X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=scheme.4th;h=c69f0ecbf67570f1c8400c4802dc186cae4b992d;hb=21606409845e717c4760793e95326c25e4e95029;hp=fa53d670558d12cfc24fc8dfab2af92ffa9a224c;hpb=8772ce0cfd9d1140df94efcad344deb931101f42;p=scheme.forth.jl.git diff --git a/scheme.4th b/scheme.4th index fa53d67..c69f0ec 100644 --- a/scheme.4th +++ b/scheme.4th @@ -6,14 +6,15 @@ include defer-is.4th \ ------ Types ------ -0 constant number-type +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-type +7 constant primitive-proc-type +8 constant compound-proc-type : istype? ( obj type -- obj bool ) over = ; @@ -103,6 +104,66 @@ variable nextfree objvar symbol-table +: duplicate-charlist ( charlist -- copy ) + 2dup nil objeq? false = if + 2dup car 2swap cdr recurse cons + then ; + +: charlist-equiv ( charlist charlist -- bool ) + + 2over 2over + + \ One or both nil + nil? -rot 2drop + if + nil? -rot 2drop + if + 2drop 2drop true exit + else + 2drop 2drop false exit + then + else + nil? -rot 2drop + if + 2drop 2drop false exit + then + then + + 2over 2over + + \ Neither nil + car drop -rot car drop = if + cdr 2swap cdr recurse + else + 2drop 2drop false + then +; + +: charlist>symbol ( charlist -- symbol-obj ) + + symbol-table fetchobj + + begin + nil? false = + while + 2over 2over + car drop pair-type + charlist-equiv if + 2swap 2drop + car + exit + else + cdr + then + repeat + + 2drop + drop symbol-type 2dup + symbol-table fetchobj cons + symbol-table setobj +; + + : (create-symbol) ( addr n -- symbol-obj ) dup 0= if 2drop nil @@ -137,6 +198,7 @@ create-symbol define define-symbol create-symbol set! set!-symbol create-symbol ok ok-symbol create-symbol if if-symbol +create-symbol lambda lambda-symbol \ }}} @@ -273,21 +335,41 @@ global-env setobj cons symbol-table setobj - rot primitive-type ( var prim ) + rot primitive-proc-type ( var prim ) global-env fetchobj define-var ; -: add-prim ( args -- ) - nil objeq? if - 0 number-type +: 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 - 2dup cdr recurse drop - -rot car drop - + number-type + -rot 2dup nil objeq? if + arg-count-error + then + + cdr rot 1- recurse then ; -' add-prim make-primitive + +: 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 \ }}} @@ -357,12 +439,27 @@ parse-idx-stack parse-idx-sp ! nextchar [char] ) = or ; +: commentstart? ( -- bool ) + nextchar [char] ; = ; + : eatspaces + + false \ Indicates whether or not we're eating a comment + begin - whitespace? + dup whitespace? or commentstart? or while + dup nextchar '\n' = and if + invert \ Stop eating comment + else + dup false = commentstart? and if + invert \ Begin eating comment + then + then + inc-parse-idx repeat + drop ; : digit? ( -- bool ) @@ -373,10 +470,23 @@ parse-idx-stack parse-idx-sp ! : minus? ( -- bool ) nextchar [char] - = ; -: number? ( -- bool ) - digit? minus? or false = if - false - exit +: plus? ( -- bool ) + nextchar [char] + = ; + +: fixnum? ( -- bool ) + minus? plus? or if + inc-parse-idx + + delim? if + dec-parse-idx + false exit + else + dec-parse-idx + then + else + digit? false = if + false exit + then then push-parse-idx @@ -463,8 +573,11 @@ parse-idx-stack parse-idx-sp ! nextchar [char] " = ; : readnum ( -- num-atom ) - minus? dup if + plus? minus? or if + minus? inc-parse-idx + else + false then 0 @@ -476,7 +589,7 @@ parse-idx-stack parse-idx-sp ! swap if negate then - number-type + fixnum-type ; : readbool ( -- bool-atom ) @@ -548,60 +661,6 @@ parse-idx-stack parse-idx-sp ! cons ; -: charlist-equiv ( charlist charlist -- bool ) - - 2over 2over - - \ One or both nil - nil? -rot 2drop - if - nil? -rot 2drop - if - 2drop 2drop true exit - else - 2drop 2drop false exit - then - else - nil? -rot 2drop - if - 2drop 2drop false exit - then - then - - 2over 2over - - \ Neither nil - car drop -rot car drop = if - cdr 2swap cdr recurse - else - 2drop 2drop false - then -; - -: charlist>symbol ( charlist -- symbol-obj ) - - symbol-table fetchobj - - begin - nil? false = - while - 2over 2over - car drop pair-type - charlist-equiv if - 2swap 2drop - car - exit - else - cdr - then - repeat - - 2drop - drop symbol-type 2dup - symbol-table fetchobj cons - symbol-table setobj -; - : readpair ( -- pairobj ) eatspaces @@ -649,7 +708,7 @@ parse-idx-stack parse-idx-sp ! eatspaces - number? if + fixnum? if readnum exit then @@ -705,6 +764,7 @@ parse-idx-stack parse-idx-sp ! then eof? if + inc-parse-idx bold fg blue ." Moriturus te saluto." reset-term ." ok" cr quit then @@ -722,7 +782,7 @@ defer eval : self-evaluating? ( obj -- obj bool ) boolean-type istype? if true exit then - number-type istype? if true exit then + fixnum-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 @@ -821,7 +881,7 @@ defer eval : true? ( boolobj -- bool ) false? invert ; -: applicaion? ( obj -- obj bool) +: application? ( obj -- obj bool) pair-type istype? ; : operator ( obj -- operator ) @@ -851,6 +911,21 @@ defer eval then ; +: apply ( proc args ) + 2swap dup case + primitive-proc-type of + drop execute + endof + + compound-proc-type of + ." Compound procedures not yet implemented." + endof + + bold fg red ." Object not applicable. Aboring." reset-term cr + abort + endcase +; + :noname ( obj env -- result ) 2swap @@ -897,16 +972,10 @@ defer eval application? if 2over 2over operator 2swap eval - - primitive-type istype? false = if - bold fg red ." Object not applicable. Aboring." reset-term cr - abort - then - -2rot operands 2swap list-of-vals - 2swap drop execute + apply exit then @@ -982,14 +1051,14 @@ defer print 2drop ." " ; :noname ( obj -- ) - number-type istype? if printnum exit then + fixnum-type istype? if printnum exit then boolean-type istype? if printbool exit then character-type istype? if printchar exit then string-type istype? if printstring exit then symbol-type istype? if printsymbol exit then nil-type istype? if printnil exit then pair-type istype? if ." (" printpair ." )" exit then - primitive-type istype? if printprim exit then + primitive-proc-type istype? if printprim exit then bold fg red ." Error printing expression - unrecognized type. Aborting" reset-term cr abort