Re: How can i understand the code below

awilson

Member

February 24, 2022 at 12:00 am

Code reads right to left

.Q.en[tabPath] get table
// Fetch table (defined by sym/hsym 'table') and enumerate any symbol columns (to sym file located in directory tabPath)
(` sv (tabPath; ` ; table; ` ) ) set ...
// Save the table (splayed) to a directory defined by '/'-separated path (tabPath/table/)
@[;pvar; `p#] pvar xasc ...
// Sort by pvar and apply the parted attribute to this column in the table
: ...
// Return the result (the path to the saved table)
` sv (scalar from vector) joins elements of a filepath.
e.g.
q)` sv (`:path/to/dir; `filename)
`:path/to/dir/filename
q)` sv (`:path/to/dir; `filename; `)
`:path/to/dir/filename/

It is explained here https://code.kx.com/q/ref/sv/#filepath-components

`p# asserts that the array/column is parted (i.e. common values are adjacent)

It is explained here https://code.kx.com/q/ref/set-attribute/#grouped-and-parted

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awilson