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added If, And, Or

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This commit is contained in:
Moritz Gmeiner 2024-08-26 17:26:59 +02:00
commit dbcdbc216f
5 changed files with 120 additions and 58 deletions
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34
lib/interpreter.ml
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@ -28,7 +28,18 @@ let rec interpret_expr (env : environment) (expr : expr_node) : (lox_value, runt
let* value = interpret_expr env expr in
Env.update env name value;
Ok value
| BinaryExpr { op; left; right } -> (
| Unary { op; expr } -> (
let* expr = interpret_expr env expr in
match (op, expr) with
| Neg, Number x -> Ok (Number (-.x))
| Not, Bool b -> Ok (Bool (not b))
| _, _ ->
let msg =
Printf.sprintf "Invalid operant of type %s to operator %s"
(type_string_of_lox_value expr) (show_unary_op op)
in
Error (RuntimeError.make pos msg))
| Binary { op; left; right } -> (
let* left = interpret_expr env left in
let* right = interpret_expr env right in
match (left, op, right) with
@ -58,17 +69,11 @@ let rec interpret_expr (env : environment) (expr : expr_node) : (lox_value, runt
(type_string_of_lox_value left) (type_string_of_lox_value right) (show_binary_op op)
in
Error { pos; msg })
| UnaryExpr { op; expr } -> (
let* expr = interpret_expr env expr in
match (op, expr) with
| Neg, Number x -> Ok (Number (-.x))
| Not, Bool b -> Ok (Bool (not b))
| _, _ ->
let msg =
Printf.sprintf "Invalid operant of type %s to operator %s"
(type_string_of_lox_value expr) (show_unary_op op)
in
Error (RuntimeError.make pos msg))
| Logical { op; left; right } -> (
let* left = interpret_expr env left in
match (op, lox_value_to_bool left) with
| And, false | Or, true -> Ok left (* short circuit *)
| _ -> interpret_expr env right)
let rec interpret_stmt (env : environment) (stmt : stmt_node) : (unit, runtime_error) result =
let { pos; stmt } = stmt in
@ -98,3 +103,8 @@ let rec interpret_stmt (env : environment) (stmt : stmt_node) : (unit, runtime_e
| [] -> Ok ()
in
_interpret stmts
| If { cond; then_; else_ } ->
let* cond = interpret_expr env cond in
let cond = lox_value_to_bool cond in
if cond then interpret_stmt env then_
else Option.map (interpret_stmt env) else_ |> Option.value ~default:(Ok ())