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Additional functions for tables

Name	Description / comments
ej[<tbl1>;<tbl2>]	Each join
except[<tbl1>;<tbl2>]	Returns table1 entries which are not in table2
xcol[<names>;<tbl>]	Rename table columns
xcols[<names>;<tbl>]	Reorder table columns
.o.en[<tbl>;<sym>]	Returns table with columns enumerated
.o.sym[<tbl>]	Returns table with enum columns converted into symbols

.o.en

As you probably know, symbols cannot be part of splayed tables due to technical reasons. In order to permit symbol-like behaviour in tables, enums are used. The usual task of converting symbols into enums can be done using .o.en function.

Syntax: .o.en[t;sym]

whеre t is a table or table symbol for in-place modification;

sym is a global domain symbol, i.e. `sym .

All symbol fields in the table will be converted into enum fields. Global domain vector will contain new symbols (if necessary) added to its back.

o)load "core";
o)t:+`a`b`c!(1 2;3 4;`c`d);
o)sym:`symbol$();
o)r:.o.en[t;`sym];
o)r`c
`sym$`c`d
o)

When a table has just been loaded from disk, all its enum fields are not bind to any domain vector. One can use the same .o.en function to rebind them back.

o)load "core";
o)sym:`c`d;
o)t:+`a`b`c!(1 2;3 4;`sym$`c`d);
o)`:/tmp/tbl/ set t; t:0;
o)load `:/tmp/tbl/;
o)tbl
a b c
------
1 3 0
2 4 1i
o).o.en[`tbl;`sym];
o)tbl
a b c
------
1 3 `c
2 4 `d

.o.sym

A less frequent, but still useful procedure is turning enums into ordinary symbols. It's done using .o.sym function.

Syntax: .o.sym[t]

whеre t is a table or table symbol for in-place modification.

o)load "core";
o)sym:`c`d;
o)t:+`a`b`c!(1 2;3 4;`sym$`c`d);
o).o.sym[`t];                // destructive enums -> symbols
o)t
a b c
-----
1 3 c
2 4 d
o)t`c
`c`d

Tables