Function Names
table expand headersDescription
This function resolves specified table headers headers in the following way and returns the result in the return value.
- Ranges, e.g. {Street address, '..', Country}, are rolled out, e.g. resulting in {Street address, Town, Region, Country}.
- Prefixes like '<' and '>' are also resolved by referencing to the neighboring columns directly.
- Asterisks '*' translate to all column headers listed indiviudally.
- Shifted table column specifications are also resolved, e.g. '>City' refers to the next column to the right of 'City'.
This function provides three different options to resolve header specifications:
- The header names, as specified in row 0 are returned.
Note: This option is risky because of ambiguities with tables containing multiple identical header names and/or multiple blank headers. - Like above, but column numbers are provided for repeated headers and blank headers, allowing to access every header directly.
- Column numbers are provided. Works similar like table column numbers().
Call as: function
Restrictions
Indirect parameter passing is disabled
Parameter count
2-3
Parameters
| No. | Type | Description |
|---|---|---|
| 1 input |
string | Name of existing table |
| 2 input |
table columns | Columns Specific rules apply for this function:
See table columns as function parameters for general ruling for this parameter. |
| 3 input |
string | Option Following options are available:
See table columns as function parameters for general ruling for this parameter. |
Return value
| Type | Description |
|---|---|
| set | Expanded list of headers Individual header names, and/or column numbers. |
Exceptions
Table not found
Columns not found
Examples
table initialize( t, { { Name, Street, '', '', Town, Postal Code, Town, Region, Country, Continent, Phone, 'E-Mail' } } );
echo( "Table headers: ", [t:..,0], new line);
echo( "Input: { Name, '', 3, Town, '>Town', '..', Continent, 1 }");
echo( " ", table resolve headers( t, { Name, '', 3, Town, '>Town', '..', Continent, 1 } ) );
echo( " ", table resolve headers( t, { Name, '', 3, Town, '>Town', '..', Continent, 1 }, prefer names ) ); // Same as above
echo( " ", table resolve headers( t, { Name, '', 3, Town, '>Town', '..', Continent, 1 }, use names ) );
echo( " ", table resolve headers( t, { Name, '', 3, Town, '>Town', '..', Continent, 1 }, use numbers ) );
echo(new line, "And when all columns are selected:");
echo( " ", table resolve headers( t, '*', prefer names ) );
echo( " ", table resolve headers( t, '..', prefer names ) ); // Same as above
echo( " ", table resolve headers( t, '*', use names ) );
echo( " ", table resolve headers( t, '*', use numbers ) );
Output
Table headers: {'Name','Street','','','Town','Postal Code','Town','Region','Country','Continent','Phone','E-Mail'}
Input: { Name, '', 3, Town, '>Town', '..', Continent, 1 }
{'Name',2,3,'Town','Postal Code',6,'Region','Country','Continent','Street'}
{'Name',2,3,'Town','Postal Code',6,'Region','Country','Continent','Street'}
{'Name','','','Town','Postal Code','Town','Region','Country','Continent','Street'}
{0,2,3,4,5,6,7,8,9,1}
And when all columns are selected:
{'Name','Street',2,3,'Town','Postal Code',6,'Region','Country','Continent','Phone','E-Mail'}
{'Name','Street',2,3,'Town','Postal Code',6,'Region','Country','Continent','Phone','E-Mail'}
{'Name','Street','','','Town','Postal Code','Town','Region','Country','Continent','Phone','E-Mail'}
{0,1,2,3,4,5,6,7,8,9,10,11}