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Code Issues 1 Releases Wiki Activity

Add string/triml, string/trimr, and string/trim.

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This commit is contained in:
Calvin Rose
2019-05-10 16:09:49 -04:00
parent 3388acd2db
commit 232ea22dc5
3 changed files with 83 additions and 1 deletions
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72
src/core/string.c
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@@ -467,6 +467,60 @@ static Janet cfun_string_format(int32_t argc, Janet *argv) {
return janet_stringv(buffer->data, buffer->count);
}
static int trim_help_checkset(JanetByteView set, uint8_t x) {
for (int32_t j = 0; j < set.len; j++)
if (set.bytes[j] == x)
return 1;
return 0;
}
static int32_t trim_help_leftedge(JanetByteView str, JanetByteView set) {
for (int32_t i = 0; i < str.len; i++)
if (!trim_help_checkset(set, str.bytes[i]))
return i;
return str.len;
}
static int32_t trim_help_rightedge(JanetByteView str, JanetByteView set) {
for (int32_t i = str.len - 1; i >= 0; i--)
if (!trim_help_checkset(set, str.bytes[i]))
return i + 1;
return 0;
}
static void trim_help_args(int32_t argc, Janet *argv, JanetByteView *str, JanetByteView *set) {
janet_arity(argc, 1, 2);
*str = janet_getbytes(argv, 0);
if (argc >= 2) {
*set = janet_getbytes(argv, 1);
} else {
set->bytes = (const uint8_t *)(" \t\r\n\v\f");
set->len = 6;
}
}
static Janet cfun_string_trim(int32_t argc, Janet *argv) {
JanetByteView str, set;
trim_help_args(argc, argv, &str, &set);
int32_t left_edge = trim_help_leftedge(str, set);
int32_t right_edge = trim_help_rightedge(str, set);
return janet_stringv(str.bytes + left_edge, right_edge - left_edge);
}
static Janet cfun_string_triml(int32_t argc, Janet *argv) {
JanetByteView str, set;
trim_help_args(argc, argv, &str, &set);
int32_t left_edge = trim_help_leftedge(str, set);
return janet_stringv(str.bytes + left_edge, str.len - left_edge);
}
static Janet cfun_string_trimr(int32_t argc, Janet *argv) {
JanetByteView str, set;
trim_help_args(argc, argv, &str, &set);
int32_t right_edge = trim_help_rightedge(str, set);
return janet_stringv(str.bytes, right_edge);
}
static const JanetReg string_cfuns[] = {
{
"string/slice", cfun_string_slice,
@@ -574,6 +628,24 @@ static const JanetReg string_cfuns[] = {
"Similar to snprintf, but specialized for operating with janet. Returns "
"a new string.")
},
{
"string/trim", cfun_string_trim,
JDOC("(string/trim str [,set])\n\n"
"Trim leading and trailing whitespace from a byte sequence. If the argument "
"set is provided, consider only characters in set to be whitespace.")
},
{
"string/triml", cfun_string_triml,
JDOC("(string/triml str [,set])\n\n"
"Trim leading whitespace from a byte sequence. If the argument "
"set is provided, consider only characters in set to be whitespace.")
},
{
"string/trimr", cfun_string_trimr,
JDOC("(string/trimr str [,set])\n\n"
"Trim trailing whitespace from a byte sequence. If the argument "
"set is provided, consider only characters in set to be whitespace.")
},
{NULL, NULL, NULL}
};