core: Rename variable type to binding.

This change allows us to use "variable" in the Guile sense, which is
an anonymous box for storing a value.

* include/mes/constants.h (TVARIABLE): Rename this...
(TBINDING): ...to this.
* include/mes/mes.h (scm): Rename the 'variable' field to 'binding'.
* include/mes/symbols.h (cell_type_variable): Rename this...
(cell_type_binding): ...to this.
* src/gc.c (gc_cellcpy, gc_loop, gc_dump_arena): Adjust accordingly.
* src/eval-apply.c (make_variable_): Rename this...
(make_binding_): ...to this.
(set_env_x, expand_variable_, eval_apply): Adjust accordingly.
* src/symbol.c (init_symbol): Adjust accordingly and rename the
'<cell:variable>' symbol to '<cell:binding>'.
* mes/module/mes/type-0.mes (cell:type-alist): Adjust accordingly.
(variable?): Rename this...
(binding?): ...to this.
* src/display.c (display_helper): Adjust accordingly and print
"binding" instead of "variable".
* mes/module/mes/display.mes (display): Likewise.

include/mes/constants.h

@@ -54,8 +54,8 @@
 #define TSYMBOL           13
 // CONSTANT TVALUES       14
 #define TVALUES           14
-// CONSTANT TVARIABLE     15
+// CONSTANT TBINDING      15
-#define TVARIABLE         15
+#define TBINDING          15
 // CONSTANT TVECTOR       16
 #define TVECTOR           16
 // CONSTANT TBROKEN_HEART 17

include/mes/mes.h

@@ -34,7 +34,7 @@ struct scm
     char *bytes;
     long length;
     struct scm *ref;
-    struct scm *variable;
+    struct scm *binding;
     struct scm *macro;
     long port;
   };

include/mes/symbols.h

@@ -131,7 +131,7 @@ extern struct scm *cell_type_string;
 extern struct scm *cell_type_struct;
 extern struct scm *cell_type_symbol;
 extern struct scm *cell_type_values;
-extern struct scm *cell_type_variable;
+extern struct scm *cell_type_binding;
 extern struct scm *cell_type_vector;
 extern struct scm *cell_type_broken_heart;
 extern struct scm *cell_symbol_program;

mes/module/mes/display.mes

@@ -123,8 +123,8 @@
         (display " ")
         (display (core:car x) port)
         (display ">" port))
-       ((variable? x)
+       ((binding? x)
-        (display "#<variable " port)
+        (display "#<binding " port)
         (write (list->string (car (core:car x))) port)
         (display ">" port))
        ((number? x)

mes/module/mes/type-0.mes

@@ -40,7 +40,7 @@
         (cons <cell:struct> (quote <cell:struct>))
         (cons <cell:symbol> (quote <cell:symbol>))
         (cons <cell:values> (quote <cell:values>))
-        (cons <cell:variable> (quote <cell:variable>))
+        (cons <cell:binding> (quote <cell:binding>))
         (cons <cell:vector> (quote <cell:vector>))
         (cons <cell:broken-heart> (quote <cell:broken-heart>))))
 
@@ -97,8 +97,8 @@
 (define (values? x)
   (eq? (core:type x) <cell:values>))
 
-(define (variable? x)
+(define (binding? x)
-  (eq? (core:type x) <cell:variable>))
+  (eq? (core:type x) <cell:binding>))
 
 (define (variable-global? x)
   (core:cdr x))

src/display.c

@@ -136,10 +136,10 @@ display_helper (struct scm *x, int cont, char *sep, int fd, int write_p)
       display_helper (x->cdr, cont, "", fd, 0);
       fdputs (">", fd);
     }
-  else if (t == TVARIABLE)
+  else if (t == TBINDING)
     {
-      fdputs ("#<variable ", fd);
+      fdputs ("#<binding ", fd);
-      display_helper (x->variable->car, cont, "", fd, 0);
+      display_helper (x->binding->car, cont, "", fd, 0);
       fdputs (">", fd);
     }
   else if (t == TNUMBER)

src/eval-apply.c

@@ -124,8 +124,8 @@ struct scm *
 set_env_x (struct scm *x, struct scm *e, struct scm *a)
 {
   struct scm *p;
-  if (x->type == TVARIABLE)
+  if (x->type == TBINDING)
-    p = x->variable;
+    p = x->binding;
   else
     p = assert_defined (x, module_variable (a, x));
   if (p->type != TPAIR)
@@ -149,9 +149,9 @@ make_closure_ (struct scm *args, struct scm *body, struct scm *a)       /*:((int
 }
 
 struct scm *
-make_variable_ (struct scm *var)        /*:((internal)) */
+make_binding_ (struct scm *handle)      /*:((internal)) */
 {
-  return make_cell (TVARIABLE, var, 0);
+  return make_cell (TBINDING, handle, 0);
 }
 
 struct scm *
@@ -277,7 +277,7 @@ expand_variable_ (struct scm *x, struct scm *formals, int top_p)        /*:((int
             {
               v = module_variable (R0, a);
               if (v != cell_f)
-                x->car = make_variable_ (v);
+                x->car = make_binding_ (v);
             }
         }
       x = x->cdr;
@@ -706,9 +706,9 @@ eval:
       R1 = assert_defined (R1, module_ref (R0, R1));
       goto vm_return;
     }
-  else if (t == TVARIABLE)
+  else if (t == TBINDING)
     {
-      x = R1->variable;
+      x = R1->binding;
       R1 = x->cdr;
       goto vm_return;
     }

src/gc.c

@@ -402,7 +402,7 @@ gc_cellcpy (struct scm *dest, struct scm *src, size_t n)
       if (t == TMACRO
           || t == TPAIR
           || t == TREF
-          || t == TVARIABLE)
+          || t == TBINDING)
         dest->car_value = a - dist;
       else
         dest->car_value = a;
@@ -560,7 +560,7 @@ gc_loop (struct scm *scan)
       if (t == TMACRO
           || t == TPAIR
           || t == TREF
-          || t == TVARIABLE)
+          || t == TBINDING)
         /* *INDENT-ON* */
         {
           car = gc_copy (scan->car);
@@ -812,7 +812,7 @@ gc_dump_arena (struct scm *cells, long size)
               if (t == TMACRO
                   || t == TPAIR
                   || t == TREF
-                  || t == TVARIABLE)
+                  || t == TBINDING)
                 {
                   dumps (ltoa ((cells->car - dist) / M2_CELL_SIZE));
                   /* dumps ("["); dumps (ltoa (a)); dumps ("]"); */

src/symbol.c

@@ -167,7 +167,7 @@ init_symbols_ ()                  /*:((internal)) */
   cell_type_struct = init_symbol (g_symbol, TSYMBOL, "<cell:struct>");
   cell_type_symbol = init_symbol (g_symbol, TSYMBOL, "<cell:symbol>");
   cell_type_values = init_symbol (g_symbol, TSYMBOL, "<cell:values>");
-  cell_type_variable = init_symbol (g_symbol, TSYMBOL, "<cell:variable>");
+  cell_type_binding = init_symbol (g_symbol, TSYMBOL, "<cell:binding>");
   cell_type_vector = init_symbol (g_symbol, TSYMBOL, "<cell:vector>");
   cell_type_broken_heart = init_symbol (g_symbol, TSYMBOL, "<cell:broken-heart>");
 
@@ -211,7 +211,7 @@ init_symbols ()                  /*:((internal)) */
   a = acons (cell_type_struct, make_number (TSTRUCT), a);
   a = acons (cell_type_symbol, make_number (TSYMBOL), a);
   a = acons (cell_type_values, make_number (TVALUES), a);
-  a = acons (cell_type_variable, make_number (TVARIABLE), a);
+  a = acons (cell_type_binding, make_number (TBINDING), a);
   a = acons (cell_type_vector, make_number (TVECTOR), a);
   a = acons (cell_type_broken_heart, make_number (TBROKEN_HEART), a);