X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=scheme.4th;h=7c1a31606045a96f092d71327a86c91ddea1e440;hb=167e0b9dcc4de39b9479abcfcc80cc039023e1a7;hp=bac32831cd66c30a1ddccafd5b7c54d99a72e89a;hpb=5d741836f2b7b3af569d43c9c29e20a55565102b;p=scheme.forth.jl.git diff --git a/scheme.4th b/scheme.4th index bac3283..7c1a316 100644 --- a/scheme.4th +++ b/scheme.4th @@ -3,20 +3,23 @@ scheme definitions include term-colours.4th include defer-is.4th -include throw-catch.4th include float.4th +include debugging.4th + defer read defer eval defer print +defer collect-garbage + \ ------ Types ------ variable nexttype 0 nexttype ! : make-type create nexttype @ , - nexttype @ 1+ nexttype ! + 1 nexttype +! does> @ ; make-type fixnum-type @@ -29,20 +32,44 @@ make-type pair-type make-type symbol-type make-type primitive-proc-type make-type compound-proc-type +make-type fileport-type : istype? ( obj type -- obj bool ) over = ; -\ ------ Cons cell memory ------ {{{ +\ ------ List-structured memory ------ {{{ -10000 constant N -create car-cells N allot -create car-type-cells N allot -create cdr-cells N allot -create cdr-type-cells N allot +10000 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 @ + @ + nextfree ! + + nextfree @ scheme-memsize >= if + collect-garbage + then + + nextfree @ scheme-memsize >= if + fg red bold + ." Out of memory! Aborting." + reset-term abort + then +; + : cons ( car-obj cdr-obj -- pair-obj ) cdr-type-cells nextfree @ + ! cdr-cells nextfree @ + ! @@ -50,8 +77,7 @@ variable nextfree car-cells nextfree @ + ! nextfree @ pair-type - - 1 nextfree +! + inc-nextfree ; : car ( pair-obj -- car-obj ) @@ -114,6 +140,37 @@ variable nextfree \ }}} +\ ---- Port I/O ---- {{{ + +: fileport>fid ( fileport -- fid ) + drop ; + +: fid>fileport ( fid -- fileport ) + fileport-type ; + +: open-input-file ( addr n -- fileport ) + r/o open-file drop fid>fileport +; + +: close-port ( fileport -- ) + fileport>fid close-file drop +; + +objvar console-i/o-port +0 fileport-type console-i/o-port obj! + +objvar current-input-port +console-i/o-port obj@ current-input-port obj! + +: read-port ( fileport -- obj ) + current-input-port obj! + read ; + +: read-console ( -- obj ) + console-i/o-port obj@ read-port ; + +\ }}} + \ ---- Pre-defined symbols ---- {{{ objvar symbol-table @@ -178,7 +235,7 @@ objvar symbol-table ; -: (create-symbol) ( addr n -- symbol-obj ) +: cstr>charlist ( addr n -- symbol-obj ) dup 0= if 2drop nil else @@ -194,7 +251,7 @@ objvar symbol-table bl word count - (create-symbol) + cstr>charlist drop symbol-type 2dup @@ -214,6 +271,7 @@ create-symbol ok ok-symbol create-symbol if if-symbol create-symbol lambda lambda-symbol create-symbol λ λ-symbol +create-symbol begin begin-symbol \ }}} @@ -335,59 +393,6 @@ global-env obj! \ }}} -\ ---- Primitives ---- {{{ - -: make-primitive ( cfa -- ) - bl word - count - - (create-symbol) - drop symbol-type - - 2dup - - symbol-table obj@ - cons - symbol-table obj! - - rot primitive-proc-type ( var prim ) - global-env obj@ define-var -; - -: arg-count-error - bold fg red ." Incorrect argument count." reset-term cr - abort -; - -: ensure-arg-count ( args n -- ) - dup 0= if - drop nil objeq? false = if - arg-count-error - then - else - -rot 2dup nil objeq? if - arg-count-error - then - - cdr rot 1- recurse - then -; - -: arg-type-error - bold fg red ." Incorrect argument type." reset-term cr - abort -; - -: ensure-arg-type ( arg type -- arg ) - istype? false = if - arg-type-error - then -; - -include scheme-primitives.4th - -\ }}} - \ ---- Read ---- {{{ variable parse-idx @@ -416,13 +421,24 @@ parse-idx-stack parse-idx-sp ! '\n' parse-str parse-str-span @ + ! 1 parse-str-span +! ; +: append-eof + 4 parse-str parse-str-span @ + ! + 1 parse-str-span +! ; + : empty-parse-str 0 parse-str-span ! 0 parse-idx ! ; : getline - parse-str 160 expect cr - span @ parse-str-span ! + current-input-port obj@ console-i/o-port obj@ objeq? if + parse-str 160 expect cr + span @ parse-str-span ! + else + parse-str 160 current-input-port obj@ fileport>fid read-line + drop swap parse-str-span ! + + parse-str-span @ 0= and if append-eof then + then append-newline 0 parse-idx ! ; @@ -439,12 +455,16 @@ parse-idx-stack parse-idx-sp ! charavailable? false = if getline then parse-str parse-idx @ + @ ; +: '\t' 9 ; : whitespace? ( -- bool ) nextchar BL = - nextchar '\n' = or ; + nextchar '\n' = + nextchar '\t' = + or or ; +: EOF 4 ; : eof? ( -- bool ) - nextchar 4 = ; + nextchar EOF = ; : delim? ( -- bool ) whitespace? @@ -513,16 +533,16 @@ parse-idx-stack parse-idx-sp ! ; : realnum? ( -- bool ) - \ Record starting parse idx: - \ Want to detect whether any characters were eaten. - parse-idx @ - 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 @@ -541,6 +561,10 @@ parse-idx-stack parse-idx-sp ! inc-parse-idx then + digit? invert if + drop pop-parse-idx false exit + then + begin digit? while inc-parse-idx repeat @@ -658,7 +682,7 @@ parse-idx-stack parse-idx-sp ! realnum-type ; -: readbool ( -- bool-atom ) +: readbool ( -- bool-obj ) inc-parse-idx nextchar [char] f = if @@ -672,7 +696,7 @@ parse-idx-stack parse-idx-sp ! boolean-type ; -: readchar ( -- char-atom ) +: readchar ( -- char-obj ) inc-parse-idx inc-parse-idx @@ -835,9 +859,9 @@ parse-idx-stack parse-idx-sp ! then eof? if + EOF character-type inc-parse-idx - bold fg blue ." Moriturus te saluto." reset-term ." ok" cr - quit + exit then \ Anything else is parsed as a symbol @@ -984,6 +1008,35 @@ parse-idx-stack parse-idx-sp ! drop compound-proc-type ; +: begin? ( obj -- obj bool ) + begin-symbol tagged-list? ; + +: begin-actions ( obj -- actions ) + cdr ; + +: eval-sequence ( explist env -- finalexp env ) + ( Evaluates all bar the final expressions in + an an expression list. The final expression + is returned to allow for tail optimization. ) + + 2swap ( env explist ) + + \ Abort on empty list + 2dup nil objeq? if 2swap exit then + + begin + 2dup cdr ( env explist nextexplist ) + 2dup nil objeq? false = + while + -2rot car 2over ( nextexplist env exp env ) + eval + 2drop \ discard result + 2swap ( env nextexplist ) + repeat + + 2drop car 2swap ( finalexp env ) +; + : application? ( obj -- obj bool) pair-type istype? ; @@ -1036,19 +1089,7 @@ parse-idx-stack parse-idx-sp ! extend-env ( body env ) - 2swap ( env body ) - - begin - 2dup cdr 2dup nil objeq? false = - while - -2rot car 2over ( nextbody env exp env ) - eval - 2drop \ discard result - 2swap ( env nextbody ) - repeat - - 2drop ( env body ) - car 2swap ( exp env ) + eval-sequence R> drop ['] eval goto-deferred \ Tail call optimization endof @@ -1109,6 +1150,10 @@ parse-idx-stack parse-idx-sp ! exit then + begin? if + \ TODO + then + application? if 2over 2over operator 2swap eval @@ -1211,6 +1256,216 @@ parse-idx-stack parse-idx-sp ! \ }}} +\ ---- Garbage Collection ---- {{{ + +variable gc-enabled +false gc-enabled ! + +variable gc-stack-depth + +: enable-gc + depth gc-stack-depth ! + true gc-enabled ! ; + +: disable-gc + 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-unmark ( -- ) + scheme-memsize 0 do + 1 nextfrees i + ! + loop +; + +: gc-mark-obj ( obj -- ) + + pairlike? invert if 2drop exit then + pairlike-marked? if 2drop exit then + + mark-pairlike + + drop pair-type 2dup + + car recurse + cdr recurse +; + +: gc-sweep + scheme-memsize nextfree ! + 0 scheme-memsize 1- do + nextfrees i + @ 0<> if + nextfree @ nextfrees i + ! + i nextfree ! + then + -1 +loop +; + +\ Following a GC, this gives the amount of free memory +: gc-count-marked + 0 + scheme-memsize 0 do + nextfrees i + @ 0= if 1+ then + loop +; + +\ Debugging word - helps spot memory that is retained +: gc-zero-unmarked + scheme-memsize 0 do + nextfrees i + @ 0<> if + 0 car-cells i + ! + 0 cdr-cells i + ! + then + loop +; + +:noname + \ ." GC! " + + gc-unmark + + symbol-table obj@ gc-mark-obj + global-env obj@ gc-mark-obj + + depth gc-stack-depth @ do + PSP0 i + 1 + @ + PSP0 i + 2 + @ + + gc-mark-obj + 2 +loop + + gc-sweep + + \ ." (" gc-count-marked . ." pairs marked as used.)" cr +; is collect-garbage + +\ }}} + +\ ---- Primitives ---- {{{ + +: make-primitive ( cfa -- ) + bl word + count + + \ 2dup ." Defining primitive " type ." ..." cr + + cstr>charlist + drop symbol-type + + 2dup + + symbol-table obj@ + cons + symbol-table obj! + + rot primitive-proc-type ( var prim ) + global-env obj@ define-var +; + +: arg-count-error + bold fg red ." Incorrect argument count." reset-term cr + abort +; + +: ensure-arg-count ( args n -- ) + dup 0= if + drop nil objeq? false = if + arg-count-error + then + else + -rot 2dup nil objeq? if + arg-count-error + then + + cdr rot 1- recurse + then +; + +: arg-type-error + bold fg red ." Incorrect argument type." reset-term cr + abort +; + +: ensure-arg-type ( arg type -- arg ) + istype? false = if + arg-type-error + then +; + +include scheme-primitives.4th + +\ }}} + +\ ---- Loading files ---- {{{ + +: charlist>cstr ( charlist addr -- n ) + + dup 2swap ( origaddr addr charlist ) + + begin + 2dup nil objeq? false = + while + 2dup cdr 2swap car + drop ( origaddr addr charlist char ) + -rot 2swap ( origaddr charlist addr char ) + over ! + 1+ -rot ( origaddr nextaddr charlist ) + repeat + + 2drop ( origaddr finaladdr ) + swap - +; + +: load ( addr n -- finalResult ) + open-input-file + + empty-parse-str + + ok-symbol ( port res ) + + begin + 2over read-port ( port res obj ) + + 2dup EOF character-type objeq? if + 2drop 2swap close-port + exit + then + + 2swap 2drop ( port obj ) + + global-env obj@ eval ( port res ) + again +; + +:noname ( args -- finalResult ) + 2dup 1 ensure-arg-count + car string-type ensure-arg-type + + drop pair-type + pad charlist>cstr + pad swap load +; make-primitive load + +\ }}} + \ ---- REPL ---- : repl @@ -1219,10 +1474,20 @@ parse-idx-stack parse-idx-sp ! empty-parse-str + enable-gc + begin cr bold fg green ." > " reset-term - read + read-console + + 2dup EOF character-type objeq? if + 2drop + bold fg blue ." Moriturus te saluto." reset-term cr + exit + then + global-env obj@ eval + fg cyan ." ; " print reset-term again ;