diff options
Diffstat (limited to 'math.c')
| -rw-r--r-- | math.c | 106 |
1 files changed, 47 insertions, 59 deletions
| @@ -1,3 +1,4 @@ | |||
| 1 | /* vi: set sw=4 ts=4: */ | ||
| 1 | #include "internal.h" | 2 | #include "internal.h" |
| 2 | #include <stdio.h> | 3 | #include <stdio.h> |
| 3 | #include <stdlib.h> | 4 | #include <stdlib.h> |
| @@ -8,126 +9,114 @@ | |||
| 8 | 9 | ||
| 9 | static const char math_usage[] = "math expression ..."; | 10 | static const char math_usage[] = "math expression ..."; |
| 10 | 11 | ||
| 11 | static double stack[100]; | 12 | static double stack[100]; |
| 12 | static unsigned int pointer; | 13 | static unsigned int pointer; |
| 13 | 14 | ||
| 14 | static void | 15 | static void push(double a) |
| 15 | push(double a) | ||
| 16 | { | 16 | { |
| 17 | if ( pointer >= (sizeof(stack) / sizeof(*stack)) ) { | 17 | if (pointer >= (sizeof(stack) / sizeof(*stack))) { |
| 18 | fprintf(stderr, "math: stack overflow\n"); | 18 | fprintf(stderr, "math: stack overflow\n"); |
| 19 | exit(-1); | 19 | exit(-1); |
| 20 | } | 20 | } else |
| 21 | else | ||
| 22 | stack[pointer++] = a; | 21 | stack[pointer++] = a; |
| 23 | } | 22 | } |
| 24 | 23 | ||
| 25 | static double | 24 | static double pop() |
| 26 | pop() | ||
| 27 | { | 25 | { |
| 28 | if ( pointer == 0 ) { | 26 | if (pointer == 0) { |
| 29 | fprintf(stderr, "math: stack underflow\n"); | 27 | fprintf(stderr, "math: stack underflow\n"); |
| 30 | exit(-1); | 28 | exit(-1); |
| 31 | } | 29 | } |
| 32 | return stack[--pointer]; | 30 | return stack[--pointer]; |
| 33 | } | 31 | } |
| 34 | 32 | ||
| 35 | static void | 33 | static void add() |
| 36 | add() | ||
| 37 | { | 34 | { |
| 38 | push(pop() + pop()); | 35 | push(pop() + pop()); |
| 39 | } | 36 | } |
| 40 | 37 | ||
| 41 | static void | 38 | static void sub() |
| 42 | sub() | ||
| 43 | { | 39 | { |
| 44 | double subtrahend = pop(); | 40 | double subtrahend = pop(); |
| 45 | 41 | ||
| 46 | push(pop() - subtrahend); | 42 | push(pop() - subtrahend); |
| 47 | } | 43 | } |
| 48 | 44 | ||
| 49 | static void | 45 | static void mul() |
| 50 | mul() | ||
| 51 | { | 46 | { |
| 52 | push(pop() * pop()); | 47 | push(pop() * pop()); |
| 53 | } | 48 | } |
| 54 | 49 | ||
| 55 | static void | 50 | static void divide() |
| 56 | divide() | ||
| 57 | { | 51 | { |
| 58 | double divisor = pop(); | 52 | double divisor = pop(); |
| 53 | |||
| 59 | push(pop() / divisor); | 54 | push(pop() / divisor); |
| 60 | } | 55 | } |
| 61 | 56 | ||
| 62 | static void | 57 | static void and() |
| 63 | and() | ||
| 64 | { | 58 | { |
| 65 | push((unsigned int)pop() & (unsigned int)pop()); | 59 | push((unsigned int) pop() & (unsigned int) pop()); |
| 66 | } | 60 | } |
| 67 | 61 | ||
| 68 | static void | 62 | static void or() |
| 69 | or() | ||
| 70 | { | 63 | { |
| 71 | push((unsigned int)pop() | (unsigned int)pop()); | 64 | push((unsigned int) pop() | (unsigned int) pop()); |
| 72 | } | 65 | } |
| 73 | 66 | ||
| 74 | static void | 67 | static void eor() |
| 75 | eor() | ||
| 76 | { | 68 | { |
| 77 | push((unsigned int)pop() ^ (unsigned int)pop()); | 69 | push((unsigned int) pop() ^ (unsigned int) pop()); |
| 78 | } | 70 | } |
| 79 | 71 | ||
| 80 | static void | 72 | static void not() |
| 81 | not() | ||
| 82 | { | 73 | { |
| 83 | push(~(unsigned int)pop()); | 74 | push(~(unsigned int) pop()); |
| 84 | } | 75 | } |
| 85 | 76 | ||
| 86 | static void | 77 | static void print() |
| 87 | print() | ||
| 88 | { | 78 | { |
| 89 | printf("%g\n", pop()); | 79 | printf("%g\n", pop()); |
| 90 | } | 80 | } |
| 91 | 81 | ||
| 92 | struct op { | 82 | struct op { |
| 93 | const char * name; | 83 | const char *name; |
| 94 | void (*function)(); | 84 | void (*function) (); |
| 95 | }; | 85 | }; |
| 96 | 86 | ||
| 97 | static const struct op operators[] = { | 87 | static const struct op operators[] = { |
| 98 | { "add", add }, | 88 | {"add", add}, |
| 99 | { "and", and }, | 89 | {"and", and}, |
| 100 | { "div", divide }, | 90 | {"div", divide}, |
| 101 | { "eor", eor }, | 91 | {"eor", eor}, |
| 102 | { "mul", mul }, | 92 | {"mul", mul}, |
| 103 | { "not", not }, | 93 | {"not", not}, |
| 104 | { "or", or }, | 94 | {"or", or}, |
| 105 | { "sub", sub }, | 95 | {"sub", sub}, |
| 106 | { 0, 0 } | 96 | {0, 0} |
| 107 | }; | 97 | }; |
| 108 | 98 | ||
| 109 | static void | 99 | static void stack_machine(const char *argument) |
| 110 | stack_machine(const char * argument) | ||
| 111 | { | 100 | { |
| 112 | char * endPointer = 0; | 101 | char *endPointer = 0; |
| 113 | double d; | 102 | double d; |
| 114 | const struct op * o = operators; | 103 | const struct op *o = operators; |
| 115 | 104 | ||
| 116 | if ( argument == 0 ) { | 105 | if (argument == 0) { |
| 117 | print(); | 106 | print(); |
| 118 | return; | 107 | return; |
| 119 | } | 108 | } |
| 120 | 109 | ||
| 121 | d = strtod(argument, &endPointer); | 110 | d = strtod(argument, &endPointer); |
| 122 | 111 | ||
| 123 | if ( endPointer != argument ) { | 112 | if (endPointer != argument) { |
| 124 | push(d); | 113 | push(d); |
| 125 | return; | 114 | return; |
| 126 | } | 115 | } |
| 127 | 116 | ||
| 128 | while ( o->name != 0 ) { | 117 | while (o->name != 0) { |
| 129 | if ( strcmp(o->name, argument) == 0 ) { | 118 | if (strcmp(o->name, argument) == 0) { |
| 130 | (*(o->function))(); | 119 | (*(o->function)) (); |
| 131 | return; | 120 | return; |
| 132 | } | 121 | } |
| 133 | o++; | 122 | o++; |
| @@ -136,10 +125,9 @@ stack_machine(const char * argument) | |||
| 136 | exit(-1); | 125 | exit(-1); |
| 137 | } | 126 | } |
| 138 | 127 | ||
| 139 | int | 128 | int math_main(int argc, char **argv) |
| 140 | math_main(int argc, char * * argv) | ||
| 141 | { | 129 | { |
| 142 | while ( argc >= 2 ) { | 130 | while (argc >= 2) { |
| 143 | stack_machine(argv[1]); | 131 | stack_machine(argv[1]); |
| 144 | argv++; | 132 | argv++; |
| 145 | argc--; | 133 | argc--; |