Add hashsum functor with examples

Makefile

@@ -8,17 +8,23 @@ WORD_SIZE=32
 # rudimentary
 all: libsoufflenum.so num_tests mappings_tests keccak256_tests
 
-libsoufflenum.so: $(KECCAK_OBJ) num256.o mappings.o keccak256.o lists.o smt-api.o
-	g++ -std=c++17 -shared -o libsoufflenum.so $(KECCAK_OBJ) smt-api.o num256.o mappings.o keccak256.o lists.o -march=native -lz3 -fopenmp -DRAM_DOMAIN_SIZE=$(WORD_SIZE)
+libsoufflenum.so: $(KECCAK_OBJ) num256.o mappings.o keccak256.o lists.o smt-api.o hashsum_functor.o lub_functor.o
+	g++ -std=c++17 -shared -o libsoufflenum.so $(KECCAK_OBJ) smt-api.o num256.o mappings.o keccak256.o lists.o hashsum_functor.o lub_functor.o -march=native -lz3 -fopenmp -DRAM_DOMAIN_SIZE=$(WORD_SIZE)
 	ln -sf libsoufflenum.so libfunctors.so
 
+hashsum_functor.o: hashsum_functor.cpp
+	g++ -std=c++17 hashsum_functor.cpp -lz3 -fopenmp -DRAM_DOMAIN_SIZE=$(WORD_SIZE) -c -fPIC -o hashsum_functor.o
+
+lub_functor.o: lub_functor.cpp
+	g++ -std=c++17 lub_functor.cpp -lz3 -fopenmp -DRAM_DOMAIN_SIZE=$(WORD_SIZE) -c -fPIC -o lub_functor.o
+
 smt-api.o: smt-api.cpp
-	g++ -std=c++17  smt-api.cpp -lz3 -fopenmp -DRAM_DOMAIN_SIZE=$(WORD_SIZE) -c -fPIC -o smt-api.o
+	g++ -std=c++17 smt-api.cpp -lz3 -fopenmp -DRAM_DOMAIN_SIZE=$(WORD_SIZE) -c -fPIC -o smt-api.o
 
 num256.o: num256.cpp
 	g++ -std=c++17 -O2 num256.cpp -c -fPIC -o num256.o -lz3 -fopenmp
 
-num_tests:	num256.cpp num256_test.cpp 
+num_tests: num256.cpp num256_test.cpp 
 	g++ -std=c++17 -o num_tests num256_test.cpp
 	./num_tests
 

hashsum-example.dl

@@ -0,0 +1,19 @@
+.decl numbers(x:number)
+.decl sum_result(x:number)
+.decl hsum_result(x:number)
+.output sum_result()
+.output hsum_result()
+.functor hashsum(i1:number, i2:number):number stateful
+
+numbers(-1).
+numbers(1).
+numbers(2).
+numbers(3).
+numbers(4).
+numbers(5).
+
+sum_result(x) :-
+    x = sum a : { numbers(a), a > 0 }.
+
+hsum_result(x) :- 
+    x = @@hashsum a : 0, { numbers(a), a > 0 }.

hashsum_functor.cpp

@@ -0,0 +1,36 @@
+#include "souffle/SouffleFunctor.h"
+#include "souffle/utility/MiscUtil.h"
+#include <cassert>
+
+#if RAM_DOMAIN_SIZE == 64
+using FF_int = int64_t;
+using FF_uint = uint64_t;
+using FF_float = double;
+#else
+using FF_int = int32_t;
+using FF_uint = uint32_t;
+using FF_float = float;
+#endif
+
+extern "C" {
+    souffle::RamDomain hashsum(souffle::SymbolTable* symbolTable, souffle::RecordTable* recordTable,
+            souffle::RamDomain arg1, souffle::RamDomain arg2);
+    unsigned long djb2(const std::string &str);
+}
+
+souffle::RamDomain hashsum(souffle::SymbolTable* symbolTable, souffle::RecordTable* recordTable, souffle::RamDomain arg1, souffle::RamDomain arg2) {
+    assert(symbolTable && "NULL symbol table");
+    assert(recordTable && "NULL record table");
+
+    std::string result = std::to_string(arg1 + djb2(std::to_string(arg2)));
+    return arg1 + djb2(std::to_string(arg2));
+}
+
+unsigned long djb2(const std::string &str) {
+    unsigned long hash = 5381; // Initialize hash with a prime number
+    for (char c : str) {
+        // Multiply hash by 33 and add the current character
+        hash = ((hash << 5) + hash) + c; // hash * 33 + c
+    }
+    return hash;
+}

lub_functor.cpp

@@ -0,0 +1,39 @@
+#include "souffle/SouffleFunctor.h"
+#include "souffle/utility/MiscUtil.h"
+#include <cassert>
+
+#if RAM_DOMAIN_SIZE == 64
+using FF_int = int64_t;
+using FF_uint = uint64_t;
+using FF_float = double;
+#else
+using FF_int = int32_t;
+using FF_uint = uint32_t;
+using FF_float = float;
+#endif
+
+extern "C" {
+souffle::RamDomain lub(souffle::SymbolTable* symbolTable, souffle::RecordTable* recordTable,
+        souffle::RamDomain i1, souffle::RamDomain i2);
+souffle::RamDomain lub_number(souffle::SymbolTable* symbolTable, souffle::RecordTable* recordTable,
+        souffle::RamDomain i, souffle::RamDomain x);
+}
+
+souffle::RamDomain lub(souffle::SymbolTable*, souffle::RecordTable* recordTable, souffle::RamDomain i1,
+        souffle::RamDomain i2) {
+    const souffle::RamDomain* interval1 = recordTable->unpack(i1, 2);
+    const souffle::RamDomain* interval2 = recordTable->unpack(i2, 2);
+    auto lb = std::min(interval1[0], interval2[0]);
+    auto ub = std::max(interval1[1], interval2[1]);
+    const souffle::RamDomain res[2] = {lb, ub};
+    return recordTable->pack(res, 2);
+}
+
+souffle::RamDomain lub_number(souffle::SymbolTable*, souffle::RecordTable* recordTable, souffle::RamDomain i,
+        souffle::RamDomain x) {
+    const souffle::RamDomain* interval = recordTable->unpack(i, 2);
+    auto lb = std::min(interval[0], x);
+    auto ub = std::max(interval[1], x);
+    const souffle::RamDomain res[2] = {lb, ub};
+    return recordTable->pack(res, 2);
+}