Adding pair/list primitives.

[scheme.forth.jl.git] / scheme.4th

diff --git a/scheme.4th b/scheme.4th
index fa53d67..9d86461 100644 (file)
--- a/scheme.4th
+++ b/scheme.4th
@@ -6,7 +6,7 @@ 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
@@ -103,6 +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
@@ -277,17 +337,37 @@ global-env setobj
     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
+;
+
+: 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
 ;
 
-' add-prim make-primitive +
+include scheme-primitives.4th
 
 \ }}}
 
@@ -357,12 +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 )
@@ -373,10 +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
@@ -463,8 +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
@@ -476,7 +587,7 @@ parse-idx-stack parse-idx-sp !
 
     swap if negate then
 
-    number-type
+    fixnum-type
 ;
 
 : readbool ( -- bool-atom )
@@ -548,60 +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
-;
-
 : readpair ( -- pairobj )
     eatspaces
 
@@ -649,7 +706,7 @@ parse-idx-stack parse-idx-sp !
 
     eatspaces
 
-    number? if
+    fixnum? if
         readnum
         exit
     then
@@ -722,7 +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
@@ -821,7 +878,7 @@ defer eval
 : true? ( boolobj -- bool )
     false? invert ;
 
-: applicaion? ( obj -- obj bool)
+: application? ( obj -- obj bool)
     pair-type istype? ;
 
 : operator ( obj -- operator )
@@ -982,7 +1039,7 @@ defer print
     2drop ." <primitive procedure>" ;
 
 :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