index function

index and related functions

index(.data, ...)

index_(.data, ..., .dots)

indexif(.data, ...)

indexif_(.data, ..., .dots)

dotindex(.data, ...)

dotindex_(.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

Details

• index/index_ - queries like: .[], .[0], .[1:5], .["foo"]
• indexif/indexif_ - queries like: .["foo"]?
• dotindex/dotindex_ - queries like: .[].foo, .[].foo.bar

Examples

str <- '[{"name":"JSON", "good":true}, {"name":"XML", "good":false}]'
str %>% index
'{"name":"JSON", "good":true}' %>% indexif(name)
'{"name":"JSON", "good":true}' %>% indexif(good)
'{"name":"JSON", "good":true}' %>% indexif(that)
'{"a": 1, "b": 1}' %>% index
'[]' %>% index
'[{"name":"JSON", "good":true}, {"name":"XML", "good":false}]' %>% index(0)
'["a","b","c","d","e"]' %>% index(2)
'["a","b","c","d","e"]' %>% index('2:4')
'["a","b","c","d","e"]' %>% index('2:5')
'["a","b","c","d","e"]' %>% index(':3')
'["a","b","c","d","e"]' %>% index('-2:')

str %>% index %>% select(bad = .name)

'[{"name":"JSON", "good":true}, {"name":"XML", "good":false}]' %>%
  dotindex(name)
'[{"name":"JSON", "good":true}, {"name":"XML", "good":false}]' %>%
  dotindex(good)
'[{"name":"JSON", "good":{"foo":5}}, {"name":"XML", "good":{"foo":6}}]' %>%
  dotindex(good)
'[{"name":"JSON", "good":{"foo":5}}, {"name":"XML", "good":{"foo":6}}]' %>%
  dotindex(good.foo)