Arithmetic equality fixed.

src/arith/peano.c

@@ -748,3 +748,29 @@ struct cons_pointer lisp_divide( struct
 
     return result;
 }
+
+/**
+ * @brief Function: return a real (approcimately) equal in value to the ratio 
+ * which is the first argument.
+ * 
+ * @param frame 
+ * @param frame_pointer 
+ * @param env 
+ * @return struct cons_pointer a pointer to a real
+ */
+// struct cons_pointer lisp_eval( struct stack_frame *frame, struct cons_pointer frame_pointer,
+//            struct cons_pointer env )
+struct cons_pointer lisp_ratio_to_real( struct stack_frame *frame, struct cons_pointer frame_pointer,
+    struct cons_pointer env) {
+    struct cons_pointer result = NIL;
+    struct cons_pointer rat = frame->arg[0];
+
+    debug_print( L"\nc_ratio_to_ld: ", DEBUG_ARITH);
+    debug_print_object( rat, DEBUG_ARITH);
+
+    if ( ratiop( rat)) {
+        result = make_real( c_ratio_to_ld( rat));
+    } // TODO: else throw an exception?
+
+    return result;
+}

src/arith/peano.h

@@ -75,4 +75,7 @@ struct cons_pointer
 lisp_divide( struct stack_frame *frame, struct cons_pointer frame_pointer,
              struct cons_pointer env );
 
+struct cons_pointer lisp_ratio_to_real( struct stack_frame *frame, struct cons_pointer frame_pointer,
+    struct cons_pointer env);
+
 #endif /* PEANO_H */

src/arith/ratio.c

@@ -11,15 +11,17 @@
 #include <math.h>
 #include <stdio.h>
 
+#include "arith/integer.h"
+#include "arith/peano.h"
+#include "arith/ratio.h"
+#include "arith/real.h"
+#include "debug.h"
+#include "io/print.h"
 #include "memory/conspage.h"
 #include "memory/consspaceobject.h"
-#include "debug.h"
+#include "memory/stack.h"
 #include "ops/equal.h"
-#include "arith/integer.h"
 #include "ops/lispops.h"
-#include "arith/peano.h"
-#include "io/print.h"
-#include "arith/ratio.h"
 
 
 /**
@@ -91,11 +93,10 @@ struct cons_pointer add_ratio_ratio( struct cons_pointer arg1,
                                      struct cons_pointer arg2 ) {
     struct cons_pointer r, result;
 
-    debug_print( L"add_ratio_ratio( arg1 = ", DEBUG_ARITH );
+    debug_print( L"\naadd_ratio_ratio: ", DEBUG_ARITH);
-    debug_print_object( arg1, DEBUG_ARITH );
+    debug_print_object( arg1, DEBUG_ARITH);
-    debug_print( L"; arg2 = ", DEBUG_ARITH );
+    debug_print( L" + ", DEBUG_ARITH);
-    debug_print_object( arg2, DEBUG_ARITH );
+    debug_print_object( arg2, DEBUG_ARITH);
-    debug_print( L")\n", DEBUG_ARITH );
 
     if ( ratiop( arg1 ) && ratiop( arg2 ) ) {
         struct cons_space_object cell1 = pointer2cell( arg1 );
@@ -111,7 +112,7 @@ struct cons_pointer add_ratio_ratio( struct cons_pointer arg1,
             lcm = least_common_multiple( dr1v, dr2v ),
             m1 = lcm / dr1v, m2 = lcm / dr2v;
 
-        debug_printf( DEBUG_ARITH, L"); lcm = %ld; m1 = %ld; m2 = %ld", lcm,
+        debug_printf( DEBUG_ARITH, L"; lcm = %ld; m1 = %ld; m2 = %ld", lcm,
                       m1, m2 );
 
         if ( dr1v == dr2v ) {
@@ -170,6 +171,11 @@ struct cons_pointer add_integer_ratio( struct cons_pointer intarg,
                                        struct cons_pointer ratarg ) {
     struct cons_pointer result;
 
+    debug_print( L"\nadd_integer_ratio: ", DEBUG_ARITH);
+    debug_print_object( intarg, DEBUG_ARITH);
+    debug_print( L" + ", DEBUG_ARITH);
+    debug_print_object( ratarg, DEBUG_ARITH);
+
     if ( integerp( intarg ) && ratiop( ratarg ) ) {
         // TODO: not longer works
         struct cons_pointer one = acquire_integer( 1, NIL ),
@@ -188,6 +194,10 @@ struct cons_pointer add_integer_ratio( struct cons_pointer intarg,
                                                               NIL ) ) ), NIL );
     }
 
+    debug_print( L" => ", DEBUG_ARITH );
+    debug_print_object( result, DEBUG_ARITH );
+    debug_print( L"\n", DEBUG_ARITH );
+
     return result;
 }
 
@@ -199,6 +209,10 @@ struct cons_pointer add_integer_ratio( struct cons_pointer intarg,
  */
 struct cons_pointer divide_ratio_ratio( struct cons_pointer arg1,
                                         struct cons_pointer arg2 ) {
+    debug_print( L"\ndivide_ratio_ratio: ", DEBUG_ARITH);
+    debug_print_object( arg1, DEBUG_ARITH);
+    debug_print( L" / ", DEBUG_ARITH);
+    debug_print_object( arg2, DEBUG_ARITH);
     // TODO: this now has to work if `arg1` is an integer
     struct cons_pointer i =
         make_ratio( pointer2cell( arg2 ).payload.ratio.divisor,
@@ -207,6 +221,10 @@ struct cons_pointer divide_ratio_ratio( struct cons_pointer arg1,
 
     dec_ref( i );
 
+    debug_print( L" => ", DEBUG_ARITH );
+    debug_print_object( result, DEBUG_ARITH );
+    debug_print( L"\n", DEBUG_ARITH );
+
     return result;
 }
 
@@ -259,6 +277,10 @@ struct cons_pointer multiply_ratio_ratio( struct
                              NIL );
     }
 
+    debug_print( L" => ", DEBUG_ARITH );
+    debug_print_object( result, DEBUG_ARITH );
+    debug_print( L"\n", DEBUG_ARITH );
+
     return result;
 }
 
@@ -272,6 +294,11 @@ struct cons_pointer multiply_integer_ratio( struct cons_pointer intarg,
                                             struct cons_pointer ratarg ) {
     struct cons_pointer result;
 
+    debug_print( L"\nmultiply_integer_ratio: ", DEBUG_ARITH);
+    debug_print_object( intarg, DEBUG_ARITH);
+    debug_print( L" * ", DEBUG_ARITH);
+    debug_print_object( ratarg, DEBUG_ARITH);
+
     if ( integerp( intarg ) && ratiop( ratarg ) ) {
         // TODO: no longer works; fix
         struct cons_pointer one = acquire_integer( 1, NIL ),
@@ -286,6 +313,10 @@ struct cons_pointer multiply_integer_ratio( struct cons_pointer intarg,
                              NIL );
     }
 
+    debug_print( L" => ", DEBUG_ARITH );
+    debug_print_object( result, DEBUG_ARITH );
+    debug_print( L"\n", DEBUG_ARITH );
+
     return result;
 }
 
@@ -298,6 +329,11 @@ struct cons_pointer multiply_integer_ratio( struct cons_pointer intarg,
  */
 struct cons_pointer subtract_ratio_ratio( struct cons_pointer arg1,
                                           struct cons_pointer arg2 ) {
+    debug_print( L"\nsubtract_ratio_ratio: ", DEBUG_ARITH);
+    debug_print_object( arg1, DEBUG_ARITH);
+    debug_print( L" * ", DEBUG_ARITH);
+    debug_print_object( arg2, DEBUG_ARITH);
+
     struct cons_pointer i = negative( arg2 ),
         result = add_ratio_ratio( arg1, i );
 
@@ -361,3 +397,35 @@ bool equal_ratio_ratio( struct cons_pointer a, struct cons_pointer b ) {
 
     return result;
 }
+
+/**
+ * @brief convert a ratio to an equivalent long double.
+ * 
+ * @param rat a pointer to a ratio.
+ * @return long double 
+ */
+long double c_ratio_to_ld( struct cons_pointer rat) {
+    long double result = NAN;
+
+    debug_print( L"\nc_ratio_to_ld: ", DEBUG_ARITH);
+    debug_print_object( rat, DEBUG_ARITH);
+
+    if ( ratiop( rat)) {
+        struct cons_space_object * cell_a = & pointer2cell( rat);
+        struct cons_pointer dv = cell_a->payload.ratio.divisor;
+        struct cons_space_object * dv_cell = &pointer2cell( dv);
+        struct cons_pointer dd = cell_a->payload.ratio.dividend;
+        struct cons_space_object * dd_cell = &pointer2cell( dd);
+        
+        if ( nilp( dv_cell->payload.integer.more) && nilp( dd_cell->payload.integer.more)) {
+            result = ((long double) dd_cell->payload.integer.value) / ((long double) dv_cell->payload.integer.value);;
+        } else {
+            fwprintf( stderr, L"real conversion is not yet implemented for bignums rationals.");
+        } 
+    }
+
+    debug_printf( DEBUG_ARITH, L"\nc_ratio_to_ld returning %d\n", result );
+
+    return result;
+}
+

src/arith/ratio.h

@@ -36,4 +36,6 @@ struct cons_pointer make_ratio( struct cons_pointer dividend,
 
 bool equal_ratio_ratio( struct cons_pointer a, struct cons_pointer b );
 
+long double c_ratio_to_ld( struct cons_pointer rat);
+
 #endif

src/init.c

@@ -20,6 +20,7 @@
 /* libcurl, used for io */
 #include <curl/curl.h>
 
+#include "arith/ratio.h"
 #include "version.h"
 #include "memory/conspage.h"
 #include "memory/consspaceobject.h"
@@ -347,6 +348,7 @@ int main( int argc, char *argv[] ) {
     bind_function( L"print", &lisp_print );
     bind_function( L"put!", lisp_hashmap_put );
     bind_function( L"put-all!", &lisp_hashmap_put_all );
+    bind_function( L"ratio->real", &lisp_ratio_to_real );
     bind_function( L"read", &lisp_read );
     bind_function( L"read-char", &lisp_read_char );
     bind_function( L"repl", &lisp_repl );

src/ops/equal.c

@@ -51,11 +51,11 @@ bool end_of_string( struct cons_pointer string ) {
 
 /**
  * @brief compare two long doubles and returns true if they are the same to
- * within a tolerance of one part in a million.
+ * within a tolerance of one part in a billion.
  * 
  * @param a 
  * @param b 
- * @return true if `a` and `b` are equal to within one part in a million.
+ * @return true if `a` and `b` are equal to within one part in a billion.
  * @return false otherwise.
  */
 bool equal_ld_ld( long double a, long double b) {
@@ -66,7 +66,7 @@ bool equal_ld_ld( long double a, long double b) {
     /* average magnitude of the two */
     long double av = (fa > fb) ? ( fa - diff) : ( fb - diff);
     /* amount of difference we will tolerate for equality */
-    long double tolerance = av * 0.0000001;
+    long double tolerance = av * 0.000000001;
 
     bool result = ( fabsl( a - b) < tolerance);
 
@@ -164,20 +164,9 @@ bool equal_real_number( struct cons_pointer a, struct cons_pointer b) {
                 result = equal_ld_ld( cell_a->payload.real.value, cell_b->payload.real.value);
             }
             break;
-        case RATIOTV: {
+        case RATIOTV: 
                 struct cons_space_object * cell_a = & pointer2cell( a);
-                struct cons_pointer dv = cell_a->payload.ratio.divisor;
+                result = equal_ld_ld( c_ratio_to_ld( b), cell_a->payload.real.value);
-                struct cons_space_object * dv_cell = &pointer2cell( dv);
-                struct cons_pointer dd = cell_a->payload.ratio.dividend;
-                struct cons_space_object * dd_cell = &pointer2cell( dd);
-                
-                if ( nilp( dv_cell->payload.integer.more) && nilp( dd_cell->payload.integer.more)) {
-                    long double bv = ((long double) dv_cell->payload.integer.value) / ((long double) dd_cell->payload.integer.value);
-                    result = equal_ld_ld( bv, cell_a->payload.real.value);
-                } else {
-                    fwprintf( stderr, L"\nequality is not yet implemented for bignums rationals compared to reals.");
-                }
-            }
             break;
         }