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Functions and Expressions
Use HCL Link functions and expressions to create component rules and map rules.
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.
CACHEREAD
The CACHEREAD function reads the value associated to a cache variable from the cache.

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.
  - CACHEDELETE
    The CACHEDELETE function deletes a cache variable from the cache.
  - CACHEREAD
    The CACHEREAD function reads the value associated to a cache variable from the cache.
  - CACHEWRITE
    The CACHEWRITE function sets a new or updates an existing cache variable in the cache.
- 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.
- 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.

CACHEREAD

The CACHEREAD function reads the value associated to a cache variable from the cache.

This function returns a default value if specified, or an empty value if the cache variable has not been defined, or if it has been deleted prior to making this function invocation. Otherwise, it returns the associated value of the cache variable to the map in text format.

Syntax:: CACHEREAD (single-text-expression [, single-text-expression])
Meaning:: CACHEREAD (variable_name [, default_value])
Returns:: A single text item.

Examples

flowlib->CACHEREAD (“Greeting”)
Returns the current value associated to cache variable, Greeting, if exists in the cache.
Otherwise, returns empty.
flowlib->CACHEREAD (“Greeting”, “Hi”)
Returns the current value associated to cache variable, Greeting, if exists in the cache.
Otherwise, returns the default value, Hi, to the map.