[true, /^\d+\.\d+/g, TokenKind.Flo],
[true, /^true/g, TokenKind.Bool],
[true, /^false/g, TokenKind.Bool],
- [true, /^([+\-*/a-zA-Z_][0-9+\-*/a-zA-Z_]*|[<>]=?|==)/g, TokenKind.Id],
+ [true, /^([+\-*/a-zA-Z_][0-9+\-*/a-zA-Z_]*|[<>]=?|!?=)/g, TokenKind.Id],
[true, /^\"([^\"]|\\\")+\"/g, TokenKind.Str],
[true, /^[(]/g, TokenKind.LParen],
[true, /^[)]/g, TokenKind.RParen],
[true, /^\\/g, TokenKind.BSlash],
[true, /^([^+\-*/a-zA-Z_0-9\[\]()'\s\t\r\n\\]+)/g, TokenKind.Other],
]);
-/**
+/*
* ## BNF
LISP = UNIT | LISPS | CON_STR
LISPS = "(" LISP ")" | "'" "(" LISP ")"
};
}
function applyBool(value) {
- if (value.text == "true") {
+ if (value.text === "true") {
return {
type: ItemType.Bool,
bool: true,
return value;
}
function applyQuoted(value) {
- let head = { type: ItemType.Id, id: "quote" };
- let merged = [head, value];
+ const head = { type: ItemType.Id, id: "quote" };
+ const merged = [head, value];
return merged;
}
function applyStrings(value) {
- let head = [{ type: ItemType.Id, id: "%concat" }];
- let merged = head.concat(value);
+ const head = [{ type: ItemType.Id, id: "%concat" }];
+ const merged = head.concat(value);
return merged;
}
/** for convinence to omit the spaces and newlines */
-let __ = (0, typescript_parsec_2.opt)((0, typescript_parsec_2.tok)(TokenKind.SpaceNL));
+const __ = (0, typescript_parsec_2.opt)((0, typescript_parsec_2.tok)(TokenKind.SpaceNL));
LISP.setPattern((0, typescript_parsec_2.alt)((0, typescript_parsec_2.kleft)(SINGLE, __), (0, typescript_parsec_2.kleft)(LISPS, __), (0, typescript_parsec_2.kleft)(CON_STR, __)));
SINGLE.setPattern((0, typescript_parsec_2.alt)((0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.Id), applyId), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.Int), applyInt), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.Flo), applyFlo), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.Str), applyStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.Bool), applyBool)));
LISPS.setPattern((0, typescript_parsec_2.alt)((0, typescript_parsec_2.apply)((0, typescript_parsec_2.kmid)((0, typescript_parsec_2.seq)((0, typescript_parsec_2.str)("("), __), (0, typescript_parsec_2.rep_sc)(LISP), (0, typescript_parsec_2.str)(")")), applyList), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.kright)((0, typescript_parsec_2.str)("'"), (0, typescript_parsec_2.kmid)((0, typescript_parsec_2.seq)((0, typescript_parsec_2.str)("("), __), (0, typescript_parsec_2.rep_sc)(LISP), (0, typescript_parsec_2.str)(")"))), applyQuoted)));
CON_STR_INNER.setPattern((0, typescript_parsec_2.alt)((0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.Id), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.Int), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.Flo), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.Str), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.Other), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.tok)(TokenKind.SpaceNL), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.kright)((0, typescript_parsec_2.tok)(TokenKind.BSlash), (0, typescript_parsec_2.tok)(TokenKind.LParen)), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.kright)((0, typescript_parsec_2.tok)(TokenKind.BSlash), (0, typescript_parsec_2.tok)(TokenKind.RParen)), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.kright)((0, typescript_parsec_2.tok)(TokenKind.BSlash), (0, typescript_parsec_2.tok)(TokenKind.LBrack)), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.kright)((0, typescript_parsec_2.tok)(TokenKind.BSlash), (0, typescript_parsec_2.tok)(TokenKind.RBrack)), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.kright)((0, typescript_parsec_2.tok)(TokenKind.BSlash), (0, typescript_parsec_2.tok)(TokenKind.Apos)), tokenToStr), (0, typescript_parsec_2.apply)((0, typescript_parsec_2.kright)((0, typescript_parsec_2.tok)(TokenKind.BSlash), (0, typescript_parsec_2.tok)(TokenKind.BSlash)), bSlashTokenToStr), LISPS));
CON_STR.setPattern((0, typescript_parsec_2.apply)((0, typescript_parsec_2.kmid)((0, typescript_parsec_2.str)("["), (0, typescript_parsec_2.rep_sc)(CON_STR_INNER), (0, typescript_parsec_2.str)("]")), applyStrings));
-function astToString(ast) {
+function astToString(ast, isInQuoted) {
if (Array.isArray(ast)) {
- let ast2 = ast.map(astToString);
+ const ast2 = ast.map((x) => astToString(x, isInQuoted));
return "(" + ast2.join(" ") + ")";
}
else {
- if (ast.type == ItemType.Str) {
+ if (ast.type === ItemType.Str) {
return "`" + ast.str + "`";
}
- else if (ast.type == ItemType.Id) {
+ else if (ast.type === ItemType.Id) {
return ast.id;
}
- else if (ast.type == ItemType.Flo) {
+ else if (ast.type === ItemType.Flo) {
return ast.flo.toString();
}
- else if (ast.type == ItemType.Bool) {
+ else if (ast.type === ItemType.Bool) {
return ast.bool.toString();
}
- else if (ast.type == ItemType.Clos) {
- let binding = astToString(ast.vars);
- let body = astToString(ast.body);
+ else if (ast.type === ItemType.Clos) {
+ const binding = astToString(ast.vars);
+ const body = astToString(ast.body);
return `<closure; binding : ${binding}, body : ${body}>`;
}
- else if (ast.type == ItemType.Ls) {
- let body = astToString(ast.list);
- return "'" + body;
+ else if (ast.type === ItemType.Ls) {
+ const body = astToString(ast.list, true);
+ if (isInQuoted) {
+ return body;
+ }
+ else {
+ return "'" + body;
+ }
}
else {
return ast.int.toString();
function isItem(x) {
return !Array.isArray(x);
}
-function interpBinary(op, argsMapped, isBool) {
- let fst = argsMapped[0];
- let snd = argsMapped[1];
- if (argsMapped.length == 2 && isItem(fst) && isItem(snd)) {
- if (fst.type == ItemType.Flo && snd.type == ItemType.Flo) {
- if (isBool == true) {
- return {
- type: ItemType.Bool,
- bool: op(fst.flo, snd.flo),
- };
- }
+function interpBinary(op, argsMapped) {
+ const fst = argsMapped[0];
+ const snd = argsMapped[1];
+ if (argsMapped.length === 2 && isItem(fst) && isItem(snd)) {
+ if (fst.type === ItemType.Flo && snd.type === ItemType.Flo) {
return {
type: ItemType.Flo,
flo: op(fst.flo, snd.flo),
};
}
- else if (fst.type == ItemType.Int && snd.type == ItemType.Int) {
- if (isBool == true) {
- return {
- type: ItemType.Bool,
- bool: op(fst.int, snd.int),
- };
- }
+ else if (fst.type === ItemType.Int && snd.type === ItemType.Int) {
return {
type: ItemType.Int,
int: op(fst.int, snd.int),
};
}
else {
- throw new Error("the type of add should be (int, int) or (flo, flo");
+ throw new Error("the type of add should be (int, int) or (flo, flo)");
+ }
+ }
+ else {
+ throw new Error(`the number of args of ${op} should be 2, but it's ${argsMapped}`);
+ }
+}
+function interpBinaryBool(op, argsMapped) {
+ const fst = argsMapped[0];
+ const snd = argsMapped[1];
+ if (argsMapped.length === 2 && isItem(fst) && isItem(snd)) {
+ if (fst.type === ItemType.Flo && snd.type === ItemType.Flo) {
+ return {
+ type: ItemType.Bool,
+ bool: op(fst.flo, snd.flo),
+ };
+ }
+ else if (fst.type === ItemType.Int && snd.type === ItemType.Int) {
+ return {
+ type: ItemType.Bool,
+ bool: op(fst.int, snd.int),
+ };
+ }
+ else {
+ throw new Error("the type of add should be (int, int) or (flo, flo)");
}
}
else {
return x > y;
}
function eq(x, y) {
- return x == y;
+ return x === y;
}
function le(x, y) {
return x <= y;
}
+function ne(x, y) {
+ return x !== y;
+}
function ge(x, y) {
return x >= y;
}
+function concatString(l, r) {
+ const rtn = {
+ type: ItemType.Str,
+ str: l.str + r.str,
+ };
+ return rtn;
+}
/** list manipulation */
function car(x) {
- let fst = x.list[0];
+ const fst = x.list[0];
if (Array.isArray(fst)) {
- let rtnList = {
+ const rtnList = {
type: ItemType.Ls,
list: fst,
};
return fst;
}
}
+function cdr(x) {
+ if (x.list.length == 0) {
+ throw new Error("the argument of 'cdr' can't be a empty list.");
+ }
+ const remained = x.list.slice(1);
+ const rtnList = {
+ type: ItemType.Ls,
+ list: remained,
+ };
+ return rtnList;
+}
+function cons(h, t) {
+ const inner = [h].concat(t.list);
+ const rtnList = {
+ type: ItemType.Ls,
+ list: inner,
+ };
+ return rtnList;
+}
function extendEnv(env, vari, isRec, data) {
// add var
if (!(vari in env)) {
- env[vari] = [{ isRec: isRec, value: data }];
+ env[vari] = [{ isRec, value: data }];
// update
}
else {
- env[vari] = [{ isRec: isRec, value: data }].concat(env[vari]);
+ env[vari] = [{ isRec, value: data }].concat(env[vari]);
}
return env;
}
-var emptyEnv = {};
+const emptyEnv = {};
/**
* @throws {Error}
*/
function interp(prog, env) {
if (Array.isArray(prog)) {
if (!Array.isArray(prog[0])) {
- let op = prog[0];
- if (op.type == ItemType.Id) {
+ const op = prog[0];
+ if (op.type === ItemType.Id) {
// a list
- if (op.id == "quote") {
- let body = prog[1];
+ if (op.id === "quote") {
+ const body = prog[1];
if (!Array.isArray(body)) {
throw new Error("the argument of quote, aka: " + body + ", is not a list.");
}
};
}
}
- /**lambda */
- else if (op.id == "lambda") {
- let vars = prog[1];
- if (prog.length != 3) {
+ /* lambda */
+ else if (op.id === "lambda") {
+ const vars = prog[1];
+ if (prog.length !== 3) {
throw invalidLengthException('lambda', 2);
}
else if (!isItemArray(vars)) {
else {
return {
type: ItemType.Clos,
- env: env,
- vars: vars,
+ env,
+ vars,
body: prog[2],
};
}
}
/** let function */
- else if (op.id == "let" || op.id == "letrec") {
- let bindings = prog[1];
- if (prog.length != 3) {
- if (op.id == "let") {
+ else if (op.id === "let" || op.id === "letrec") {
+ const bindings = prog[1];
+ if (prog.length !== 3) {
+ if (op.id === "let") {
throw invalidLengthException('let', 2);
}
else {
throw new Error("the bindings should be array");
}
else {
- var newEnv = structuredClone(env);
- for (var i = 0; i < bindings.length; i++) {
- let binding = bindings[i];
+ let newEnv = structuredClone(env);
+ for (let i = 0; i < bindings.length; i++) {
+ const binding = bindings[i];
if (!Array.isArray(binding)
- || (binding).length != 2) {
- if (op.id == "let") {
+ || binding.length !== 2) {
+ if (op.id === "let") {
throw new Error("malformed of let.");
}
else {
}
}
else {
- let vari = binding[0];
+ const vari = binding[0];
if (vari.hasOwnProperty("id")) {
- let variName = vari.id;
- let data = interp(binding[1], env);
- if (op.id == "letrec") {
+ const variName = vari.id;
+ const data = interp(binding[1], env);
+ if (op.id === "letrec") {
newEnv = extendEnv(newEnv, variName, true, data);
}
else {
}
}
}
- let body = prog[2];
+ const body = prog[2];
return interp(body, newEnv);
}
}
// end of let
- else if (op.id == "if") {
- if (prog.length != 4) {
+ else if (op.id === "if") {
+ if (prog.length !== 4) {
throw invalidLengthException('if', 3);
}
else {
- let cond = interp(prog[1], env);
+ const cond = interp(prog[1], env);
if (Array.isArray(cond)) {
throw new Error("cond can't be reduced to a constant");
}
- else if (cond.type != ItemType.Bool) {
+ else if (cond.type !== ItemType.Bool) {
throw new Error("type error of cond, not a bool");
}
- else if (cond.bool == true) {
+ else if (cond.bool === true) {
return interp(prog[2], env);
// if cond is false
}
}
}
else {
- let argsMapped = prog.slice(1).map((x) => {
+ const argsMapped = prog.slice(1).map((x) => {
return interp(x, env);
});
// binary basic operator
- if (op.id == "+") {
+ if (op.id === "+") {
return interpBinary(add, argsMapped);
}
- else if (op.id == "-") {
+ else if (op.id === "-") {
return interpBinary(sub, argsMapped);
}
- else if (op.id == "*") {
+ else if (op.id === "*") {
return interpBinary(mul, argsMapped);
}
- else if (op.id == "/") {
+ else if (op.id === "/") {
return interpBinary(div, argsMapped);
// bool calculation
}
- else if (op.id == ">") {
- return interpBinary(gt, argsMapped, true);
+ else if (op.id === ">") {
+ return interpBinaryBool(gt, argsMapped);
}
- else if (op.id == "<") {
- return interpBinary(lt, argsMapped, true);
+ else if (op.id === "<") {
+ return interpBinaryBool(lt, argsMapped);
}
- else if (op.id == ">=") {
- return interpBinary(ge, argsMapped, true);
+ else if (op.id === ">=") {
+ return interpBinaryBool(ge, argsMapped);
}
- else if (op.id == "<=") {
- return interpBinary(le, argsMapped, true);
+ else if (op.id === "<=") {
+ return interpBinaryBool(le, argsMapped);
}
- else if (op.id == "==") {
- return interpBinary(eq, argsMapped, true);
+ else if (op.id === "=") {
+ return interpBinaryBool(eq, argsMapped);
}
- else if (op.id == "car") {
- let arg = argsMapped[0];
- if (prog.length != 2) {
+ else if (op.id === "!=") {
+ return interpBinaryBool(ne, argsMapped);
+ }
+ else if (op.id === "car") {
+ const arg = argsMapped[0];
+ if (prog.length !== 2) {
throw invalidLengthException('car', 1);
}
- else if (!arg.hasOwnProperty('type') || arg.type != ItemType.Ls) {
+ else if (!arg.hasOwnProperty('type') || arg.type !== ItemType.Ls) {
throw new Error("the arg of 'car' is not a list.");
}
else {
return car(arg);
}
- // other named function call
}
+ else if (op.id === "cdr") {
+ const arg = argsMapped[0];
+ if (prog.length !== 2) {
+ throw invalidLengthException('cdr', 1);
+ }
+ else if (!arg.hasOwnProperty('type') || arg.type !== ItemType.Ls) {
+ throw new Error("the arg of 'cdr' is not a list.");
+ }
+ else {
+ return cdr(arg);
+ }
+ }
+ else if (op.id === "cons") {
+ const arg = argsMapped;
+ if (prog.length !== 3) {
+ throw invalidLengthException('cdr', 2);
+ }
+ else if (!arg[1].hasOwnProperty('type') || arg[1].type !== ItemType.Ls) {
+ throw new Error("the 2nd arg of 'cons' is not a list.");
+ }
+ else {
+ return cons(arg[0], arg[1]);
+ }
+ } // string manipulations
+ else if (op.id === "++") {
+ const lhs = prog[1];
+ const rhs = prog[2];
+ if (prog.length !== 3) {
+ throw invalidLengthException('++', 2);
+ }
+ else if (!isItem(lhs) || !isItem(rhs)
+ || lhs.type != ItemType.Str || rhs.type != ItemType.Str) {
+ throw new Error("at least one of the arg. of '++' is not a str.");
+ }
+ else {
+ return concatString(lhs, rhs);
+ }
+ }
+ // other named function call
else {
- let caller = interp(prog[0], env);
- let varArgs = caller.vars;
- let varArgLen = varArgs.length;
- let argsMappedLen = argsMapped.length;
- if (argsMappedLen != varArgLen) {
+ const caller = interp(prog[0], env);
+ const varArgs = caller.vars;
+ const varArgLen = varArgs.length;
+ const argsMappedLen = argsMapped.length;
+ if (argsMappedLen !== varArgLen) {
throw new Error("the number of the arguments is"
+ " not the same of that of the input vars.");
}
else {
- var newEnv = structuredClone(caller.env);
- for (var i = 0; i < Object.keys(env).length; i++) {
- let currentKey = Object.keys(env)[i];
- let currentValue = env[currentKey];
- if (currentValue[0].isRec !== undefined && currentValue[0].isRec == true) {
- newEnv = extendEnv(newEnv, currentKey, true, currentValue[0].value);
- }
- }
- var fuBody = caller.body;
- for (var i = 0; i < argsMapped.length; i++) {
- let varArg = varArgs[i];
- var varArgIsRec = false;
- if (varArg.isRec !== undefined && varArg.isRec == true) {
+ let newEnv = structuredClone(caller.env);
+ // for recursion function usage
+ /*for(const key in env){
+ const currentKey = key;
+ const currentValue = env[currentKey];
+ if (currentValue[0].isRec !== undefined && currentValue[0].isRec === true){
+ newEnv = extendEnv(newEnv, currentKey, true, currentValue[0].value);
+ }
+ }*/
+ const fuBody = caller.body;
+ for (let i = 0; i < argsMapped.length; i++) {
+ const varArg = varArgs[i];
+ let varArgIsRec = false;
+ if (varArg.isRec !== undefined && varArg.isRec === true) {
varArgIsRec = true;
}
newEnv = extendEnv(newEnv, varArgs[i].id, varArgIsRec, argsMapped[i]);
// the caller which is a higher-function call
}
else {
- let argsMapped = prog.slice(1).map((x) => {
+ const argsMapped = prog.slice(1).map((x) => {
return interp(x, env);
});
- let caller = interp(prog[0], env);
- let varArgs = caller.vars;
- let varArgLen = varArgs.length;
- let argsMappedLen = argsMapped.length;
- if (argsMappedLen != varArgLen) {
+ const caller = interp(prog[0], env);
+ const varArgs = caller.vars;
+ const varArgLen = varArgs.length;
+ const argsMappedLen = argsMapped.length;
+ if (argsMappedLen !== varArgLen) {
throw new Error("the number of the arguments is"
+ " not the same of that of the input vars.");
}
else {
- var fuBody = caller.body;
- var newEnv = structuredClone(env);
+ const fuBody = caller.body;
+ let newEnv = structuredClone(env);
// for recursion function usage
- for (var i = 0; i < argsMapped.length; i++) {
- var varArgIsRec = false;
- if (varArgs[i].isRec !== undefined && varArgs[i].isRec == true) {
+ for (let i = 0; i < argsMapped.length; i++) {
+ let varArgIsRec = false;
+ if (varArgs[i].isRec !== undefined && varArgs[i].isRec === true) {
varArgIsRec = true;
}
newEnv = extendEnv(newEnv, varArgs[i].id, varArgIsRec, argsMapped[i]);
}
else {
// constant
- if (prog.type != ItemType.Id) {
+ if (prog.type !== ItemType.Id) {
return prog;
}
// other variable
else {
- let varName = prog.id;
- let isRecAndVal = env[varName][0];
+ const varName = prog.id;
+ const isRecAndVal = env[varName][0];
+ // for letrec's usage
+ if (isRecAndVal.isRec === true) {
+ let value = isRecAndVal.value;
+ if (isClosure(value)) {
+ for (const key in env) {
+ const valueOfKey = env[key][0];
+ if (valueOfKey.isRec == true) {
+ value.env = extendEnv(value.env, key, true, valueOfKey.value);
+ }
+ }
+ return value;
+ }
+ }
return isRecAndVal.value;
}
}
}
function evaluate(expr) {
- let input = (0, typescript_parsec_1.expectSingleResult)((0, typescript_parsec_1.expectEOF)(LISP.parse(tokenizer.parse(expr))));
- let interped = interp(input, emptyEnv);
+ const input = (0, typescript_parsec_1.expectSingleResult)((0, typescript_parsec_1.expectEOF)(LISP.parse(tokenizer.parse(expr))));
+ const interped = interp(input, emptyEnv);
return astToString(interped);
}
-//evaluate(`(main '((text 12)) [ 快狐跳懶狗\\\\\\\[\\\]\\\(\\\)(italic "fox and dog") (bold [OK])])`)
-//evaluate("@(let (a 17) (+ a 10))@")
+// evaluate(`(main '((text 12)) [ 快狐跳懶狗\\\\\\\[\\\]\\\(\\\)(italic "fox and dog") (bold [OK])])`)
+// evaluate("@(let (a 17) (+ a 10))@")
// eval print loop
const readline = require("node:readline");
const rl = readline.createInterface({
[true, /^\d+\.\d+/g, TokenKind.Flo],
[true, /^true/g, TokenKind.Bool],
[true, /^false/g, TokenKind.Bool],
- [true, /^([+\-*/a-zA-Z_][0-9+\-*/a-zA-Z_]*|[<>]=?|==)/g, TokenKind.Id],
+ [true, /^([+\-*/a-zA-Z_][0-9+\-*/a-zA-Z_]*|[<>]=?|!?=)/g, TokenKind.Id],
[true, /^\"([^\"]|\\\")+\"/g, TokenKind.Str],
[true, /^[(]/g, TokenKind.LParen],
[true, /^[)]/g, TokenKind.RParen],
apply(kmid(str("["), rep_sc(CON_STR_INNER), str("]")), applyStrings)
);
-function astToString(ast: AST): string {
+function astToString(ast: AST, isInQuoted? : boolean): string {
if (Array.isArray(ast)) {
- const ast2 = ast.map(astToString);
+ const ast2 = ast.map((x)=>astToString(x, isInQuoted));
return "(" + ast2.join(" ") + ")";
} else {
if (ast.type === ItemType.Str) {
const body = astToString(ast.body);
return `<closure; binding : ${binding}, body : ${body}>`;
}else if (ast.type === ItemType.Ls){
- const body = astToString(ast.list);
- return "'"+body;
+ const body = astToString(ast.list, true);
+ if (isInQuoted){
+ return body;
+ }else{
+ return "'"+body;
+ }
}
else {
return ast.int.toString();
throw new Error("the type of add should be (int, int) or (flo, flo)");
}
} else {
- throw new Error("the number of args should be 2.");
+ throw new Error(`the number of args of ${op} should be 2, but it's ${argsMapped}`);
}
}
function le(x: number, y: number): boolean {
return x <= y;
}
+function ne(x: number, y: number): boolean {
+ return x !== y;
+}
function ge(x: number, y: number): boolean {
return x >= y;
}
+function concatString(l: ItemStr, r : ItemStr) : ItemStr {
+ const rtn : ItemStr = {
+ type: ItemType.Str,
+ str: l.str + r.str,
+ }
+ return rtn;
+}
+
/** list manipulation */
function car(x : List) : Item {
list: fst,
}
return rtnList;
-}else{
- return fst;
+ }else{
+ return fst;
+ }
}
+function cdr(x : List) : Item {
+ if (x.list.length == 0){
+ throw new Error("the argument of 'cdr' can't be a empty list.")
+ }
+ const remained = (x.list as AST[]).slice(1);
+ const rtnList : List = {
+ type: ItemType.Ls,
+ list: remained,
+ }
+ return rtnList;
}
+function cons(h: AST, t : List) : List {
+ const inner = [h].concat(t.list);
+ const rtnList : List = {
+ type: ItemType.Ls,
+ list: inner,
+ }
+ return rtnList;
+}
+
function extendEnv(env : Env, vari : string, isRec: boolean, data : AST) : Env{
// add var
return interpBinaryBool(ge, argsMapped);
} else if (op.id === "<=") {
return interpBinaryBool(le, argsMapped);
- } else if (op.id === "==") {
+ } else if (op.id === "=") {
return interpBinaryBool(eq, argsMapped);
+ } else if (op.id === "!=") {
+ return interpBinaryBool(ne, argsMapped);
} else if (op.id === "car") {
const arg = argsMapped[0];
if (prog.length !== 2){
}else{
return car((arg as List));
}
+ }
+ else if (op.id === "cdr") {
+ const arg = argsMapped[0];
+ if (prog.length !== 2){
+ throw invalidLengthException('cdr', 1);
+ }else if (!arg.hasOwnProperty('type') || (arg as Item).type !== ItemType.Ls){
+ throw new Error("the arg of 'cdr' is not a list.")
+ }else{
+ return cdr((arg as List));
+ }
+ }else if (op.id === "cons") {
+ const arg = argsMapped;
+ if (prog.length !== 3){
+ throw invalidLengthException('cdr', 2);
+ }else if (!arg[1].hasOwnProperty('type') || (arg[1] as Item).type !== ItemType.Ls){
+ throw new Error("the 2nd arg of 'cons' is not a list.")
+ }else{
+ return cons(arg[0], (arg[1] as List));
+ }
+ } // string manipulations
+ else if (op.id === "++") {
+ const lhs = prog[1];
+ const rhs = prog[2];
+ if (prog.length !== 3){
+ throw invalidLengthException('++', 2);
+ }else if (!isItem(lhs) || !isItem(rhs)
+ || lhs.type != ItemType.Str || rhs.type != ItemType.Str){
+ throw new Error("at least one of the arg. of '++' is not a str.")
+ }else{
+ return concatString(lhs, rhs);
+ }}
+
+
// other named function call
- } else {
+ else {
const caller = interp(prog[0],env);
// for recursion function usage
- for(const key in env){
+ /*for(const key in env){
const currentKey = key;
const currentValue = env[currentKey];
if (currentValue[0].isRec !== undefined && currentValue[0].isRec === true){
newEnv = extendEnv(newEnv, currentKey, true, currentValue[0].value);
}
- }
+ }*/
const fuBody = (caller as Closure).body;
for(let i=0;i<argsMapped.length;i++){
else{
const varName = prog.id;
const isRecAndVal = env[varName][0];
+
+ // for letrec's usage
+ if (isRecAndVal.isRec === true){
+ let value = isRecAndVal.value;
+ if (isClosure(value)){
+ for (const key in env){
+ const valueOfKey = env[key][0];
+ if (valueOfKey.isRec == true){
+ value.env = extendEnv(value.env, key, true, valueOfKey.value);
+ }
+ }
+
+ return value;
+ }
+ }
return isRecAndVal.value;
}
}
projects / anotherTypesetter / commitdiff