fixes unsigned range souffle-lang/souffle#2182

src/include/souffle/utility/EvaluatorUtil.h

@@ -24,7 +24,7 @@
 namespace souffle::evaluator {
 
 template <typename A, typename F /* Tuple<RamDomain,1> -> void */>
-void runRange(A from, A to, A step, F&& go) {
+void runRange(const A from, const A to, const A step, F&& go) {
 #define GO(x) go(Tuple<RamDomain, 1>{ramBitCast(x)})
     if (0 < step) {
         for (auto x = from; x < to; x += step) {
@@ -42,8 +42,26 @@ void runRange(A from, A to, A step, F&& go) {
 }
 
 template <typename A, typename F /* Tuple<RamDomain,1> -> void */>
-void runRange(A from, A to, F&& go) {
-    return runRange(from, to, A(from <= to ? 1 : -1), std::forward<F>(go));
+void runRangeBackward(const A from, const A to, F&& func) {
+    assert(from > to);
+    if (from > to) {
+        for (auto x = from; x > to; --x) {
+            func(Tuple<RamDomain, 1>{ramBitCast(x)});
+        }
+    }
+}
+
+template <typename A, typename F /* Tuple<RamDomain,1> -> void */>
+void runRange(const A from, const A to, F&& go) {
+    if constexpr (std::is_unsigned<A>()) {
+        if (from <= to) {
+            runRange(from, to, static_cast<A>(1U), std::forward<F>(go));
+        } else {
+            runRangeBackward(from, to, std::forward<F>(go));
+        }
+    } else {
+        return runRange(from, to, A(from <= to ? 1 : -1), std::forward<F>(go));
+    }
 }
 
 template <typename A>

tests/evaluation/rangeop/out10.csv

@@ -0,0 +1,4 @@
+-0.25
+-0.5
+-0.75
+-1

tests/evaluation/rangeop/out5.csv

@@ -0,0 +1,9 @@
+1
+2
+3
+4
+5
+6
+7
+8
+9

tests/evaluation/rangeop/out6.csv

@@ -0,0 +1,9 @@
+1
+2
+3
+4
+5
+6
+7
+8
+9

tests/evaluation/rangeop/out7.csv

@@ -0,0 +1,8 @@
+1.25
+2.25
+3.25
+4.25
+5.25
+6.25
+7.25
+8.25

tests/evaluation/rangeop/out8.csv

@@ -0,0 +1,13 @@
+-0.5
+-1
+-1.5
+-2
+-2.5
+-3
+-3.5
+-4
+-4.5
+0
+0.5
+1
+1.5

tests/evaluation/rangeop/out9.csv

@@ -0,0 +1,10 @@
+-0.5
+-1.5
+-2.5
+-3.5
+-4.5
+0.5
+1.5
+2.5
+3.5
+4.5

tests/evaluation/rangeop/rangeop.dl

@@ -16,6 +16,11 @@ out1(X) :- X = range(1, 10).
 .output out2()
 out2(X) :- X = range(9, 0, -1).
 
+// Range with contradicting step
+.decl out2b(X:number)
+.output out2b()
+out2b(X) :- X = range(9, 0, 1).
+
 // Range appearing twice with the same endpoints
 .decl out3(X:number, Y:number)
 .output out3()
@@ -25,3 +30,29 @@ out3(X,Y) :- X = range(1,3), Y = range(1,3).
 .decl out4(X:number, Y:number)
 .output out4()
 out4(X,Y) :- X = range(0,3), Y = range(0,3), X < Y, X + Y = 3.
+
+// Unsigned range
+.decl out5(X:unsigned)
+.output out5
+out5(X) :- X = range(1, 10).
+
+.decl out6(X:unsigned)
+.output out6
+out6(X) :- X = range(9, 0).
+
+// Float range
+.decl out7(X:float)
+.output out7
+out7(X) :- X = range(1.25, 9.25).
+
+.decl out8(X:float)
+.output out8
+out8(X) :- X = range(1.5, -4.6, -0.5).
+
+.decl out9(X:float)
+.output out9
+out9(X) :- X = range(4.5, -4.6).
+
+.decl out10(X:float)
+.output out10
+out10(X) :- X = range(-1, 0, 0.25).

tests/semantic/range/b_u.csv

@@ -0,0 +1,4 @@
+2
+3
+4
+5