOException;
 
-	ASPCore2Program parse(Map<String, PredicateInterpretation> externalPredicateDefinitions, Path... programSources) throws IOException;
+	InputProgram parse(Map<String, PredicateInterpretation> externalPredicateDefinitions, Path... programSources) throws IOException;
 
-	ASPCore2Program parse(Iterable<Path> programSources, Map<String, PredicateInterpretation> externalPredicateDefinitions) throws IOException;
+	InputProgram parse(Iterable<Path> programSources, Map<String, PredicateInterpretation> externalPredicateDefinitions) throws IOException;
 
 }

alpha-cli-app/build.gradle.kts

@@ -69,5 +69,6 @@ tasks.create<Jar>("bundledJar") {
 }
 
 tasks.test {
+	dependsOn(":alpha-solver:test")
 	useJUnitPlatform()
 }

alpha-cli-app/src/main/java/at/ac/tuwien/kr/alpha/Main.java

@@ -50,8 +50,8 @@
 import at.ac.tuwien.kr.alpha.api.config.AlphaConfig;
 import at.ac.tuwien.kr.alpha.api.config.InputConfig;
 import at.ac.tuwien.kr.alpha.api.config.SystemConfig;
-import at.ac.tuwien.kr.alpha.api.impl.AlphaImpl;
-import at.ac.tuwien.kr.alpha.api.programs.ASPCore2Program;
+import at.ac.tuwien.kr.alpha.api.impl.AlphaFactory;
+import at.ac.tuwien.kr.alpha.api.programs.InputProgram;
 import at.ac.tuwien.kr.alpha.api.programs.NormalProgram;
 import at.ac.tuwien.kr.alpha.api.programs.analysis.ComponentGraph;
 import at.ac.tuwien.kr.alpha.api.programs.analysis.DependencyGraph;
@@ -80,9 +80,9 @@ public static void main(String[] args) {
 			Main.exitWithMessage(commandLineParser.getUsageMessage(), 1);
 		}
 
-		Alpha alpha = new AlphaImpl(cfg.getSystemConfig());
+		Alpha alpha = AlphaFactory.newAlpha(cfg.getSystemConfig());
 
-		ASPCore2Program program = null;
+		InputProgram program = null;
 		try {
 			program = alpha.readProgram(cfg.getInputConfig());
 		} catch (FileNotFoundException e) {

alpha-cli-app/src/main/java/at/ac/tuwien/kr/alpha/app/config/CommandLineParser.java

@@ -90,16 +90,12 @@ public class CommandLineParser {
 			.desc("Write answer sets to excel files, i.e. xlsx workbooks (one workbook per answer set)").build();
 
 	// general system-wide config
-	private static final Option OPT_GROUNDER = Option.builder("g").longOpt("grounder").hasArg(true).argName("grounder")
-			.desc("the grounder implementation to use (default: " + SystemConfig.DEFAULT_GROUNDER_NAME + ")").build();
 	private static final Option OPT_SOLVER = Option.builder("s").longOpt("solver").hasArg(true).argName("solver")
 			.desc("the solver implementation to use (default: " + SystemConfig.DEFAULT_SOLVER_NAME + ")").build();
 	private static final Option OPT_NOGOOD_STORE = Option.builder("r").longOpt("store").hasArg(true).argName("store")
 			.desc("the nogood store to use (default: " + SystemConfig.DEFAULT_NOGOOD_STORE_NAME + ")").build();
 	private static final Option OPT_SORT = Option.builder("sort").longOpt("sort").hasArg(false)
 			.desc("sort answer sets (default: " + SystemConfig.DEFAULT_SORT_ANSWER_SETS + ")").build();
-	private static final Option OPT_DETERMINISTIC = Option.builder("d").longOpt("deterministic").hasArg(false)
-			.desc("disables randomness (default: " + SystemConfig.DEFAULT_DETERMINISTIC + ")").build();
 	private static final Option OPT_SEED = Option.builder("e").longOpt("seed").hasArg(true).argName("seed").type(Integer.class)
 			.desc("set seed (default: System.nanoTime())").build();
 	private static final Option OPT_DEBUG_INTERNAL_CHECKS = Option.builder("dbgs").longOpt("DebugEnableInternalChecks")
@@ -167,11 +163,9 @@ public class CommandLineParser {
 		CommandLineParser.CLI_OPTS.addOption(CommandLineParser.OPT_DEBUG_PREPROCESSING);
 		CommandLineParser.CLI_OPTS.addOption(CommandLineParser.OPT_WRITE_XSLX);
 
-		CommandLineParser.CLI_OPTS.addOption(CommandLineParser.OPT_GROUNDER);
 		CommandLineParser.CLI_OPTS.addOption(CommandLineParser.OPT_SOLVER);
 		CommandLineParser.CLI_OPTS.addOption(CommandLineParser.OPT_NOGOOD_STORE);
 		CommandLineParser.CLI_OPTS.addOption(CommandLineParser.OPT_SORT);
-		CommandLineParser.CLI_OPTS.addOption(CommandLineParser.OPT_DETERMINISTIC);
 		CommandLineParser.CLI_OPTS.addOption(CommandLineParser.OPT_SEED);
 		CommandLineParser.CLI_OPTS.addOption(CommandLineParser.OPT_DEBUG_INTERNAL_CHECKS);
 		CommandLineParser.CLI_OPTS.addOption(CommandLineParser.OPT_BRANCHING_HEURISTIC);
@@ -225,11 +219,9 @@ private void initializeGlobalOptionHandlers() {
 		 */
 		// help is handled separately, therefore dummy handler
 		this.globalOptionHandlers.put(CommandLineParser.OPT_HELP.getOpt(), (o, c) -> { });
-		this.globalOptionHandlers.put(CommandLineParser.OPT_GROUNDER.getOpt(), this::handleGrounder);
 		this.globalOptionHandlers.put(CommandLineParser.OPT_SOLVER.getOpt(), this::handleSolver);
 		this.globalOptionHandlers.put(CommandLineParser.OPT_NOGOOD_STORE.getOpt(), this::handleNogoodStore);
 		this.globalOptionHandlers.put(CommandLineParser.OPT_SORT.getOpt(), this::handleSort);
-		this.globalOptionHandlers.put(CommandLineParser.OPT_DETERMINISTIC.getOpt(), this::handleDeterministic);
 		this.globalOptionHandlers.put(CommandLineParser.OPT_SEED.getOpt(), this::handleSeed);
 		this.globalOptionHandlers.put(CommandLineParser.OPT_DEBUG_INTERNAL_CHECKS.getOpt(), this::handleInternalChecks);
 		this.globalOptionHandlers.put(CommandLineParser.OPT_BRANCHING_HEURISTIC.getOpt(), this::handleBranchingHeuristic);
@@ -335,10 +327,6 @@ private void handleInput(Option opt, InputConfig cfg) {
 		cfg.getFiles().add(optVal);
 	}
 
-	private void handleGrounder(Option opt, SystemConfig cfg) {
-		cfg.setGrounderName(opt.getValue(SystemConfig.DEFAULT_GROUNDER_NAME));
-	}
-
 	private void handleSolver(Option opt, SystemConfig cfg) {
 		cfg.setSolverName(opt.getValue(SystemConfig.DEFAULT_SOLVER_NAME));
 	}
@@ -362,12 +350,10 @@ private void handleSort(Option opt, SystemConfig cfg) {
 	}
 
 	private void handleDeterministic(Option opt, SystemConfig cfg) {
-		cfg.setDeterministic(true);
 		cfg.setSeed(0);
 	}
 
 	private void handleSeed(Option opt, SystemConfig cfg) {
-		cfg.setDeterministic(false);
 		String optVal = opt.getValue();
 		long seed;
 		if (optVal != null) {

alpha-cli-app/src/test/java/at/ac/tuwien/kr/alpha/MainTest.java

@@ -49,10 +49,10 @@ public class MainTest {
 
 	private static Stream<Arguments> provideCommandLineArguments() {
 		return Stream.of(
-				Arguments.of((Object) new String[]{"-DebugEnableInternalChecks", "-g", "naive", "-s", "default", "-e", "1119654162577372", "-n", "20", "-str", INPUT}),
-				Arguments.of((Object) new String[]{"-DebugEnableInternalChecks", "-g", "naive", "-s", "default", "-n", "0", "-str", INPUT}),
-				Arguments.of((Object) new String[]{"-DebugEnableInternalChecks", "-g", "naive", "-s", "default", "-n", "1", "-str", INPUT}),
-				Arguments.of((Object) new String[]{"-g", "naive", "-s", "default", "-r", "naive", "-e", "1119654162577372", "--numAS", "1", "-str", INPUT}));
+				Arguments.of((Object) new String[]{"-DebugEnableInternalChecks", "-s", "default", "-e", "1119654162577372", "-n", "20", "-str", INPUT}),
+				Arguments.of((Object) new String[]{"-DebugEnableInternalChecks", "-s", "default", "-n", "0", "-str", INPUT}),
+				Arguments.of((Object) new String[]{"-DebugEnableInternalChecks", "-s", "default", "-n", "1", "-str", INPUT}),
+				Arguments.of((Object) new String[]{"-s", "default", "-r", "naive", "-e", "1119654162577372", "--numAS", "1", "-str", INPUT}));
 	}
 
 	/**