k&r 04-05: added math.h bindings

k&r/04-funcs-and-prog-struct/04-calc.c

@@ -1,34 +1,116 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <math.h>
 
 
 #define printerr(format, ...) printf("error: " format "\n", ##__VA_ARGS__)
+int stack_len(void);
 void push(double x);
 double pop(void);
-int stack_len(void);
+double peek(void);
+void clear(void);
+
+/* --------- PROMPT FORMATS */
+#define PROMPT_F     ">> "
+#define POP_PRINT_F  "pop -> %.8g\n"
+#define PEEK_PRINT_F "peek -> %.8g\n"
+#define EMPTY_F      "empty\n"
 
 /* --------- ERROR MESSAGES */
 #define ZERODIV_ERR "zero divisor"
+#define DOMAIN_ERR "operand not in domain [%d, %d]"
+#define NEG_ERR "negative operand %g"
+#define FULL_STACK_ERR  "stack full, can't push %g"
+#define EMPTY_STACK_ERR "stack empty" 
+
+/* --------- CALCULATOR FUNCTION TYPES */
+/* renaming macro */
+#define CALL(TOKEN, F, APPLY, ...) APPLY(F, ##__VA_ARGS__)
+
+/* value */
+#define VALUE(ID) push(ID)
+
+/* command */
+#define COMMAND(CMD) CMD()
+
+/* commutative operator */
+#define COMM_OP(OP) push(pop() OP pop()) 
+/* non-commutative operator */
+#define NONC_OP(OP, T, ...) \
+    do { T op = pop(); __VA_ARGS__ push(((T) pop()) OP op); } while (0)
+/* nonzero second operand */
+#define NONZ_SND_OP if (!op) printerr(ZERODIV_ERR); else
+
+/* unary function */
+#define UNARY_FUN(F) push(F(pop()))
+/* unary function with tests */
+#define UNARY_T_FUN(F, T, ...) do { double op = pop(); __VA_ARGS__ push(F(op)); } while (0)
+/* operator in range */
+#define IN_RANGE(A, B) if (op < A || op > B) printerr(DOMAIN_ERR, A, B); else
+/* operator > 0 */
+#define NON_NEG if (op < 0) printerr(NEG_ERR, op); else
+
+/* commutative function */
+#define COMM_FUN(F) push(F(pop(), pop()))
+/* non-commutative function */
+#define NONC_FUN(F, T, ...) \
+    do { T op = pop(); __VA_ARGS__ push(F(pop(), op)); } while (0)
+
 
 
 /* --------- CALCULATOR FUNCTIONS */
-/* commutative operator application */
-#define COMM_OP(OP) push(pop() OP pop()) 
-/* non-commutative operator application */
-#define NONC_OP(OP, T, ...) \
-    do { T op2 = pop(); __VA_ARGS__ push(((T) pop()) OP op2); } while (0)
-/* nonzero second operand operator application */
-#define NONZ_OP(OP, T) \
-    NONC_OP(OP, T, if (!op2) printerr(ZERODIV_ERR); else)
 
-#define FUNCTIONS \
+#define COMMANDS \
+    X(print, COMMAND) \
+    X(dup, COMMAND) \
+    X(swap, COMMAND) \
+    X(clear, COMMAND) 
+
+#define OPERATORS \
     X(+, COMM_OP) \
     X(*, COMM_OP) \
     X(-, NONC_OP, double) \
-    X(/, NONZ_OP, double) \
-    X(%, NONZ_OP, int) 
+    X(/, NONC_OP, double, NONZ_SND_OP) \
+    X(%, NONC_OP, int, NONZ_SND_OP) \
+    X(>, NONC_OP, double) \
+    X(<, NONC_OP, double) \
+    X(<=, NONC_OP, double) \
+    X(>=, NONC_OP, double)
 
+#define MATH_H_BINDINGS \
+    X(sin, UNARY_FUN) \
+    X(cos, UNARY_FUN) \
+    X(tan, UNARY_FUN) \
+    X(acos, UNARY_T_FUN, double, IN_RANGE(-1, 1)) \
+    X(asin, UNARY_T_FUN, double, IN_RANGE(-1, 1)) \
+    X(atan, UNARY_FUN) \
+    X(exp, UNARY_FUN) \
+    X(log, UNARY_T_FUN, double, NON_NEG) \
+    X(log10, UNARY_T_FUN, double, NON_NEG) \
+    X(log2, UNARY_T_FUN, double, NON_NEG) \
+    X(pow, NONC_FUN, double) \
+    X(sqrt, UNARY_T_FUN, double, NON_NEG) \
+    X(ceil, UNARY_FUN) \
+    X(floor, UNARY_FUN) \
+    X(round, UNARY_FUN) \
+    X(abs, CALL, fabs, UNARY_FUN) \
+    X(max, CALL, fmax, COMM_FUN) \
+    X(min, CALL, fmin, COMM_FUN) \
+    X(pi, CALL, M_PI, VALUE)
+    
+
+#define TOKENS \
+    COMMANDS \
+    OPERATORS \
+    MATH_H_BINDINGS
+
+/* --------- COMMAND DEFINITIONS */ 
+
+#define print() printf(PEEK_PRINT_F, peek())
+#define dup() push(peek())
+#define swap() \
+    do { double fst, snd; snd = pop(), fst = pop(); push(snd), push(fst); } while (0)
 
 
 #define MAXTOKEN 100
@@ -40,20 +122,28 @@ int main()
     char token[MAXTOKEN + 1];
     double op2;
     int t_len;
-
+    
+    printf(PROMPT_F);
     while (t_len = gettoken(token, MAXTOKEN)) {
-        if (t_len < 0) 
-            printf("\t%g\n",  pop());
-        else
+        if (t_len < 0) { /* newline token */
+            if (stack_len())
+                printf(POP_PRINT_F,  pop());
+            else
+                printf(EMPTY_F);
+            printf(PROMPT_F);
+        } else
     #define X(F, APPLY, ...) \
         if (!strcmp(#F, token)) \
             APPLY(F, ##__VA_ARGS__); \
         else
-        FUNCTIONS
+        TOKENS
     #undef X
         push(atof(token));
     }
-    printf("%g\n", pop());
+    if (!stack_len())
+        putchar('\n');
+    while (stack_len())
+        printf(POP_PRINT_F, pop());
 
     return 0;
 }
@@ -98,14 +188,14 @@ int stack_len()
     return sp;
 }
 
+
 /* push: push f onto value stack */
 void push(double f)
 {
     if (sp < MAXVAL)
         val[sp++] = f;
     else
-        printf("error: stack full, can't push %g\n", f);
-
+        printerr(FULL_STACK_ERR, f);
 }
 
 /* pop: pop and return top value from stack */
@@ -113,8 +203,20 @@ double pop(void)
 {
     if (sp)
         return val[--sp];
-    printf("error: stack empty\n");
+    printerr(EMPTY_STACK_ERR);
+    return 0;
+}
+
+/* peek: return top value from stack, leave stack unchanged */
+double peek(void)
+{
+    if (sp)
+        return val[sp-1];
+    printerr(EMPTY_STACK_ERR);
     return 0.0;
 }
 
-
+void clear(void)
+{
+    sp = 0;
+}