Questo si basa su un discorso sui compilatori che ho ascoltato qualche tempo fa, ma, sfortunatamente, non ricordo quando o dove.

Crea il compilatore più corto in qualsiasi lingua in grado di compilare se stesso. Scegli come target qualsiasi ISA ragionevole (68K, x86, MIPS, ARM, SPARC, IBM BAL, ecc.) Che non abbia un'istruzione "programma di compilazione" (questo potrebbe escludere alcune versioni di VAX). Leggi i programmi sorgente stdine stampa il codice generato su stdout. È possibile utilizzare la libreria C standard per I / O e l'elaborazione delle stringhe (ad es _printf.). Non è necessario compilare l'intero linguaggio, solo qualsiasi sottoinsieme che contiene il compilatore (ad esempio, stampare semplicemente un linguaggio di assembly quine, sebbene impressionante, non conta come soluzione.)

Sottoinsieme di Haskell → C - 18926 caratteri

Questo compila un piccolo sottoinsieme di Haskell in C. Caratteristiche che supporta:

• Abbinamenti di motivi e protezioni
• Dichiarazioni sui dati
• Seleziona operatori infix
• Valutazione pigra

Le principali caratteristiche mancanti sono le variabili nidificate (che significa no lambda / let / where / case), il controllo del tipo e le classi del tipo. I programmi risultanti perdono memoria e l'auto-compilazione richiede circa 200 megabyte sul mio sistema (il Gare Collector di Boehm aiuta molto, ma solo se il compilatore ottimizza bene la ricorsione della coda).

Per eseguire il bootstrap, decommentare le prime tre righe (non conteggiate nel punteggio) e compilare con GHC. Il compilatore accetta il codice del sottoinsieme Haskell su stdin e produce il codice C su stdout.

Non è lungo perché la lingua è complessa, ma perché sono pigro. Tuttavia, attualmente non è più la soluzione più breve . Immagino che non mi annoierò questo fine settimana.

-- import Prelude hiding (fmap, lookup, snd, zip);import Data.Char
-- import Data.List hiding (lookup, zip);data P a b = P a b;data B = B
-- add=(+);sub=(-);showInt=show;append[]ys=ys;append(x:xs)ys=x:append xs ys
data Program = Program [[Constructor]] [Function]
data Toplevel = TD [Constructor] | TE Equation | TO
data Constructor = Constructor String Int
data Function = Function String Int [Equation]
data Equation = Equation String [Pattern] (Maybe Expression) Expression
data Pattern = PVar String | PCon String [Pattern]
data Expression = Var String | Con String | Int String | Char String | String String | Ap Expression Expression
data Environment = Environment [P String Int] [P String VarInfo]
data VarInfo = VBox String | VArg Int | VItem VarInfo Int
main = interact (compile . parse)
constructorName (Constructor name _) = name
functionName (Function name _ _) = name
equationName (Equation name _ _ _) = name
sortToplevels [] = (P [] [])
sortToplevels (TD x : xs) = applyFst ((:) x) (sortToplevels xs)
sortToplevels (TE x : xs) = applySnd ((:) x) (sortToplevels xs)
sortToplevels (TO : xs)   = sortToplevels xs
pcons x xs = PCon "Cons" [x, xs];pnil = PCon "Nil" []
ebinary op a b = Ap (Ap (Var op) a) b;ebinaryE op a b = Ap (Ap op a) b
econs x xs = Ap (Ap (Con "Cons") x) xs
enil = Con "Nil"
listEq eq [] [] = True
listEq eq (x:xs) (y:ys) | eq x y = listEq eq xs ys
listEq _ _ _ = False
snd (P a b) = b
zip = zipWith P
lookup q (P k v : _)  | listEq (==) q k = Just v
lookup q (_     : xs)                   = lookup q xs
lookup q _                              = Nothing
compose2 f g x y = f (g x y)
applyFst f (P x y) = P (f x) y
applySnd f (P x y) = P x (f y)
fMaybe f Nothing  = Nothing
fMaybe f (Just x) = Just (f x)
cond f t False = f
cond f t True = t
condList f t [] = f
condList f t xs = t xs
countFrom n = n : countFrom (add n 1)
range l h | l > h = []
range l h         = l : range (add l 1) h
parse = makeProgram . sortToplevels . concatMap parse_p . ((:) prelude) . preprocess
parse_p (P lineno line) = maybe (parse_err lineno line) snd (parseLine line)
parse_err lineno line = error (concat ["Parse error on line ", showInt lineno, ": `", line, "`"])
preprocess = filter (not . isCommentOrEmpty . snd) . zip (countFrom 1) . map (dropWhile isBlank) . lines
isCommentOrEmpty = parserSucceeds (pro (ignore (pro (parseS "--") (parseS "import "))) parseEof)
liftA2 f a b = ap (fmap f a) b
parserSucceeds p s = maybe False (const True) (p s)
fmap f p = fMaybe (applySnd f) . p
pure x s = Just (P s x)
ap1 b (P s x) = maybe Nothing (ap2 x) (b s)
ap2 x (P s y) = Just (P s (x y))
empty = (const Nothing)
pro a b s = maybe (b s) Just (a s)
ap a b = maybe Nothing (ap1 b) . a
prc = liftA2 (:)
pra = liftA2 append
prl = liftA2 const
prr = liftA2 (const id)
many p = pro (some p) (pure [])
some p = prc p (many p)
optional p = pro (fmap Just p) (pure Nothing)
choice = foldr pro (const Nothing)
parseEof = parseEof_1
parseEof_1 [] = Just (P "" B)
parseEof_1 _  = Nothing
parsePred pred = parsePred_1 pred
parsePred_1 pred (x:xs) | pred x = Just (P xs x)
parsePred_1 _    _               = Nothing
manyParsePred = justFlipSplit
justFlipSplit pred xs = Just (P (dropWhile pred xs) (takeWhile pred xs))
someParsePred pred = prc (parsePred pred) (manyParsePred pred)
parseC = parsePred . (==)
parseS = foldr (prc . parseC) (pure [])
wrapC = wrapSpace . parseC
wrapS = wrapSpace . parseS
skipPred pred = prr (parsePred pred) (pure B)
manySkipPred pred = prr (manyParsePred pred) (pure B)
preSep p sep = many (prr sep p)
sepBy1 p sep = prc p (many (prr sep p))
sepByChar p c = pro (sepByChar1 p c) (pure [])
sepByChar1 p c = sepBy1 p (wrapSpace (parseC c))
wrapSpace p = prl (prr skipSpace p) skipSpace
ignore = fmap (const B)
isBlank c | c == ' ' || c == '\t' = True
isBlank _                         = False
isDigit1 c = c >= '1' && c <= '9'
parseBetween l r p = prl (prr (parseC l) (wrapSpace p)) (parseC r)
skipSpace = manySkipPred isBlank
chainl1 f sep p = fmap (foldl1 f) (sepBy1 p sep)
chainr1 f sep p = fmap (foldr1 f) (sepBy1 p sep)
chainl f z sep p = pro (fmap (foldl f z) (sepBy1 p sep)) (pure z)
chainr f z sep p = pro (fmap (foldr f z) (sepBy1 p sep)) (pure z)
parseNonassoc ops term = liftA2 (flip ($)) term (pro (liftA2 flip (choice ops) term) (pure id))
parseVar = prc (parsePred (orUnderscore isLower)) (many (parsePred (orUnderscore isAlphaNum)))
orUnderscore p c | p c || c == '_' = True
orUnderscore _ _ = False
parseCon = prc (parsePred isUpper) (many (parsePred (orUnderscore isAlphaNum)))
parseInt = pro (parseS "0") (prc (parsePred isDigit1) (many (parsePred isDigit)))
parseEscape q (c:x:xs) | c == '\\' = Just (P xs (c:x:[]))
parseEscape q [c]      | c == '\\' = Just (P [] [c])
parseEscape q (c:xs)   | c /= q    = Just (P xs [c])
parseEscape q _                    = Nothing
parseStringLiteral q = pra (parseS [q]) (pra (fmap concat (many (parseEscape q))) (parseS [q]))
parsePattern = chainr1 pcons (wrapC ':') (pro (liftA2 PCon parseCon (preSep parsePatternPrimary skipSpace)) parsePatternPrimary)
parsePatternPrimary = choice [fmap PVar parseVar, fmap (flip PCon []) parseCon, parseBetween '(' ')' parsePattern, parseBetween '[' ']' (fmap (foldr pcons pnil) (sepByChar parsePattern ','))]
relops f = relops_1 (ops_c f)
otherops f = f ":" (Con "Cons") : otherops_1 (ops_c f)
ops_c f x y = f x (Var y)
relops_1 f   = [f "<=" "_le", f "<" "_lt", f "==" "_eq", f ">=" "_ge", f ">" "_gt", f "/=" "_ne"]
otherops_1 f = [f "$" "_apply", f "||" "_or", f "&&" "_and", f "." "_compose"]
parseRelops = parseNonassoc (relops parseRelops_f)
parseRelops_f op func = prr (wrapS op) (pure (ebinaryE func))
parseExpression = chainr1 (ebinary "_apply") (wrapC '$') $ chainr1 (ebinary "_or") (wrapS "||") $ chainr1 (ebinary "_and") (wrapS "&&") $ parseRelops $ chainr1 econs (wrapC ':') $ chainr1 (ebinary "_compose") (wrapC '.') $ chainl1 Ap skipSpace $ choice [fmap Var parseVar, fmap Con parseCon, fmap Int parseInt, fmap Char (parseStringLiteral '\''), fmap String (parseStringLiteral '"'), parseBetween '(' ')' (pro parseSection parseExpression), parseBetween '[' ']' (chainr econs enil (wrapC ',') parseExpression)]
parseSection = choice (append (relops parseSection_f) (otherops parseSection_f))
parseSection_f op func = prr (wrapS op) (pure func)
parseEquation = ap (ap (ap (fmap Equation parseVar) (many (prr skipSpace parsePatternPrimary))) (optional (prr (wrapC '|') parseExpression))) (prr (wrapC '=') parseExpression)
skipType = ignore (sepBy1 (sepBy1 skipTypePrimary skipSpace) (wrapS "->"))
skipTypePrimary = choice [ignore parseVar, ignore parseCon, parseBetween '(' ')' skipType, parseBetween '[' ']' skipType]
parseDataDecl = prr (parseS "data") (prr skipSpace (prr parseCon (prr (preSep parseVar skipSpace) (prr (wrapC '=') (sepByChar1 (liftA2 Constructor parseCon (fmap length (preSep skipTypePrimary skipSpace))) '|')))))
skipTypeSignature = prr parseVar (prr (wrapS "::") skipType)
skipTypeAlias = prr (parseS "type") (prr skipSpace (prr parseCon (prr (preSep parseVar skipSpace) (prr (wrapC '=') skipType))))
parseToplevel = choice [fmap (const TO) (pro skipTypeSignature skipTypeAlias), fmap TD parseDataDecl, fmap TE parseEquation]
parseLine = prl (prl (sepByChar1 parseToplevel ';') skipSpace) parseEof
patternCount (Equation _ ps _ _) = length ps
makeProgram (P ds es) = Program ds (makeFunctions es)
makeFunctions = map makeFunctions_f . groupBy makeFunctions_g
makeFunctions_f []     = error "Internal error: No equations in binding group"
makeFunctions_f (x:xs) = cond (error (concat ["Equations for ", equationName x, " have different numbers of arguments"])) (Function (equationName x) (patternCount x) (x:xs)) (all (((==) (patternCount x)) . patternCount) xs)
makeFunctions_g (Equation name_a _ _ _) (Equation name_b _ _ _) = listEq (==) name_a name_b
lookupCon name (Environment c _) = lookup name c
lookupVar name (Environment _ v) = lookup name v
walkPatterns f = walkPatterns_items f VArg
walkPatterns_items f base = concat . zipWith (walkPatterns_f2 f) (map base (countFrom 0))
walkPatterns_f2 f v (PCon name ps) = append (f v (PCon name ps)) (walkPatterns_items f (VItem v) ps)
walkPatterns_f2 f v p              = f v p
compile (Program decls funcs) = concat [header, declareConstructors decls, declareFunctions funcs, boxConstructors decls, boxFunctions funcs, compileConstructors decls, compileFunctions (globalEnv decls funcs) funcs]
globalEnv decls funcs = Environment (append (globalEnv_constructorTags decls) (globalEnv_builtinConstructors)) (append (map (globalEnv_f . functionName) funcs) globalEnv_builtinFunctions)
globalEnv_f name = (P name (VBox name))
globalEnv_constructorTags = concatMap (flip zip (countFrom 0) . map constructorName)
globalEnv_builtinConstructors = [P "Nil" 0, P "Cons" 1, P "P" 0]
globalEnv_builtinFunctions = map globalEnv_f ["add", "sub", "_lt", "_le", "_eq", "_ge", "_gt", "_ne", "_and", "_or", "divMod", "negate", "not", "error"]
localEnv ps (Environment t v) = Environment t (append (walkPatterns localEnv_f ps) v)
localEnv_f v (PVar name) = [P name v]
localEnv_f _ (PCon _ _)  = []
declareFunctions_f [] = ""
declareFunctions_f xs = concat ["static Function ", intercalate ", " xs, ";\n"]
declareConstructors = declareFunctions_f . map ((append "f_") . constructorName) . concat
declareFunctions = declareFunctions_f . map ((append "f_") . functionName)
boxConstructors = concatMap boxConstructors_f . concat
boxConstructors_f (Constructor name n) = boxThing name n
boxFunctions = concatMap boxFunctions_f
boxFunctions_f (Function name n _) = boxThing name n
boxThing name n | n == 0 = concat ["static Box b_", name, " = {0, f_", name, ", NULL};\n"]
boxThing name n = concat ["static Partial p_", name, " = {", showInt n, ", 0, f_", name, "};\n", "static Box b_", name, " = {1, NULL, &p_", name, "};\n"]
compileConstructors = concatMap (concat . zipWith compileConstructors_f (countFrom 0))
compileConstructors_f tag (Constructor name n) = concat ["static void *f_", name, "(Box **args)\n", "{\n", allocate n, "\tv->tag = ", showInt tag, ";\n", concatMap initialize (range 0 (sub n 1)), "\treturn v;\n", "}\n"]
allocate n | n == 0 = "\tValue *v = malloc(sizeof(Value));\n\t(void) args;\n"
allocate n = concat ["\tValue *v = malloc(sizeof(Value) + ", showInt n, " * sizeof(Box*));\n"]
initialize i = concat ["\tv->items[", showInt i, "] = args[", showInt i, "];\n"]
compileFunctions env = concatMap (compileFunction env)
compileFunction env (Function name argc equations) =  concat ["static void *f_", name, "(Box **args)\n", "{\n", concatMap (compileEquation env) equations, "\tNO_MATCH(", name, ");\n", "}\n"]
compileEquation genv (Equation _ patterns guard expr) = compileEquation_a (localEnv patterns genv) patterns guard expr
compileEquation_a env patterns guard expr = compileEquation_b (concat ["\treturn ", compileExpressionStrict env expr, ";\n"]) (append (compilePatterns env patterns) (compileGuard env guard))
compileEquation_b returnExpr preds = condList returnExpr (compileEquation_f returnExpr) preds
compileEquation_f returnExpr xs = concat ["\tif (", intercalate " && " xs, ")\n\t", returnExpr]
compilePatterns env = walkPatterns (compilePatterns_f env)
compilePatterns_f _ _ (PVar name) = []
compilePatterns_f env v (PCon name ps) = compilePatterns_h v name (lookupCon name env)
compilePatterns_h v name (Just n) = [concat ["match(", compileVarInfo v, ",", showInt n, ")"]]
compilePatterns_h v name Nothing  = error (append "Not in scope: data constructor " name)
compileGuard env Nothing     = []
compileGuard env (Just expr) = [concat ["isTrue(", compileExpressionStrict env expr, ")"]]
compileExpressionStrict env (Var name) = concat ["force(", compileVar (lookupVar name env) name, ")"]
compileExpressionStrict _   (Con name) = concat ["force(&b_", name, ")"]
compileExpressionStrict _   (Int s)    = concat ["mkInt(", s, ")"]
compileExpressionStrict _   (Char s)   = concat ["mkInt(", s, ")"]
compileExpressionStrict _   (String s) = concat ["mkString(", s, ")"]
compileExpressionStrict env (Ap f x)   = concat ["apply(", compileExpressionStrict env f, ",", compileExpressionLazy env x, ")"]
compileExpressionLazy env (Var name) = compileVar (lookupVar name env) name
compileExpressionLazy _   (Con name) = concat ["&b_", name, ""]
compileExpressionLazy _   (Int s)    = concat ["box(mkInt(", s, "))"]
compileExpressionLazy _   (Char s)   = concat ["box(mkInt(", s, "))"]
compileExpressionLazy _   (String s) = concat ["box(mkString(", s, "))"]
compileExpressionLazy env (Ap f x)   = concat ["deferApply(", compileExpressionLazy env f, ",", compileExpressionLazy env x, ")"]
compileVar (Just v) _    = compileVarInfo v
compileVar Nothing  name = error (append "Not in scope: " name)
compileVarInfo (VBox name) = append "&b_" name
compileVarInfo (VArg n)    = concat ["args[", showInt n, "]"]
compileVarInfo (VItem v n) = concat ["item(", compileVarInfo v, ",", showInt n, ")"]
header="#include <assert.h>\n#include <stdarg.h>\n#include <stdio.h>\n#include <stdlib.h>\n#include <string.h>\ntypedef struct Box Box;\ntypedef struct Value Value;\ntypedef struct Partial Partial;\ntypedef void *Function(Box**);\nstruct Box{int state;Function *func;void*vc;Box*fx[];};\nstruct Value{int tag;Box *items[];};\nstruct Partial{int remaining;int applied;Function *func;Box *args[];};\n#define copy(...)memdup(&(__VA_ARGS__), sizeof(__VA_ARGS__))\n#define countof(...)(sizeof(__VA_ARGS__) / sizeof(*(__VA_ARGS__)))\n#define match(box, expectedTag)(((Value*)force(box))->tag == (expectedTag))\n#define item(box, n)(((Value*)(box)->vc)->items[n])\n#define isTrue(value)(!!*(int*)(value))\n#define NO_MATCH(func)fatal(\"Non-exhaustive patterns in function \" #func)\nstatic void fatal(const char *str){fprintf(stderr,\"*** Exception: %s\\n\", str);exit(EXIT_FAILURE);}\nstatic void *memdup(void *ptr, size_t size){void*ret=malloc(size);memcpy(ret,ptr,size);return ret;}\nstatic void *force(Box *box){switch(box->state){\ncase 0:box->state=2;box->vc=box->func(box->vc);box->state=1;\ncase 1:return box->vc;\ndefault:fatal(\"infinite loop\");}}\nstatic void *apply(Partial*f,Box*x){Partial*f2=malloc(sizeof(Partial)+(f->applied+1)*sizeof(Box*));\nmemcpy(f2->args,f->args,f->applied*sizeof(Box*));f2->args[f->applied]=x;\nif(f->remaining>1){f2->remaining=f->remaining-1;f2->applied=f->applied+1;f2->func=f->func;return f2;\n}else return f->func(f2->args);}\nstatic void*deferApply_cb(Box**a){return apply(force(a[0]),a[1]);}\nstatic Box*deferApply(Box*f,Box*x){\nBox*ret=malloc(sizeof(Box)+2*sizeof(Box*));\nret->state=0;\nret->func=deferApply_cb;\nret->vc=ret->fx;\nret->fx[0]=f;\nret->fx[1]=x;\nreturn ret;}\n\nstatic Box*defer(Function*func,void*ctx){\nBox*ret=malloc(sizeof(Box));\nret->state=0;\nret->func=func;\nret->vc=ctx;\nreturn ret;}\n\nstatic Box *box(void *value)\n{\n\tBox *ret = malloc(sizeof(Box));\n\tret->state = 1;\n\tret->func = NULL;\n\tret->vc = value;\n\treturn ret;\n}\n\nstatic int *mkInt(int n)\n{\n\tint *ret = malloc(sizeof(*ret));\n\t*ret = n;\n\treturn ret;\n}\n\nstatic Function f_Nil, f_Cons, f_P;\nstatic Box b_Nil, b_Cons, b_P, b_main;\n\n#define FUNCTION(name, argc) \\\n\tstatic Function f_##name; \\\n\tstatic Partial p_##name = {argc, 0, f_##name}; \\\n\tstatic Box b_##name = {1, NULL, &p_##name}; \\\n\tstatic void *f_##name(Box **args)\n\n#define intop(name, expr) \\\n\tFUNCTION(name, 2) \\\n\t{ \\\n\t\tint a = *(int*)force(args[0]); \\\n\t\tint b = *(int*)force(args[1]); \\\n\t\treturn mkInt(expr); \\\n\t}\n\n#define intop1(name, expr) \\\n\tFUNCTION(name, 1) \\\n\t{ \\\n\t\tint a = *(int*)force(args[0]); \\\n\t\treturn mkInt(expr); \\\n\t}\n\nintop(add,  a + b)\nintop(sub,  a - b)\n\nintop(_lt,  a <  b)\nintop(_le,  a <= b)\nintop(_eq,  a == b)\nintop(_ge,  a >= b)\nintop(_gt,  a >  b)\nintop(_ne,  a != b)\nintop(_and, a && b)\nintop(_or,  a || b)\n\nintop1(negate, -a)\nintop1(not,    !a)\n\nFUNCTION(divMod, 2)\n{\n\tint n = *(int*)force(args[0]);\n\tint d = *(int*)force(args[1]);\n\tint div = n / d;\n\tint mod = n % d;\n\t\n\tif ((mod < 0 && d > 0) || (mod > 0 && d < 0)) {\n\t\tdiv--;\n\t\tmod += d;\n\t}\n\t\n\tBox *pair[2] = {box(mkInt(div)), box(mkInt(mod))};\n\treturn f_P(pair);\n}\n\nstatic void *mkString(const char *str)\n{\n\tif (*str != '\\0') {\n\t\tBox *cons[2] =\n\t\t\t{box(mkInt(*str)), defer((Function*) mkString, (void*)(str + 1))};\n\t\treturn f_Cons(cons);\n\t} else {\n\t\treturn force(&b_Nil);\n\t}\n}\n\nstatic void putStr(Value *v, FILE *f)\n{\n\tif (v->tag == 1) {\n\t\tint c = *(int*)force(v->items[0]);\n\t\tputc(c, f);\n\t\tputStr(force(v->items[1]), f);\n\t}\n}\n\nFUNCTION(error, 1)\n{\n\tfflush(stdout);\n\tfputs(\"*** Exception: \", stderr);\n\tputStr(force(args[0]), stderr);\n\tputc('\\n', stderr);\n\texit(EXIT_FAILURE);\n}\n\nstruct mkStringFromFile\n{\n\tFILE *f;\n\tconst char *name;\n};\n\nstatic void *mkStringFromFile(struct mkStringFromFile *ctx)\n{\n\tint c = fgetc(ctx->f);\n\t\n\tif (c == EOF) {\n\t\tif (ferror(ctx->f))\n\t\t\tperror(ctx->name);\n\t\treturn force(&b_Nil);\n\t}\n\t\n\tBox *cons[2] = {box(mkInt(c)), defer((Function*) mkStringFromFile, ctx)};\n\treturn f_Cons(cons);\n}\n\nint main(void)\n{\n\tstruct mkStringFromFile c_in = {stdin, \"<stdin>\"};\n\tBox *b_in = defer((Function*) mkStringFromFile, copy(c_in));\n\tputStr(apply(force(&b_main), b_in), stdout);\n\treturn 0;\n}\n"
prelude = P 0 "_apply f x=f x;_compose f g x=f(g x);data List a=Nil|Cons a(List a);data P a b=P a b;data B=B;data Maybe a=Nothing|Just a;data Bool=False|True;id x=x;const x _=x;flip f x y=f y x;foldl f z[]=z;foldl f z(x:xs)=foldl f(f z x)xs;foldl1 f(x:xs)=foldl f x xs;foldl1 _[]=error\"foldl1: empty list\";foldr f z[]=z;foldr f z(x:xs)=f x(foldr f z xs);foldr1 f[x]=x;foldr1 f(x:xs)=f x(foldr1 f xs);foldr1 _[]=error\"foldr1: empty list\";map f[]=[];map f(x:xs)=f x:map f xs;filter p[]=[];filter p(x:xs)|p x=x:filter p xs;filter p(x:xs)=filter p xs;zipWith f(x:xs)(y:ys)=f x y:zipWith f xs ys;zipWith f _ _=[];append[]ys=ys;append(x:xs)ys=x:append xs ys;concat=foldr append[];concatMap f=concat.map f;length[]=0;length(_:l)=add 1(length l);take n _|n<=0=[];take _[]=[];take n(x:xs)=x:take(sub n 1)xs;takeWhile p[]=[];takeWhile p(x:xs)|p x=x:takeWhile p xs;takeWhile _ _=[];dropWhile p[]=[];dropWhile p(x:xs)|p x=dropWhile p xs;dropWhile p xs=xs;span p[]=P[][];span p(x:xs)|p x=span_1 x(span p xs);span p xs=P[]xs;span_1 x(P ys zs)=P(x:ys)zs;break p=span(not.p);reverse=foldl(flip(:))[];groupBy _[]=[];groupBy eq(x:xs)=groupBy_1 x eq(span(eq x)xs);groupBy_1 x eq(P ys zs)=(x:ys):groupBy eq zs;maybe n f Nothing=n;maybe n f(Just x)=f x;all p=foldr(&&)True.map p;intersperse _[]=[];intersperse _[x]=[x];intersperse sep(x:xs)=x:sep:intersperse sep xs;intercalate xs xss=concat(intersperse xs xss);isDigit c=c>='0'&&c<='9';isAlphaNum c=c>='0'&&c<='9'||c>='A'&&c<='Z'||c>='a'&&c<='z';isUpper c=c>='A'&&c<='Z';isLower c=c>='a'&&c<='z';showInt n|n<0='-':showInt(negate n);showInt n|n==0=\"0\";showInt n|n>0=reverse(map(add 48)(showInt_1 n));showInt_1 n|n==0=[];showInt_1 n=showInt_2(divMod n 10);showInt_2(P div mod)=mod:showInt_1 div;lines []=[];lines s=lines_1(break((==)'\\n')s);lines_1(P l[])=[l];lines_1(P l(_:s))=l:lines s;interact=id"

Lingua personalizzata → C - (7979)

Dato che la domanda non preclude la creazione della mia lingua, ho pensato di provarlo.

L'ambiente

La lingua ha accesso a due stack, The Call Stack e The Data Stack. Lo stack di chiamate viene utilizzato per le istruzioni di salto {e }, mentre lo stack di dati viene utilizzato dalla maggior parte delle altre istruzioni. Lo stack di chiamate è opaco per le applicazioni.

Lo stack di dati può contenere tre diversi tipi di valori: intero, testo e vuoto. I numeri interi sono di tipo intptr_t, mentre il testo è memorizzato come stringhe in stile C.

L' ^istruzione ha accesso a The Array. L'array è un array costante di lunghezza 17 di elementi di testo. Probabilmente dovresti vedere la fonte per lo schema di indicizzazione poiché è un po 'traballante.

La lingua

#   -   Begin number    - Marks the beginning of a number, for example: #42.
.   -   End number      - Marks the end of a number and pushes it to the data stack.
^   -   Translate       - Pops a number, and pushes the corresponding text from The Array.
<   -   Write           - Pops a value, and prints it to stdout.
>   -   Read            - Reads a character from stdin and pushes it as a number. If EOF,
                          exit.
{   -   Start Loop      - Pushes the current location in the program to the call stack.
}   -   End Loop        - Go to the position specified by the top of the call stack.
+   -   Add             - Pop two numbers from the data stack, add them, push the result.
-   -   Subtract        - Pop into A, pop into B, push B - A. Both B & A must be numbers.
!   -   Duplicate       - Pop from The Data Stack, push that value twice.
_   -   Discard         - Pop from The Data Stack.
=   -   Skip if Equal   - Pop two values, if they are equal skip the next instruction
                          and pop one item from the call stack.
?   -   Loop            - Pop one number, subtract one, if it's less than one, pop one
                          item from the call stack and skip the next instruction.
@   -   Array Separator - Marks the end of an array item.
$   -   Program End     - Marks the end of the program.

Il compilatore

Questo è il compilatore. Non è un golf, e mi aspetto che potrebbe essere notevolmente ridotto. Dovrebbe essere possibile utilizzare direttamente il codice macchina e generare un file DOS COM, ma non ci sono ancora riuscito. So che questo sembra un programma C, ma l'implementazione effettiva del compilatore non funziona alla fine.

Attualmente il compilatore genera molte informazioni di debug su stderr.

#include <string.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <setjmp.h>
#include <stdbool.h>

const char* position;
const char* array[] = {"@"};

void die(const char* reason)
{
    fprintf(stderr, "%s\n", reason);
    exit(1);
}

//
// Stack Functions
//

#define T_EMPTY     (0)
#define T_NUMBER    (1)
#define T_TEXT      (2)

typedef struct {
    unsigned char type;
    union {
        const char* text;
        intptr_t number;
    };
} stack_entry;

#define STACK_MAX   (1024)
stack_entry stack[STACK_MAX];
size_t stack_position = 0;

stack_entry* _push()
{
    if (stack_position >= STACK_MAX) {
        die("out of stack space");
    }
    return &stack[stack_position++];
}

void push(stack_entry v)
{
    if (v.type == T_EMPTY) {
        fprintf(stderr, "\tpushed: None\n");
    } else if (v.type == T_TEXT) {
        fprintf(stderr, "\tpushed: %s\n", v.text);
    } else {
        fprintf(stderr, "\tpushed: %d\n", v.number);
    }
    stack_entry* entry = _push();
    *entry = v;
}

void push_empty()
{
    fprintf(stderr, "\tpushed: None\n");
    stack_entry* entry = _push();
    entry->type = T_EMPTY;
    entry->number = 0;
}

void push_number(intptr_t number)
{
    fprintf(stderr, "\tpushed: %d\n", number);
    stack_entry* entry = _push();
    entry->type = T_NUMBER;
    entry->number = number;
}

void push_text(const char* text)
{
    fprintf(stderr, "\tpushed: %s\n", text);
    stack_entry* entry = _push();
    entry->type = T_TEXT;
    entry->text = text;
}

// Polymorphic Push (for literals)
#define PUSH0()     do { fprintf(stderr, "literal:\n"); push_empty(); } while (0)
#define PUSH1(a)    do { fprintf(stderr, "literal:\n"); push_number(a); } while (0)

#define GET_MACRO(_0, _1, NAME, ...) NAME
#define PUSH(...) GET_MACRO(_0, ##__VA_ARGS__, PUSH1, PUSH0)(__VA_ARGS__)

stack_entry pop()
{
    if (stack_position <= 0) {
        fprintf(stderr, "\tpopped: None\n");
        return (stack_entry) {.type = T_EMPTY, .number = 0};
    }

    stack_entry v = stack[--stack_position];
    if (v.type == T_EMPTY) {
        fprintf(stderr, "\tpopped: None\n");
    } else if (v.type == T_TEXT) {
        fprintf(stderr, "\tpopped: %s\n", v.text);
    } else {
        fprintf(stderr, "\tpopped: %d\n", v.number);
    }
    return v;
}

stack_entry peek()
{
    if (stack_position <= 0) {
        return (stack_entry) {.type = T_EMPTY, .number = 0};
    }

    return stack[stack_position-1];
}

//
// Jump Functions
//

#define JUMP_MAX    (1024)
jmp_buf jump[JUMP_MAX];
size_t jump_position = 0;

#define start()                                     \
    do {                                            \
    if (jump_position >= JUMP_MAX) {                \
        die("out of jump space");                   \
    }                                               \
    fprintf(stderr, "start: %d\n", jump_position);  \
    setjmp(jump[jump_position++]);                  \
    } while (0)

void pop_jump() {
    if (jump_position <= 0) {
        die("empty jump stack");
    }
    jump_position -= 1;
}

#define end()                                       \
    do {                                            \
    if (jump_position <= 0) {                       \
        die("empty jump stack");                    \
    }                                               \
    fprintf(stderr, "end: %d\n", jump_position-1);  \
    longjmp(jump[jump_position-1],1);               \
    } while (0)

//
// Program functions
//

void translate()
{
    fprintf(stderr, "translate:\n");
    stack_entry entry = pop();
    if (entry.type == T_TEXT) {
        die("translating text");
    } else if (entry.type == T_EMPTY) {
        push_empty();
    } else {
        switch (entry.number) {
            case 0:
            case 1:
                push_text(array[entry.number]);
                break;
            case 64:
                push_text(array[2]);
                break;
            case 94:
                push_text(array[3]);
                break;
            case 45:
                push_text(array[4]);
                break;
            case 43:
                push_text(array[5]);
                break;
            case 62:
                push_text(array[6]);
                break;
            case 60:
                push_text(array[7]);
                break;
            case 33:
                push_text(array[8]);
                break;
            case 95:
                push_text(array[9]);
                break;
            case 61:
                push_text(array[10]);
                break;
            case 63:
                push_text(array[11]);
                break;
            case 123:
                push_text(array[12]);
                break;
            case 125:
                push_text(array[13]);
                break;
            case 35:
                push_text(array[14]);
                break;
            case 46:
                push_text(array[15]);
                break;
            case 36:
                push_text(array[16]);
                break;
            default:
                push_empty();
                break;
        }
    }
}

void subtract()
{
    fprintf(stderr, "subtract:\n");
    stack_entry v1 = pop();
    stack_entry v2 = pop();

    if (v1.type != T_NUMBER || v2.type != T_NUMBER) {
        die("not a number");
    }

    push_number(v2.number - v1.number);
}

void add()
{
    fprintf(stderr, "add:\n");
    stack_entry v1 = pop();
    stack_entry v2 = pop();

    if (v1.type != T_NUMBER || v2.type != T_NUMBER) {
        die("not a number");
    }

    push_number(v2.number + v1.number);
}

void read()
{
    fprintf(stderr, "read:\n");
    int in = getchar();

    if (in >= 0) {
        push_number(in);
    } else {
        die("end of input");
    }
}

void write()
{
    fprintf(stderr, "write:\n");
    stack_entry v = pop();

    if (v.type == T_NUMBER) {
        putchar(v.number);
    } else if (v.type == T_TEXT) {
        const char* x = v.text;
        char y;
        while (0 != (y=*(x++))) {
            y -= 128;
            putchar(y);
        }
    }
}

void duplicate()
{
    fprintf(stderr, "duplicate:\n");
    stack_entry v = pop();
    push(v);
    push(v);
}

void discard()
{
    fprintf(stderr, "discard:\n");
    pop();
}

bool equals()
{
    fprintf(stderr, "equals:\n");
    stack_entry x = pop();
    stack_entry y = pop();

    bool skip;

    if (x.type != y.type) {
        skip = false;
    } else if (x.type == T_EMPTY) {
        skip = true;
    } else if (x.type == T_NUMBER) {
        skip = x.number == y.number;
    } else {
        skip = strcmp(x.text, y.text) == 0;
    }

    if (skip) {
        pop_jump();
    }

    return !skip;
}

bool question()
{
    fprintf(stderr, "question:\n");
    stack_entry x = pop();

    intptr_t value;

    if (x.type == T_EMPTY) {
        value = 0;
    } else if (x.type == T_NUMBER) {
        value = x.number;
    } else {
        die("it is bad form to question text");
    }

    value -= 1;

    if (value < 1) {
        pop_jump();
        return false;
    } else {
        push_number(value);
        return true;
    }
}

int main()
{
@","@translate();@subtract();@add();@read();@write();@duplicate();@discard();@if(equals())@if(question())@start();@end();@PUSH(@);@return 0;}@

#0.^<                           Emit the preface

#17.{                           Loop for as many array slots exist
    #.{<>#128.+!#192.=}         Copy characters, adding 128 until reaching an at sign
    #128.-
    ^<                          Emit the code between array items
?}                              Return to start

#1.^<                           Emit the prologue


{{
>!^<                            Read character, translate it, and print it
!#35.=}                         Check if we have a literal
#.{<>!#46.=}^<                  If so, verbatim copy characters until a period
}                               Continue executing
$

Per compilare il codice C generato:

gcc -finput-charset=CP437 -fexec-charset=CP437 -std=gnu11

Il set di caratteri è necessario perché il compilatore sfugge ai caratteri speciali aggiungendo 128.

Il Bootstrap

Per compilare il primo compilatore, ho scritto un interprete python per la lingua.

import sys
from collections import defaultdict
KEYS = [0,1] + map(ord, ['@','^','-','+','>','<','!','_','=','?','{','}','#','.','$'])

# Read the source file
with file(sys.argv[1]) as f:
    data = f.read()
pos = 0

# Initialize the environment
array = defaultdict(str)
jmp = []
stk = []

def log(x):
    sys.stderr.write(x + '\n')

def read():
    global pos,data
    pos += 1
    return data[pos-1]

def pop():
    global stk
    try:
        x = stk.pop()
    except IndexError:
        x = None
    log('\tpopped ' + repr(x))
    return x

def push(value):
    global stk
    log('\tpushing ' + repr(value))
    stk.append(value)

# Read the array initialization section
for key in KEYS:
    while True:
        c = read()
        if c == '@':
            break
        array[key] += c

# Execute the program
while pos < len(data):
    c = read()
    if c == '^':
        log('translate:')
        push(array.get(pop(), None))
    elif c == '-':
        log('subtract:')
        x = pop()
        y = pop()
        push(y - x)
    elif c == '+':
        log('add:')
        x = pop()
        y = pop()
        push(y + x)
    elif c == '>':
        log('read:')
        push(ord(sys.stdin.read(1)))
    elif c == '<':
        log('write:')
        v = pop()
        if isinstance(v, int):
            sys.stdout.write(chr(v))
        elif v is not None:
            sys.stdout.write(v)
    elif c == '!':
        log('duplicate:')
        x = pop()
        push(x)
        push(x)
    elif c == '_':
        log('discard:')
        pop()
    elif c == '=':
        log('skip if equal:')
        x,y = pop(),pop()
        if x == y:
            pos += 1
            jmp.pop()
    elif c == '?':
        log('loop:')
        x = pop()
        x -= 1
        if x < 1:
            pos += 1
            jmp.pop()
        else:
            push(x)
    elif c == '{':
        log('start: ' + repr(pos))
        jmp.append(pos)
    elif c == '}':
        log('end:')
        pos = jmp[-1]
    elif c == '#':
        literal = ''
        while True:
            c = read()
            if c == '.':
                log('literal: ' + repr(literal))
                if literal == '':
                    push(None)
                else:
                    push(int(literal))
                break
            else:
                literal += c

Mettere tutto insieme

Supponendo di aver salvato il compilatore come compiler.cmpe il bootstrap come bootstrap.py, ecco come compilare il compilatore e quindi utilizzarlo per compilare se stesso:

$ cat compiler.cmp |
  python bootstrap.py compiler.cmp 2> trace-bootstrap |
  gcc -finput-charset=CP437 -fexec-charset=CP437 -std=gnu11 -o result -xc -
$ cat compiler.cmp | ./result 2> trace-final

Quindi non sono un programmatore C, né un designer linguistico, quindi qualsiasi suggerimento su come migliorarlo è il benvenuto!

Programmi di esempio

Ciao mondo!

Hello, World!@@@@@@@@@@@@@@@@@#0.^<$

Brainfuck esteso v0.9: 618 byte (senza contare gli avanzamenti di riga non obbligatori)

:c:n:z:g:i:t:w:a:p++++++++[->++++++++<]>[->>>>>>>[>>>>>>>>]+[<<<<<<<<]>]>>>>>>>[->>>>>>>>]@i
$i,[[-$t+$w+$i]$t[-$i+$t]+$a+++[-$w-----------$a]$w---[$a++[-$w-----------$a]$w[--[--[--[$i.
$t+++++++[-$w++++++++$t]$w[-]]$t[-$p[-]$i.$n,.[-<[<<]+[>>]<]@n$c[<<]>[-<<<+>>>>[>>]@z$p+$c[<
<]>]<<<[->>>+<<<]>>>>[->>]@z$t]$w]$t[-$i.$p+$t]$w]$t[-$i.$p-$t]$w]$t[$i.$n,.[-<[<<]+[>>]<]@n
$g[-$t+$c[<<]>+>[>>]@z>]$c[<<]>>[->>]@z$t[-$g+$t]$t]$w]$t[-$i.[-]$n,.[-<[<<]+[>>]<]@n$c[<<]>
[-<<<+>>>>[>>]@z$i+$a+$c[<<]>]<<<[->>>+<<<]>>>>[->>]@z<++++++[->++++++++++<]$w+$p[$a[-$w-]<[
@w-$p[-$z.$p]+$t]$w+$p-]$z++$w-$a[-$z.$a]$z[-]$i[-$p+$i]$t]$w$i,]

Questa è una versione golfata della mia primissima versione di EBF con supporto rimosso per commenti e codice morto per supportare la rimozione di variabili.

Quindi in pratica è BrainFuck con variabili. :xcrea variabili x. Il compilatore sa dove sei, quindi $yprodurrà <'e>> per arrivare a quella posizione. A volte hai bisogno di loop asimmetrici e quindi devi dire al compilatore dove sei@x . Come EBF attuale, viene compilato con Brainfuck.

Questa prima versione aveva solo un nome di variabile char, ma ho usato questa versione per compilare la versione successiva e così via fino alla versione corrente che ha un set di funzionalità impressionante. Durante la compilazione da sorgente github, scarica effettivamente il binario compilato a mano nelle versioni ebf intermedie bootstrap 6 per creare la versione corrente.

Per avviarlo è possibile utilizzare questo primo e unico binario nel repository git EBF che è stato compilato a mano con successo dopo un paio di tentativi.

wget -nv https://raw.githubusercontent.com/westerp/ebf-compiler/34c378c8347aafa5dbf37f4973461d42c8120ea4/ebf-handcompiled.bf
beef ebf-handcompiled.bf < ebf09.ebf > ebf09a.bf
beef ebf09a.bf < ebf09.ebf > ebf09b.bf
diff -s ebf09a.bf ebf09b.bf # Files ebf09a.bf and ebf09b.bf are identical

Brainfuck ha alcune implementazioni hardware, ad es. questo , questo e questo per citarne alcuni. Ma soprattutto è così facile da implementare che puoi praticamente implementare un interprete su qualsiasi sistema. Scherzo che Zozotez LISP , che è scritto in EBF, è probabilmente il LISP più portatile di sempre.

Esadecimale, 550 byte

Questo riguarda in particolare i sistemi x86_64 con Linux.

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

In questo linguaggio, il codice sorgente consiste di byte rappresentati come due cifre esadecimali minuscole, [0-9a-f][0-9a-f]. Questi byte possono avere qualsiasi quantità di spazio bianco circostante, ma non può succedere nulla tra le cifre che formano un singolo byte. Inoltre, '!'è un personaggio a commento di riga: viene ignorato, così come tutto ciò che lo separa dal '\n'personaggio successivo .

Se capisci l'assemblaggio x86, ecco una versione molto più leggibile del codice sorgente:

! ELF Header !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
7f 45 4c 46                !e_ident[EI_MAG0] (0x7F "ELF")
02                         !e_ident[EI_CLASS] (64-bit)
01                         !e_ident[EI_DATA] (little-endian)
01                         !e_ident[EI_VERSION] (ELF v1)
00                         !e_ident[EI_OSABI] (System V ABI)
00                         !e_ident[EI_ABIVERSION] (version 0)
00 00 00 00 00 00 00       !e_ident [EI_PAD]
02 00                      !e_type (executable)
3e 00                      !e_machine (x86_64)
01 00 00 00                !e_version (ELF v1)
78 00 40 00 00 00 00 00    !e_entry (0x40078)
40 00 00 00 00 00 00 00    !e_phoff (0x   40)
00 00 00 00 00 00 00 00    !e_shoff (0x    0)
00 00 00 00                !e_flags
40 00                      !e_ehsize (ELF header size = 64 bytes)
38 00                      !e_phentsize (Program headers = 56 bytes)
01 00                      !e_phnum (1 program header)
40 00                      !e_shentsize (Section headers = 64 bytes)
00 00                      !e_shnum (no section headers)
00 00                      !e_shstrndx (section names, not useful here)

! Program Headers !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
01 00 00 00                !p_type (LOAD)
05 00 00 00                !p_flags (R+E)
00 00 00 00 00 00 00 00    !p_offset (file-loc 0)
00 00 40 00 00 00 00 00    !p_vaddr (vmem-loc 0x40000)
00 00 40 00 00 00 00 00    !p_paddr (pmem-loc 0x40000)
13 01 00 00 00 00 00 00    !p_filesz (length 0x113 bytes)
13 01 00 00 00 00 00 00    !p_memsz (allocate 0x113 bytes)
00 00 20 00 00 00 00 00    !p_align (align pages in 0x20000 increments)


! Program Code !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!! _start: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
      e8 17 00 00 00 ! callq _gethx
               85 c0 ! test %eax,%eax
               7c 0b ! jl .+11
               31 ff ! xor %edi,%edi
               01 c7 ! add %eax,%eax
      e8 79 00 00 00 ! callq _putch
               eb ec ! jmp .-20
               31 c0 ! xor %eax,%eax
               89 c7 ! mov %eax,%edi
               b0 3c ! mov $0x3c,%al
               0f 05 ! syscall

!! _gethx: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
      e8 4c 00 00 00 ! callq _getch
            48 85 c0 ! test %rax,%rax
               7c 20 ! jl _gethx+42
               3c 21 ! cmp $0x21,al
               78 f2 ! js _gethx
               74 1b ! je _gethx+43
               89 c7 ! mov %eax,%edi
      e8 25 00 00 00 ! callq _h2d
            c0 e0 04 ! sal $4,%al
                  50 ! push %rax
      e8 31 00 00 00 ! callq _getch
               89 c7 ! mov %eax,%edi
      e8 15 00 00 00 ! callq _h2d
                  59 ! pop %rcx
               00 c8 ! add %cl,%al
                  c3 ! retq
      e8 21 00 00 00 ! callq _getch
               3c 0d ! cmp $0xd,%al
               7f f7 ! jg _gethx+43
               74 ca ! je _gethx
               3c 0a ! cmp $0xa,%al
               75 f1 ! jne _gethx+43
               eb c4 ! jmp _gethx

!! _h2d: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
               89 f8 ! mov %edi,%eax
               31 c9 ! xor %ecx,%ecx
               3c 40 ! cmp $0x40,%al
            0f 9c c1 ! setl %cl
            48 ff c9 ! dec %rcx
            80 e1 27 ! and $0x27,%cl
            80 c1 30 ! add $0x30,%cl
               28 c8 ! sub %cl,%al
                  c3 ! retq

!! _getch: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
               6a 00 ! push $0
            48 89 e6 ! mov %rsp,%rsi
               31 c0 ! xor %eax,%eax
               89 c2 ! mov %eax,%edx
               fe c2 ! inc %dl
               89 c7 ! mov %eax,%edi
               0f 05 ! syscall
               31 c9 ! xor %ecx,%ecx
               85 c0 ! test %eax,%eax
                  58 ! pop %rax
            0f 95 c1 ! setne %cl
            48 ff c9 ! dec %rcx
            48 09 c8 ! or %rcx,%rax
                  c3 ! retq

!! _putch: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
                  57 ! push %rdi
            48 89 e6 ! mov %rsp,%rsi
               31 c0 ! xor %eax,%eax
               fe c0 ! inc %al
               89 c2 ! mov %eax,%edx
               89 c7 ! mov %eax,%edi
               0f 05 ! syscall
                  58 ! pop %rax
                  c3 ! retq

Se si estrae il linguaggio assembly dai commenti seguenti ! Program Code, è possibile assemblare ed eseguire il compilatore Hex. Input e output usano stdin e stdout.

Sottoinsieme Javascript -> Java, 504 byte

document.write("public class Generated{public static void main(String[]args){"+prompt().replace(RegExp("[r]eplace(,"g"),"replaceAll(").replace(RegExp("[v]ar","g"),"double")+"}static class document{static void write(String s){System.out.print(s);}}static void prompt(){return javax.swing.JOptionPane.showInputDialog(\"\");}static void alert(String a){JOptionPane.showMessageDialog(null,a);}static double Number(String a){return Double.parseDouble(a);}static String RegExp(String a,String b){return a;}}");

05AB1E , 2 byte (possibilmente non concorrenziale)

.V

Provalo online!

Codice sulla prima riga di input, input sulle righe successive.

Legname , 0 byte

Lumber è un linguaggio di programmazione esoterico completo inventato da Unrelated String scritto in sole 10 righe di codice Prolog.

Non ci credi? Questi programmi hanno rimosso i commenti e rendono la fonte dell'interprete più concisa.

lumber_corefuncs.pl:

:- use_module(lumber_types).

lumber_types.pl

:- module(lumber_types,
          []).

lumber_corefuncs.pl contiene la libreria lumber_types; ea sua volta, questa libreria definisce un modulo che non contiene nulla. Pertanto, Lumber non fa nulla sugli input arbitrari, che a sua volta è un autocompilatore.

Zero , 0 byte

Incredibilmente, nonostante non sia completo di Turing, il linguaggio Nil è abbastanza espressivo da implementare un interprete per se stesso, molto più conciso di quanto possano fare molte lingue "appropriate". L'esempio presentato qui è una semplice implementazione, ma usando tecniche di compressione avanzate Nil sviluppatori sono stati in grado di produrre interpreti funzionanti in appena 0 righe di codice.