diff options
Diffstat (limited to 'forth')
| -rw-r--r-- | forth/step5_tco.fs | 238 | ||||
| -rw-r--r-- | forth/types.fs | 2 |
2 files changed, 239 insertions, 1 deletions
diff --git a/forth/step5_tco.fs b/forth/step5_tco.fs new file mode 100644 index 0000000..a420719 --- /dev/null +++ b/forth/step5_tco.fs @@ -0,0 +1,238 @@ +require reader.fs +require printer.fs +require core.fs + +core MalEnv. constant repl-env + +\ Fully evalutate any Mal object: +def-protocol-method mal-eval ( env ast -- val ) + +\ Invoke an object, given whole env and unevaluated argument forms: +def-protocol-method invoke ( argv argc mal-fn -- ... ) + +99999999 constant TCO-eval + +: read read-str ; +: eval ( env obj ) + begin + 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 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 ;; +drop + +\ eval all but the first item of list, storing in temporary memory +\ that should be freed with free-eval-rest when done. +: eval-rest { env list -- mem-token argv argc } + \ Pass args on dictionary stack (!) + \ TODO: consider allocate and free of a real MalList instead + \ Normal list, evaluate and invoke + here { val-start } + list MalList/start @ cell+ { expr-start } + list MalList/count @ 1- dup { argc } 0 ?do + env expr-start i cells + @ eval , + loop + val-start val-start argc ; + +: free-eval-rest ( mem-token/val-start -- ) + here - allot ; + +MalNativeFn + extend invoke ( env list this -- list ) + MalNativeFn/xt @ { xt } + eval-rest ( mem-token argv argc ) + xt execute ( mem-token return-val ) + swap free-eval-rest ;; +drop + +SpecialOp + extend 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 + ; + +defspecial quote ( env list -- form ) + nip MalList/start @ cell+ @ ;; + +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 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 + +MalUserFn + extend invoke { call-env list mal-fn -- list } + call-env list eval-rest { mem-token argv argc } + + 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 + f-args i 1+ cells + @ ( more-args-symbol ) + MalList new ( sym more-args ) + argc i - dup { c } over MalList/count ! + c cells allocate throw dup { start } over MalList/start ! + argv i cells + start c cells cmove + env env/set + leave + endif + argv i cells + @ + env env/set + loop + + env mal-fn MalUserFn/body @ TCO-eval + + mem-token free-eval-rest ;; + +defspecial fn* { env list -- val } + list MalList/start @ cell+ { arg0 } + MalUserFn new + env over MalUserFn/env ! + arg0 @ to-list over MalUserFn/formal-args ! + arg0 cell+ @ over MalUserFn/body ! ;; + +MalSymbol + extend mal-eval { env sym -- val } + 0 sym env get + dup 0= if + drop + ." Symbol '" + sym as-native safe-type + ." ' not found." cr + 1 throw + 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 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 + +: rep ( str -- val ) + read + repl-env swap eval + print ; + +create buff 128 allot +77777777777 constant stack-leak-detect + +: read-lines + begin + ." user> " + stack-leak-detect + buff 128 stdin read-line throw + while + buff swap + ['] rep + \ execute safe-type + catch ?dup 0= if safe-type else ." Caught error " . endif + cr + stack-leak-detect <> if ." --stack leak--" cr endif + repeat ; + +read-lines +cr +bye diff --git a/forth/types.fs b/forth/types.fs index 1a132be..bf159ad 100644 --- a/forth/types.fs +++ b/forth/types.fs @@ -152,7 +152,7 @@ MalType% deftype MalFalse MalFalse new constant mal-false pxt >name name>string type ." ' extended to type '" obj mal-type @ type-name type - ." '" + ." '" cr 1 throw endif trace if ." Calling '" pxt >name name>string type ." ' on " obj mal-type @ type-name type cr endif |