Tigerインタプリタで文字列リテラルを評価したい

https://gyazo.com/5ee5fd67da12869886a4e9e23a1de96e

文字列リテラルは日本語も扱えるようにしたいんだけど、Lexerの書き方が難しかったため ASCII のみを対象とした。

code:diff

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

index 67f5dc8..6da3359 100644

--- a/bin/main.ml

+++ b/bin/main.ml

@@ -4,5 +4,5 @@ let () =

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

let result = Tiger.Eval.f expr in

print_string "Result: ";

- print_int result;

+ Tiger.Eval.print_val result;

print_newline ()

diff --git a/lib/dune b/lib/dune

index a32b54b..c3efbf4 100644

--- a/lib/dune

+++ b/lib/dune

@@ -2,4 +2,5 @@

(name tiger))

(ocamllex lexer)

+

(ocamlyacc parser)

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

index bdec676..52d98d6 100644

--- a/lib/eval.ml

+++ b/lib/eval.ml

@@ -1,11 +1,24 @@

+type val_t = IntVal of int | StringVal of string

+

let rec f expr =

match expr with

- Syntax.IntExp n -> n

+ Syntax.IntExp n -> IntVal(n)

+ | Syntax.StringExp s -> StringVal(s)

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

- let v1 = f e1 in

- let v2 = f e2 in

+ let v1 = match (f e1) with

+ IntVal(n) -> n

+ | _ -> failwith "integer value expected" in

+ let v2 = match (f e2) with

+ IntVal(n) -> n

+ | _ -> failwith "integer value expected" in

(match op with

- Syntax.Plus -> v1 + v2

- | Syntax.Minus -> v1 - v2

- | Syntax.Times -> v1 * v2

- | Syntax.Divide -> v1 / v2)

+ Syntax.Plus -> IntVal(v1 + v2)

+ | Syntax.Minus -> IntVal(v1 - v2)

+ | Syntax.Times -> IntVal(v1 * v2)

+ | Syntax.Divide -> IntVal(v1 / v2))

+

+let string_of_val v = match v with

+ IntVal(n) -> string_of_int n

+ | StringVal(s) -> s

+

+let print_val v = print_string (string_of_val v)

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

index 2af6c5e..f8e9759 100644

--- a/lib/lexer.mll

+++ b/lib/lexer.mll

@@ -5,7 +5,13 @@

(* 正規表現の略記 *)

+let letter = lower | upper

+let printable = symbol | letter | digit

+(* 字句解析器 *)

(* 字句解析の規則 *)

rule token = parse

space+ { token lexbuf } (* 空白は読み飛ばす *)

@@ -15,4 +21,10 @@ rule token = parse

| "*" { Parser.TIMES }

| "/" { Parser.DIVIDE }

| eof { Parser.EOF }

+ (* 文字列リテラル *)

+ | "\"" (printable | space)* "\"" {

+ (* 両端のダブルクォートを取り除く *)

+ let str = String.sub (Lexing.lexeme lexbuf) 1 ((String.length (Lexing.lexeme lexbuf)) - 2) in

+ Parser.STRING(str)

+ }

| _ { failwith ("invalid character " ^ (Lexing.lexeme lexbuf)) }

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

index b1df3e8..e973287 100644

--- a/lib/parser.mly

+++ b/lib/parser.mly

@@ -4,6 +4,7 @@

// トークンの定義

%token EOF

%token <int> INT

+%token <string> STRING

%token PLUS MINUS TIMES DIVIDE

%token EOF

@@ -21,6 +22,7 @@ program: exp EOF { $1 }

exp:

INT { Syntax.IntExp($1) }

+| STRING { Syntax.StringExp($1) }

| exp PLUS exp { Syntax.OpExp($1, Syntax.Plus, $3) }

| exp MINUS exp { Syntax.OpExp($1, Syntax.Minus, $3) }

| exp TIMES exp { Syntax.OpExp($1, Syntax.Times, $3) }

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

index a03eb72..a9e9c04 100644

--- a/lib/syntax.ml

+++ b/lib/syntax.ml

@@ -2,4 +2,5 @@ type op_t = Plus | Minus | Times | Divide

type t =

IntExp of int (* 整数 *)

+ | StringExp of string (* 文字列 *)

| OpExp of t * op_t * t (* 二項演算子 *)

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

index 4ae9527..4cda5b1 100644

--- a/test/tiger_test.expected

+++ b/test/tiger_test.expected

@@ -3,3 +3,4 @@ result: 60

result: 20

result: 3

result: 100

+result: A

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

index 181b65f..58401ff 100644

--- a/test/tiger_test.ml

+++ b/test/tiger_test.ml

@@ -7,33 +7,40 @@ let eval src =

let () =

let src = "4649" in

print_string "result: ";

- print_int (eval src);

+ Tiger.Eval.print_val (eval src);

print_newline ()

(* 足し算 *)

let () =

let src = "10 + 20 + 30" in

print_string "result: ";

- print_int (eval src);

+ Tiger.Eval.print_val (eval src);

print_newline ()

(* 引き算 *)

let () =

let src = "50 - 20 - 10" in

print_string "result: ";

- print_int (eval src);

+ Tiger.Eval.print_val (eval src);

print_newline ()

(* 掛け算 *)

let () =

let src = "1 + 2 * 3 - 4" in

print_string "result: ";

- print_int (eval src);

+ Tiger.Eval.print_val (eval src);

print_newline ()

(* 割り算 *)

let () =

let src = "98 + 20 / 2 / 5" in

print_string "result: ";

- print_int (eval src);

+ Tiger.Eval.print_val (eval src);

+ print_newline ()

+

+(* 文字列リテラル *)

+let () =

+ let src = "\"A\"" in

+ print_string "result: ";

+ Tiger.Eval.print_val (eval src);

print_newline ()