Added new_hashset function to initialize a hash table

src/hashset.asm

@@ -1,16 +1,31 @@
-; struct Allocator {
-;     alloc: (U32) -> ptr
-;     realloc: (ptr, U32) -> ptr
-;     free: (ptr) -> ()
-; }
-;
+;struct Allocator {
+;   alloc: (U32) -> ptr
+;   realloc: (ptr, U32) -> ptr
+;   free: (ptr) -> ()
+;}
+
+;struct HashSet {
+;   count: U32
+;   capacity: U32
+;   alloc_ptr: U32
+;   hash_ptr: U32
+;   hash_context: U32
+;   eq_ptr: U32
+;   eq_context: U32
+;   data_ptr: U32
+;} - 28 bytes
+
+;struct HashItem {
+;   hash: U32
+;   value: U32
+;}
 
 ; Creates a hashset for the specified allocator, hash function and equality function
 ; Arguments:
 ; r1 - The pointer to the allocator
 ; r2 - The hash function
-; r3 - The equality function
-; r4 - The hash function context
+; r3 - The hash function context
+; r4 - The equality function
 ; r5 - The equality function context
 ; Result:
 ; r1 - The pointer to the hashset structure
@@ -20,4 +35,68 @@
 ; The equality function should follow the stdlib calling convention
 ; The equality function receives two arguments (the value of the two items) and should return either a zero (when the items are not equal) or any other value (if they are equal).
 pub new_hashset:
-    
+    ; First let's free up all the registers
+    push r8
+    push r9
+    push r10
+    push r11
+    push r12
+    push r13 ; We will be calling alloc
+
+    mov r8, r1
+    mov r9, r2
+    mov r10, r3
+    mov r11, r4
+    mov r12, r5
+
+    load_32 r5, [r8] ; Loading the alloc function address
+    mov r1, 28
+    counter r13
+    add r13, r13, 12
+    jmp r5 ; allocating the space for the hashset struct itself
+
+    ; Now r1 has the pointer to memory, r2-r7 are clobbered
+
+    store_32 [r1], rz ; count is 0 at the start
+
+    add r1, r1, 4
+    mov r2, 8
+    store_32 [r1], r2 ; initial capacity at 8 item slots
+
+    add r1, r1, 4
+    store_32 [r1], r8 ; allocator pointer is in r8
+
+    add r1, r1, 4
+    store_32 [r1], r9 ; hash pointer is in r9
+
+    add r1, r1, 4
+    store_32 [r1], r10 ; hash context is in r10
+
+    add r1, r1, 4
+    store_32 [r1], r11 ; eq pointer is in r11
+
+    add r1, r1, 4
+    store_32 [r1], r12 ; eq context is in r12
+
+    push r1
+
+    load_32 r5, [r8] ; Loading the alloc function address
+    mov r1, 64
+    counter r13
+    add r13, r13, 12
+    jmp r5 ; allocating the space for the data
+
+    load r2, [sp] ; Now r1 is data pointer, r2 is hashset pointer at eq context
+
+    add r2, r2, 4
+    store_32 [r2], r1 ; data pointer saved
+
+    pop r1 ; Popping the pointer to start of the hashset
+
+    pop r13 ; Everything's set up, return
+    pop r12
+    pop r11
+    pop r10
+    pop r9
+    pop r8
+    jmp r13