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3.4.4 Arrays and Tables
If the table does not have a tocom tag method (for Lua 4) or __tocom
metamethod (for Lua 5), LuaCOM first checks if the table can be describing a date. A table is a date
if it has one of those fields: Day, DayOfWeek, Month, Year,
Hour, Minute, Second, Milliseconds. LuaCOM initializes the
date with the fields that are present; the others are kept at their default values.
If the table is not a date, LuaCOM converts Lua tables to SAFEARRAY's and vice-versa. To be converted, Lua tables must be ``array-like'', that is, all of its elements must be or ``scalars'' or tables of the same length. These tables must also be ``array-like''. Here are some samples of how is this conversion done:
| Lua table | Safe Array | |
table = {"name", "phone"} |
|
|
table = {{1,2},{4,9}} |
|
![\begin{displaymath} \left[\begin{array}{cc} ''name'' & ''phone'' \\ \end{array}\right] \end{displaymath}](img1.png)
![\begin{displaymath} \left[\begin{array}{cc} 1 & 2 \\ 4 & 9 \\ \end{array} \right] \end{displaymath}](img2.png)
If the table has the conversion tag/metamethod, LuaCOM uses it
to guide the conversion. If the tag/metamethod is a method, LuaCOM
calls it, passing the table and the COM type. The method should return a COM object
that LuaCOM will pass on. If the tag/metamethod is a table, LuaCOM will
look for a typelib field, an interfacefield , and a coclass field,
and pass those as arguments to the ImplInterfaceFromTypelib API call. If the table
does not have a typelib field, LuaCOM will look for a progid field and
an interface field, and pass those to the ImplInterface API call. Either way,
LuaCOM will pass the returned object to COM.
Next: 3.4.5 CURRENCY type Up: 3.4 Type Conversion Previous: 3.4.3 Pointers to IUnknown Contents Fabio Mascarenhas de Queiroz 2005-01-07