select function

Select - filtering

The function select(foo) produces its input unchanged if foo returns TRUE for that input, and produces no output otherwise

select(.data, ...)

select_(.data, ..., .dots)

Arguments

• .data: input. This can be JSON input, or an object of class jqr that has JSON and query params combined, which is passed from function to function when using the jqr DSL.
• ...: Comma separated list of unquoted variable names
• .dots: Used to work around non-standard evaluation
• dots: dots

Note

this function has changed what it does dramatically. we were using this function for object construction, which is now done with build_object

Examples

jq('[1,5,3,0,7]', 'map(select(. >= 2))')
'[1,5,3,0,7]' %>% map(select(. >= 2)) 

'{"foo": 4, "bar": 7}' %>% select(.foo == 4)
'{"foo": 5, "bar": 7} {"foo": 4, "bar": 7}' %>% select(.foo == 4)
'[{"foo": 5, "bar": 7}, {"foo": 4, "bar": 7}]' %>% index() %>% 
  select(.foo == 4)
'{"foo": 4, "bar": 7} {"foo": 5, "bar": 7} {"foo": 8, "bar": 7}' %>% 
  select(.foo < 6)

x <- '{"foo": 4, "bar": 2} {"foo": 5, "bar": 4} {"foo": 8, "bar": 12}'
jq(x, 'select((.foo < 6) and (.bar > 3))')
jq(x, 'select((.foo < 6) or (.bar > 3))')
x %>% select((.foo < 6) && (.bar > 3))
x %>% select((.foo < 6) || (.bar > 3))

x <- '[{"foo": 5, "bar": 7}, {"foo": 4, "bar": 7}, {"foo": 4, "bar": 9}]'
jq(x, '.[] | select(.foo == 4) | {user: .bar}')
x %>% index() %>% select(.foo == 4) %>% build_object(user = .bar)