LAE

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Originally posted by: dhrobertson

hi all,

I'm sure there is a very simple way of doing this but I'm currently having a brain freeze...

I want to work out if a particular field(column name) exists in the input and if so then to do something, else if not do something else.

in other scripting languages there are functions like If exists 'field' then do something.
however in BrainScript I can find an equivalent. I have hit on a function called inputFields which, from my interpretation of the help files, suggests that if I say something like:

temp = inputFields("in1")

then I should get a list in temp of the column headers in input 1. maybe I don't understand the help correctly....

If I do this and then try and emit temp, it fails with error: Unable to Print value of type: const-array

what am I doing wrong? and if what I want to achieve is not possible with inputFields, is there some other way of listing the column headers into a variable, after which I can then do a strFindI for that relevant column name and if exists then do an IF statement etc.etc

any help appreciated!

thanks

doug

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Originally posted by: stonysmith

temp = inputFields("in1") works properly, but it produces a LIST datatype, instead of a string.
While in Brainscript, you can use any of the LIST operators against "temp" such as
At this time, LAE can not EMIT a LIST datatype, you'd need to convert it to a string. (there is an open enhancement request to be able to emit LIST datatypes)

The simplest way to do this is:

which will return a column like this:
"{color;id;type;rand;junk}"

It's rather awkward, but for a comma-separated list, what I prefer to use is this:
edit: fixed the last replace() above.