X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=scheme.4th;h=3c4744e59f464c61d47dfe44ab6ce61899b4f421;hb=41a8ffdeecfc1bf848f83a9ccbf97f73a2e8e739;hp=893b20b711a271f0efe076b7055f5de8805166cf;hpb=d42b0088f674ffdcd607016213c66455864b7588;p=scheme.forth.jl.git diff --git a/scheme.4th b/scheme.4th index 893b20b..3c4744e 100644 --- a/scheme.4th +++ b/scheme.4th @@ -3,32 +3,66 @@ scheme definitions include term-colours.4th include defer-is.4th +include float.4th + +include debugging.4th + +defer read +defer eval +defer print \ ------ Types ------ -0 constant fixnum-type -1 constant boolean-type -2 constant character-type -3 constant string-type -4 constant nil-type -5 constant pair-type -6 constant symbol-type -7 constant primitive-proc-type -8 constant compound-proc-type +variable nexttype +0 nexttype ! +: make-type + create nexttype @ , + 1 nexttype +! + does> @ ; + +make-type fixnum-type +make-type realnum-type +make-type boolean-type +make-type character-type +make-type string-type +make-type nil-type +make-type pair-type +make-type symbol-type +make-type primitive-proc-type +make-type compound-proc-type : istype? ( obj type -- obj bool ) over = ; \ ------ Cons cell memory ------ {{{ -1000 constant N -create car-cells N allot -create car-type-cells N allot -create cdr-cells N allot -create cdr-type-cells N allot +1000 constant scheme-memsize +create car-cells scheme-memsize allot +create car-type-cells scheme-memsize allot +create cdr-cells scheme-memsize allot +create cdr-type-cells scheme-memsize allot +create nextfrees scheme-memsize allot +:noname + scheme-memsize 0 do + i 1+ nextfrees i + ! + loop +; execute + variable nextfree 0 nextfree ! +: inc-nextfree + nextfrees nextfree @ + @ + + dup scheme-memsize < if + nextfree ! + else + bold fg red + ." Out of memory! Aborting." + reset-term abort + then +; + : cons ( car-obj cdr-obj -- pair-obj ) cdr-type-cells nextfree @ + ! cdr-cells nextfree @ + ! @@ -36,8 +70,7 @@ variable nextfree car-cells nextfree @ + ! nextfree @ pair-type - - 1 nextfree +! + inc-nextfree ; : car ( pair-obj -- car-obj ) @@ -100,6 +133,64 @@ variable nextfree \ }}} +\ ---- Garbage Collection ---- {{{ + +variable gc-enabled +false gc-enabled ! + +: gc-enable + true gc-enabled ! ; + +: gc-disable + false gc-enabled ! ; + +: gc-enabled? + gc-enabled @ ; + +: pairlike? ( obj -- obj bool ) + pair-type istype? if true exit then + string-type istype? if true exit then + symbol-type istype? if true exit then + compound-proc-type istype? if true exit then + + false +; + +: pairlike-marked? ( obj -- obj bool ) + over nextfrees + 0= +; + +: mark-pairlike ( obj -- obj ) + over nextfrees + 0 swap ! +; + +: gc-mark-obj ( obj -- ) + + pairlike? if + pairlike-marked? if 2drop exit then + + mark-pairlike + + 2dup + + car recurse + cdr recurse + else + 2drop + then +; + +: gc-sweep + scheme-memsize nextfree ! + 0 scheme-memsize 1- do + nextfrees i + @ 0<> if + nextfree @ nextfrees i + ! + i nextfree ! + then + -1 +loop ; + +\ }}} + \ ---- Pre-defined symbols ---- {{{ objvar symbol-table @@ -327,6 +418,8 @@ global-env obj! bl word count + \ 2dup ." Defining primitive " type ." ..." cr + (create-symbol) drop symbol-type @@ -376,8 +469,6 @@ include scheme-primitives.4th \ ---- Read ---- {{{ -defer read - variable parse-idx variable stored-parse-idx create parse-str 161 allot @@ -497,13 +588,52 @@ parse-idx-stack parse-idx-sp ! inc-parse-idx repeat - delim? if - pop-parse-idx - true - else - pop-parse-idx - false + delim? pop-parse-idx +; + +: realnum? ( -- bool ) + push-parse-idx + + minus? plus? or if + inc-parse-idx then + + \ Record starting parse idx: + \ Want to detect whether any characters (following +/-) were eaten. + parse-idx @ + + begin digit? while + inc-parse-idx + repeat + + [char] . nextchar = if + inc-parse-idx + begin digit? while + inc-parse-idx + repeat + then + + [char] e nextchar = [char] E nextchar = or if + inc-parse-idx + + minus? plus? or if + inc-parse-idx + then + + digit? invert if + drop pop-parse-idx false exit + then + + begin digit? while + inc-parse-idx + repeat + then + + \ This is a real number if characters were + \ eaten and the next characer is a delimiter. + parse-idx @ < delim? and + + pop-parse-idx ; : boolean? ( -- bool ) @@ -573,7 +703,7 @@ parse-idx-stack parse-idx-sp ! : string? ( -- bool ) nextchar [char] " = ; -: readnum ( -- num-atom ) +: readfixnum ( -- num-atom ) plus? minus? or if minus? inc-parse-idx @@ -593,6 +723,24 @@ parse-idx-stack parse-idx-sp ! fixnum-type ; +: readrealnum ( -- realnum ) + + \ Remember that at this point we're guaranteed to + \ have a parsable real on this line. + + parse-str parse-idx @ + + + begin delim? false = while + inc-parse-idx + repeat + + parse-str parse-idx @ + over - + + float-parse + + realnum-type +; + : readbool ( -- bool-atom ) inc-parse-idx @@ -710,7 +858,12 @@ parse-idx-stack parse-idx-sp ! eatspaces fixnum? if - readnum + readfixnum + exit + then + + realnum? if + readrealnum exit then @@ -766,7 +919,7 @@ parse-idx-stack parse-idx-sp ! eof? if inc-parse-idx - bold fg blue ." Moriturus te saluto." reset-term ." ok" cr + bold fg blue ." Moriturus te saluto." reset-term cr quit then @@ -785,11 +938,10 @@ parse-idx-stack parse-idx-sp ! \ ---- Eval ---- {{{ -defer eval - : self-evaluating? ( obj -- obj bool ) boolean-type istype? if true exit then fixnum-type istype? if true exit then + realnum-type istype? if true exit then character-type istype? if true exit then string-type istype? if true exit then nil-type istype? if true exit then @@ -972,7 +1124,7 @@ defer eval begin 2dup cdr 2dup nil objeq? false = while - -2rot car over ( nextbody env exp env ) + -2rot car 2over ( nextbody env exp env ) eval 2drop \ discard result 2swap ( env nextbody ) @@ -981,8 +1133,7 @@ defer eval 2drop ( env body ) car 2swap ( exp env ) - ['] eval goto-prime \ Tail call optimization - \ eval \ No tail call optimization + R> drop ['] eval goto-deferred \ Tail call optimization endof bold fg red ." Object not applicable. Aboring." reset-term cr @@ -1030,7 +1181,8 @@ defer eval if-alternative then - 2swap ['] eval goto + 2swap + ['] eval goto-deferred then lambda? if @@ -1058,9 +1210,9 @@ defer eval \ ---- Print ---- {{{ -defer print +: printfixnum ( fixnumobj -- ) drop 0 .R ; -: printnum ( numobj -- ) drop 0 .R ; +: printrealnum ( realnumobj -- ) drop float-print ; : printbool ( numobj -- ) drop if @@ -1125,7 +1277,8 @@ defer print 2drop ." " ; :noname ( obj -- ) - fixnum-type istype? if printnum exit then + fixnum-type istype? if printfixnum exit then + realnum-type istype? if printrealnum exit then boolean-type istype? if printbool exit then character-type istype? if printchar exit then string-type istype? if printstring exit then @@ -1147,12 +1300,15 @@ defer print cr ." Welcome to scheme.forth.jl!" cr ." Use Ctrl-D to exit." cr + empty-parse-str begin cr bold fg green ." > " reset-term read + global-env obj@ eval + fg cyan ." ; " print reset-term again ;