1 files changed, 61 insertions, 0 deletions
diff --git a/src/str.rs b/src/str.rs
new file mode 100644
index 0000000..90f3600
--- /dev/null
+++ b/src/str.rs
@@ -0,0 +1,61 @@
+use once_cell::sync::Lazy;
+use regex::{Captures, Regex};
+
+static C_PTR_RE: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r"(const )?([a-zA-Z0-9_]+)\s?\*(.*)").unwrap());
+
+static REST_C_PTR_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"(const)?\s?\*").unwrap());
+
+pub fn c_ptr_to_rust_ptr(c_ptr: &str) -> String
+{
+    C_PTR_RE
+        .replace(c_ptr, |captures: &Captures| {
+            let const_or_mut = captures.get(1).map_or_else(|| "mut", |_| "const");
+
+            let type_name = captures.get(2).unwrap().as_str();
+
+            let rest = captures.get(3).unwrap();
+
+            let rest_ptr_matches = REST_C_PTR_RE.captures_iter(rest.as_str());
+
+            let rest_ptrs = rest_ptr_matches
+                .map(|capts| {
+                    let const_or_mut = capts.get(1).map_or_else(|| "mut", |_| "const");
+
+                    format!("*{const_or_mut} ")
+                })
+                .collect::<Vec<_>>();
+
+            format!("{}*{const_or_mut} {type_name}", rest_ptrs.join(" "))
+        })
+        .to_string()
+}
+
+#[cfg(test)]
+mod tests
+{
+    use pretty_assertions::assert_str_eq;
+
+    use super::*;
+
+    #[test]
+    fn c_ptr_to_rust_ptr_works()
+    {
+        assert_str_eq!(c_ptr_to_rust_ptr("void *"), "*mut void");
+        assert_str_eq!(c_ptr_to_rust_ptr("const void*"), "*const void");
+        assert_str_eq!(c_ptr_to_rust_ptr("GLint *"), "*mut GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("const GLint*"), "*const GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("const GLint *"), "*const GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("const GLint **"), "*mut *const GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("const GLint * *"), "*mut *const GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("GLint **"), "*mut *mut GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("GLuint * const*"), "*const *mut GLuint");
+
+        assert_str_eq!(
+            c_ptr_to_rust_ptr("const GLuint * const*"),
+            "*const *const GLuint"
+        );
+
+        assert_str_eq!(c_ptr_to_rust_ptr("GLchar"), "GLchar");
+    }
+}