Avoid copy of key for hash table bucket lookup (#783)

src/typechecker/TypeCheckerExpressions.cpp

@@ -490,9 +490,6 @@ std::any TypeChecker::visitPostfixUnaryExpr(PostfixUnaryExprNode *node) {
     AssignExprNode *indexAssignExpr = node->subscriptIndexExpr;
     const auto index = std::any_cast<ExprResult>(visit(indexAssignExpr));
     HANDLE_UNRESOLVED_TYPE_ER(index.type)
-    // Check if the index is of the right type
-    if (!index.type.isOneOf({TY_INT, TY_LONG}))
-      SOFT_ERROR_ER(node, ARRAY_INDEX_NOT_INT_OR_LONG, "Array index must be of type int or long")
 
     // Check is there is an overloaded operator function available, if yes accept it
     const auto [type, _] = opRuleManager.isOperatorOverloadingFctAvailable<2>(node, OP_FCT_SUBSCRIPT, {operand, index}, 0);
@@ -503,6 +500,10 @@ std::any TypeChecker::visitPostfixUnaryExpr(PostfixUnaryExprNode *node) {
 
     operandType = operandType.removeReferenceWrapper();
 
+    // Check if the index is of the right type
+    if (!index.type.isOneOf({TY_INT, TY_LONG}))
+      SOFT_ERROR_ER(node, ARRAY_INDEX_NOT_INT_OR_LONG, "Array index must be of type int or long")
+
     // Check if we can apply the subscript operator on the lhs type
     if (!operandType.isOneOf({TY_ARRAY, TY_PTR, TY_STRING}))
       SOFT_ERROR_ER(node, OPERATOR_WRONG_DATA_TYPE,

std/data/hash-table.spice

@@ -146,8 +146,7 @@ inline f<LinkedList<HashEntry<K, V>>&> HashTable.getBucket(const K& key) {
 }
 
 inline f<unsigned long> HashTable.hash(const K& key) {
-    const K keyCopy = key; // ToDo: Avoid copy of key
-    return hash(keyCopy) % this.buckets.getSize();
+    return hash(key) % this.buckets.getSize();
 }
 
 /**

std/math/hash.spice

@@ -3,34 +3,77 @@ type TT int|long|short|bool; // Trivially hashable types
 type TC byte|char; // Trivially hashable types with one additional cast
 type T dyn; // Any type
 
+// Aliases
+public type Hash alias unsigned long;
+
 public type IHashable interface {
-    public f<unsigned long> hash<T>(const T&);
+    public f<Hash> hash();
 }
 
-public f<unsigned long> hash<TT>(TT input) {
-    return cast<unsigned long>(input);
+/**
+ * Hash primitive numeric type
+ *
+ * @param input Primitieve numeric to hash
+ * @return Hash of primitive numeric
+ */
+public f<Hash> hash<TT>(TT input) {
+    return cast<Hash>(input);
 }
 
-public f<unsigned long> hash<TC>(TC input) {
-    return cast<unsigned long>(input);
+/**
+ * Hash primitive numeric type
+ *
+ * @param input Primitieve numeric to hash
+ * @return Hash of primitive numeric
+ */
+public f<Hash> hash<TC>(TC input) {
+    return cast<Hash>(cast<unsigned int>(input));
 }
 
-public f<unsigned long> hash(double input) {
+/**
+ * Hash a double value
+ *
+ * @param input Double to hash
+ * @return Hash of double
+ */
+public f<Hash> hash(double input) {
     unsafe {
-        return *(cast<unsigned long*>(&input));
+        return *(cast<Hash*>(&input));
     }
 }
 
-// djb2 hash
-public f<unsigned long> hash(string input) {
-    unsigned long hash = 5381l;
+/**
+ * Hash contents of an immutable string
+ *
+ * @param input String to hash
+ * @return Hash of string
+ */
+public f<Hash> hash(string input) {
+    // Hash using djb2 algorithm
+    Hash hash = 5381l;
     for unsigned long i = 0l; i < len(input); i++ {
-        unsigned long c = cast<unsigned long>(cast<unsigned int>(input[i]));
+        Hash c = cast<Hash>(cast<unsigned int>(input[i]));
         hash = ((hash << 5l) + hash) + c; // hash * 33 + c
     }
     return hash;
 }
 
-/*public f<unsigned long> hash<T>(const T& input) {
-    return input.hash();
-}*/
+/**
+ * Hash contents of a mutable String object
+ *
+ * @param input String to hash
+ * @return Hash of string
+ */
+public f<Hash> hash(const String& input) {
+    return hash(input.getRaw());
+}
+
+/**
+ * Dispatch function for structs, that implement the IHashable interface
+ *
+ * @param hashable Hashable object
+ * @return Hash of the struct
+ */
+public f<Hash> hash(const IHashable& hashable) {
+    return hashable.hash();
+}

test/test-files/std/data/unordered-map-complex-key/source.spice

@@ -0,0 +1,38 @@
+import "std/data/unordered-map";
+
+f<int> main() {
+    UnorderedMap<String, int> map = UnorderedMap<String, int>();
+    assert map.getSize() == 0;
+    assert map.isEmpty();
+    map.upsert(String("one"), 1);
+    map.upsert(String("two"), 2);
+    map.upsert(String("three"), 3);
+    map.upsert(String("four"), 4);
+    assert map.getSize() == 4;
+    assert !map.isEmpty();
+    assert map.contains(String("one"));
+    assert map.contains(String("two"));
+    assert map.contains(String("three"));
+    assert map.contains(String("four"));
+    assert !map.contains(String("five"));
+    assert map.get(String("one")) == 1;
+    assert map[String("two")] == 2;
+    assert map.get(String("three")) == 3;
+    assert map.get(String("four")) == 4;
+    const Result<int> item5 = map.getSafe(String("five"));
+    assert item5.isErr();
+    map.remove(String("two"));
+    assert !map.contains(String("two"));
+    assert map.getSize() == 3;
+    map.clear();
+    assert map.getSize() == 0;
+    assert map.isEmpty();
+    map.upsert(String("one"), 1);
+    map.upsert(String("one"), 11);
+    assert map.getSize() == 1;
+    assert map[String("one")] == 11;
+    map.remove(String("one"));
+    assert map.isEmpty();
+
+    printf("All assertions passed!\n");
+}

test/test-files/std/data/unordered-map-complex-value/cout.out

@@ -0,0 +1 @@
+All assertions passed!

test/test-files/std/math/hash-basic/cout.out

@@ -1,7 +1,9 @@
+Hash (double): 4638355772470722560
 Hash (int): 123
-Hash (long): 123
 Hash (short): 123
-Hash (char): 0
-Hash (byte): 0
-Hash (string): -1763540338
-Hash (double): 0
+Hash (long): 123
+Hash (char): 123
+Hash (byte): 123
+Hash (string): 5904905660241445518
+Hash (String): 5904905660241445518
+Hash (HashableType): 124

test/test-files/std/math/hash-basic/source.spice

@@ -1,13 +1,24 @@
 import "std/math/hash";
 
+type HashableType struct : IHashable {
+    unsigned long content = 124l
+}
+
+f<Hash> HashableType.hash() {
+    return this.content;
+}
+
 f<int> main() {
-    // Trivial hashes
-    printf("Hash (int): %d\n", hash(123));
-    printf("Hash (long): %d\n", hash(123l));
-    printf("Hash (short): %d\n", hash(123s));
-    printf("Hash (char): %d\n", hash(123.0));
-    printf("Hash (byte): %d\n", hash(123.0));
-    printf("Hash (string): %d\n", hash("Hello, World!"));
-    // Complex hashes
-    printf("Hash (double): %d\n", hash(123.0));
+    // Commonly used hash functions
+    printf("Hash (double): %lu\n", hash(123.0));
+    printf("Hash (int): %lu\n", hash(123));
+    printf("Hash (short): %lu\n", hash(123s));
+    printf("Hash (long): %lu\n", hash(123l));
+    printf("Hash (char): %lu\n", hash(cast<char>(123)));
+    printf("Hash (byte): %lu\n", hash(cast<byte>(123)));
+    printf("Hash (string): %lu\n", hash("Hello, World!"));
+    printf("Hash (String): %lu\n", hash(String("Hello, World!")));
+    // Custom hash implementation
+    const HashableType ht;
+    printf("Hash (HashableType): %lu\n", hash(ht));
 }