convert.type: Types in R Grokit.
In tera-insights/gtBase: R Interface for the Grokit System

Details on the specification of types in R Grokit.

1	convert.type(type)

To convert user-specified or detected types, two S3 method pipelines are used consecutively. First, convert.types is called by functions that process types. This set of methods ensures that the output is a list of objects of class template. The list is necessary as the types will be translated to piggy by a call to lapply. If a single template exists by itself and not within a length one list, the lapply would instead go over the list representing the type. The structure of convert.types closely mimics that of convert.exprs, as they are both used to produce lists to be processed. Secondly, convert.type does the actual conversion. This function should only ever be called by function convert.types.

Types can be specified by the user as a call or a symbol. In the former case, each argument that is a call is itself processed and then the whole call is processed using the function called as the name and the arguments as the template arguments.

Additionally, types can be a value rather than a call. Although a user could technically cause this directly, this usually arises from the automatic detection of types within a file that is being read. In such a case, types in R are directly mapped onto Grokit types. It should be noted that factors are treated as strings rather than as factors or categories, as not information can be discerned from a single value to template the type.

The types that can be converted is subject to change as more types are added to Grokit. If a type can be converted, then the S3 function convert.type must have a method defined for that class. Otherwise, an error is thrown.

tera-insights/gtBase documentation built on May 31, 2019, 8:35 a.m.