Merge pull request #19 from calcit-lang/read-file-by-line

new API read-file-by-line!

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "calcit_std"
-version = "0.0.20"
+version = "0.1.1"
 authors = ["jiyinyiyong <jiyinyiyong@gmail.com>"]
 edition = "2021"
 

README.md

@@ -27,6 +27,8 @@ calcit.std.fs/create-dir! path
 calcit.std.fs/create-dir-all! path
 
 calcit.std.fs/rename! from to
+
+calcit.std.fs/read-file-by-line! a $ fn (line) (println line)
 ```
 
 ```cirru

compact.cirru

@@ -1,6 +1,6 @@
 
 {} (:package |calcit.std)
-  :configs $ {} (:init-fn |calcit.std.test/main!) (:reload-fn |calcit.std.test/reload!) (:version |0.1.0)
+  :configs $ {} (:init-fn |calcit.std.test/main!) (:reload-fn |calcit.std.test/reload!) (:version |0.1.1)
     :modules $ []
   :entries $ {}
   :files $ {}
@@ -74,6 +74,9 @@
         |read-file! $ quote
           defn read-file! (name)
             &call-dylib-edn (get-dylib-path "\"/dylibs/libcalcit_std") "\"read_file" name
+        |read-file-by-line! $ quote
+          defn read-file-by-line! (name cb)
+            &blocking-dylib-edn-fn (get-dylib-path "\"/dylibs/libcalcit_std") "\"read_file_by_line" name cb
         |rename! $ quote
           defn rename! (from to)
             &call-dylib-edn (get-dylib-path "\"/dylibs/libcalcit_std") "\"rename_path" from to
@@ -232,6 +235,10 @@
             println $ >
               count $ read-file! "\"README.md"
               , 1000
+            let
+                *c $ atom 0
+              read-file-by-line! "\"README.md" $ fn (line) (; println "\"readling line:" line) (swap! *c inc)
+              println "\"lines" @*c
             println (path-exists? "\"README.md") (path-exists? "\"build.js")
             println $ read-dir! "\"./"
             println "\"dirs:" $ execute! ([] "\"ls")
@@ -245,7 +252,7 @@
       :ns $ quote
         ns calcit.std.test.fs $ :require
           calcit.std.$meta :refer $ calcit-filename calcit-dirname
-          calcit.std.fs :refer $ read-file! append-file! write-file! path-exists? read-dir! create-dir! create-dir-all! rename! check-write-file! walk-dir! glob!
+          calcit.std.fs :refer $ read-file! append-file! write-file! path-exists? read-dir! create-dir! create-dir-all! rename! check-write-file! walk-dir! glob! read-file-by-line!
           calcit.std.process :refer $ execute!
     |calcit.std.test.json $ {}
       :defs $ {}

src/fs.rs

@@ -2,8 +2,11 @@
 
 use cirru_edn::Edn;
 use glob::glob;
-use std::fs;
+use std::fs::File;
+use std::io::{self, BufRead};
 use std::path::Path;
+use std::sync::Arc;
+use std::{fs, vec};
 use walkdir::WalkDir;
 
 #[no_mangle]
@@ -23,6 +26,48 @@ pub fn read_file(args: Vec<Edn>) -> Result<Edn, String> {
   }
 }
 
+// The output is wrapped in a Result to allow matching on errors
+// Returns an Iterator to the Reader of the lines of the file.
+fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
+where
+  P: AsRef<Path>,
+{
+  let file = File::open(filename)?;
+  Ok(io::BufReader::new(file).lines())
+}
+
+#[no_mangle]
+pub fn read_file_by_line(
+  args: Vec<Edn>,
+  handler: Arc<dyn Fn(Vec<Edn>) -> Result<Edn, String> + Send + Sync + 'static>,
+  finish: Box<dyn FnOnce() + Send + Sync + 'static>,
+) -> Result<Edn, String> {
+  if args.len() == 1 {
+    if let Edn::Str(name) = &args[0] {
+      match read_lines(&**name) {
+        Ok(lines) => {
+          // Consumes the iterator, returns an (Optional) String
+          for line in lines {
+            if let Ok(ip) = line {
+              match handler(vec![Edn::str(ip)]) {
+                Ok(_) => {}
+                Err(e) => return Err(format!("failed reading line: {}", e)),
+              }
+            }
+          }
+          finish();
+          Ok(Edn::Nil)
+        }
+        Err(e) => Err(format!("Failed to read file {name:?}: {e}")),
+      }
+    } else {
+      Err(format!("read-file-by-line expected 1 filename, got {:?}", &args[0]))
+    }
+  } else {
+    Err(format!("read-file-by-line expected 1 argument, got {args:?}"))
+  }
+}
+
 #[no_mangle]
 pub fn write_file(args: Vec<Edn>) -> Result<Edn, String> {
   if args.len() == 2 {