用于拆分分隔字符串的 ESQL 字符串拆分器函数

Question

ESQL 没有像 Java 这样的内置字符串拆分功能，虽然它很容易构建静态函数并将 *.jar 添加到 IIB 类路径中，但我工作过的几个网站都全面禁止使用 Java。

那么，ESQL 中高效的字符串拆分器是什么样的。

Answer 1

主题的以下四个变体可用于拆分 ESQL 字符串。

我选择了使用函数名称而不是标志的选项，而不是添加大量参数并以相当复杂的内部逻辑结束。

拆分字符串

不添加空字符串，但会添加多个空格的字符串。

CREATE PROCEDURE SplitString(
    IN CompositeString CHAR,         -- Composite string that needs to be split
    IN Delimiter CHAR,               -- Delimiter to be used when splitting the string
    IN ArrayName CHAR,               -- Name of the array for the results of the function
    IN NewArray BOOLEAN,             -- Use TRUE to clear a pre-existing array, FALSE appends new element
    IN EnvRef REFERENCE              -- Reference to Environment tree
)
BEGIN        
    IF NewArray THEN
        DELETE FIELD EnvRef.SplitterArrays.{ArrayName};
    END IF;

    DECLARE Element CHAR;
    DECLARE Remainder CHAR CompositeString;

    DECLARE SplitterArrayRef REFERENCE TO EnvRef.SplitterArrays.{ArrayName};
    IF NOT LASTMOVE(SplitterArrayRef) THEN
        CREATE LASTCHILD OF EnvRef.SplitterArrays AS SplitterArrayRef NAME ArrayName;
    END IF;

    WHILE LENGTH(Remainder) <> 0 DO
        IF POSITION(Delimiter IN Remainder) > 0 THEN
            DECLARE Element CHAR SUBSTRING(Remainder BEFORE Delimiter);
            IF LENGTH(Element) > 0 THEN
                CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE Element;
            END IF;

            SET Remainder = SUBSTRING(Remainder AFTER Delimiter);
        ELSE
            DECLARE Element CHAR Remainder;
            IF LENGTH(Element) > 0 THEN
                CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE Element;
            END IF;

            SET Remainder = '';
        END IF;
    END WHILE;
END;

SplitStringTrim

修剪元素字符串中的前导和尾随空格。
不添加空字符串。

CREATE PROCEDURE SplitStringTrim(
    IN CompositeString CHAR,         -- Composite string that needs to be split
    IN Delimiter CHAR,               -- Delimiter to be used when splitting the string
    IN ArrayName CHAR,               -- Name of the array for the results of the function
    IN NewArray BOOLEAN,             -- Use TRUE to clear a pre-existing array, FALSE appends new element
    IN EnvRef REFERENCE              -- Reference to Environment tree
)
BEGIN        
    IF NewArray THEN
        DELETE FIELD EnvRef.SplitterArrays.{ArrayName};
    END IF;

    DECLARE Element CHAR;
    DECLARE Remainder CHAR TRIM(CompositeString);

    DECLARE SplitterArrayRef REFERENCE TO EnvRef.SplitterArrays.{ArrayName};
    IF NOT LASTMOVE(SplitterArrayRef) THEN
        CREATE LASTCHILD OF EnvRef.SplitterArrays AS SplitterArrayRef NAME ArrayName;
    END IF;

    WHILE LENGTH(Remainder) <> 0 DO
        IF POSITION(Delimiter IN Remainder) > 0 THEN
            DECLARE Element CHAR TRIM(SUBSTRING(Remainder BEFORE Delimiter));
            IF LENGTH(Element) > 0 THEN
                CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE Element;
            END IF;

            SET Remainder = SUBSTRING(Remainder AFTER Delimiter;
        ELSE
            DECLARE Element CHAR TRIM(Remainder);
            IF LENGTH(Element) > 0 THEN
                CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE Element;
            END IF;

            SET Remainder = '';
        END IF;
    END WHILE;
END;

SplitStringAddEmpty

向 SplitterArray 添加空元素，确保至少有一个元素。
保留空白。

CREATE PROCEDURE SplitStringAddEmpty(
    IN CompositeString CHAR,         -- Composite string that needs to be split
    IN Delimiter CHAR,               -- Delimiter to be used when splitting the string
    IN ArrayName CHAR,               -- Name of the array for the results of the function
    IN NewArray BOOLEAN,             -- Use TRUE to clear a pre-existing array, FALSE appends new element
    IN EnvRef REFERENCE              -- Reference to Environment tree
)
BEGIN        
    IF NewArray THEN
        DELETE FIELD EnvRef.SplitterArrays.{ArrayName};
    END IF;

    DECLARE Element CHAR;
    DECLARE Remainder CHAR CompositeString;
    DECLARE EndsWithDelimiter BOOLEAN ENDSWITH(Remainder, Delimiter);

    DECLARE SplitterArrayRef REFERENCE TO EnvRef.SplitterArrays.{ArrayName};
    IF NOT LASTMOVE(SplitterArrayRef) THEN
        CREATE LASTCHILD OF EnvRef.SplitterArrays AS SplitterArrayRef NAME ArrayName;
    END IF;

    IF LENGTH(Remainder) = 0 THEN
        CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE '';
    ELSE
        WHILE LENGTH(Remainder) <> 0 DO
            IF POSITION(Delimiter IN Remainder) > 0 THEN
                CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE SUBSTRING(Remainder BEFORE Delimiter);

                SET Remainder = SUBSTRING(Remainder AFTER Delimiter);
            ELSE
                CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE Remainder;

                SET Remainder = '';
            END IF;
        END WHILE;

        IF EndsWithDelimiter THEN
            CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE '';
        END IF;
    END IF;
END;

SplitStringAddEmptyTrim

向 SplitterArray 添加空元素，确保至少有一个元素。
修剪元素字符串的前导和尾随空格。

CREATE PROCEDURE SplitStringAddEmptyTrim(
    IN CompositeString CHAR,         -- Composite string that needs to be split
    IN Delimiter CHAR,               -- Delimiter to be used when splitting the string
    IN ArrayName CHAR,               -- Name of the array for the results of the function
    IN NewArray BOOLEAN,             -- Use TRUE to clear a pre-existing array, FALSE appends new element
    IN EnvRef REFERENCE              -- Reference to Environment tree
)
BEGIN        
    IF NewArray THEN
        DELETE FIELD EnvRef.SplitterArrays.{ArrayName};
    END IF;

    DECLARE Element CHAR;
    DECLARE Remainder CHAR TRIM(CompositeString);
    DECLARE EndsWithDelimiter BOOLEAN ENDSWITH(Remainder, Delimiter);

    DECLARE SplitterArrayRef REFERENCE TO EnvRef.SplitterArrays.{ArrayName};
    IF NOT LASTMOVE(SplitterArrayRef) THEN
        CREATE LASTCHILD OF EnvRef.SplitterArrays AS SplitterArrayRef NAME ArrayName;
    END IF;

    IF LENGTH(Remainder) = 0 THEN
        CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE '';
    ELSE
        WHILE LENGTH(Remainder) <> 0 DO
            IF POSITION(Delimiter IN Remainder) > 0 THEN
                CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE TRIM(SUBSTRING(Remainder BEFORE Delimiter));

                SET Remainder = SUBSTRING(Remainder AFTER Delimiter);
            ELSE
                CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE TRIM(Remainder);

                SET Remainder = '';
            END IF;
        END WHILE;

        IF EndsWithDelimiter THEN
            CREATE LASTCHILD OF SplitterArrayRef NAME 'Element' VALUE '';
        END IF;
    END IF;
END;