Tigerインタプリタで組み込み関数を呼び出せるようにしたい

https://gyazo.com/1a3bc5fd8828827adbbc253309636016

code:diff

diff --git a/bin/main.ml b/bin/main.ml

index 631e1e0..4659dea 100644

--- a/bin/main.ml

+++ b/bin/main.ml

@@ -2,7 +2,18 @@

let () =

let buff = Lexing.from_channel stdin in

let expr = Tiger.Parser.program Tiger.Lexer.token buff in

- let result, _ = Tiger.Eval.f expr [] in

- print_string "#=> ";

+ let result, _ = Tiger.Eval.f expr [

+ (* 組み込み関数 print(s: string) *)

+ ("print", Tiger.Eval.BuiltInFunction(

+ fun args _ ->

+ match args with

+ print_string s;

+ (* NOTE: 本当は unit を返したいけどまだ未実装なので 0 を返してる *)

+ Tiger.Eval.IntVal(0)

+ | _ -> failwith "invalid arguments"

+ ))

+ ] in

+ print_string "\n#=> ";

Tiger.Eval.print_val result;

print_newline ()

diff --git a/lib/eval.ml b/lib/eval.ml

index 1aa1f6e..b4af632 100644

--- a/lib/eval.ml

+++ b/lib/eval.ml

@@ -1,6 +1,10 @@

type id = string

and table = (id * val_t) list

-and val_t = IntVal of int | StringVal of string | FunctionDec of id list * Syntax.t

+and val_t =

+ IntVal of int

+ | StringVal of string

+ | FunctionDec of id list * Syntax.t

+ | BuiltInFunction of (val_t list -> table -> val_t)

let rec f expr env: val_t * table =

match expr with

@@ -27,6 +31,17 @@ let rec f expr env: val_t * table =

in

let new_env = get_args args env field_names in

f body new_env

+ | BuiltInFunction builtin_func ->

+ (let rec eval_args args env =

+ match args with

+ | [] -> ([], env)

+ | arg::args ->

+ let v, env = f arg env in

+ let vs, env = eval_args args env in

+ (v::vs, env)

+ in

+ let args, env = eval_args args env in

+ (builtin_func args env, env))

| _ -> failwith "type error")

| Syntax.OpExp (e1, op, e2) ->

match op with

@@ -79,5 +94,6 @@ and string_of_val v =

IntVal n -> string_of_int n

| StringVal s -> s

| FunctionDec _ -> "<fun>"

+ | BuiltInFunction _ -> "<builtin>"

and print_val v = print_string (string_of_val v)

diff --git a/test/tiger_test.expected b/test/tiger_test.expected

index 9c6d8c4..aac8ff3 100644

--- a/test/tiger_test.expected

+++ b/test/tiger_test.expected

@@ -25,3 +25,6 @@ result: 30

result: 99

result: 5678

result: 100

+result: 20

+result: 4649

+Hello World!!

diff --git a/test/tiger_test.ml b/test/tiger_test.ml

index 8800e2b..3ada260 100644

--- a/test/tiger_test.ml

+++ b/test/tiger_test.ml

@@ -5,7 +5,18 @@ let eval_with_env src env =

result

let eval src =

- eval_with_env src []

+ eval_with_env src [

+ (* 組み込み関数 print(s: string) *)

+ ("print", Tiger.Eval.BuiltInFunction(

+ fun args _ ->

+ match args with

+ print_string s;

+ (* NOTE: 本当は unit を返したいけどまだ未実装なので 0 を返してる *)

+ Tiger.Eval.IntVal(0)

+ | _ -> failwith "invalid arguments"

+ ))

+ ]

(* 整数リテラル *)

let () =

@@ -211,3 +222,58 @@ let () =

print_string "result: ";

Tiger.Eval.print_val (eval src);

print_newline ()

+

+(* 組み込み関数 double の呼び出し *)

+let () =

+ let src = {|

+ let

+ in

+ double(10)

+ end

+ |}

+ in

+ print_string "result: ";

+ let env = [

+ ("double", Tiger.Eval.BuiltInFunction (

+ fun args (_:Tiger.Eval.table) ->

+ match args with

+ | _ -> failwith "invalid arguments"

+ ));

+ ] in

+ Tiger.Eval.print_val (eval_with_env src env);

+ print_newline ()

+

+(* 組み込み関数 foo の呼び出し *)

+let () =

+ let src = {|

+ let

+ in

+ foo(4, 6, 4, 9)

+ end

+ |}

+ in

+ print_string "result: ";

+ let env = [

+ ("foo", Tiger.Eval.BuiltInFunction (

+ fun args (_:Tiger.Eval.table) ->

+ match args with

+ Tiger.Eval.IntVal(a * 1000 + b * 100 + c * 10 + d)

+ | _ -> failwith "invalid arguments"

+ ));

+ ] in

+ Tiger.Eval.print_val (eval_with_env src env);

+ print_newline ()

+

+(* 組み込み関数 print(s: string) の呼び出し *)

+let () =

+ let src = {|

+ let in

+ print("Hello World!!")

+ end

+ |}

+ in

+ ignore(eval src);

+ print_newline ()