Construct SPARQL filter

Source: R/construct_filter.R

This query derives SPARQL filter statement using the IN syntax.

construct_filter(sparql_variable, filter_values, use_str = FALSE)

Arguments

sparql_variable

A character scalar to be used in IN clause, without ?.
filter_values

A vector of filter values to be verified against in the filter statement.
use_str

A logical, defaults to FALSE, if TRUE it produces str(?variable) instead of ?variable.

Value

A character scalar corresponding to SPARQL filter expression.

Details

For instance, arguments sparql_variable = "time" and filter_values = c(2011, 2012) will result in a expression FILTER (?time IN ( "2011, 2012" )).

Examples

# This function is not exported from the package as it's mostly used
# internally.
SmarterScotland:::construct_filter(sparql_variable = "time",
                                   filter_values = c(2011, 2012))
#> [1] "FILTER (?time IN ('2011', '2012'))"
SmarterScotland:::construct_filter(sparql_variable = "time", use_str = TRUE,
                                   filter_values = c(2011, 2012))
#> [1] "FILTER (str(?time) IN ('2011', '2012'))"