X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=scheme.4th;h=9d86461accd46f972012b8663bbc2c79a32fbfad;hb=8a9d83b586844a04f7ee19f98b56f460063bdcad;hp=1f0211464f792819dcdc204d71295e33ce4527c3;hpb=4f600fd1014c0684aad06ec8fdbc8d3ee9c324a4;p=scheme.forth.jl.git diff --git a/scheme.4th b/scheme.4th index 1f02114..9d86461 100644 --- a/scheme.4th +++ b/scheme.4th @@ -6,13 +6,14 @@ 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 : istype? ( obj type -- obj bool ) over = ; @@ -102,6 +103,66 @@ 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 @@ -257,8 +318,63 @@ global-env setobj \ }}} +\ ---- Primitives ---- {{{ + +: make-primitive ( cfa -- ) + bl word + count + + (create-symbol) + drop symbol-type + + 2dup + + symbol-table fetchobj + cons + symbol-table setobj + + rot primitive-type ( var prim ) + global-env fetchobj 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 ---- {{{ +defer read + variable parse-idx variable stored-parse-idx create parse-str 161 allot @@ -321,12 +437,27 @@ 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 ) @@ -337,10 +468,23 @@ 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 @@ -427,8 +571,11 @@ 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 @@ -440,7 +587,7 @@ parse-idx-stack parse-idx-sp ! swap if negate then - number-type + fixnum-type ; : readbool ( -- bool-atom ) @@ -512,62 +659,6 @@ 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 -; - -defer read - : readpair ( -- pairobj ) eatspaces @@ -615,7 +706,7 @@ defer read eatspaces - number? if + fixnum? if readnum exit then @@ -688,7 +779,7 @@ 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 @@ -784,9 +875,39 @@ defer eval then ; -: true? ( boolobj -- boolean ) +: true? ( boolobj -- bool ) false? invert ; +: application? ( obj -- obj bool) + pair-type istype? ; + +: operator ( obj -- operator ) + car ; + +: operands ( obj -- operands ) + cdr ; + +: nooperands? ( operands -- bool ) + nil objeq? ; + +: first-operand ( operands -- operand ) + car ; + +: rest-operands ( operands -- other-operands ) + cdr ; + +: list-of-vals ( args env -- vals ) + 2swap + + 2dup nooperands? if + 2swap 2drop + else + 2over 2over first-operand 2swap eval + -2rot rest-operands 2swap recurse + cons + then +; + :noname ( obj env -- result ) 2swap @@ -830,6 +951,22 @@ defer eval 2swap ['] eval goto then + 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 + exit + then + bold fg red ." Error evaluating expression - unrecognized type. Aborting." reset-term cr abort ; is eval @@ -838,6 +975,8 @@ defer eval \ ---- Print ---- {{{ +defer print + : printnum ( numobj -- ) drop 0 .R ; : printbool ( numobj -- ) @@ -887,7 +1026,6 @@ defer eval : printnil ( nilobj -- ) 2drop ." ()" ; -defer print : printpair ( pairobj -- ) 2dup car print @@ -897,14 +1035,18 @@ defer print ." . " print ; +: printprim ( primobj -- ) + 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 bold fg red ." Error printing expression - unrecognized type. Aborting" reset-term cr abort