diff options
Diffstat (limited to 'main.c')
| -rw-r--r-- | main.c | 100 |
1 files changed, 45 insertions, 55 deletions
diff --git a/main.c b/main.c index 2b79001..09fc6ab 100644 --- a/main.c +++ b/main.c @@ -1,12 +1,13 @@ -#include <math.h> -#include <stdio.h> +#include "cmds.h" #include "state.h" #include "util.h" -#include <stdlib.h> -#include <string.h> -#include "cmds.h" +#include <ctype.h> #include <err.h> #include <errno.h> +#include <math.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> #define BUF_SIZE 50 @@ -27,76 +28,65 @@ int main() { s.command_count = 0; init_state(&s); + fprintf(s.defout, "welcome to rpncalc! type 'list' to see a list of " + "commands, or 'quit' to leave.\n"); - fprintf(s.defout,"welcome to rpncalc! type 'list' to see a list of commands, or 'quit' to leave.\n"); - - /* start reading from defbuf */ char buf[BUF_SIZE]; - while(1){ + while (1) { + int execval = 0; + /* prompt the user for input */ fprintf(s.defout, s.prompt, s.command_count, s.last_op); s.last_op = 0; char *endptr = NULL; + /* get input */ char *check = fgets(buf, BUF_SIZE, s.defbuf); - if (check == NULL) exit(0); + if (check == NULL) + exit(0); + /* strip newline */ buf[strcspn(buf, "\n")] = 0; + /* parse input as a number */ double interpreted = strtod(buf, &endptr); if (errno == ERANGE) { - fprintf(s.defout,"sorry, this number is too big\n"); + fprintf(s.defout, "sorry, this number is too big\n"); continue; } - if (interpreted == (double)0 && endptr == buf) { /* strtod returned the char it could not read */ - TYPE t = discriminate(buf); - if (t == OPERATOR ) { - if (s.stk.count <= 1) { - fprintf(s.defout, "not enough arguments\n"); - continue; - } - char operator = buf[0]; - if (operator == '+') { - s.stk.val[s.stk.count-2] = s.stk.val[s.stk.count-1]+s.stk.val[s.stk.count-2]; - s.stk.val[s.stk.count--] = 0; /* lower count by 1 */ - s.last_op = '+'; - } else if (operator == '-') { - s.stk.val[s.stk.count-2] = s.stk.val[s.stk.count-2]-s.stk.val[s.stk.count-1]; - s.stk.val[s.stk.count--] = 0; /* lower count by 1 */ - s.last_op = '-'; - } else if (operator == '*') { - s.stk.val[s.stk.count-2] = s.stk.val[s.stk.count-2]*s.stk.val[s.stk.count-1]; - s.stk.val[s.stk.count--] = 0; /* lower count by 1 */ - s.last_op = '*'; - } else if (operator == '/') { - s.stk.val[s.stk.count-2] = s.stk.val[s.stk.count-2]/s.stk.val[s.stk.count-1]; - s.stk.val[s.stk.count--] = 0; /* lower count by 1 */ - s.last_op = '/'; - } else if (operator == '^') { - s.stk.val[s.stk.count-2] = pow(s.stk.val[s.stk.count-2],s.stk.val[s.stk.count-1]); - s.stk.val[s.stk.count--] = 0; /* lower count by 1 */ - s.last_op = '^'; - } else; - } else if (t == FUNCTION) { - /* check for special commands, else pass to exec() */ - if (strcmp(buf, "quit") == 0) { - fprintf(s.defout, "quitting, bye!\n"); - exit(0); - } else if (strcmp(buf, "list") == 0) { - for (int i = 0; i < s.numel; i++) { - fprintf(s.defout, "[%s]\t->\t%s\n", s.sorted[i].name, s.sorted[i].description); - } - continue; - } else exec(buf, &s); + /* special functions, quit and list, that do not interact with the stack directly */ + if (strcmp(buf, "quit") == 0) { + fprintf(s.defout, "quitting, bye!\n"); + exit(0); + } else if (strcmp(buf, "list") == 0) { + for (int i = 0; i < s.numel; i++) { + fprintf(s.defout, "[%s]\t->\t%s\n", s.sorted[i].name, + s.sorted[i].description); + } + continue; + } else if ((execval = exec(buf, &s)) == -1 || execval > 0) { /* try to execute a known function. + if we fail, we either catch an + incorrect number of arguments + error, or we pass it to the next + else clause.*/ + if (execval > 0) { + fprintf(s.defout, "this function requires %d arguments\n", execval); + continue; } } else { /* we found a number */ - if (s.stk.count == STACK_SIZE - 1) { - fprintf(s.defout, "exceeded stack size %d\n", STACK_SIZE); + /* test if provided input could not be parsed by strtod, in this case we are not against + a number, so error out */ + if (endptr == buf) { + fprintf(s.defout, "function %s not found\n", buf); continue; } + if (s.stk.count == STACK_SIZE - 1) { + fprintf(s.defout, "exceeded stack size %d\n", STACK_SIZE); + continue; + } s.stk.val[s.stk.count++] = interpreted; } - + /* add one to the command count, and print the updated stack */ s.command_count++; for (int i = 0; i < s.stk.count; i++) { - fprintf(s.defout,"%d → %f\n",i, s.stk.val[i]); + fprintf(s.defout, "%d → %f\n", i, s.stk.val[i]); } } } |