Files
lci/lib/miniImp/Semantics.ml
2024-10-25 21:29:49 +02:00

143 lines
4.3 KiB
OCaml

open Types
module Utility = Utility;;
Random.self_init ()
let rec evaluate (mem: memory) (command: c_exp) =
match command with
Skip -> mem
| Assignment (v, exp_a) -> {
(* Map.add replaces the previeus value *)
assignments = VariableMap.add v (evaluate_a mem exp_a) mem.assignments
}
| Sequence (exp_c1, exp_c2) -> (
let mem2 = evaluate mem exp_c1 in
evaluate mem2 exp_c2
)
| If (exp_b, exp_c1, exp_c2) -> (
if evaluate_b mem exp_b then
evaluate mem exp_c1
else
evaluate mem exp_c2
)
| While (exp_b, exp_c) -> (
if evaluate_b mem exp_b then
let mem2 = evaluate mem exp_c in
evaluate mem2 command
else
mem
)
| For (exp_c1, exp_b, exp_c2, body_c) -> (
let mem2 = evaluate mem exp_c1 in
let rec f localmem =
if (evaluate_b localmem exp_b)
then f (
let tmpmem = (evaluate localmem body_c) in
(evaluate tmpmem exp_c2))
else localmem
in
f mem2
)
and evaluate_a (mem: memory) (exp_a: a_exp) =
match exp_a with
Variable v -> (
match VariableMap.find_opt v mem.assignments with
None -> raise (AbsentAssignment ("The variable " ^ v ^ " is not defined."))
| Some a -> a
)
| Integer n -> n
| Plus (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
exp_a1val + exp_a2val
)
| Minus (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
exp_a1val - exp_a2val
)
| Times (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
exp_a1val * exp_a2val
)
| Division (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
try
exp_a1val / exp_a2val
with Division_by_zero -> raise (DivisionByZero "Dividing by zero")
)
| Modulo (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
exp_a1val mod exp_a2val
)
| Power (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
Utility.pow exp_a1val exp_a2val
)
| PowerMod (exp_a1, exp_a2, exp_a3) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
let exp_a3val = evaluate_a mem exp_a3 in
Utility.powmod exp_a1val exp_a3val exp_a2val
)
| Rand (exp_a) -> (
Random.int (evaluate_a mem exp_a)
)
and evaluate_b (mem: memory) (exp_b: b_exp) =
match exp_b with
Boolean b -> b
| BAnd (exp_b1, exp_b2) -> (
let exp_b1val = evaluate_b mem exp_b1 in
let exp_b2val = evaluate_b mem exp_b2 in
exp_b1val && exp_b2val
)
| BOr (exp_b1, exp_b2) -> (
let exp_b1val = evaluate_b mem exp_b1 in
let exp_b2val = evaluate_b mem exp_b2 in
exp_b1val || exp_b2val
)
| BNot (exp_b) -> (
not (evaluate_b mem exp_b)
)
| BCmp (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
exp_a1val = exp_a2val
)
| BCmpLess (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
exp_a1val < exp_a2val
)
| BCmpLessEq (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
exp_a1val <= exp_a2val
)
| BCmpGreater (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
exp_a1val > exp_a2val
)
| BCmpGreaterEq (exp_a1, exp_a2) -> (
let exp_a1val = evaluate_a mem exp_a1 in
let exp_a2val = evaluate_a mem exp_a2 in
exp_a1val >= exp_a2val
)
let reduce (program: p_exp) (iin : int) =
match program with
Main (vin, vout, expression) -> (
let mem : memory = {assignments = (VariableMap.empty |> VariableMap.add vin iin)} in
match VariableMap.find_opt vout (evaluate mem expression).assignments with
None -> raise (AbsentAssignment ("The output variable is not defined (" ^ vout ^ ")"))
| Some a -> a
)