remove hello world example and make first str_count

Author: snowmerak

NAMESPACE

@@ -1,4 +1,3 @@
 # Generated by roxygen2: do not edit by hand
 
-export(hello_world)
 useDynLib(stringer, .registration = TRUE)

R/extendr-wrappers.R

@@ -8,7 +8,7 @@
 #' @useDynLib stringer, .registration = TRUE
 NULL
 
-#' Return string `"Hello world!"` to R.
-#' @export
-hello_world <- function() .Call(wrap__hello_world)
+str_regex_count <- function(strings, pattern) .Call(wrap__str_regex_count, strings, pattern)
+
+str_text_count <- function(strings, sub) .Call(wrap__str_text_count, strings, sub)
 

R/interface.R

@@ -0,0 +1,26 @@
+setClass(
+    "text",
+    representation(value = "character")
+)
+
+setClass(
+    "regex",
+    representation(value = "character")
+)
+
+text <- function(x) {
+    new("text", value = x)
+}
+
+regex <- function(x) {
+    new("regex", value = x)
+}
+
+str_count <- function(l, pattern) {
+    switch(
+        class(pattern),
+        text = str_text_count(l, pattern@value),
+        regex = str_regex_count(l, pattern@value),
+        character = str_regex_count(l, pattern)
+    )
+}

man/hello_world.Rd

@@ -9,3 +9,4 @@ name = 'stringer'
 
 [dependencies]
 extendr-api = '*'
+regex = "1.5"

src/rust/Cargo.lock

@@ -1,16 +1,36 @@
 use extendr_api::prelude::*;
+use regex::Regex;
 
-/// Return string `"Hello world!"` to R.
-/// @export
-#[extendr]
-fn hello_world() -> &'static str {
-    "Hello world!"
-}
-
-// Macro to generate exports.
-// This ensures exported functions are registered with R.
-// See corresponding C code in `entrypoint.c`.
 extendr_module! {
     mod stringer;
-    fn hello_world;
+    fn str_regex_count;
+    fn str_text_count;
+}
+
+#[extendr]
+fn str_regex_count(strings: Vec<String>, pattern: String) -> Vec<i64> {
+    let re = match Regex::new(pattern.as_str()) {
+        Ok(re) => re,
+        Err(err) => panic!("{}", err),
+    };
+    strings.iter().map(|x| {
+        let c = re.split(x.as_str()).count();
+        if c > 0 {
+            (c - 1) as i64
+        } else {
+            0 as i64
+        }
+    }).collect()
 }
+
+#[extendr]
+fn str_text_count(strings: Vec<String>, sub: String) -> Vec<i64> {
+    strings.iter().map(|x| {
+        let c = x.split(&sub).count();
+        if c > 0 {
+            (c - 1) as i64
+        } else {
+            0 as i64
+        }
+    }).collect()
+}