Remove jsonlite dependency

DESCRIPTION

@@ -26,8 +26,6 @@ VignetteBuilder: quarto
 Config/testthat/edition: 3
 URL: https://hugogruson.fr/grumpy/, https://github.com/Bisaloo/grumpy
 BugReports: https://github.com/Bisaloo/grumpy/issues
-Imports: 
-    jsonlite
 Config/Needs/website:
     Huber-group-EMBL/Rarr
 Config/roxygen2/version: 8.0.0

R/read_npy.R

@@ -88,8 +88,7 @@ parse_npy_descr <- function(bytes) {
   # We just ignore it, at least for now.
   header <- bytes |>
     rawToChar() |>
-    convert_py_dict_to_json() |>
-    jsonlite::fromJSON(simplifyMatrix = FALSE)
+    py_dict_to_r_list()
 
   parsed_descr <- parse_npy_datatype(header$descr)
 
@@ -251,13 +250,30 @@ convert_bytes_to_array <- function(bytes, what, shape, size, endian) {
   return(res)
 }
 
-convert_py_dict_to_json <- function(dict_str) {
-  dict_str |>
-    gsub("'", '"', x = _, fixed = TRUE) |>
-    gsub("None", "null", x = _, fixed = TRUE) |>
-    gsub("True", "true", x = _, fixed = TRUE) |>
-    gsub("False", "false", x = _, fixed = TRUE) |>
-    gsub("(", "[", x = _, fixed = TRUE) |>
-    gsub(")", "]", x = _, fixed = TRUE) |>
-    gsub(",\\s*(}|\\])", "\\1", x = _) # trailing commas
+py_dict_to_r_list <- function(x) {
+  x |>
+    # Logicals
+    gsub("\\bNone\\b", "NA", x = _) |>
+    gsub("\\bTrue\\b", "TRUE", x = _) |>
+    gsub("\\bFalse\\b", "FALSE", x = _) |>
+    # Trailing commas (before closing brackets/braces)
+    gsub(",\\s*([]})])", "\\1", x = _) |>
+    # Dict (single-quoted) keys to list names.
+    #   Keys are composed of:
+    #   - anything that is not the quote itself or a backslash,
+    #   - a backslash followed by any character (to allow for escaped quotes).
+    gsub("'(([^'\\\\]|\\\\.)*)'\\s*:", "'\\1' =", x = _) |>
+    # Dict (double-quoted) keys to list names.
+    gsub('"(([^"\\\\]|\\\\.)*)"\\s*:', '"\\1" =', x = _) |>
+    # Tuples to c(...)
+    gsub("(", "c(", x = _, fixed = TRUE) |>
+    # Lists to list(...)
+    gsub("[", "list(", x = _, fixed = TRUE) |>
+    gsub("{", "list(", x = _, fixed = TRUE) |>
+    # Closing brackets/braces
+    gsub("]", ")", x = _, fixed = TRUE) |>
+    gsub("}", ")", x = _, fixed = TRUE) |>
+    # Evaluate the resulting R expression
+    parse(text = _) |>
+    eval()
 }

README.md

@@ -18,9 +18,9 @@ As a file format generated by a Python package, `.npy` files are prime
 candidates for using the `{reticulate}` package to read them into R.
 However, this comes with downsides in terms of performance, flexibility,
 and robustness of the R package infrastructure. `{grumpy}`, on the other
-hand, is a pure R package with a single dependency (`{jsonlite}`), and
-is performant, flexible. Overall, it is designed to be used deep in the
-dependency graph of other packages.
+hand, is a pure R package with no dependency and is performant,
+flexible. Overall, it is designed to be used deep in the dependency
+graph of other packages.
 
 For more details on the motivation and design principles underpinning
 `{grumpy}`, see the dedicated vignette:

README.qmd

@@ -27,7 +27,7 @@ The `{grumpy}` R package provides a way to read NumPy's `.npy` files into R. It
 
 As a file format generated by a Python package, `.npy` files are prime candidates for using the `{reticulate}` package to read them into R.
 However, this comes with downsides in terms of performance, flexibility, and robustness of the R package infrastructure. 
-`{grumpy}`, on the other hand, is a pure R package with a single dependency (`{jsonlite}`), and is performant, flexible. Overall, it is designed to be used deep in the dependency graph of other packages.
+`{grumpy}`, on the other hand, is a pure R package with no dependency and is performant, flexible. Overall, it is designed to be used deep in the dependency graph of other packages.
 
 For more details on the motivation and design principles underpinning `{grumpy}`, see the dedicated vignette: `vignette("design", package = "grumpy")`.