read-file-lines function added

debug.lsp

@@ -1,30 +1,6 @@
+(write-file "/tmp/f.txt" "line 1\nline 2\nline3")
+(read-file-lines "/tmp/f.txt" (lambda (ln) (print ln)))
 
-;https://github.com/anthay/Lisp90/blob/master/lisp90.cpp
-;http://howtowriteaprogram.blogspot.com/2010/11/lisp-interpreter-in-90-lines-of-c.html
-
-; https://stackoverflow.com/questions/526082/in-scheme-whats-the-point-of-set
-;; (define x 3)
-;; (defun foo() (do (define x 4) x))
-;; (defun bar() (do (set! x 4) x))
-
-;; (foo) ; returns 4
-;; x     ; still 3
-;; (bar) ; returns 4
-;; x     ; is now 4
-
-
-;; (defun mini-uuid (uuid_len) (do
-;; 	(define a_list '("_" "-" "0" "1" "2" "3" "4" "5" "6" "7" "8" "9" "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" "x" "y" "z" "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" "T" "U" "V" "W" "X" "Y" "Z"))
-;; 	(reduce (lambda (acc y) (+ acc y)) "" (map (lambda (e) (index a_list (random  0 (- (len a_list) 1)))) (range 0 uuid_len)))
-;; ))
-
-;; (benchmark "uuid 1000x :" (define i 0) (while (< i 1000) (do (mini-uuid 5) (define i (+ i 1)))))
-
-
-;; (define first_tid (thread-create (while 1 (do (thread-under-lock "ilock" (print 1)) (thread-sleep 50)))))
-;; (define second_tid (thread-create (while 1 (do (thread-under-lock "ilock" (print 2)) (thread-sleep 75)))))
-;; (print "first thread id:" first_tid)
-;; (print "second thread id:" second_tid)
-;; (threads-join)
-;; (print "ok")
-
+(define counter (lambda (ln) (do (set! ii (+ ii 1)) t ii))))
+(define ii 0)
+(print (read-file-lines "/tmp/f.txt" counter))

doc/Doc.md

@@ -56,12 +56,13 @@
 |`(random low high)`|Get a random number between two numbers inclusively||
 |`(include file)`|Read a file and execute its code||
 |`(read-file filename)`|Get the contents of a file||
-|`(write-file filename)`|Write a string to a file||
+|`(read-file-lines filename lambda)`|Reads file and for each line call lambda with passing the line as a parameter|`(read-file-lines "/tmp/f.txt" (lambda (ln) (print ln))`|
+|`(write-file filename content-str)`|Write a string to a file||
 |`(read-url url [headers])`|Reads URL|Returns list (status-code content)|
 |`(system-cmd command_str)`|Execute system command||
-|`(ls-dir ..)`|List a dir|List of directory entries|
-|`(is-file? ..)`|Returns true if passed filename is a file||
-|`(is-dir? ..)`|Returns true if passed filename is a directory||
+|`(ls-dir dir)`|List a dir|List of directory entries|
+|`(is-file? filename)`|Returns true if passed filename is a file||
+|`(is-dir? filename)`|Returns true if passed filename is a directory||
 |`(parse-csv string)`|Parse CSV string||
 |`(parse-json json_string)`|Parse JSON string||
 |`(save-csv ..)`|||

ml.cpp

@@ -19,6 +19,7 @@
 #include <sstream>
 #include <cstdlib>
 #include <iostream>
+#include <fstream>
 #include <ctime>
 #include <chrono>
 #include <thread>
@@ -1126,6 +1127,30 @@ namespace builtin {
 	    return MlValue::string(read_file_contents(args[0].as_string()));
     }
 
+    // Reads file line by line and call passed lambda
+    MlValue read_file_lines(std::vector<MlValue> args, MlEnvironment &env) {
+	    eval_args(args, env);
+
+	    if (args.size() != 2)
+		    throw MlError(MlValue("read-file-lines", read_file_lines), env, args.size() > 1 ? TOO_MANY_ARGS : TOO_FEW_ARGS);
+		// TODO check args[1].is_lambda
+
+		long lines_nr = 0;
+		std::vector<MlValue> lambda_par{MlValue::nil()};
+		std::ifstream file(args[0].as_string());
+		if (file.is_open()) {
+ 			std::string line;
+			while (std::getline(file, line)) {
+				lines_nr++;
+				lambda_par[0] = MlValue::string(line);
+				args[1].apply(lambda_par, env);
+			}
+			file.close();
+		}
+
+		return MlValue{lines_nr};
+	}
+
     // Write a string to a file
     MlValue write_file(std::vector<MlValue> args, MlEnvironment &env) {
 	    eval_args(args, env);
@@ -1978,6 +2003,7 @@ MlValue MlEnvironment::get(const std::string &name) const {
 	if (name == "random") return MlValue("random", builtin::random);
 	if (name == "include") return MlValue("include", builtin::include);
 	if (name == "read-file") return MlValue("read-file", builtin::read_file);
+	if (name == "read-file-lines") return MlValue("read-file-lines", builtin::read_file_lines);
 	if (name == "write-file") return MlValue("write-file", builtin::write_file);
 	if (name == "read-url") return MlValue("read-url", builtin::read_url);
 	if (name == "system-cmd") return MlValue("system-cmd", builtin::system_cmd);

tests/test.lsp

@@ -14,6 +14,11 @@
       (+ n (scitej (- n 1)))
     ))
 
+(write-file "/tmp/f.txt" "line 1\nline 2\nline3")
+(define counter (lambda (ln) (do (set! ii (+ ii 1)) )))
+(define ii 0)
+
+
 (define json_list (parse-json "{\"k1\":\"v1\", \"k2\":42, \"k3\":[\"a\",123,true,false,null]}"))
 
 
@@ -108,6 +113,7 @@
 (ut::define-test "result of (start-of-year)" '(ut::assert-equal 1609459200 (start-of-year (str-to-date "2021-05-13 10:32:12" "%Y-%m-%d %H:%M:%S"))))
 (ut::define-test "result of (end-of-year)" '(ut::assert-equal 1640995199 (end-of-year (str-to-date "2021-05-13 10:32:12" "%Y-%m-%d %H:%M:%S"))))
 
+(ut::define-test "(read-file-lines \"/tmp/f.txt\" counter)" '(ut::assert-equal 3 (read-file-lines "/tmp/f.txt" counter)))
 
 ;(ut::define-test "result of " '(ut::assert-true )
 (ut::run-tests)