Custom Scaffolding of R Wrappers for Python Functions
This function can be used to generate R wrapper for a specified
Python function while allowing to inject custom code for critical parts of
the wrapper generation, such as process the any part of the docs obtained
from py_function_docs() and append additional roxygen fields. The result
from execution of python_function is assigned to a variable called
python_function_result that can also be processed by postprocess_fn
before writing the closing curly braces for the generated wrapper function.
py_function_custom_scaffold(
python_function,
r_function = NULL,
additional_roxygen_fields = NULL,
process_docs_fn = function(docs) docs,
process_param_fn = function(param, docs) param,
process_param_doc_fn = function(param_doc, docs) param_doc,
postprocess_fn = function() { },
file_name = NULL
)python_function |
Fully qualified name of Python function or class
constructor (e.g. |
r_function |
Name of R function to generate (defaults to name of Python function if not specified) |
additional_roxygen_fields |
A list of additional roxygen fields to write
to the roxygen docs, e.g. |
process_docs_fn |
A function to process docs obtained from
|
process_param_fn |
A function to process each parameter needed for
|
process_param_doc_fn |
A function to process the roxygen docstring for each parameter. |
postprocess_fn |
A function to inject any custom code in the form of a string before writing the closing curly braces for the generated wrapper function. |
file_name |
The file name to write the generated wrapper function to. If
|
## Not run:
library(tensorflow)
library(stringr)
# Example of a `process_param_fn` to cast parameters with default values
# that contains "L" to integers
process_int_param_fn <- function(param, docs) {
# Extract the list of parameters that have integer values as default
int_params <- gsub(
" = [-]?[0-9]+L",
"",
str_extract_all(docs$signature, "[A-z]+ = [-]?[0-9]+L")[[1]])
# Explicitly cast parameter in the list obtained above to integer
if (param %in% int_params) {
param <- paste0("as.integer(", param, ")")
}
param
}
# Note that since the default value of parameter `k` is `1L`. It is wrapped
# by `as.integer()` to ensure it's casted to integer before sending it to `tf$nn$top_k`
# for execution. We then print out the python function result.
py_function_custom_scaffold(
"tf$nn$top_k",
r_function = "top_k",
process_param_fn = process_int_param_fn,
postprocess_fn = function() { "print(python_function_result)" })
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.