tuple_str_first_ntuple_str_first_nTupleStrFirstNTupleStrFirstNtuple_str_first_n (算子)

名称

tuple_str_first_ntuple_str_first_nTupleStrFirstNTupleStrFirstNtuple_str_first_n — 将第一个字符剪切到字符串元组中的 “n” 位置。

签名

描述

tuple_str_first_ntuple_str_first_nTupleStrFirstNTupleStrFirstNTupleStrFirstNtuple_str_first_n cuts the first characters up to position “n” out of each string of the input tuple StringStringStringStringstringValstring and returns them as new strings in the output tuple SubstringSubstringSubstringSubstringsubstringsubstring (remark: the position within strings starts with 0 for the first character of a string). The number “n” is determined by the second input tuple PositionPositionPositionPositionpositionposition. If PositionPositionPositionPositionpositionposition only contains one element, this element contains the number “n”. If StringStringStringStringstringValstring and PositionPositionPositionPositionpositionposition have got the same number of elements, the first element of PositionPositionPositionPositionpositionposition determines the position “n” for the first string of StringStringStringStringstringValstring, the second element of PositionPositionPositionPositionpositionposition does so for the second string of StringStringStringStringstringValstring and so on. If PositionPositionPositionPositionpositionposition contains more than one element and StringStringStringStringstringValstring contains only one string, tuple_str_first_ntuple_str_first_nTupleStrFirstNTupleStrFirstNTupleStrFirstNtuple_str_first_n cuts more than one substrings out of this string. The elements of PositionPositionPositionPositionpositionposition then determine the lengths of these substrings. If both input tuples contain more than one element but differ in the number of elements, tuple_str_first_ntuple_str_first_nTupleStrFirstNTupleStrFirstNTupleStrFirstNtuple_str_first_n returns an error.

If both input tuples are empty, the operator returns an empty tuple. Similarly, if StringStringStringStringstringValstring is empty and PositionPositionPositionPositionpositionposition is not, the operator returns an empty tuple. In contrast, if PositionPositionPositionPositionpositionposition is empty and StringStringStringStringstringValstring is not, an exception is raised.

Unicode 码点与字节

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')set_system("tsp_tuple_string_operator_mode","byte")SetSystem("tsp_tuple_string_operator_mode","byte")SetSystem("tsp_tuple_string_operator_mode","byte")SetSystem("tsp_tuple_string_operator_mode","byte")set_system("tsp_tuple_string_operator_mode","byte")。If 'filename_encoding'"filename_encoding""filename_encoding""filename_encoding""filename_encoding""filename_encoding" is set to 'locale'"locale""locale""locale""locale""locale" (legacy), this operator always uses the byte mode.

For general information about string operations see Tuple / String Operations。

HDevelop 内联操作

HDevelop provides an in-line operation for tuple_str_first_ntuple_str_first_nTupleStrFirstNTupleStrFirstNTupleStrFirstNtuple_str_first_n, which can be used in an expression in the following syntax:

Substring := str_firstn(String, Position)

执行信息

• 多线程类型：独立（即使使用独占算子也能并行运行）。
• 多线程作用域：全局（可从任何线程调用）。
• 未采用并行化处理。

参数

替代

tuple_str_last_ntuple_str_last_nTupleStrLastNTupleStrLastNTupleStrLastNtuple_str_last_n, tuple_substrtuple_substrTupleSubstrTupleSubstrTupleSubstrtuple_substr, tuple_strstrtuple_strstrTupleStrstrTupleStrstrTupleStrstrtuple_strstr, tuple_strrstrtuple_strrstrTupleStrrstrTupleStrrstrTupleStrrstrtuple_strrstr, tuple_strlentuple_strlenTupleStrlenTupleStrlenTupleStrlentuple_strlen, tuple_strchrtuple_strchrTupleStrchrTupleStrchrTupleStrchrtuple_strchr, tuple_strrchrtuple_strrchrTupleStrrchrTupleStrrchrTupleStrrchrtuple_strrchr, tuple_splittuple_splitTupleSplitTupleSplitTupleSplittuple_split, tuple_environmenttuple_environmentTupleEnvironmentTupleEnvironmentTupleEnvironmenttuple_environment

模块

基础