[SOLVED] CS python open Types

open Types
open Print

let rec rename_value x x v =
match v with
| Const _ -> v
| Fun (x, e) ->
if x = x then Fun (x, e)
else Fun (x, rename_exp x x e)
| Op _ -> v
and rename_exp x x e =
match e with
| Var x -> Var (if x = x then x else x)
| Value v -> Value (rename_value x x v)
| Let (x, e1, e2) ->
Let (x, rename_exp x x e1,
if x = x then e2
else rename_exp x x e2)
| If (e1, e2, e3) ->
If (rename_exp x x e1, rename_exp x x e2, rename_exp x x e3)
| App (e1, e2) ->
App (rename_exp x x e1, rename_exp x x e2)

let uniq_vars e =
let ctr = ref 0 in
let new_var () =
let n = !ctr in
let _ = ctr := n + 1 in
x ^ (string_of_int n)
in
let rec uv_value v =
match v with
| Const _ | Op _ -> v
| Fun (x, e) ->
let x = new_var () in
Fun (x, uv_exp (rename_exp x x e))
and uv_exp e =
match e with
| Var _ -> e
| Value v -> Value (uv_value v)
| Let (x, e1, e2) ->
let x = new_var () in
Let (x, uv_exp e1, uv_exp (rename_exp x x e2))
| If (e1, e2, e3) ->
If (uv_exp e1, uv_exp e2, uv_exp e3)
| App (e1, e2) ->
App (uv_exp e1, uv_exp e2)
in
uv_exp e

let rec desugar_value v =
match v with
| Const _ | Op _ -> v
| Fun (x, e) -> Fun (x, desugar_exp e)
and desugar_exp e =
match e with
| Var _ -> e
| Value v -> Value (desugar_value v)
| Let (x, e1, e2) -> App (Value (Fun (x, desugar_exp e2)), desugar_exp e1)
| If (e1, e2, e3) ->
If (desugar_exp e1, desugar_exp e2, desugar_exp e3)
| App (e1, e2) -> App (desugar_exp e1, desugar_exp e2)

let const_to_python =
function True -> True
| False -> False
| Int n -> string_of_int n

let op_to_python =
function Plus -> (lambda x: lambda y: x + y)
| Minus -> (lambda x: lambda y: x y)
| Times -> (lambda x: lambda y: x * y)
| Div -> (lambda x: lambda y: x / y)
| Lt -> (lambda x: lambda y: x < y)” | Gt -> (lambda x: lambda y: x > y)
| Le -> (lambda x: lambda y: x <= y)” | Ge -> (lambda x: lambda y: x >= y)
| Eq -> (lambda x: lambda y: x == y)
| And -> (lambda x: lambda y: x & y)
| Or -> (lambda x: lambda y: x | y)

let exp_to_python e =
let rec val_to_python v =
match v with
| Const c -> const_to_python c
| Op o -> op_to_python o
| Fun (x, e) -> Printf.sprintf (lambda %s: %s) x (exp_to_python e)
and exp_to_python e =
match e with
| Var x -> x
| Value v -> val_to_python v
| Let _ -> failwith Should be desugared
| If (e1, e2, e3) ->
Printf.sprintf (%s) if (%s) else (%s)
(exp_to_python e2)
(exp_to_python e1)
(exp_to_python e3)
| App (e1, e2) -> Printf.sprintf (%s)(%s)
(exp_to_python e1)
(exp_to_python e2)
in
let e = uniq_vars e in
let e = desugar_exp e in
exp_to_python e