From 3f25710a891dfcd17f597c16dfedf5499bc1bbd6 Mon Sep 17 00:00:00 2001
From: pacien
Date: Fri, 20 Apr 2018 23:32:38 +0200
Subject: Modularize everything

---
 instptr.ml | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 instptr.ml

(limited to 'instptr.ml')

diff --git a/instptr.ml b/instptr.ml
new file mode 100644
index 0000000..9e472c4
--- /dev/null
+++ b/instptr.ml
@@ -0,0 +1,51 @@
+(*
+ * UPEM / L3 / Functional programming / Project: URM
+ * Pacien TRAN-GIRARD, Adam NAILI
+ *)
+
+open Common
+
+(* Creates a pointer of instruction from an urm command list *)
+let instptr_mk urmcmd_list =
+  let rec aux urmcmd_list count acc =
+    match urmcmd_list with
+    | [] -> acc
+    | instr :: tail -> aux tail (count + 1) ((count, instr) :: acc)
+  in InstPtr([], List.rev (aux urmcmd_list 0 []))
+
+(* Moves the pointer to the previous instruction *)
+let instptr_move_up = function
+  | InstPtr([], list2) -> InstPtr([], list2)
+  | InstPtr(instr :: list1, list2) -> InstPtr(list1, instr :: list2)
+
+(* Moves the pointer to the next instruction *)
+let instptr_move_down = function
+  | InstPtr(list1, []) -> InstPtr(list1, [])
+  | InstPtr(list1, instr :: list2) -> InstPtr(instr :: list1, list2)
+
+(* Returns the couple from the current pointer position : (line, instruction) where instruction is an urm command or fails if there is no instruction pointed *)
+let instptr_get = function
+  | InstPtr(list1, (l, Zero(a)) :: tail)-> (l, Zero(a))
+  | InstPtr(list1, (l, Succ(a)) :: tail) -> (l, Succ(a))
+  | InstPtr(list1, (l, Copy(a, b)) :: tail) -> (l, Copy(a, b))
+  | InstPtr(list1, (l, Jump(a, b, c)) :: tail) -> (l, Jump(a, b, c))
+  | InstPtr(_, [])-> failwith "No instruction left"
+
+(* Converts the current instruction pointed into a string (line and instruction formatted). If there is no instruction, returns "null" *)
+let instptr_string instptr =
+  let aux = function
+    | l, Zero(a) -> (string_of_int l) ^ ": Zero " ^ (string_of_int a)
+    | l, Succ(a) -> (string_of_int l) ^ ": Succ " ^ (string_of_int a)
+    | l, Copy(a, b) -> (string_of_int l) ^ ": Copy " ^ (string_of_int a) ^ " " ^ (string_of_int b)
+    | l, Jump(a, b, c) -> (string_of_int l) ^ ": Jump " ^ (string_of_int a) ^ " " ^ (string_of_int b) ^ " " ^ (string_of_int c)
+  in try aux (instptr_get instptr) with _ -> "null"
+
+(* Returns true if the instruction pointer is not pointing on any instruction (end of the instruction list) *)
+let instptr_end = function
+  | InstPtr(_, []) -> true
+  | _ -> false
+
+let rec instptr_jump ptr offset = match offset with
+  | 0 -> ptr
+  | _ when offset > 0 -> instptr_jump (instptr_move_up ptr) (offset - 1)
+  | _ -> instptr_jump (instptr_move_down ptr) (offset + 1)
-- 
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