[hackers] [sbase] Fixing validfmt and optimizing the algorithm. (Thanks David Galos) || Christoph Lohmann

From: <hg_AT_suckless.org>
Date: Wed, 18 Apr 2012 13:41:15 +0200 (CEST)

changeset: 107:a9f4ddff0da7
tag: tip
user: Christoph Lohmann <20h_AT_r-36.net>
date: Wed Apr 18 13:41:05 2012 +0200
files: seq.c
description:
Fixing validfmt and optimizing the algorithm. (Thanks David Galos)


diff -r 172527f61bd3 -r a9f4ddff0da7 seq.c
--- a/seq.c Mon Apr 16 21:48:50 2012 +0200
+++ b/seq.c Wed Apr 18 13:41:05 2012 +0200
_AT_@ -5,7 +5,6 @@
 #include <unistd.h>
 #include <stdbool.h>
 #include <libgen.h>
-#include <regex.h>
 
 #include "util.h"
 
_AT_@ -30,12 +29,12 @@
         char *exp;
         int shift;
 
- if (d[0] == '-' || d[0] == '+')
+ if (d[0] == '+')
                 d++;
         exp = strpbrk(d, "eE");
         shift = exp? atoi(exp+1) : 0;
 
- return MAX(0, strspn(d, "0123456789")+shift);
+ return MAX(0, strspn(d, "-0123456789")+shift);
 }
 
 int
_AT_@ -44,8 +43,6 @@
         char *exp;
         int shift, after;
 
- if (d[0] == '-' || d[0] == '+')
- d++;
         exp = strpbrk(d, "eE");
         shift = exp ? atoi(exp+1) : 0;
         after = (d = strchr(d, '.'))? strspn(d+1, "0123456789") : 0;
_AT_@ -56,15 +53,36 @@
 int
 validfmt(char *fmt)
 {
- regex_t reg;
- int ret;
+ int occur;
 
- regcomp(&reg, "\\([^%]|%%\\)*%[0-9]*\\.[0-9]*[fFgG]"
- "\\([^%]|%%\\)*", REG_NOSUB);
- ret = regexec(&reg, fmt, 0, NULL, 0);
- regfree(&reg);
+ occur = 0;
 
- return (ret == 0);
+NonFormat:
+ while(*fmt) {
+ if (*fmt++ == '%')
+ goto Format;
+ }
+ return (occur == 1);
+Format:
+ if (*fmt == '%') {
+ fmt++;
+ goto NonFormat;
+ }
+ fmt += strspn(fmt, "-+#0 '");
+ fmt += strspn(fmt, "0123456789");
+ if (*fmt == '.') {
+ fmt ++;
+ fmt += strspn(fmt, "0123456789");
+ }
+ if (*fmt == 'L')
+ fmt++;
+ if (*fmt == '\0')
+ return 0;
+ if (strchr("fFgGeEaA", *fmt)) {
+ occur++;
+ goto NonFormat;
+ }
+ return 0;
 }
 
 int
_AT_@ -72,7 +90,7 @@
 {
         char c, *fmt, ftmp[4096], *sep, *starts, *steps, *ends;
         bool wflag, fflag;
- double start, step, end, out;
+ double start, step, end, out, dir;
         int left, right;
 
         sep = "\n";
_AT_@ -134,17 +152,12 @@
         start = atof(starts);
         step = atof(steps);
         end = atof(ends);
+ dir = (step > 0)? 1.0 : -1.0;
 
         if (step == 0)
                 return EXIT_FAILURE;
-
- if (start > end) {
- if (step > 0)
- return EXIT_FAILURE;
- } else if (start < end) {
- if (step < 0)
- return EXIT_FAILURE;
- }
+ if (start * dir > end * dir)
+ return EXIT_FAILURE;
 
         right = MAX(digitsright(starts),
                         MAX(digitsright(ends),
_AT_@ -163,18 +176,8 @@
                 printf(fmt, out);
 
                 out += step;
- if (start > end) {
- if (out >= end) {
- printf("%s", sep);
- } else {
- break;
- }
- } else if (start < end) {
- if (out <= end) {
- printf("%s", sep);
- } else {
- break;
- }
+ if (out * dir <= end * dir) {
+ printf("%s", sep);
                 } else {
                         break;
                 }
Received on Wed Apr 18 2012 - 13:41:15 CEST