Merge pull request #56 from wcho21/dev

support built-in functions

README.md

@@ -2,21 +2,24 @@
 [![Korean](https://img.shields.io/badge/Lang-ko-blue)][readme-ko]
 
 [readme-en]: ./
-[readme-ko]: ./docs/README_KR.md
+[readme-ko]: ./docs/README.ko.md
 
 
 
-# 🗡️ KAL
+# 🗡️ KALANG
 
-<img src="./docs/images/kal-logo.png" alt="KAL logo" width="128px" height="128px" />
+<img src="./docs/images/kal-logo.png" alt="KALANG logo" width="192px" height="192px" />
 
-_KAL: Korean Algorithmic Language_.
+_KALANG: Korean Programming Language_.
 
-A simple interpreted language which supports Korean.
+- < 0.03 MB.
+- Tested with >250 cases
+- Written in JavaScript, natively runs on web browsers.
+- Minimal syntax with Korean keywords.
 
-You can load a _KAL_ interpreter in browsers, or build manually (see below).
+Try _KALANG_ at [Playground][playground].
 
-Try _KAL_ at [KAL Playground][playground].
+You can load a _KALANG_ interpreter in browsers, or build manually (see below).
 
 [playground]: https://kal-playground.rooi.dev/
 
@@ -30,12 +33,17 @@ Load the interpreter script in HTML as follows:
 <script src="https://cdn.jsdelivr.net/gh/wcho21/kal@latest/dist/index.min.js"></script>
 ```
 
-After that, you can execute _KAL_ code with `kal.execute(code-to-execute)` as follows:
+After that, you can execute _KALANG_ code with `kal.execute(code-to-execute)` as follows:
 
-```HTML
-<script>
-  kal.execute("5+5"); // === 10
-</script>
+```javascript
+kal.execute("5+5"); // === 10
+```
+
+You can attach an event handler for standard output writing as follows:
+```javascript
+const stdouts = [];
+
+kal.execute("쓰기('사과')", stdout => stdouts.push(stdout)); // stdout === ["사과"]
 ```
 
 
@@ -89,6 +97,27 @@ which yields `43`.
 
 
 
+### Builtin functions
+
+`쓰기()`:
+```
+쓰기('사과')
+쓰기('포도', '바나나')
+```
+which yields
+```
+사과
+포도 바나나
+```
+
+`길이()`:
+```
+길이('사과')
+```
+which yields `2`.
+
+
+
 ### Types
 
 _Number type_: any floating-point numbers
@@ -114,9 +143,9 @@ _Boolean type_: `참`, `거짓`
 
 Note that building process is based on [Node.js][node].
 
-With [`pnpm`][pnpm], you can build a _KAL_ interpreter by running `pnpm install && pnpm build && pnpm bundle`.
+With [`pnpm`][pnpm], you can build a _KALANG_ interpreter by running `pnpm install && pnpm build`.
 
-The output will be in the directory `/bundle/index.js`.
+The output will be in the directory `/dist/index.min.js`.
 
-[pnpm]: https://pnpm.io/
 [node]: https://nodejs.org/
+[pnpm]: https://pnpm.io/

docs/README_KR.md → docs/README.ko.md

@@ -6,17 +6,22 @@
 
 
 
-# 🗡️ KAL
+# 🗡️ KALANG
 
-<img src="./images/kal-logo.png" alt="KAL logo" width="128px" height="128px" />
+<img src="./images/kal-logo.png" alt="KALANG logo" width="192px" height="192px" />
 
-_KAL: Korean Algorithmic Language_.
+_KALANG: Korean Programming Language_.
 
-한국어를 지원하는 인터프리터 언어.
+한국어 프로그래밍 언어.
 
-_KAL_ 인터프리터를 브라우저에 로드하거나 직접 빌드하는 방법은 아래를 참고하세요.
+- < 0.03 MB.
+- 250 개 이상의 테스트 케이스.
+- 브라우저에서 바로 동작하는 자바스크립트 구현체.
+- 한국어 키워드로 구성된 간단한 문법.
 
-_KAL_ 을 [플레이그라운드][playground]에서 체험해보세요.
+_KALANG_ 을 [플레이그라운드][playground]에서 체험해보세요.
+
+_KALANG_ 인터프리터를 브라우저에 로드하거나 직접 빌드하는 방법은 아래를 참고하세요.
 
 [playground]: https://kal-playground.rooi.dev/
 
@@ -30,12 +35,17 @@ _KAL_ 을 [플레이그라운드][playground]에서 체험해보세요.
 <script src="https://cdn.jsdelivr.net/gh/wcho21/kal@latest/dist/index.min.js"></script>
 ```
 
-이후, _KAL_ 코드는 다음과 같이 `kal.execute(code-to-execute)`로 실행합니다.
+이후, _KALANG_ 코드는 다음과 같이 `kal.execute(code-to-execute)`로 실행합니다.
 
-```HTML
-<script>
-  kal.execute("5+5"); // === 10
-</script>
+```javascript
+kal.execute("5+5"); // === 10
+```
+
+표준 출력을 위해 이벤트 핸들러를 등록할 수 있습니다.
+```javascript
+const stdouts = [];
+
+kal.execute("쓰기('사과')", stdout => stdouts.push(stdout)); // stdout === ["사과"]
 ```
 
 
@@ -89,6 +99,27 @@ _KAL_ 을 [플레이그라운드][playground]에서 체험해보세요.
 
 
 
+### 내장 함수
+
+`쓰기()`:
+```
+쓰기('사과')
+쓰기('포도', '바나나')
+```
+결과는 다음과 같습니다.
+```
+사과
+포도 바나나
+```
+
+`길이()`:
+```
+길이('사과')
+```
+결과는 `2`입니다.
+
+
+
 ### 타입들
 
 _숫자 타입_: 아무 부동소수점 숫자
@@ -116,15 +147,9 @@ _불리언 타입_: `참`, `거짓`
 
 빌드 과정은 [Node.js][node]를 기반으로 합니다.
 
-_KAL_ 인터프리터를 다음 커맨드로 [`pnpm`]을 이용해 빌드합니다.
+[`pnpm`][pnpm]을 이용해, _KALANG_ 인터프리터를 `pnpm install && pnpm build`로 빌드할 수 있습니다.
 
-```
-pnpm install && pnpm build && pnpm bundle`
-```
+빌드 결과는 `/dist/index.min.js` 디렉토리에 위치합니다.
 
-
-
-결과는 `/bundle/index.js` 디렉토리에 위치합니다.
-
-[pnpm]: https://pnpm.io/
 [node]: https://nodejs.org/
+[pnpm]: https://pnpm.io/

src/evaluator/builtin/index.ts

@@ -0,0 +1,42 @@
+import type * as Value from "../value";
+import * as value from "../value";
+
+export type BuiltinFunction = (args: any[], onStdout?: (toWrite: string) => void) => Value.Value;
+
+const len: BuiltinFunction = (args) => {
+  const arg = args[0];
+  if (arg.type === "string") {
+    const length = arg.value.length;
+    return value.createNumberValue({ value: length }, String(length), arg.range);
+  }
+
+  throw new Error();
+};
+
+const write: BuiltinFunction = (args, onStdout) => {
+  if (args.length === 0) {
+    throw new Error();
+  }
+
+  const str = args.map(arg => arg.representation).join(" ");
+  if (onStdout !== undefined) {
+    onStdout(str);
+  }
+
+  const range = { begin: args[0].range.begin, end: args[args.length-1].range.end };
+  return value.createEmptyValue({ value: null }, "(없음)", range);
+};
+
+const builtins = {
+  get(identifier: string): BuiltinFunction | null {
+    switch (identifier) {
+      case "길이":
+        return len;
+      case "쓰기":
+        return write;
+      default:
+        return null;
+    }
+  }
+};
+export default builtins;

src/evaluator/index.test.ts

@@ -3,12 +3,15 @@ import Parser from "../parser";
 import Evaluator, * as Eval from "./";
 import Environment from "./environment";
 
-const evaluateInput = (input: string) => {
+const evaluateInput = (input: string, onStdout?: (toWrite: string) => void) => {
   const lexer = new Lexer(input);
   const parser = new Parser(lexer);
   const parsed = parser.parseSource();
 
   const evaluator = new Evaluator();
+  if (onStdout !== undefined) {
+    evaluator.onStdout(onStdout);
+  }
   const env = new Environment();
   const evaluated = evaluator.evaluate(parsed, env);
   return evaluated;
@@ -35,6 +38,14 @@ const testEvaluatingFunction = ({ input, expectedParamsLength }: { input: string
   expect(evaluated).toHaveProperty("environment");
 };
 
+const testEvaluatingStdout = ({ input, expected }: { input: string, expected: any }): void => {
+  const stdouts: string[] = [];
+
+  evaluateInput(input, toWrite => stdouts.push(toWrite));
+
+  expect(stdouts).toEqual(expected);
+};
+
 describe("evaluate()", () => {
   describe("single numbers", () => {
     const cases = [
@@ -357,6 +368,47 @@ describe("evaluate()", () => {
     it.each(cases)("evaluate $name", testEvaluatingPrimitive);
   });
 
+  describe("builtin function calls", () => {
+    describe("길이()", () => {
+      const cases = [
+        {
+          name: "empty string",
+          input: "길이('')",
+          expected: 0,
+        },
+        {
+          name: "nonempty string",
+          input: "길이('사과')",
+          expected: 2,
+        },
+      ];
+
+      it.each(cases)("evaluate $name", testEvaluatingPrimitive);
+    });
+
+    describe("쓰기()", () => {
+      const cases = [
+        {
+          name: "single string",
+          input: "쓰기('사과')",
+          expected: ["사과"],
+        },
+        {
+          name: "multiple string",
+          input: "쓰기('사과', '포도', '바나나')",
+          expected: ["사과 포도 바나나"],
+        },
+        {
+          name: "multiple calls",
+          input: "쓰기('사과') 쓰기('포도')",
+          expected: ["사과", "포도"],
+        },
+      ];
+
+      it.each(cases)("evaluate $name", testEvaluatingStdout);
+    });
+  });
+
   describe("errors", () => {
     const cases = [
       {