Operator Reference
tuple_strstr (Operator)
tuple_strstr
— Forward search for strings within a string tuple.
Signature
Description
tuple_strstr
searches within the strings of the input tuple
String
for the strings of the input tuple ToFind
. Both
input tuples may only consist of strings. Otherwise tuple_strstr
returns an error. If String
contains only one string, all strings of
ToFind
are searched in it. Thus, the output tuple consists of as many
elements as ToFind
. Whenever a searched string has been found, the
position of its first occurrence gets stored in the output tuple
Position
(positions in strings are counted starting with 0). If a
string can not be found, -1 will be returned instead of its position. If both
input tuples show the same number of elements, the strings are searched
elementwise. I.e., the first string of ToFind
is searched within
the first string of String
, the second string of ToFind
is
searched within the second string of String
and so on. The results
of the elementwise searches are returned with Position
that contains
as many elements as String
and ToFind
. If ToFind
only contains one string, this is searched within all strings of
String
. Thus, in this case Position
consists of as many
elements as String
. If both input tuples contain more than one
element and the number of elements differs for the input tuples,
tuple_strstr
returns an error.
If either or both of the input tuples are empty, the operator returns an empty tuple.
Unicode code points versus bytes
The position references Unicode code points. One Unicode code point may be
composed of multiple bytes in the UTF-8 string. If the position should
reference the raw bytes of the string, this operator can be switched to byte
mode with set_system('tsp_tuple_string_operator_mode','byte')
. If
'filename_encoding' is set to 'locale' (legacy), this
operator always uses the byte mode.
For general information about string operations see Tuple / String Operations.
HDevelop In-line Operation
HDevelop provides an in-line operation for tuple_strstr
,
which can be used in an expression in the following syntax:
Position := strstr(String, ToFind)
Execution Information
- Multithreading type: independent (runs in parallel even with exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Processed without parallelization.
Parameters
String
(input_control) string(-array) →
(string)
Input tuple with string(s) to examine.
ToFind
(input_control) string(-array) →
(string)
Input tuple with string(s) to search.
Position
(output_control) integer(-array) →
(integer)
Position of searched string(s) within the examined string(s).
Alternatives
tuple_strrstr
,
tuple_strlen
,
tuple_strchr
,
tuple_strrchr
,
tuple_substr
,
tuple_str_first_n
,
tuple_str_last_n
,
tuple_split
,
tuple_environment
Module
Foundation