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How can I replicate "each til count subs"
I am studying a sample from official KDB repo: (https://github.com/kxcontrib/websocket/blob/master/AppendixB/pubsub.q) . There is a line (https://github.com/kxcontrib/websocket/blob/ad2f0b268afaee1fc5f4dda2fc2467440c7e2f0c/AppendixB/pubsub.q#L39) . My overall understanding is that we call function pub with parameters generated by each til count subs . However, while I try to replicate the result from each til count subs in a q console, I get an error as attached.
My question is, how I can replicate the parameters generated from each til count?
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2 Replies
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q)tab:([] a:`a`b`c;b:1 2 3) //Create a table q)tab 0 //Index in to the table to row 0. A dictionary is returned a| `a b| 1 q)til 3 0 1 2 q)count tab // tab contains 3 rows 3 q)til count tab // 'til' returns numbers up to entered value 0 1 2 q){show tab x}each til count tab //Using 'each' and 'show' in a lambda to display each row a| `a b| 1 a| `b b| 2 a| `c b| 3- “A simple table is a list of dictionaries” https://code.kx.com/q/learn/dicts-tables/
- https://code.kx.com/q/kb/faq/#row-indexing
- https://code.kx.com/q4m3/6_Functions/#618-anonymous-functions-and-lambda-expressions
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Each is an iterator/adverb – what that line does is applies pub to each item of ’til count subs’, not applying pub to ‘each til count subs’.
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