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Methods Available in 'squarebrackets'

Source: R/aaa01_squarebrackets_methods.R
aaa01_squarebrackets_methods.Rd

This help page gives an overview of the methods available in 'squarebrackets'.

Main Methods

The main methods of 'squarebrackets' use the naming convention <indexform>_<operation>:
<indexform> tells you what form of indices the method uses;
<operation> tells you what operation is performed.

For the <indexform> part, the following is available:

  • ii_: operates on subsets of atomic/recursive vectors/arrays by interior indices.

  • ss_: operates on subsets of atomic/recursive arrays of any dimensionality by subscripts.

  • sbt_: operates on subsets of data.frames and atomic/recursive matrices by tabular indices.

  • slice_: uses index-less, sequence-based, and efficient operations on (mutatomic) long vectors.

  • slicev_: uses index-less & value-based and efficient operations on (mutatomic) long vectors.

For the <operation> part, the following is available:

  • _x: extract, exchange, or duplicate (if applicable) subsets.

  • _wo: returns the original object without the provided subsets.

  • _mod: modify subsets and return copy.

  • _set: modify subsets using pass-by-reference semantics.

To illustrate, let's take the methods used for extracting subsets (_x):

  • If y is a vector or array (of any dimension),
    ii_x(y, i) corresponds to y[i].

  • If y is a 3d array,
    ss_x(y, n(i, k), c(1, 3)) corresponds to y[i, , k, drop = FALSE].

  • If y is a matrix or data.frame-like object,
    sbt_x(y, i, j) corresponds to y[i, j, drop = FALSE].

Other Methods

Besides the main methods, 'squarebrackets' provides some additional methods that do not neatly fit into the above methods.

First, there is the lst_ set of methods, which deal with sub-set operations that are only relevant for (nested) lists, but not for the other types of supported objects.

Second, there is idx method, which works on both recursive and non-recursive objects, and transforms/translates indices to be used in R's default copy-on-modify semantics.

Finally, there are the sb_ sets of methods, which cover miscellaneous operations for atomic/recursive objects.

Finding the Appropriate Help Pages

With knowledge of the naming convention of the main methods, one can easily find out information about a particular method by usign the ? operator.
So to find out about modifying objects by subscripts using Pass-by-Reference semantics, type in:
?ss_set