Implemented read-level portion of quasiquote forms.

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

diff --git a/scheme.4th b/scheme.4th
index 3728257..fc307d7 100644 (file)
--- a/scheme.4th
+++ b/scheme.4th
@@ -262,15 +262,18 @@ objvar symbol-table
     does> dup @ swap 1+ @
 ;
 
-create-symbol quote         quote-symbol
-create-symbol define        define-symbol
-create-symbol define-macro  define-macro-symbol
-create-symbol set!          set!-symbol
-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
+create-symbol quote             quote-symbol
+create-symbol quasiquote        quasiquote-symbol
+create-symbol unquote           unquote-symbol
+create-symbol unquote-splicing  unquote-splicing-symbol
+create-symbol define            define-symbol
+create-symbol define-macro      define-macro-symbol
+create-symbol set!              set!-symbol
+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
 
 \ }}}
 
@@ -966,6 +969,21 @@ parse-idx-stack parse-idx-sp !
         quote-symbol recurse nil cons cons exit
     then
 
+    nextchar [char] ` = if
+        inc-parse-idx
+        quasiquote-symbol recurse nil cons cons exit
+    then
+
+    nextchar [char] , = if
+        inc-parse-idx
+        nextchar [char] @ = if
+            inc-parse-idx
+            unquote-splicing-symbol recurse nil cons cons exit
+        else
+            unquote-symbol recurse nil cons cons exit
+        then
+    then
+
     eof? if
         EOF character-type
         inc-parse-idx
@@ -1022,43 +1040,25 @@ parse-idx-stack parse-idx-sp !
 : make-lambda ( params body -- lambda-exp )
     lambda-symbol -2rot cons cons ;
 
-( Handles recursive expansion of defines in
+( Handles iterative expansion of defines in
   terms of nested lambdas. Most Schemes only
-  handle one level of expansion! )
-: (definition-var-val) ( val var -- val' var' )
-    symbol-type istype? if 2swap car 2swap exit then
+  handle one iteration of expansion! )
+: definition-var-val ( obj -- var val )
 
-    2dup cdr 2swap car
-    symbol-type istype? if
-        2swap ( body procname procargs )
-        2rot ( procname procargs body )
-        make-lambda ( procname lambda-exp )
-        2swap
-        exit
-    then
+    cdr 2dup cdr 2swap car ( val var )
 
-    ( body procargs nextval )
-    -2rot 2swap ( nextval procargs body )
-    make-lambda nil cons ( nextval lambda-exp )
-    2swap ( lambda-exp nextval )
-    recurse
-;
+    begin
+        symbol-type istype? false =
+    while
+        2dup cdr 2swap car ( val formals var' )
+        -2rot 2swap ( var' formals val )
+        make-lambda nil cons ( var' val' )
+        2swap ( val' var' )
+    repeat
 
-: definition-var-val ( obj -- var val )
-    cdr 2dup cdr 2swap car
-    (definition-var-val)
-    2swap
+    2swap car
 ;
 
-: assignment? ( obj -- obj bool )
-    set!-symbol tagged-list? ;
-
-: assignment-var ( obj -- var )
-    cdr car ;
-    
-: assignment-val ( obj -- val )
-    cdr cdr car ;
-
 : eval-definition ( obj env -- res )
     2dup 2rot ( env env obj )
     definition-var-val ( env env var val )
@@ -1069,7 +1069,16 @@ parse-idx-stack parse-idx-sp !
 
     ok-symbol
 ;
+
+: assignment? ( obj -- obj bool )
+    set!-symbol tagged-list? ;
+
+: assignment-var ( obj -- var )
+    cdr car ;
     
+: assignment-val ( obj -- val )
+    cdr cdr car ;
+
 : eval-assignment ( obj env -- res )
     2swap 
     2over 2over ( env obj env obj )
@@ -1370,9 +1379,7 @@ hide env
             ( env exp env opname mproc )
             2swap 2drop -2rot 2drop cdr ( env mproc body )
 
-            2dup print cr
             macro-expand
-            2dup print cr
 
             2swap
             ['] eval goto-deferred