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Data update

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Ingy döt Net 2026-02-01 16:33:20 -08:00
parent 5150844a7d
commit 4bb20c9b71
7735 changed files with 38060 additions and 199180 deletions
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32
Task/Arithmetic-evaluation/Standard-ML/arithmetic-evaluation.ml
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@ -1,10 +1,10 @@
(* AST *)
datatype expression =
Con of int (* constant *)
| Add of expression * expression (* addition *)
| Mul of expression * expression (* multiplication *)
| Sub of expression * expression (* subtraction *)
| Div of expression * expression (* division *)
Con of int (* constant *)
| Add of expression * expression (* addition *)
| Mul of expression * expression (* multiplication *)
| Sub of expression * expression (* subtraction *)
| Div of expression * expression (* division *)
(* Evaluator *)
fun eval (Con x) = x
@ -15,13 +15,13 @@ fun eval (Con x) = x
(* Lexer *)
datatype token =
CON of int
| ADD
| MUL
| SUB
| DIV
| LPAR
| RPAR
CON of int
| ADD
| MUL
| SUB
| DIV
| LPAR
| RPAR
fun lex nil = nil
| lex (#"+" :: cs) = ADD :: lex cs
@ -43,7 +43,7 @@ exception Error of string
fun match (a,ts) t = if null ts orelse hd ts <> t
then raise Error "match"
else (a, tl ts)
else (a, tl ts)
fun extend (a,ts) p f = let val (a',tr) = p ts in (f(a,a'), tr) end
@ -64,6 +64,6 @@ and parseP (CON c :: ts) = (Con c, ts)
(* Test *)
fun lex_parse_eval (str:string) =
case parseE (lex (explode str)) of
(exp, nil) => eval exp
| _ => raise Error "not parseable stuff at the end"
case parseE (lex (explode str)) of
(exp, nil) => eval exp
| _ => raise Error "not parseable stuff at the end"