Fix/adjust TextOutput

* Don't repeat "ANSWER" line in aspcomp format when ifs is set to '\n'.
  See: potassco/clingo#355

* In general, TextOutput now only repeats the active category if the
  ifs is '\n' and the category string itself does not end with a '\n'.

* Don't use ifs in comments and summary lines and instead always use
  the default single space. This is not only simpler but also avoids
  strange mixing of category and summary keys, e.g. in case of
  multi-level optimization.

clasp/cli/clasp_output.h

@@ -246,6 +246,9 @@ class TextOutput : public Output, private StatsVisitor {
 	void        printChildren(const StatisticObject& s, unsigned level = 0, const char* prefix = 0);
 	int         printChildKey(unsigned level, const char* key, uint32 idx, const char* prefix = 0) const;
 private:
+	void        printCostsImpl(const SumVec&, char ifs, const char* ifsSuffix = "") const;
+	const char* getIfsSuffix(char ifs, CategoryKey cat) const;
+	const char* getIfsSuffix(CategoryKey cat) const;
 	struct SolveProgress {
 		int lines;
 		int last;

src/clasp_output.cpp

@@ -806,7 +806,7 @@ void TextOutput::printSummary(const ClaspFacade::Summary& run, bool final) {
 			if (run.optimize())     {
 				if (run.optimal() > 1){ printKeyValue("  Optimal", "%" PRIu64"\n", run.optimal()); }
 				printKey("Optimization");
-				printCosts(*run.costs());
+				printCostsImpl(*run.costs(), ' ');
 				printf("\n");
 			}
 			if (run.consequences()) {
@@ -927,27 +927,37 @@ void TextOutput::printSolveProgress(const Event& ev) {
 	printf("%s%s%c", format[cat_comment], line, lEnd);
 }
 
-const char* TextOutput::fieldSeparator() const { return ifs_; }
-int TextOutput::printSep(CategoryKey k) const {
-	return printf("%s%s", fieldSeparator(), *fieldSeparator() != '\n' ? "" : format[k]);
+static inline bool endsWith(const char* str, char c) {
+	return *str && str[strlen(str) - 1] == c;
+}
+
+const char* TextOutput::getIfsSuffix(char ifs, CategoryKey c) const {
+	return ifs != '\n' || endsWith(format[c], '\n') ? "" : format[c];
 }
+const char* TextOutput::getIfsSuffix(CategoryKey c) const {  return getIfsSuffix(ifs_[0], c);  }
+const char* TextOutput::fieldSeparator() const { return ifs_; }
+int TextOutput::printSep(CategoryKey k) const { return printf("%s%s", fieldSeparator(), getIfsSuffix(k)); }
 uintp TextOutput::doPrint(const OutPair& s, UPtr data) {
+	const uint32 MSB = 31u;
 	uint32& accu    = reinterpret_cast<UPair*>(data)->first;
 	uint32& maxLine = reinterpret_cast<UPair*>(data)->second;
-	if      (accu < maxLine) { accu += printSep(cat_value); }
+	if (accu == 0 && *getIfsSuffix(cat_value)) store_set_bit(accu, MSB);
+	const char* suf = test_bit(accu, MSB) ? format[cat_value] : "";
+	store_clear_bit(accu, MSB);
+	if      (accu < maxLine) { accu += printf("%c%s", *fieldSeparator(), suf); }
 	else if (!maxLine)       { maxLine = s.first || *fieldSeparator() != ' ' ? UINT32_MAX : 70; }
-	else                     { printf("\n%s", format[cat_value]); accu = 0; }
+	else                     { printf("%c%s", '\n', getIfsSuffix('\n', cat_value)); accu = 0; }
 	if (s.first){ accu += printf(format[cat_atom_name], s.first); }
 	else        { accu += printf(format[cat_atom_var] + !s.second.sign(), static_cast<int>(s.second.var())); }
+	if (*suf) store_set_bit(accu, MSB);
 	return data;
 }
 void TextOutput::printValues(const OutputTable& out, const Model& m) {
 	printf("%s", format[cat_value]);
 	UPair data;
 	printWitness(out, m, reinterpret_cast<UPtr>(&data));
 	if (*format[cat_value_term]) {
-		printSep(cat_value);
-		printf("%s", format[cat_value_term]);
+		printf("%c%s%s", *fieldSeparator(), getIfsSuffix(cat_value), format[cat_value_term]);
 	}
 	printf("\n");
 }
@@ -979,9 +989,8 @@ void TextOutput::printUnsat(const OutputTable& out, const LowerBound* lower, con
 		const SumVec* costs = prevModel ? prevModel->costs : 0;
 		printf("%s%-12s: ", format[cat_comment], "Progression");
 		if (costs && costs->size() > lower->level) {
-			const char* next = *fieldSeparator() != '\n' ? "" : format[cat_comment];
 			for (uint32 i = 0; i != lower->level; ++i) {
-				printf("%" PRId64 "%s%s", (*costs)[i], fieldSeparator(), next);
+				printf("%" PRId64 " ", (*costs)[i]);
 			}
 			wsum_t ub = (*costs)[lower->level];
 			int w = 1; for (wsum_t x = ub; x > 9; ++w) { x /= 10; }
@@ -1000,26 +1009,30 @@ void TextOutput::printUnsat(const OutputTable& out, const LowerBound* lower, con
 }
 
 void TextOutput::printBounds(const SumVec& lower, const SumVec& upper) const {
-	for (uint32 i = 0, uMax = upper.size(), lMax = lower.size(), end = std::max(uMax, lMax), seps = end; i != end; ++i) {
+	const char* sep = "";
+	for (uint32 i = 0, uMax = upper.size(), lMax = lower.size(), end = std::max(uMax, lMax); i != end; ++i) {
 		if (i >= uMax) {
-			printf("[%" PRId64";*]", lower[i]);
+			printf("%s[%" PRId64";*]", sep, lower[i]);
 		}
 		else if (i >= lMax || lower[i] == upper[i]) {
-			printf("%" PRId64, upper[i]);
+			printf("%s%" PRId64, sep, upper[i]);
 		}
 		else {
-			printf("[%" PRId64";%" PRId64"]", lower[i], upper[i]);
+			printf("%s[%" PRId64";%" PRId64"]", sep, lower[i], upper[i]);
 		}
-		if (--seps) { printSep(cat_objective); }
+		sep = " ";
 	}
 }
 
 void TextOutput::printCosts(const SumVec& costs) const {
+	printCostsImpl(costs, *fieldSeparator(), getIfsSuffix(cat_objective));
+}
+
+void TextOutput::printCostsImpl(const SumVec& costs, char ifs, const char* ifsSuffix) const {
 	if (!costs.empty()) {
 		printf("%" PRId64, costs[0]);
 		for (uint32 i = 1, end = (uint32)costs.size(); i != end; ++i) {
-			printSep(cat_objective);
-			printf("%" PRId64, costs[i]);
+			printf("%c%s%" PRId64, ifs, ifsSuffix, costs[i]);
 		}
 	}
 }