Building a Data Table from a Parameters List
It may be necessary to build a Data Table from a string-encoded comma-separated list of parameters, e.g. "param1", 'param2', null. For example, this method is used for calling a function from a reference or a query.
Iotellect uses a common algorithm to construct a Data Table from a string-encoded parameter list. This algorithm uses field types defined in format to convert string parameters into the proper field values for putting into the various cells within the Data Table. This format may be, for example, input format of the function those input Data Table is being constructed.
Simply speaking, the system knows format of table that is being built, takes string values from the source list one-by-one, converts them into proper types and fills table cells.
Parameters in the list must be separated by commas (","), and it may contain the following types of values:
Value | Example | Description |
Non-quoted string, Single-quoted string |
| Quotes are trimmed from the string, if it's quoted. The resulting value is treated as an expression that is evaluated and evaluation result is used as the value of a cell in the function's input parameters table. If you're not sure what an expression is, you can think of it like a spreadsheet formula for now (1+1, for example). The chapter Iotellect Expression Language explains all about it. |
Double-quoted string |
| Quotes are trimmed from the string. The resulting value is not treated as an expression -- rather, it is converted to whatever data type the function expects for this argument. Conversion is done on a "best effort" basis -- you can't always convert any data type to any other data type. |
Rules for encoding/decoding values of different types to/from strings may be found here.
Each cell in the table gets its value from the corresponding argument in the argument list (i.e. the value of the first cell is the value of the first argument in the list).
 | If a Data Table to be constructed has dynamic (unspecified) format, the system constructs a single-row Data Table with all string fields. Every source parameter is put in a separate field. |
Very rarely, a function might expect more than one row of fields (i.e, more than one "record") as its input. If the function's input format defines N fields, the first N arguments are used for filling the first row, second N arguments for the second row etc.
 | Example: Let's say you have a function, func1 (just an arbitrary name), which expects the following input Data Table with two fields and two rows: |
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