wiki/debug.state.md

In ProvTools/provDebugR: A Time-Travelling Debugger

For each queried line, debug.state returns a data frame showing the state at that line, after it has been executed.

Each data frame contains the following columns: name The names of variables in the state. value The value of each variable. container The type of the container of each variable. dimension The size of the container. type The data type(s) contained within the container. scriptNum The script number associated with each variable. scriptName The name of the script the variable is associated with. startLine The line number associated with each variable.

If no paramters are given, debug.state will return the state at the end of execution.

Usage

The function signature for debug.state is:

debug.state(..., script.num = 1)

The parameters of this function are: ... The line numbers to be queried. script.num The script number of the queried line numbers. This is ignored if no line numbers are given. If script.num == "all", all possible script numbers will be queried. Defaults to script number 1 (main script).

This function may be called only after initialising the debugger using either prov.debug, prov.debug.run, or prov.debug.file. For example:

prov.debug.run("myScript.R")
debug.state()
debug.state(5)
debug.state(10, 20, script.num = 2)
debug.state(5, script.num = "all")

Output Examples

Let myScript.R be the following:

a <- "one"
a <- 2L

b <- 3L
b <- "four"

1. State at the end of execution

When there are no parameters, this function returns the state at the end of execution.

Therefore, the result for debug.state() is:

State at the end of execution:
$`1`
  name  value container dimension      type scriptNum scriptName startLine
1    a      2    vector         1   integer         1 myScript.R         2
2    b "four"    vector         1 character         1 myScript.R         5

2. State at a line

This function returns the state at the queried line, after the line has been executed.

For example, the result for debug.state(1) is:

Results for:
  startLine scriptNum
1         1         1

$`1`
  name value container dimension      type scriptNum scriptName startLine
1    a "one"    vector         1 character         1 myScript.R         1

Similarly, the result for debug.state(4) is:

Results for:
  startLine scriptNum
1         4         1

$`1`
  name value container dimension    type scriptNum scriptName startLine
1    a     2    vector         1 integer         1 myScript.R         2
2    b     3    vector         1 integer         1 myScript.R         4

3. State at multiple lines

When multiple lines are queried in a function call, the results for each line are bound into a list.

For example, the result for debug.state(2,4) is:

Results for:
  startLine scriptNum
1         2         1
2         4         1

$`1`
  name value container dimension    type scriptNum scriptName startLine
1    a     2    vector         1 integer         1 myScript.R         2

$`2`
  name value container dimension    type scriptNum scriptName startLine
1    a     2    vector         1 integer         1 myScript.R         2
2    b     3    vector         1 integer         1 myScript.R         4

ProvTools/provDebugR documentation built on April 29, 2021, 7:22 p.m.