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Functions and Expressions
Use HCL Link functions and expressions to create component rules and map rules.
Text functions
These functions are used to convert the text item in a map rule.
LEFT
The LEFT function returns a specified number of characters from a text expression beginning with the leftmost byte of a text item.

Functions and Expressions
Use HCL Link functions and expressions to create component rules and map rules.
- Expressions and evaluations
  The documentation provided here describes HCL Link functions and expressions. Functions and expressions are used to create component rules and map rules.
- Using functions
  A function is an expression that generates an output by performing a certain operation on one or more inputs.
- Syntax of a function
  The following is an example of a function:
- Function argument syntax
  Arguments typically have some restrictions on the expression used for that argument.
- Character-set encoding functions
  Functions that use the HCL Link EXIT architecture convert data to the native character set of the platform as part of the function call.
- General functions
  There are several general functions you can call from map rule to process input.
- Bidirectional functions
  Bidirectional languages such as Arabic and Hebrew are languages in which the text is presented to the user ordered from right to left, but numbers and Latin alphabetic strings within the text are presented left to right.
- Bit manipulation and testing functions
  You can use this function to manipulate and to test a bit in a binary number.
- Cache functions
  Use cache functions to specify a value for each of the cache variables defined for a flow, and additionally, to alter an already specified value for a cache variable.
- Conversion functions
  You can use this function to convert an expression from one datatype to another datatype.
- Date/time functions
  You can use this function to perform various operations on date and time.
- Error handling functions
  You can use this function in evaluating the type of error during map execution.
- External interface functions
  You can use this function to retrieve data from a database from within in a map rule.
- Flow functions
  Use Flow functions to specify a value for each of the flow variables defined for a flow, and additionally, to alter an already specified value for a flow variable.
- Inspection functions
  You can use this function to test and inspect the object.
- Logical functions
  Logical functions provide a way to use logical conditions to display one of several values.
- Lookup and reference functions
  These function search operates by scanning the appropriate set of items in sequence, attempting to match the logical condition.
- Math and statistics functions
  Precede all MATHLIB functions with mathlib->
- Text functions
  These functions are used to convert the text item in a map rule.
  - BCDTOTEXT
    The BCDTOTEXT function converts the digits in a BCD (Binary Coded Decimal) item to a text item containing the digits of the BCD-encoded item as a string of characters.
  - COUNTSTRING
    You can use the COUNTSTRING function when you need to know the number of times a specific text string appears within another text string.
  - CPACKAGE
    The CPACKAGE specifies the character set of the output of the function.
  - CSERIESTOTEXT
    The CSERIESTOTEXT specifies the character set of the output of the function.
  - CSIZE
    The CSIZE function returns an integer representing the size of a specified object in characters, exclusive of any pad characters.
  - CTEXT
    The CTEXT specifies the character set of the output of the function.
  - DATETOTEXT
    The DATETOTEXT function converts a date object or expression to a text item.
  - FILLLEFT
    The FILLLEFT function returns a text item of the length specified. In the output, the text item is preceded with the specified pad value.
  - FILLRIGHT
    The FILLRIGHT function returns a text item of the length specified. In the output, the text item is appended with the specified pad value.
  - FIND
    The FIND function looks for one text string within another text string and returns to its starting position, if found.
  - HEXTEXTTOSTREAM
    The HEXTEXTTOSTREAM is the reverse of STREAMTOHEXTEXT.
  - LEAVEALPHA
    The LEAVEALPHA function removes all non-alphabetic characters from a specified text item.
  - LEAVEALPHANUM
    The LEAVEALPHANUM function removes all non-alphanumeric characters (such as symbols) from a specified text item.
  - LEAVENUM
    The LEAVENUM function removes all non-numeric characters from a text item.
  - LEAVEPRINT
    The LEAVEPRINT function removes all non-printable characters from a text item.
  - LEFT
    The LEFT function returns a specified number of characters from a text expression beginning with the leftmost byte of a text item.
  - LOWERCASE
    The LOWERCASE function converts an alphabetic text item to all lowercase characters.
  - MAX
    The MAX function returns the maximum value from a series of number, date, time, or text values.
  - MID
    You can use the MID function when you need specific characters from a text item.
  - MIN
    Use MIN when you need the minimum value from a series of number, date, time, or text values.
  - NORMXML
    Use this function to remove XML formatting from an input XML fragment.
  - NUMBERTOTEXT
    The NUMBERTOTEXT function converts a character number to a text item that looks like the original object.
  - PACKAGE
    The PACKAGE function converts a group or item object to a text item, including its initiator, terminator, and any delimiters it contains.
  - PROPERCASE
    Use PROPERCASE to convert the first alphabetic character in each word to uppercase and all remaining characters to lowercase.
  - RANDDATA
    The RANDDATA function returns random text based on the properties of the output type. The RAND function returns a pseudo-random integer between 0 and RAND_MAX (guaranteed to be at least 32,767). The RANDDATA function generates a valid random value of the item type that is being built when it is invoked. In other words, if the rule were "A:Card = RandData ()", the random value would be valid data for type "A"—where that type "A" is a component of the specified "Card". The type "A" can be text, a date/time object, or a number.
  - REVERSEBYTE
    Use the REVERSEBYTE function when you need the bytes in the opposite sequence.
  - RIGHT
    You can use RIGHT when you need a specific part of a text item.
  - SEED
    The SEED function primes the RAND and RANDDATA functions so they produce repeated results.
  - SERIESTOTEXT
    You can use the SERIESTOTEXT function to project your input data as a series and to interpret it as a text item for output.
  - SQUEEZE
    The SQUEEZE function removes consecutive duplicate occurrences of a specified character or characters from a text item.
  - SUBSTITUTE
    You can use the SUBSTITUTE function to replace or remove a character.
  - TEXT
    You can use the TEXT function to convert an object to a text item or when echoing entire data objects to another map.
  - TEXTTOBCD
    The TEXTTOBCD function converts a text item from decimal digits to BCD (Binary Coded Decimal) format.
  - TEXTTONUMBER
    Use TEXTTONUMBER to convert text to a number.
  - TEXTTOTIME
    Use TEXTTOTIME when you want to convert an object defined as text that is in HHMM or HHMMSS presentation, to an item defined as time.
  - TIMETOTEXT
    You can use the TIMETOTEXT function to perform text concatenation.
  - TODATETIME
    The TODATETIME function converts a text string of a specified format to a date-time item.
  - TONUMBER
    The TONUMBER function converts a text string of a specified format to a number.
  - TRIMLEFT
    You can use the TRIMLEFT function to remove spaces or a text string at the beginning of some text.
  - TRIMRIGHT
    You can use the TRIMRIGHT function to remove spaces or a text string at the end of text.
  - UPPERCASE
    The UPPERCASE function converts text to all uppercase characters.
  - WORD
    You can use the WORD function to parse a text item that is delimited by some character, such as a space or a comma.
- XML functions
  There are several XML functions that you can call from component rules and map rules to process input XML data.
- Custom functions
  From the Type Designer or Map Designer, you can create custom functions to call external libraries.
- Date and time format strings
  You can use the listed format strings for numbers, dates and times in functions such as the CURRENTDATETIME, FROMNUMBER, TONUMBER, FROMDATETIME, and TODATETIME.
- Number format strings
  You can create custom number formats by using the given format strings.
- RUN function return codes
  The RUN function return codes and messages might result when using the RUN function.
- Character set codes for CPACKAGE, CSERIESTOTEXT, and CTEXT
  The second argument of the CPACKAGE, CSERIESTOTEXT, and CTEXT functions specifies the character set of the output of the function. The value of the second argument (the character set of the object content), must be a valid character set code.

LEFT

The LEFT function returns a specified number of characters from a text expression beginning with the leftmost byte of a text item.

You can use LEFT when you need a specific part of a text item. For example, a customer number might have several uses and sometimes only the first 10 characters are needed. Therefore, LEFT can be used to return only the leftmost 10 characters.

Syntax:: LEFT (single-text-expression , single-integer-expression)
Meaning:: LEFT (text_to_extract_from , number_of_characters_to_extract)
Returns:: A single text item

LEFT returns the leftmost number_of_characters_to_extract characters from text_to_extract_from starting at the first (the leftmost) character in text_to_extract_from.

If number_of_characters_to_extract evaluates to an integer whose value is less than 1, LEFT evaluates to "none". If number_of_characters_to_extract evaluates to an integer whose value is greater than the size of text_to_extract_from, LEFT evaluates to the entire value of text_to_extract_from.

Examples

LEFT ("Abcd", 2)
Returns Ab
LEFT ("Abcd", 6)
Returns Abcd
LEFT (LastName + ", " + FirstName, 25)
Returns the leftmost 25 characters of the text string resulting from the concatenation of LastName and FirstName (separated by a comma and a space).

Related functions

RIGHT
MID
FIND