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Add string/has-prefix? and string/has-suffix?.

This commit is contained in:
Andrew Chambers 2019-05-03 19:51:56 +12:00 committed by Calvin Rose
parent 5694998382
commit c70d59edee
2 changed files with 38 additions and 0 deletions

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@ -274,6 +274,28 @@ static Janet cfun_string_find(int32_t argc, Janet *argv) {
: janet_wrap_integer(result);
}
static Janet cfun_string_hasprefix(int32_t argc, Janet *argv) {
janet_fixarity(argc, 2);
const uint8_t *prefix = janet_getstring(argv, 0);
const uint8_t *s = janet_getstring(argv, 1);
int32_t prefix_len = janet_string_length(prefix);
int32_t s_len = janet_string_length(s);
return s_len < prefix_len
? janet_wrap_false()
: janet_wrap_boolean(memcmp(prefix, s, prefix_len) == 0);
}
static Janet cfun_string_hassuffix(int32_t argc, Janet *argv) {
janet_fixarity(argc, 2);
const uint8_t *suffix = janet_getstring(argv, 0);
const uint8_t *s = janet_getstring(argv, 1);
int32_t suffix_len = janet_string_length(suffix);
int32_t s_len = janet_string_length(s);
return s_len < suffix_len
? janet_wrap_false()
: janet_wrap_boolean(memcmp(suffix, s+s_len-suffix_len, suffix_len) == 0);
}
static Janet cfun_string_findall(int32_t argc, Janet *argv) {
int32_t result;
struct kmp_state state;
@ -507,6 +529,16 @@ static const JanetReg string_cfuns[] = {
"will only contribute to finding at most on occurrence of pattern. If no "
"occurrences are found, will return an empty array.")
},
{
"string/has-prefix?", cfun_string_hasprefix,
JDOC("(string/has-prefix? pfx str)\n\n"
"Tests whether str starts with pfx.")
},
{
"string/has-suffix?", cfun_string_hassuffix,
JDOC("(string/has-suffix? sfx str)\n\n"
"Tests whether str ends with sfx.")
},
{
"string/replace", cfun_string_replace,
JDOC("(string/replace patt subst str)\n\n"

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@ -64,6 +64,12 @@
(assert (= 3 (string/find "abc" " abcdefghijklmnop")) "string/find 1")
(assert (= nil (string/find "" "")) "string/find 2")
(assert (= 0 (string/find "A" "A")) "string/find 3")
(assert (string/has-prefix? "" "foo") "string/has-prefix? 1")
(assert (string/has-prefix? "fo" "foo") "string/has-prefix? 2")
(assert (not (string/has-prefix? "o" "foo")) "string/has-prefix? 3")
(assert (string/has-suffix? "" "foo") "string/has-suffix? 1")
(assert (string/has-suffix? "oo" "foo") "string/has-suffix? 2")
(assert (not (string/has-suffix? "f" "foo")) "string/has-suffix? 3")
(assert (= (string/replace "X" "." "XXX...XXX...XXX") ".XX...XXX...XXX") "string/replace 1")
(assert (= (string/replace-all "X" "." "XXX...XXX...XXX") "...............") "string/replace-all 1")
(assert (= (string/replace-all "XX" "." "XXX...XXX...XXX") ".X....X....X") "string/replace-all 2")