The stdlib function ⎕force_indexing

Runtime forcing of indexing

A Pometo shape is defined by this Erlang record:

-record('$shape¯', {
                    indexed    = false,
                    dimensions = [],
                    forcing    = none,
                    type       = none,
                    line_no    = none,
                    char_no    = none
                   }).

In an unindexed record the arguments are a simple list:

{'$ast¯',{'$shape¯',false,[2,2],none,number,2,16},
                [1,22,333,444],
                2,16}

In an indexed shape the arguments are a map with integer keys:

The stdlib function ⎕make_indexed takes one of these and converts it to an indexed vector:

{'$ast¯',{'$shape¯',true,[2,2],none,number,2,16},
                 #{1 => 1,2 => 22,3 => 333,4 => 444},
                 2,16}

The field forcing (which by default has a value of none) can be used to hint to the runtime as how to proceed. If the data structure is unindexed but will be needed to consumed as an indexed data structure the value of forcing will be set to indexed and at the next traversal of the data structure its internal representation will be changed.

This function allows Developers working on the Pometo runtime (and not people ordinarily writing Pometo programmes to toggle data structures for the purposes of testing.

For more details please see the discussion in the discussion of ⎕make_indexed.