Re: Array access indirection

[Tim Channon <tc@...>]

Mark Meijer wrote:

>> require"tprint"
>>
>> var="fred"
>>
>> pa1="john"
>> va1="sam"
>> pa2="ken"
>> va2="sal"
>>
>> rt={}
>>
>> rt[var]={[pa1]=va1}
>>
>> rt[var]={[pa2]=va2} -- does not add pair
>> [...]
> 
> Firstly, for the record, the table constructor notation used here, is
> the same variant as the one Geoff used above to smack some sense into
> me ;)
> 
> The variable var, used as index in the last two statements, resolves
> to "fred" in both those statements. So, since keys in Lua tables are
> unique, in the second statement you're simply overwriting the entry
> you created in the first statement (i.e. the entry named rt.fred). If
> you change var to something else before the second statement (or in
> any other way change what the expression used as index there resolves
> to), then there should be no problem.

I find the Lua syntax very difficult and seems to catch many people.

The intention is that rt is a table of key/table pairs

Hence rt[var] is intended to address the table which is the value
associated with key [var]

Within that subtable I want to add key/value pairs.

Obviously I am doing something wrong but no amount of experimenting or
reading over weeks has provided a clue on how it can be done.