jqr: jqr: An R client for the C library jq

Description Low-level High-level DSL Pipes NSE and SE jq version indexing output data format

View source: R/jqr.R

Description

jqr: An R client for the C library jq

Low-level

Low level interface, in which you can execute 'jq' code just as you would on the command line. Available via jq

High-level DSL

High-level, uses a suite of functions to construct queries. Queries are constucted, then excuted internally with jq

Pipes

The high level DSL supports piping, though you don't have to use pipes.

NSE and SE

Most DSL functions have NSE (non-standard evaluation) and SE (standard evaluation) versions, which make jqr easy to use for interactive use as well as programming.

jq version

We link to jq through the installed version on your system, so the version can vary. Run jq --version to get your jq version

indexing

note that jq indexing starts at 0, whereas R indexing starts at 1. So when you want the first thing in an array using jq, for example, you want 0, not 1

output data format

Note that with both the low level interface and the high level DSL, we print the output to look like a valid JSON object to make it easier to look at. However, it's important to know that the output is really just a simple character string or vector of strings - it's just the print function that pretty prints it and makes it look like a single JSON object. What jq is giving you often is a stream of valid JSON objects, each one of which is valid, but altogether are not valid. However, a trick you can do is to wrap your jq program in brackets like [.[]] instead of .[] to give a single JSON object

Related to above, you can use the function provided string with the high level DSL to get back a character string instead of pretty printed version


ropensci/jqr documentation built on Oct. 26, 2018, 7:15 p.m.