diff options
Diffstat (limited to 'forth/stepA_mal.fs')
| -rw-r--r-- | forth/stepA_mal.fs | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/forth/stepA_mal.fs b/forth/stepA_mal.fs new file mode 100644 index 0000000..af5f5d8 --- /dev/null +++ b/forth/stepA_mal.fs @@ -0,0 +1,390 @@ +require reader.fs +require printer.fs +require core.fs + +core MalEnv. constant repl-env + +99999999 constant TCO-eval + +: read read-str ; +: eval ( env obj ) + begin + \ ." eval-> " dup pr-str safe-type cr + mal-eval + dup TCO-eval = + while + drop + repeat ; +: print + \ ." Type: " dup mal-type @ type-name safe-type cr + pr-str ; + +MalDefault extend mal-eval nip ;; drop \ By default, evalutate to yourself + +MalKeyword + extend eval-invoke { env list kw -- val } + 0 kw env list MalList/start @ cell+ @ eval get + ?dup 0= if + \ compute not-found value + list MalList/count @ 1 > if + env list MalList/start @ 2 cells + @ TCO-eval + else + mal-nil + endif + endif ;; + extend invoke { argv argc kw -- val } + 0 kw argv @ get + ?dup 0= if + argc 1 > if + argv cell+ @ + else + mal-nil + endif + endif ;; +drop + +\ eval all but the first item of list +: eval-rest { env list -- argv argc } + list MalList/start @ cell+ { expr-start } + list MalList/count @ 1- { argc } + argc cells allocate throw { target } + argc 0 ?do + env expr-start i cells + @ eval + target i cells + ! + loop + target argc ; + +MalNativeFn + extend eval-invoke { env list this -- list } + env list eval-rest ( argv argc ) + this invoke ;; + extend invoke ( argv argc this -- val ) + MalNativeFn/xt @ execute ;; +drop + +SpecialOp + extend eval-invoke ( env list this -- list ) + SpecialOp/xt @ execute ;; +drop + +: install-special ( symbol xt ) + SpecialOp. repl-env env/set ; + +: defspecial + parse-allot-name MalSymbol. + ['] install-special + :noname + ; + +: is-pair? ( obj -- bool ) + empty? mal-false = ; + +defspecial quote ( env list -- form ) + nip MalList/start @ cell+ @ ;; + +s" concat" MalSymbol. constant concat-sym +s" cons" MalSymbol. constant cons-sym + +defer quasiquote +: quasiquote0 { ast -- form } + ast is-pair? 0= if + here quote-sym , ast , here>MalList + else + ast to-list MalList/start @ { ast-start } + ast-start @ { ast[0] } + ast[0] unquote-sym m= if + ast-start cell+ @ + else + ast[0] is-pair? if + ast[0] to-list MalList/start @ { ast[0]-start } + ast[0]-start @ splice-unquote-sym m= if + here + concat-sym , + ast[0]-start cell+ @ , + ast to-list MalList/rest quasiquote , + here>MalList + false + else true endif + else true endif + if + here + cons-sym , + ast[0] quasiquote , + ast to-list MalList/rest quasiquote , + here>MalList + endif + endif + endif ; +' quasiquote0 is quasiquote + +defspecial quasiquote ( env list ) + MalList/start @ cell+ @ ( ast ) + quasiquote TCO-eval ;; + +defspecial def! { env list -- val } + list MalList/start @ cell+ { arg0 } + arg0 @ ( key ) + env arg0 cell+ @ eval dup { val } ( key val ) + env env/set val ;; + +defspecial defmacro! { env list -- val } + list MalList/start @ cell+ { arg0 } + arg0 @ ( key ) + env arg0 cell+ @ eval { val } + true val MalUserFn/is-macro? ! + val env env/set + val ;; + +defspecial let* { old-env list -- val } + old-env MalEnv. { env } + list MalList/start @ cell+ dup { arg0 } + @ to-list + dup MalList/start @ { bindings-start } ( list ) + MalList/count @ 0 +do + bindings-start i cells + dup @ swap cell+ @ ( sym expr ) + env swap eval + env env/set + 2 +loop + env arg0 cell+ @ TCO-eval + \ TODO: dec refcount of env + ;; + +defspecial do { env list -- val } + list MalList/start @ { start } + list MalList/count @ dup 1- { last } 1 ?do + env start i cells + @ + i last = if + TCO-eval + else + eval drop + endif + loop ;; + +defspecial if { env list -- val } + list MalList/start @ cell+ { arg0 } + env arg0 @ eval ( test-val ) + dup mal-false = if + drop -1 + else + mal-nil = + endif + if + \ branch to false + list MalList/count @ 3 > if + env arg0 cell+ cell+ @ TCO-eval + else + mal-nil + endif + else + \ branch to true + env arg0 cell+ @ TCO-eval + endif ;; + +s" &" MalSymbol. constant &-sym + +: new-user-fn-env { argv argc mal-fn -- env } + mal-fn MalUserFn/formal-args @ { f-args-list } + mal-fn MalUserFn/env @ MalEnv. { env } + + f-args-list MalList/start @ { f-args } + f-args-list MalList/count @ ?dup 0= if else + \ pass nil for last arg, unless overridden below + 1- cells f-args + @ mal-nil env env/set + endif + argc 0 ?do + f-args i cells + @ + dup &-sym m= if + drop + argc i - { c } + c cells allocate throw { start } + argv i cells + start c cells cmove + f-args i 1+ cells + @ ( more-args-symbol ) + start c MalList. env env/set + leave + endif + argv i cells + @ + env env/set + loop + env ; + +MalUserFn + extend eval-invoke { call-env list mal-fn -- list } + mal-fn MalUserFn/is-macro? @ if + list MalList/start @ cell+ \ argv + list MalList/count @ 1- \ argc + mal-fn new-user-fn-env { env } + env mal-fn MalUserFn/body @ eval + call-env swap TCO-eval + else + call-env list eval-rest + mal-fn invoke + endif ;; + + extend invoke ( argv argc mal-fn ) + dup { mal-fn } new-user-fn-env { env } + env mal-fn MalUserFn/body @ TCO-eval ;; +drop + +defspecial fn* { env list -- val } + list MalList/start @ cell+ { arg0 } + MalUserFn new + false over MalUserFn/is-macro? ! + env over MalUserFn/env ! + arg0 @ to-list over MalUserFn/formal-args ! + arg0 cell+ @ over MalUserFn/body ! ;; + +defspecial macroexpand ( env list[_,form] -- form ) + MalList/start @ cell+ @ swap over ( form env form ) + MalList/start @ @ ( form env macro-name-expr ) + eval { macro-fn } ( form ) + dup MalList/start @ cell+ swap MalList/count @ 1- macro-fn ( argv argc fn ) + new-user-fn-env ( env ) + macro-fn MalUserFn/body @ TCO-eval ;; + +5555555555 constant pre-try + +defspecial try* { env list -- val } + list MalList/start @ cell+ { arg0 } + pre-try + env arg0 @ ['] eval catch ?dup 0= if + nip + else { errno } + begin pre-try = until + errno 1 <> if + s" forth-errno" MalKeyword. errno MalInt. MalMap/Empty assoc + to exception-object + endif + arg0 cell+ @ ( list[catch*,sym,form] ) + MalList/start @ cell+ { catch0 } + env MalEnv. { catch-env } + catch0 @ exception-object catch-env env/set + catch-env catch0 cell+ @ TCO-eval + endif ;; + +defspecial . { env coll -- rtn-list } + depth { old-depth } + coll to-list dup MalList/count @ swap MalList/start @ { count start } + count cells start + start cell+ +do + env i @ eval as-native + cell +loop ;; + +MalSymbol + extend mal-eval { env sym -- val } + sym env env/get-addr + dup 0= if + drop + 0 0 s" ' not found" sym pr-str s" '" ...throw-str + else + @ + endif ;; +drop + +: eval-ast { env list -- list } + here + list MalList/start @ { expr-start } + list MalList/count @ 0 ?do + env expr-start i cells + @ eval , + loop + here>MalList ; + +MalList + extend mal-eval { env list -- val } + env list MalList/start @ @ eval + env list rot eval-invoke ;; +drop + +MalVector + extend mal-eval ( env vector -- vector ) + MalVector/list @ eval-ast + MalVector new swap over MalVector/list ! ;; +drop + +MalMap + extend mal-eval ( env map -- map ) + MalMap/list @ eval-ast + MalMap new swap over MalMap/list ! ;; +drop + +defcore eval ( argv argc ) + drop @ repl-env swap eval ;; + +: rep ( str-addr str-len -- str-addr str-len ) + read + repl-env swap eval + print ; + +: mk-args-list ( -- ) + here + begin + next-arg 2dup 0 0 d<> while + MalString. , + repeat + 2drop here>MalList ; + +create buff 128 allot +77777777777 constant stack-leak-detect + +: nop ; + +defcore map ( argv argc -- list ) + drop dup @ swap cell+ @ to-list { fn list } + here + list MalList/start @ list MalList/count @ cells over + swap +do + i 1 fn invoke + dup TCO-eval = if drop eval endif + , + cell +loop + here>MalList ;; + +defcore readline ( argv argc -- mal-string ) + drop @ unpack-str type stdout flush-file drop + buff 128 stdin read-line throw + if buff swap MalString. else drop mal-nil endif ;; + +s\" (def! *host-language* \"forth\")" rep 2drop +s\" (def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))" rep 2drop +s\" (defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))" rep 2drop +s\" (defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) `(let* (or_FIXME ~(first xs)) (if or_FIXME or_FIXME (or ~@(rest xs))))))))" rep 2drop +s\" (def! swap! (fn* [a f & args] (reset! a (apply f @a args))))" rep 2drop + +: repl ( -- ) + s\" (println (str \"Mal [\" *host-language* \"]\"))" rep 2drop + begin + ." user> " + stack-leak-detect + buff 128 stdin read-line throw + while ( num-bytes-read ) + buff swap ( str-addr str-len ) + ['] rep + \ execute ['] nop \ uncomment to see stack traces + catch ?dup 0= if + safe-type cr + stack-leak-detect <> if ." --stack leak--" cr endif + else { errno } + begin stack-leak-detect = until + errno 1 <> if + s" forth-errno" MalKeyword. errno MalInt. MalMap/Empty assoc + to exception-object + endif + ." Uncaught exception: " + exception-object pr-str safe-type cr + endif + repeat ; + +: main ( -- ) + mk-args-list { args-list } + args-list MalList/count @ 0= if + s" *ARGV*" MalSymbol. MalList/Empty repl-env env/set + repl + else + args-list MalList/start @ @ { filename } + s" *ARGV*" MalSymbol. args-list MalList/rest repl-env env/set + + repl-env + here s" load-file" MalSymbol. , filename , here>MalList + eval print + endif ; + +main +cr +bye |