Add page for creation of non-Python test libraries

Author: mneiferbag

website/docs/extending_robot_framework/custom-libraries/non-python_library.md

@@ -0,0 +1,70 @@
+---
+sidebar_position: 0
+sidebar_label: Create Non-Python Libraries
+title: Non-Python Libraries
+---
+
+### Rust
+
+Create a dynamic system library (crate_type = "cdylib") from the following source code.
+
+```rust
+#![allow(non_snake_case)]
+
+use std::collections::HashMap;
+
+use pyo3::prelude::*;
+
+#[pyfunction]
+fn sum_as_string(a: i32, b: i32) -> PyResult<String> {
+    Ok((a + b).to_string())
+}
+
+#[pyfunction]
+fn join_strings(a: Vec<String>) -> PyResult<String> {
+    Ok(a.join(","))
+}
+
+#[pyfunction]
+fn sum_values(a: HashMap<String, i32>) -> PyResult<i32> {
+    let mut values_sum = 0;
+    for (_key, value) in &a {
+        values_sum += value;
+    }
+    Ok(values_sum)
+}
+
+#[pymodule]
+fn RustyLibrary(_py: Python, m: &PyModule) -> PyResult<()> {
+    m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;
+    m.add_function(wrap_pyfunction!(join_strings, m)?)?;
+    m.add_function(wrap_pyfunction!(sum_values, m)?)?;
+    Ok(())
+}
+```
+
+The library can then be used as follows.
+
+```robotframework
+*** Settings ***
+Library    RustyLibrary
+
+*** Test Cases ***
+Integer Argument Conversion Test
+    ${x} =    Sum As String    ${5}    ${20}
+    Should Be Equal    ${x}    25
+
+List Argument Conversion Test
+    @{MY_LIST} =    Create List    spam    eggs
+
+    ${y} =    Join Strings    ${MY_LIST}
+    Should Be Equal    ${y}    spam,eggs
+
+Dictionary Argument Conversion Test
+    &{MY_DICT} =    Create Dictionary    spam    ${11}    eggs    ${22}
+
+    ${z} =    Sum Values    ${MY_DICT}
+    Should Be Equal    ${z}    ${33}
+```
+
+A complete working example that includes all build files (e.g. Cargo.toml) can be found on [GitHub / mneiferbag / robot-python-test-library](https://github.com/mneiferbag/robot-rust-test-library).