diff --git a/gitlab-pages/docs/language-basics/loops.md b/gitlab-pages/docs/language-basics/loops.md index 8f81c93ae..e6d26adea 100644 --- a/gitlab-pages/docs/language-basics/loops.md +++ b/gitlab-pages/docs/language-basics/loops.md @@ -57,45 +57,21 @@ constant, therefore it makes no sense in CameLIGO to feature loops, which we understand as syntactic constructs where the state of a stopping condition is mutated, as with "while" loops in PascaLIGO. -Instead, CameLIGO implements a *folded operation* by means of a -predefined function named `Loop.fold_while`. It takes an initial value -of a certain type, called an *accumulator*, and repeatedly calls a -given function, called *folded function*, that takes that -accumulator and returns the next value of the accumulator, until a -condition is met and the fold stops with the final value of the -accumulator. The iterated function needs to have a special type: if -the type of the accumulator is `t`, then it must have the type `bool * -t` (not simply `t`). It is the boolean value that denotes whether the -stopping condition has been reached. +Instead, CameLIGO loops are written by means of a tail recursive function Here is how to compute the greatest common divisors of two natural numbers by means of Euclid's algorithm: ```cameligo group=a -let iter (x,y : nat * nat) : bool * (nat * nat) = - if y = 0n then false, (x,y) else true, (y, x mod y) +let rec iter (x,y : nat * nat) : nat = + if y = 0n then x else iter (y, x mod y) let gcd (x,y : nat * nat) : nat = let x,y = if x < y then y,x else x,y in - let x,y = Loop.fold_while iter (x,y) - in x + iter (x,y) ``` -To ease the writing and reading of the iterated functions (here, -`iter`), two predefined functions are provided: `Loop.resume` and -`Loop.stop`: - -```cameligo group=a -let iter (x,y : nat * nat) : bool * (nat * nat) = - if y = 0n then Loop.stop (x,y) else Loop.resume (y, x mod y) - -let gcd (x,y : nat * nat) : nat = - let x,y = if x < y then y,x else x,y in - let x,y = Loop.fold_while iter (x,y) - in x -``` - -> Note that `stop` and `continue` (now `Loop.resume`) are +> Note that `fold_while`, `stop` and `continue` (now `Loop.resume`) are > *deprecated*. You can call the function `gcd` defined above using the LIGO compiler @@ -114,47 +90,22 @@ constant, therefore it makes no sense in ReasonLIGO to feature loops, which we understand as syntactic constructs where the state of a stopping condition is mutated, as with "while" loops in PascaLIGO. -Instead, ReasonLIGO features a *fold operation* as a predefined -function named `Loop.fold_while`. It takes an initial value of a -certain type, called an *accumulator*, and repeatedly calls a given -function, called *iterated function*, that takes that accumulator and -returns the next value of the accumulator, until a condition is met -and the fold stops with the final value of the accumulator. The -iterated function needs to have a special type: if the type of the -accumulator is `t`, then it must have the type `bool * t` (not simply -`t`). It is the boolean value that denotes whether the stopping -condition has been reached. +Instead, ReasonLIGO loops are written by means of tail recursive functions Here is how to compute the greatest common divisors of two natural numbers by means of Euclid's algorithm: ```reasonligo group=a -let iter = ((x,y) : (nat, nat)) : (bool, (nat, nat)) => - if (y == 0n) { (false, (x,y)); } else { (true, (y, x mod y)); }; +let rec iter = ((x,y) : (nat, nat)) : nat => + if (y == 0n) { x; } else { iter ((y, x mod y)); }; let gcd = ((x,y) : (nat, nat)) : nat => { let (x,y) = if (x < y) { (y,x); } else { (x,y); }; - let (x,y) = Loop.fold_while (iter, (x,y)); - x + iter ((x,y)) }; ``` -To ease the writing and reading of the iterated functions (here, -`iter`), two predefined functions are provided: `Loop.resume` and -`Loop.stop`: - -```reasonligo group=b -let iter = ((x,y) : (nat, nat)) : (bool, (nat, nat)) => - if (y == 0n) { Loop.stop ((x,y)); } else { Loop.resume ((y, x mod y)); }; - -let gcd = ((x,y) : (nat, nat)) : nat => { - let (x,y) = if (x < y) { (y,x); } else { (x,y); }; - let (x,y) = Loop.fold_while (iter, (x,y)); - x -}; -``` - -> Note that `stop` and `continue` (now `Loop.resume`) are +> Note that `fold_while`, `stop` and `continue` (now `Loop.resume`) are > *deprecated*. diff --git a/src/bin/expect_tests/contract_tests.ml b/src/bin/expect_tests/contract_tests.ml index 9bd5723bf..1bb5d7969 100644 --- a/src/bin/expect_tests/contract_tests.ml +++ b/src/bin/expect_tests/contract_tests.ml @@ -1174,7 +1174,7 @@ let%expect_test _ = let%expect_test _ = run_ligo_bad [ "compile-contract" ; bad_contract "create_contract_toplevel.mligo" ; "main" ] ; [%expect {| -ligo: in file "create_contract_toplevel.mligo", line 4, character 35 to line 8, character 8. No free variable allowed in this lambda: variable 'store' {"expression":"CREATE_CONTRACT(lambda (#P:Some(( nat * string ))) : None return let rhs#810 = #P in let p = rhs#810.0 in let s = rhs#810.1 in ( list[] : (TO_list(operation)) , store ) , NONE() : (TO_option(key_hash)) , 300000000mutez , \"un\")","location":"in file \"create_contract_toplevel.mligo\", line 4, character 35 to line 8, character 8"} +ligo: in file "create_contract_toplevel.mligo", line 4, character 35 to line 8, character 8. No free variable allowed in this lambda: variable 'store' {"expression":"CREATE_CONTRACT(lambda (#P:Some(( nat * string ))) : None return let rhs#808 = #P in let p = rhs#808.0 in let s = rhs#808.1 in ( list[] : (TO_list(operation)) , store ) , NONE() : (TO_option(key_hash)) , 300000000mutez , \"un\")","location":"in file \"create_contract_toplevel.mligo\", line 4, character 35 to line 8, character 8"} If you're not sure how to fix this error, you can @@ -1187,7 +1187,7 @@ ligo: in file "create_contract_toplevel.mligo", line 4, character 35 to line 8, run_ligo_bad [ "compile-contract" ; bad_contract "create_contract_var.mligo" ; "main" ] ; [%expect {| -ligo: in file "create_contract_var.mligo", line 6, character 35 to line 10, character 5. No free variable allowed in this lambda: variable 'a' {"expression":"CREATE_CONTRACT(lambda (#P:Some(( nat * int ))) : None return let rhs#813 = #P in let p = rhs#813.0 in let s = rhs#813.1 in ( list[] : (TO_list(operation)) , a ) , NONE() : (TO_option(key_hash)) , 300000000mutez , 1)","location":"in file \"create_contract_var.mligo\", line 6, character 35 to line 10, character 5"} +ligo: in file "create_contract_var.mligo", line 6, character 35 to line 10, character 5. No free variable allowed in this lambda: variable 'a' {"expression":"CREATE_CONTRACT(lambda (#P:Some(( nat * int ))) : None return let rhs#811 = #P in let p = rhs#811.0 in let s = rhs#811.1 in ( list[] : (TO_list(operation)) , a ) , NONE() : (TO_option(key_hash)) , 300000000mutez , 1)","location":"in file \"create_contract_var.mligo\", line 6, character 35 to line 10, character 5"} If you're not sure how to fix this error, you can diff --git a/src/passes/2-simplify/cameligo.ml b/src/passes/2-simplify/cameligo.ml index 2f7e7e32e..0895c5323 100644 --- a/src/passes/2-simplify/cameligo.ml +++ b/src/passes/2-simplify/cameligo.ml @@ -345,7 +345,7 @@ let rec simpl_expression : trace (simplifying_expr t) @@ match t with Raw.ELetIn e -> - let Raw.{binding; body; attributes; _} = e.value in + let Raw.{kwd_rec; binding; body; attributes; _} = e.value in let inline = List.exists (fun (a: Raw.attribute) -> a.value = "inline") attributes in let Raw.{binders; lhs_type; let_rhs; _} = binding in begin match binders with @@ -393,10 +393,50 @@ let rec simpl_expression : (chain_let_in tl body) | [] -> body (* Precluded by corner case assertion above *) in - if List.length prep_vars = 1 - then ok (chain_let_in prep_vars body) - (* Bind the right hand side so we only evaluate it once *) - else ok (e_let_in (rhs_b, ty_opt) false inline rhs' (chain_let_in prep_vars body)) + let%bind ty_opt = match ty_opt with + | None -> (match let_rhs with + | EFun {value={binders;lhs_type}} -> + let f_args = nseq_to_list (binders) in + let%bind lhs_type' = bind_map_option (fun x -> simpl_type_expression (snd x)) lhs_type in + let%bind ty = bind_map_list typed_pattern_to_typed_vars f_args in + let aux acc ty = Option.map (t_function (snd ty)) acc in + ok @@ (List.fold_right' aux lhs_type' ty) + | _ -> ok None + ) + | Some t -> ok @@ Some t + in + let%bind ret_expr = if List.length prep_vars = 1 + then ok (chain_let_in prep_vars body) + (* Bind the right hand side so we only evaluate it once *) + else ok (e_let_in (rhs_b, ty_opt) false inline rhs' (chain_let_in prep_vars body)) + in + let%bind ret_expr = match kwd_rec with + | None -> ok @@ ret_expr + | Some _ -> + match ret_expr.expression_content with + | E_let_in li -> ( + let%bind lambda = + let rec aux rhs = match rhs.expression_content with + | E_lambda l -> ok @@ l + | E_ascription a -> aux a.anno_expr + | _ -> fail @@ corner_case "recursive only supported for lambda" + in + aux rhs' + in + let fun_name = fst @@ List.hd prep_vars in + let%bind fun_type = match ty_opt with + | Some t -> ok @@ t + | None -> match rhs'.expression_content with + | E_ascription a -> ok a.type_annotation + | _ -> fail @@ untyped_recursive_function e + in + let expression_content = E_recursive {fun_name;fun_type;lambda} in + let expression_content = E_let_in {li with rhs = {li.rhs with expression_content}} in + ok @@ {ret_expr with expression_content} + ) + | _ -> fail @@ corner_case "impossible" + in + ok ret_expr (* let f p1 ps... = rhs in body *) | (f, p1 :: ps) -> @@ -670,7 +710,8 @@ and simpl_fun lamb' : expr result = e_lambda ~loc (binder) (Some input_type) output_type (layer_arguments tl) | [] -> body in - return @@ layer_arguments params' + let ret_lamb = layer_arguments params' in + return @@ ret_lamb and simpl_logic_expression ?te_annot (t:Raw.logic_expr) : expr result = diff --git a/src/passes/2-simplify/pascaligo.ml b/src/passes/2-simplify/pascaligo.ml index 6282766c1..fa87cbf15 100644 --- a/src/passes/2-simplify/pascaligo.ml +++ b/src/passes/2-simplify/pascaligo.ml @@ -1263,11 +1263,12 @@ and simpl_for_int : Raw.for_int -> (_ -> expression result) result = fun fi -> let%bind bound = simpl_expression fi.bound in let cond = e_annotation (e_constant C_LE [var ; bound]) t_bool in let step = e_int 1 in + let continue_expr = e_constant C_FOLD_CONTINUE [(e_variable binder)] in let ctrl = - e_let_in (it,Some t_int) false false (e_constant C_ADD [ var ; step ]) - (e_let_in (binder, None) false false (e_update (e_variable binder) "1" var) - (e_variable binder)) - in + e_let_in (it,Some t_int) false false (e_constant C_ADD [ var ; step ]) @@ + e_let_in (binder, None) false false (e_update (e_variable binder) "1" var)@@ + continue_expr + in (* Modify the body loop*) let%bind for_body = simpl_block fi.block.value in let%bind for_body = for_body @@ Some ctrl in @@ -1281,11 +1282,10 @@ and simpl_for_int : Raw.for_int -> (_ -> expression result) result = fun fi -> let restore = fun expr -> List.fold_right aux captured_name_list expr in (*Prep the lambda for the fold*) - let continue_expr = e_constant C_FOLD_CONTINUE [restore(for_body)] in let stop_expr = e_constant C_FOLD_STOP [e_variable binder] in let aux_func = e_lambda binder None None @@ e_let_in (it,Some t_int) false false (e_accessor (e_variable binder) "1") @@ - e_cond cond continue_expr (stop_expr) in + e_cond cond (restore for_body) (stop_expr) in (* Make the fold_while en precharge the vakye *) let loop = e_constant C_FOLD_WHILE [aux_func; e_variable env_rec] in diff --git a/src/passes/6-transpiler/transpiler.ml b/src/passes/6-transpiler/transpiler.ml index 8b39e6c4a..9b2d3308d 100644 --- a/src/passes/6-transpiler/transpiler.ml +++ b/src/passes/6-transpiler/transpiler.ml @@ -101,6 +101,15 @@ them. please report this to the developers." in ("value" , fun () -> Format.asprintf "%a" Mini_c.PP.value value) ; ] in error ~data title content + + let unsupported_recursive_function expression_variable = + let title () = "unsupported recursive function yet" in + let content () = "only fuction with one variable are supported" in + let data = [ + ("value" , fun () -> Format.asprintf "%a" AST.PP.expression_variable expression_variable) ; + ] in + error ~data title content + end open Errors @@ -521,12 +530,14 @@ and transpile_lambda l (input_type , output_type) = ok @@ Combinators.Expression.make_tpl (closure , tv) and transpile_recursive {fun_name; fun_type; lambda} = - let rec map_lambda : AST.expression_variable -> type_value -> AST.expression -> expression result = fun fun_name loop_type e -> + let rec map_lambda : AST.expression_variable -> type_value -> AST.expression -> (expression * expression_variable list) result = fun fun_name loop_type e -> match e.expression_content with E_lambda {binder;result} -> - let%bind body = map_lambda fun_name loop_type result in - ok @@ Expression.make (E_closure {binder;body}) loop_type| - _ -> replace_callback fun_name loop_type e + let%bind (body,l) = map_lambda fun_name loop_type result in + ok @@ (Expression.make (E_closure {binder;body}) loop_type, binder::l) + | _ -> + let%bind res = replace_callback fun_name loop_type e in + ok @@ (res, []) and replace_callback : AST.expression_variable -> type_value -> AST.expression -> expression result = fun fun_name loop_type e -> match e.expression_content with @@ -629,10 +640,13 @@ and transpile_recursive {fun_name; fun_type; lambda} = let%bind fun_type = transpile_type fun_type in let%bind (input_type,output_type) = get_t_function fun_type in let loop_type = t_union (None, input_type) (None, output_type) in - let%bind body = map_lambda fun_name loop_type lambda.result in - let expr = Expression.make_tpl (E_variable fun_name, input_type) in + let%bind (body,binder) = map_lambda fun_name loop_type lambda.result in + let binder = lambda.binder::binder in + List.iter (Format.printf "inder %a\n%!" Var.pp) binder ; + let%bind binder = match binder with hd::[] -> ok @@ hd | _ -> fail @@ unsupported_recursive_function fun_name in + let expr = Expression.make_tpl (E_variable binder, input_type) in let body = Expression.make (E_iterator (C_LOOP_LEFT, ((lambda.binder, loop_type),body), expr)) output_type in - ok @@ Expression.make (E_closure {binder=fun_name;body}) fun_type + ok @@ Expression.make (E_closure {binder;body}) fun_type let transpile_declaration env (d:AST.declaration) : toplevel_statement result = match d with diff --git a/src/stages/ast_typed/combinators.ml b/src/stages/ast_typed/combinators.ml index 0a54bc708..d6f1e8da5 100644 --- a/src/stages/ast_typed/combinators.ml +++ b/src/stages/ast_typed/combinators.ml @@ -168,6 +168,17 @@ let get_t_function (t:type_expression) : (type_expression * type_expression) res | T_arrow {type1;type2} -> ok (type1,type2) | _ -> simple_fail "not a function" +let get_t_function_full (t:type_expression) : (type_expression * type_expression) result = + let%bind _ = get_t_function t in + let rec aux n t = match t.type_content with + | T_arrow {type1;type2} -> + let (l, o) = aux (n+1) type2 in + ((Label (string_of_int n),type1)::l,o) + | _ -> ([],t) + in + let (input,output) = aux 0 t in + ok @@ (t_record (LMap.of_list input) (),output) + let get_t_sum (t:type_expression) : type_expression constructor_map result = match t.type_content with | T_sum m -> ok m | _ -> fail @@ Errors.not_a_x_type "sum" t () diff --git a/src/stages/ast_typed/combinators.mli b/src/stages/ast_typed/combinators.mli index 1b3f31aea..a42abd3cc 100644 --- a/src/stages/ast_typed/combinators.mli +++ b/src/stages/ast_typed/combinators.mli @@ -62,6 +62,7 @@ val get_t_key_hash : type_expression -> unit result val get_t_tuple : type_expression -> type_expression list result val get_t_pair : type_expression -> ( type_expression * type_expression ) result val get_t_function : type_expression -> ( type_expression * type_expression ) result +val get_t_function_full : type_expression -> ( type_expression * type_expression ) result val get_t_sum : type_expression -> type_expression constructor_map result val get_t_record : type_expression -> type_expression label_map result val get_t_map : type_expression -> ( type_expression * type_expression ) result diff --git a/src/test/contracts/loop.mligo b/src/test/contracts/loop.mligo index 82da7268e..1333cf66a 100644 --- a/src/test/contracts/loop.mligo +++ b/src/test/contracts/loop.mligo @@ -1,10 +1,9 @@ (* Test functional iterators in CameLIGO *) -let aux_simple (i : int) : bool * int = - if i < 100 then Loop.resume (i + 1) else Loop.stop i +let rec aux_simple (i : int) : int = + if i < 100 then aux_simple (i + 1) else i -let counter_simple (n : int) : int = - Loop.fold_while aux_simple n +let counter_simple (n : int) : int = aux_simple n type sum_aggregator = { counter : int; @@ -13,25 +12,23 @@ type sum_aggregator = { let counter (n : int) : int = let initial : sum_aggregator = {counter=0; sum=0} in - let aggregate = fun (prev : sum_aggregator) -> + let rec aggregate : sum_aggregator -> int = fun (prev: sum_aggregator) -> if prev.counter <= n then - Loop.resume {counter = prev.counter + 1; + aggregate {counter = prev.counter + 1; sum = prev.counter + prev.sum} else - Loop.stop {counter = prev.counter; sum = prev.sum} in - let out : sum_aggregator = - Loop.fold_while aggregate initial - in out.sum + prev.sum + in + aggregate initial -let aux_nest (prev : sum_aggregator) : bool * sum_aggregator = +let rec aux_nest (prev : sum_aggregator) : int = if prev.counter < 100 then - let sum : int = - prev.sum + Loop.fold_while aux_simple prev.counter - in Loop.resume {counter = prev.counter + 1; sum = sum} + let sum = prev.sum + (aux_simple prev.counter) in + aux_nest {counter = prev.counter + 1; sum = sum} else - Loop.stop {counter = prev.counter; sum = prev.sum} + prev.sum let counter_nest (n : int) : int = let initial : sum_aggregator = {counter=0; sum=0} in - let out : sum_aggregator = Loop.fold_while aux_nest initial - in out.sum + let out = aux_nest initial + in out diff --git a/src/test/contracts/loop.religo b/src/test/contracts/loop.religo index a1d8b6e44..010542d1d 100644 --- a/src/test/contracts/loop.religo +++ b/src/test/contracts/loop.religo @@ -1,9 +1,9 @@ /* Test loops in ReasonLIGO */ -let aux_simple = (i : int) : (bool, int) => - if (i < 100) { Loop.resume (i + 1); } else { Loop.stop (i); }; +let rec aux_simple = (i : int) : int => + if (i < 100) { aux_simple (i + 1); } else { i; }; -let counter_simple = (n : int) : int => Loop.fold_while (aux_simple, n); +let counter_simple = (n : int) : int => aux_simple (n); type sum_aggregator = { counter : int, @@ -12,30 +12,28 @@ type sum_aggregator = { let counter = (n : int) : int => { let initial : sum_aggregator = {counter: 0, sum: 0}; - let aggregate = (prev : sum_aggregator) => + let rec aggregate = (prev : sum_aggregator):int => if (prev.counter <= n) { - Loop.resume ({counter : prev.counter + 1, + aggregate ({counter : prev.counter + 1, sum : prev.counter + prev.sum}); } else { - Loop.stop ({counter: prev.counter, sum: prev.sum}); + prev.sum; }; - let out : sum_aggregator = - Loop.fold_while (aggregate, initial); - out.sum; + aggregate (initial); }; -let aux_nest = (prev : sum_aggregator) : (bool, sum_aggregator) => +let rec aux_nest = (prev : sum_aggregator) : sum_aggregator => if (prev.counter < 100) { let sum : int = - prev.sum + Loop.fold_while (aux_simple, prev.counter); - Loop.resume ({counter: prev.counter + 1, + prev.sum + aux_simple (prev.counter); + aux_nest ({counter: prev.counter + 1, sum: sum}); } else { - Loop.stop ({counter: prev.counter, sum: prev.sum}); + ({counter: prev.counter, sum: prev.sum}); }; let counter_nest = (n : int) : int => { let initial : sum_aggregator = {counter: 0, sum: 0}; - let out : sum_aggregator = Loop.fold_while (aux_nest, initial); + let out : sum_aggregator = aux_nest (initial); out.sum; };