Nutting out macro issues.

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

diff --git a/scheme.4th b/scheme.4th
index 7ac6355..8c5b159 100644 (file)
--- a/scheme.4th
+++ b/scheme.4th
@@ -180,7 +180,7 @@ console-i/o-port obj@ current-input-port obj!
 objvar symbol-table
 
 : duplicate-charlist ( charlist -- copy )
-    2dup nil objeq? false = if
+    nil? false = if
         2dup car 2swap cdr recurse cons
     then ;
 
@@ -336,7 +336,7 @@ objvar vals
 : get-vars-vals ( var env -- vars? vals? bool )
 
     begin
-        2dup nil objeq? false =
+        nil? false =
     while
         2over 2over first-frame
         get-vars-vals-frame if
@@ -408,7 +408,9 @@ global-env obj!
 
 objvar macro-table
 
-: lookup-macro ( name_symbol -- proc? bool )
+( Look up macro in macro table. Returns nil if
+  no macro is found. )
+: lookup-macro ( name_symbol -- proc )
     macro-table obj@
 
     begin
@@ -418,11 +420,13 @@ objvar macro-table
         car car objeq? if
             2swap 2drop
             car cdr
-            true exit
+            exit
         then
+
+        cdr
     repeat
 
-    2drop false
+    2swap 2drop
 ;
 
 : make-macro ( name_symbol params body env -- )
@@ -442,6 +446,8 @@ objvar macro-table
             set-cdr!
             exit
         then
+
+        cdr
     repeat
 
     2drop
@@ -1029,6 +1035,31 @@ parse-idx-stack parse-idx-sp !
 : macro-definition? ( obj -- obj bool )
     define-macro-symbol tagged-list? ;
 
+: macro-definition-name ( exp -- mname )
+    cdr car car ;
+
+: macro-definition-params ( exp -- params )
+    cdr car cdr ;
+
+: macro-definition-body ( exp -- body )
+    cdr cdr ;
+
+objvar env
+: eval-define-macro ( obj env -- res )
+    env obj!
+
+    2dup macro-definition-name 2swap ( name obj )
+    2dup macro-definition-params 2swap ( name params obj )
+    macro-definition-body ( name params body )
+
+    env obj@ ( name params body env )
+
+    make-macro
+
+    ok-symbol
+;
+hide env
+
 : if? ( obj -- obj bool )
     if-symbol tagged-list? ;
 
@@ -1040,7 +1071,7 @@ parse-idx-stack parse-idx-sp !
 
 : if-alternative ( ifobj -- alt|false )
     cdr cdr cdr
-    2dup nil objeq? if
+    nil? if
         2drop false
     else
         car
@@ -1080,14 +1111,14 @@ parse-idx-stack parse-idx-sp !
     2swap ( env explist )
 
     \ Abort on empty list
-    2dup nil objeq? if
+    nil? if
         2drop none
         2swap exit
     then
 
     begin
         2dup cdr ( env explist nextexplist )
-        2dup nil objeq? false =
+        nil? false =
     while
         -2rot car 2over ( nextexplist env exp env )
         eval
@@ -1248,25 +1279,30 @@ parse-idx-stack parse-idx-sp !
 
     application? if
 
-        2over 2over
-        operator
+        2over 2over ( env exp env exp )
+        operator 2dup ( env exp env opname opname )
 
-        find-macro-proc nil objeq? if
+        lookup-macro nil? if
             \ Regular function application
 
-            2swap eval
-            -2rot
-            operands 2swap list-of-vals
+            2drop ( env exp env opname )
+
+            2swap eval ( env exp proc )
+            -2rot ( proc env exp )
+            operands 2swap ( proc operands env )
+            list-of-vals ( proc argvals )
 
             apply
         else
             \ Macro function evaluation
 
-            2swap 2drop 2swap ( env mproc exp )
+            ." Macro eval"
 
-            apply 2swap ( expanded-exp env )
+            ( env exp env opname mproc )
+            2swap 2drop -2rot 2drop cdr ( env mproc body )
 
-            ['] eval goto-deferred
+            \ TODO: evaluate macro procedure on expression body
+            ." ABORTED: Macros not yet fully implemented!" abort
         then
         exit
     then
@@ -1503,7 +1539,7 @@ variable gc-stack-depth
             arg-count-error
         then
     else
-        -rot 2dup nil objeq? if
+        -rot nil? if
             arg-count-error
         then
         
@@ -1533,7 +1569,7 @@ include scheme-primitives.4th
     dup 2swap ( origaddr addr charlist )
 
     begin 
-        2dup nil objeq? false =
+        nil? false =
     while
         2dup cdr 2swap car 
         drop ( origaddr addr charlist char )