Tigerインタプリタで逐次実行できるようにしたい

(print("hello"); print("world"); 4649)

code:diff

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

index e1d7083..d34e630 100644

--- a/lib/eval.ml

+++ b/lib/eval.ml

@@ -28,6 +28,13 @@ let rec f expr env: val_t * table =

| Some else' -> f else' env

| None -> (UnitVal, env))

| _ -> failwith "type error")

+ | Syntax.SeqExp exprs ->

+ (match exprs with

+ | [] -> (UnitVal, env)

+ | expr::[] -> f expr env

+ | expr::exprs ->

+ let _, env = f expr env in

+ f (Syntax.SeqExp exprs) env)

| Syntax.CallExp { id; args } ->

(let func = List.assoc id env in

match func with

diff --git a/lib/lexer.mll b/lib/lexer.mll

index 7d1ebed..34e720c 100644

--- a/lib/lexer.mll

+++ b/lib/lexer.mll

@@ -38,6 +38,7 @@ rule token = parse

| ")" { Parser.RPAREN }

| "," { Parser.COMMA }

| ":" { Parser.COLON }

+ | ";" { Parser.SEMICOLON }

| digit+ { Parser.INT(int_of_string(Lexing.lexeme lexbuf)) }

| letter (letter|digit)* { Parser.ID(Lexing.lexeme lexbuf) }

| "\"" { string_literal (Buffer.create 0) lexbuf }

diff --git a/lib/parser.mly b/lib/parser.mly

index 5405e28..63b8283 100644

--- a/lib/parser.mly

+++ b/lib/parser.mly

@@ -10,7 +10,7 @@

%token EQ NEQ LT LE GT GE

%token LET IN END IF THEN ELSE

%token VAR FUNCTION ASSIGN

-%token LPAREN RPAREN COMMA COLON

+%token LPAREN RPAREN COMMA COLON SEMICOLON

%token EOF

// あとで使う

@@ -40,9 +40,8 @@ program: exp EOF { $1 }

exp:

INT { Syntax.IntExp($1) }

| STRING { Syntax.StringExp($1) }

-| LPAREN RPAREN { Syntax.UnitExp }

| ID { Syntax.VarExp($1) }

-| LPAREN exp RPAREN { $2 }

+| LPAREN exps RPAREN { Syntax.SeqExp($2) }

| exp PLUS exp { Syntax.OpExp { left = $1; op = Syntax.PlusOp; right = $3} }

| exp MINUS exp { Syntax.OpExp { left = $1; op = Syntax.MinusOp; right = $3} }

| exp TIMES exp { Syntax.OpExp { left = $1; op = Syntax.TimesOp; right = $3} }

@@ -59,6 +58,11 @@ exp:

| IF exp THEN exp { Syntax.IfExp { test = $2; then' = $4; else' = None } }

| IF exp THEN exp ELSE exp { Syntax.IfExp { test = $2; then' = $4; else' = Some ($6) } }

+exps:

+ { [] } // 空の場合

+

args:

{ [] } // 空の場合

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

index 4ce1f99..1570bda 100644

--- a/lib/syntax.ml

+++ b/lib/syntax.ml

@@ -21,6 +21,7 @@ and op_t =

| CallExp of { id: string; args: t list } (* 関数呼び出し *)

| OpExp of { left: t; op: op_t; right: t } (* 二項演算子 *)

| IfExp of { test: t; then': t; else': t option } (* if文 *)

+ | SeqExp of t list (* 式の逐次実行 *)

and dec_t =

| VarDec of symbol * t (* 変数宣言 *)

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

index 46a52c8..de9525b 100644

--- a/test/tiger_test.expected

+++ b/test/tiger_test.expected

@@ -31,3 +31,5 @@ Hello World!!

Goodbye World!!

result: 55

result: -30

+ABC

+result: ()

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

index a09b543..2d2ffa3 100644

--- a/test/tiger_test.ml

+++ b/test/tiger_test.ml

@@ -305,7 +305,7 @@ let () =

(* 負の整数リテラル *)

let () =

let src = {|

- let var a := -10

+ let var a := 20

in -10 + -a

end

|}

@@ -313,3 +313,20 @@ let () =

print_string "result: ";

Tiger.Eval.print_val (eval src);

print_newline ()

+

+(* 逐次実行 *)

+let () =

+ let src = {|

+ (print("A");

+ print("B");

+ print("C");

+ print("\n"))

+ |}

+ in ignore(eval src)

+

+(* Unit を返す *)

+let () =

+ let src = "( )" in

+ print_string "result: ";

+ Tiger.Eval.print_val (eval src);

+ print_newline ()