prov.debug: A Time-Travelling Debugger for R - Debugger Initialization
In provDebugR: A Time-Travelling Debugger

Description Usage Arguments Details Value References See Also Examples

prov.debug uses the provenance from the last execution of prov.run to initialise the debugger.

prov.debug.file reads a PROV-JSON file to initialise the debugger.

prov.debug.run executs a R or Rmd script, collects provenance, and initialises the debugger using the collected provenance.

prov.debug()

prov.debug.file(prov.file)

prov.debug.run(script, ...)

`prov.file`	Path to a PROV-JSON file.
`script`	Path to an R script.
`...`	extra parameters are passed to the provenance collector. See rdt's prov.run function or rdtLites's prov.run function for details.

Provenance is a detailed record of the execution of a script which includes information about the steps that were excecuted and the intermediate data values that were used and/or created. After it is collected, it can be used in a variety of ways to better understand the execution.

This package, provDebugR, is one such application, using provenance post-execution to help the user understand and debug their script by providing functions to look at intermediate steps and data values, as well as their forwards or backwards lineage. These functions may be used only after provDebugR has been initialised using one of the initialisation functions above.

The forwards lineage of a data object is the list of steps showing how the data object was used. The backwards lineage of a data object is the list of steps showing how the data object was produced.

provDebugR uses provenance produced by rdtLite (a provenance collection package available on CRAN), stored in PROV-JSON format.

No return value.

rdtLite (Provenance Collection Tool): https://CRAN.R-project.org/package=rdtLite

PROV-JSON output produced by rdtLite: https://github.com/End-to-end-provenance/ExtendedProvJson/blob/master/JSON-format.md

PROV-JSON standard: https://www.w3.org/Submission/2013/SUBM-prov-json-20130424/

Other provDebugR Functions (non-initialisation):

debug.error: Returns the backwards lineage of the error, if any. The error may be queried on StackOverflow.

debug.line: Returns all immediate inputs and outputs for the line(s) queried.

debug.lineage: Returns the forwards or backwards lineage of the data object(s) queried. The forwards lineage shows how the data object was used, and the backwards lineage shows how it was produced.

debug.state: Returns the state at the line(s) queried, after the line had been executed. The state is the list of all variables and their values in the environment at the queried line.

debug.type.changes: Returns a data frame for each variable in the execution containing the instances where the data type changed.

debug.variable: Returns a data frame showing all instances of the variable(s) queried.

debug.view: Opens and displays the contents of each file or variable or variable queried.

debug.warning: Returns the backwards lineage of the queried warning(s), if any.

Other tools that use provenance: https://github.com/End-to-end-provenance

## Not run: 
rdtLite::prov.run("test.R")
prov.debug()
## End(Not run)

## Not run: 
prov.debug.file("prov_test/prov.json")
## End(Not run)

## Not run: 
prov.debug.run("test.R", snapshot.size = 100)
## End(Not run)