mirror of https://github.com/janet-lang/janet
Added string/format function (snprintf like)
This commit is contained in:
J.-F. Cap
parent
ec02d55145
commit
a6f022a73d
|
|
@ -21,6 +21,7 @@
|
|||
*/
|
||||
|
||||
#include <string.h>
|
||||
#include <ctype.h>
|
||||
|
||||
#ifndef JANET_AMALG
|
||||
#include <janet/janet.h>
|
||||
|
|
@ -501,6 +502,148 @@ static Janet cfun_string_pretty(int32_t argc, Janet *argv) {
|
|||
return janet_wrap_buffer(buffer);
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* code adapted from lua/lstrlib.c http://lua.org
|
||||
*/
|
||||
|
||||
#define MAX_ITEM 256
|
||||
#define FMT_FLAGS "-+ #0"
|
||||
#define MAX_FORMAT 32
|
||||
|
||||
static const char *scanformat(const char *strfrmt, char *form,char width[3], char precision[3]) {
|
||||
const char *p = strfrmt;
|
||||
memset(width, '\0', 3);
|
||||
memset(precision, '\0', 3);
|
||||
while (*p != '\0' && strchr(FMT_FLAGS, *p) != NULL)
|
||||
p++; /* skip flags */
|
||||
if ((size_t) (p - strfrmt) >= sizeof(FMT_FLAGS) / sizeof(char))
|
||||
janet_panic("invalid format (repeated flags)");
|
||||
if (isdigit((int) (*p)))
|
||||
width[0] = *p++; /* skip width */
|
||||
if (isdigit((int) (*p)))
|
||||
width[1] = *p++; /* (2 digits at most) */
|
||||
if (*p == '.') {
|
||||
p++;
|
||||
if (isdigit((int) (*p)))
|
||||
precision[0] = *p++; /* skip precision */
|
||||
if (isdigit((int) (*p)))
|
||||
precision[1] = *p++; /* (2 digits at most) */
|
||||
}
|
||||
if (isdigit((int) (*p)))
|
||||
janet_panic("invalid format (width or precision too long)");
|
||||
*(form++) = '%';
|
||||
memcpy(form, strfrmt, ((p - strfrmt) + 1) * sizeof(char));
|
||||
form += (p - strfrmt) + 1;
|
||||
*form = '\0';
|
||||
return p;
|
||||
}
|
||||
|
||||
static Janet cfun_string_format(int32_t argc, Janet * argv) {
|
||||
janet_arity(argc, 2, -1);
|
||||
JanetBuffer *b = janet_getbuffer(argv, 0);
|
||||
const char *strfrmt = (const char *) janet_getstring(argv, 1);
|
||||
size_t sfl = strlen(strfrmt);
|
||||
const char *strfrmt_end = strfrmt + sfl;
|
||||
int32_t arg = 1;
|
||||
while (strfrmt < strfrmt_end) {
|
||||
if (*strfrmt != '%')
|
||||
janet_buffer_push_u8(b, (uint8_t) * strfrmt++);
|
||||
else if (*++strfrmt == '%')
|
||||
janet_buffer_push_u8(b, (uint8_t) * strfrmt++); /* %% */
|
||||
else { /* format item */
|
||||
char form[MAX_FORMAT],item[MAX_ITEM];
|
||||
char width[3], precision[3];
|
||||
int nb = 0; /* number of bytes in added item */
|
||||
if (++arg >= argc)
|
||||
janet_panic("no enough value for format");
|
||||
strfrmt = scanformat(strfrmt, form, width, precision);
|
||||
switch (*strfrmt++) {
|
||||
case 'c':
|
||||
{
|
||||
nb = snprintf(item, MAX_ITEM, form, (int)
|
||||
janet_getinteger(argv, arg));
|
||||
break;
|
||||
}
|
||||
case 'd':
|
||||
case 'i':
|
||||
case 'o':
|
||||
case 'u':
|
||||
case 'x':
|
||||
case 'X':
|
||||
{
|
||||
int32_t n = janet_getinteger(argv, arg);
|
||||
nb = snprintf(item, MAX_ITEM, form, n);
|
||||
break;
|
||||
}
|
||||
case 'a':
|
||||
case 'A':
|
||||
case 'e':
|
||||
case 'E':
|
||||
case 'f':
|
||||
case 'g':
|
||||
case 'G':
|
||||
{
|
||||
double d = janet_getnumber(argv, arg);
|
||||
nb = snprintf(item, MAX_ITEM, form, d);
|
||||
break;
|
||||
}
|
||||
case 's':
|
||||
{
|
||||
const uint8_t *s = janet_getstring(argv, arg);
|
||||
size_t l = janet_string_length(s);
|
||||
if (form[2] == '\0')
|
||||
janet_buffer_push_bytes(b, s, l);
|
||||
else {
|
||||
if (l != strlen((const char *) s))
|
||||
janet_panic("string contains zeros");
|
||||
if (!strchr(form, '.') && l >= 100) {
|
||||
janet_panic
|
||||
("no precision and string is too long to be formatted");
|
||||
} else {
|
||||
nb = snprintf(item, MAX_ITEM, form, s);
|
||||
}
|
||||
}
|
||||
break;
|
||||
}
|
||||
case 'V':
|
||||
{
|
||||
janet_to_string_b(b, argv[arg]);
|
||||
break;
|
||||
}
|
||||
case 'v':
|
||||
{
|
||||
janet_description_b(b, argv[arg]);
|
||||
break;
|
||||
}
|
||||
case 'p': /* janet pretty , precision = depth */
|
||||
{
|
||||
int depth = atoi(precision);
|
||||
if (depth < 1)
|
||||
depth = 4;
|
||||
janet_pretty(b, depth, argv[arg]);
|
||||
break;
|
||||
}
|
||||
default:
|
||||
{ /* also treat cases 'nLlh' */
|
||||
janet_panicf("invalid conversion '%s' to 'format'",
|
||||
form);
|
||||
}
|
||||
}
|
||||
if (nb >= MAX_ITEM)
|
||||
janet_panicf("format buffer overflow", form);
|
||||
if (nb > 0)
|
||||
janet_buffer_push_bytes(b, (uint8_t *) item, nb);
|
||||
}
|
||||
}
|
||||
return janet_wrap_buffer(b);
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
static const JanetReg string_cfuns[] = {
|
||||
{
|
||||
"string/slice", cfun_string_slice,
|
||||
|
|
@ -614,6 +757,11 @@ static const JanetReg string_cfuns[] = {
|
|||
"Pretty prints a value to a buffer. Optionally allows setting max "
|
||||
"recursion depth, as well as writing to a buffer. Returns the buffer.")
|
||||
},
|
||||
{ "string/format", cfun_string_format,
|
||||
JDOC("(string/format buffer format & values)\n\n"
|
||||
"Similar to snprintf, but specialized for operating with janet"
|
||||
"...")
|
||||
},
|
||||
{NULL, NULL, NULL}
|
||||
};
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue