version 0.2

try, throw implemented
help screen updates
some code reorganisation
readme and doc updates

Readme.md

@@ -1,41 +1,35 @@
 
-### BUGS
+## ml
--  (read-file "nonexisting/file.csv") shows only "could not open file" - should print filename
+is a small lisp interpreter based on Adam McDaniel's wisp interpreter (https://github.com/adam-mcdaniel/wisp). It's main purpose is to learn something about more recent c++ 
-- better error reporting..for example ls_dir on non existing dir should prind `pwd` dir
 
 
-### TODO
+### Example of use
-- add debug support, at least call stack
+```
-- multiline editing (kilo editor)
+cat <<EOT > /tmp/qs.lsp
-- execute system command should capture stderr
+(defun qs (l)
-- add some mem stats to benchmark
+    (if (<= (len l) 1)
-- create pastebin like web using ml
+        l
-#### Code
+        (do
-- documentation
+            (define pivot (first l))
-- rename constants in ml_profiler.h
+            (+
-- replace to_string macro in ml.cpp
+                (qs (filter (lambda (n) (> pivot n)) l))
-- add url of source/inspiration to clib/*.cpp
+                (list pivot)
-- add instrumentation (time, nr of evals, num of atoms, debug info, debug environment etc)
+                (qs (tail (filter (lambda (n) (<= pivot n)) l)))
-#### Language
+            ))
-- support for "t" symbol as a true 
+    ))
-- support for exceptions
-- string functions
-    - compare - needed for sorting, cmp ignore case
-    - regexp functions    
-- date support
-  - decode-universal-time
-- env functions 
-  - get-env, set-env; set-env cannot be implemented in stdlib.lsp, because popen is in fact subshell
-- add include-stdlib function for other libs in stdlib dir (during startup stdlib.lsp is loaded only)
-- syntax highlighting do VS Code
 
-#### Performance
+(print (qs '(10 9 8 7 6 5 4 3 2 10)))
-- define is one of most frequent callee, when in scope with very few vars, lookup sequentially
+EOT
-- first, second are often called -> implement in c++
+
-- push_back - repeatedly without reserving size
+ml -f /tmp/qs.lsp
-- range - with for(int i...) and reserving result size can be 3times faster on (range 1 10000)
+```
-- mini_sprintf - unnecesary copying between vector and list
+#### Interactive mode
-- (do, scope ..) repeatedly assign to acc
+```
+ml
+```
+
+#### Documentation
+see /doc/Doc.md
 
 #### Compile
 ```
@@ -58,10 +52,42 @@ utils/local_install.sh
 ```
 
 
-### Example of use
+### KNOWNN BUGS
-```
+
-ml -f tests/test.lsp
+
-```
+### TODO
+- add debug support, at least call stack
+- multiline editing (see kilocpp editor)
+- execute system command should capture stderr
+- add some mem stats to benchmark
+
+#### Code
+- add documentation
+- rename constants in ml_profiler.h
+- replace to_string macro in ml.cpp
+- add instrumentation (time, nr of evals, num of atoms, debug info, debug environment etc)
+
+#### Language
+- support for "t" symbol as a true 
+- support for exceptions
+- string functions
+    - compare - needed for sorting, cmp ignore case
+    - regexp match, regexp tokens    
+- date support
+  - decode-universal-time (http://www.lispworks.com/documentation/HyperSpec/Body/f_dec_un.htm)
+- env functions 
+  - get-env, set-env; set-env cannot be implemented in stdlib.lsp, because popen is in fact subshell
+- add include-stdlib function for other libs in stdlib dir (during startup stdlib.lsp is loaded only)
+- syntax highlighting do VS Code
+
+#### Performance
+- define is one of most frequent callee, when in scope with very few vars, lookup sequentially
+- first, second are often called -> implement in c++
+- push_back - repeatedly without reserving size
+- range - with for(int i...) and reserving result size can be 3times faster on (range 1 10000)
+- mini_sprintf - unnecesary copying between vector and list
+- (do, scope ..) repeatedly assign to acc
+
 
 ### Links
 https://github.com/adam-mcdaniel/wisp  
@@ -69,6 +95,5 @@ https://github.com/dropbox/json11
 https://github.com/antirez/linenoise
 
 
-
 #### read stdout and stderr from popen
-https://stackoverflow.com/questions/478898/how-do-i-execute-a-command-and-get-the-output-of-the-command-within-c-using-po
+https://stackoverflow.com/questions/478898how-do-i-execute-a-command-and-get-the-output-of-the-command-within-c-using-po

debug.lsp

@@ -1,6 +1,20 @@
-(write-file "/tmp/f.txt" "line 1\nline 2\nline3")
+(define fc 5)
-(read-file-lines "/tmp/f.txt" (lambda (ln) (print ln)))
+(define sc 5)
 
-(define counter (lambda (ln) (do (set! ii (+ ii 1)) t ii))))
+(define first_tid (thread-create (while (> fc 0) (do (thread-under-lock "ilock" (do (set! fc (dec fc))(print 1))) (thread-sleep 500)))))
-(define ii 0)
+(define second_tid (thread-create (while (> sc 0) (do (thread-under-lock "ilock" (do (set! sc (dec sc))(print 2))) (thread-sleep 750)))))
-(print (read-file-lines "/tmp/f.txt" counter))
+
+(print "first thread id:" first_tid)
+(print "second thread id:" second_tid)
+(threads-join)
+(print "ok")
+
+(try 
+    (ls-dir "nonexisting/dir")
+    (print "dir not exists"))
+
+(try 
+    (throw "my-exception")
+    (print "exception caught:" ml-exception))
+
+(/ 1 0)

doc/Doc.md

@@ -1,6 +1,24 @@
+## Command line options
+|option|Description|
+|:-|-|
+|-h|Prints help|
+|-b|Skips loadin of std lib|
+|-c code|Runs given code|
+|-f source_file ..|Executes code in files|
+|-i|Runs REPL|
+|-p|Prints profile info at the end|
+|-v|Prints version string|
+
+
+## REPL commands
+|Command|Description|
+|:-|-|
+|!q, !quit|Quit REPL|
+|!e, !env|Display environment|
+|!x, !export|Exports command from this session. Asks for filename to save|
+
 
 ## Syntax and Special Forms
-
 |Special Form|Argument Evaluations|Purpose|
 |:-|-|-|
 |`(if cond a b)`|`if` only evaluates its `cond` argument. If `cond` is truthy (non-zero), then `a` is evaluated. Otherwise, `b` is evaluated.|This special form is the main method of control flow.|
@@ -123,12 +141,17 @@
 |`(inc n)`|Return n incremented by 1|`>>> (inc 5) => 6`|
 |`(sleep time)`|Pauses execution for time interval of seconds||
 |`(get-env var)`|Return environment variable var|`>>> (get-env "HOME") => "/Users/vaclavt"`|
-|`(second l)`|Returns second element of list||
+|`(second list)`|Returns second element of list|`>>> (second '(1 2 3 4 5 6 7)) => 2`|
-|`(third l)`|Returns third element of list||
+|`(third list)`|Returns third element of list|`>>> (third '(1 2 3 4 5 6 7)) => 3`|
-|`(fourth l)`|Returns fourth element of list||
+|`(fourth list)`|Returns fourth element of list|`>>> (fourth '(1 2 3 4 5 6 7)) => 4`|
-|`(fifth l)`|Returns fifth element of list||
+|`(fifth list)`|Returns fifth element of list|`>>> (fifth '(1 2 3 4 5 6 7)) => 5`|
-|`(nth i l)`|Return i-th elemenet of list. First element has index 1||
+|`(nth i list)`|Return i-th elemenet of list. First element has index 1|`>>> (nth 7 '(1 2 3 4 5 6 7)) => 7`|
 |`( make-csv list)`|creates csv string from list of lists|(print (make-csv '(("r1c1" "r1c2") ("r2c1" "r2c2"))))
 |`(sprintf ..)`||`>>>  (sprintf "%s, %d, %.2f" (list "string" 1000 3.14)) => "string, 1000, 3.14"`|
-
+|`(thread-create code..)`|Creates new thread, starts evalueating code and returns immediatelly thread id||
+|`(thread-under-lock lockname code)`|Acquire lock with lockname and eval code. ilock currently is only allowd lockname||
+|`(thread-sleep milisecons)`|Sleeps thread for given amount of miliseconds||
+|`(threads-join)`|Wait for all running threads to finish||
+|`(try block catch_block [finally_block])`|Evaluates block and if an exception is thrown, evaluates catch_block.Eventually in both cases evals finally_block. Return evaluated last expression from block if no exception or last expression from catch_block, if exception is thrown from block. Variable ml-exception in catch block is available with astring describing exception||
+|`(throw-exception exp_desc)`|Throws an exception with exp_desc describing what happened ||
 |`(xx ..)`|||

ml.cpp

@@ -1351,6 +1351,11 @@ namespace builtin {
 
 	    if (args.size() != 2)
 		    throw MlError(MlValue("/", divide), env, args.size() > 2 ? TOO_MANY_ARGS : TOO_FEW_ARGS);
+
+		if ((args[1].get_type_name() == "int" &&  args[1] == 0l) ||
+			(args[1].get_type_name() == "float" && args[1] == 0.0))
+				throw std::invalid_argument("divide by zero.");
+
 	    return args[0] / args[1];
     }
 
@@ -1846,17 +1851,6 @@ namespace builtin {
 		return acc;
 	}
 
-	MlValue threads_join(std::vector<MlValue> args, MlEnvironment &env) {
- 		if (args.size() != 0)
-           throw MlError(MlValue("threads_join", threads_join), env, TOO_MANY_ARGS);
-
-		std::lock_guard<std::mutex> lockGuard(register_mutex);
-		for (auto &th : threads_register)
-		    if (th.joinable()) th.join();
-  		
-	    return MlValue::nil();
-	}
-
     MlValue thread_sleep(std::vector<MlValue> args, MlEnvironment &env) {
         eval_args(args, env);
 
@@ -1866,48 +1860,51 @@ namespace builtin {
         std::this_thread::sleep_for(std::chrono::milliseconds(args[0].as_int()));
         return args[0];
     }
-}
 
-void repl(MlEnvironment &env) {
+	MlValue threads_join(std::vector<MlValue> args, MlEnvironment &env) {
-	std::string code;
+ 		if (args.size() != 0)
-	std::string input;
+           throw MlError(MlValue("threads-join", threads_join), env, TOO_MANY_ARGS);
-	MlValue tmp;
-	std::vector<MlValue> parsed;
 
-	setup_linenoise(env);
+		std::lock_guard<std::mutex> lockGuard(register_mutex);
+		for (auto &th : threads_register)
+		    if (th.joinable()) th.join();
   		
-	while (true) {
+	    return MlValue::nil();
-		char *line = linenoise(">>> ");
+	}
-		if (line == nullptr) break;
 
-		linenoise_line_read(line);
 
-		input = std::string(line);
+    MlValue try_block(std::vector<MlValue> args, MlEnvironment &env) {
+        if (args.size() < 2 || args.size() > 3)
+            throw MlError(MlValue("try", try_block), env, args.size() > 3 ? TOO_MANY_ARGS : TOO_FEW_ARGS);
 
-		if (input == "!quit" || input == "!q")
+		MlValue value;
-			break;
+		size_t cs_posisition;	// unroll stack position to state when try begun to prevent "forgotten" entries in case of exception  
-		else if (input == "!env" || input == "!e")
-			std::cout << env << std::endl;
-		else if (input == "!export" || input == "!x") {
-			std::cout << "File to export to: ";
-			std::getline(std::cin, input);
 
-			write_file_contents(input, code);
+		// try block
-		} else if (input != "") {
 		try {
-				tmp = run(input, env);
+			cs_posisition = MlPerfMon::instance().get_callstack_position();
-				std::cout << " => " << tmp.debug() << std::endl;
+            value = args[0].eval(env);
-				code += input + "\n";
+		// catch block
-			} catch (MlError &e) {
-				std::cerr << e.description() << std::endl;
-				MlPerfMon::instance().clear_callstack();
 		} catch (std::exception &e) {
-				std::cerr << e.what() << std::endl;
+			MlPerfMon::instance().restore_callstack_position(cs_posisition);
-			}
+			env.set("ml-exception", MlValue::string(e.what()));
+            value = args[1].eval(env);
 		}
+		// finally block
+       	if (args.size() == 3) {
+			args[2].eval(env);
+		}
+
+		return value;
+    }
+
+    MlValue throw_exception(std::vector<MlValue> args, MlEnvironment &env) {
+        if (args.size() != 1)
+            throw MlError(MlValue("throw", throw_exception), env, args.size() > 1 ? TOO_MANY_ARGS : TOO_FEW_ARGS);
+
+		throw std::runtime_error(args[0].as_string());
 	}
 
-	close_linenoise();
 }
 
 void load_std_lib(MlEnvironment &env) {
@@ -2037,6 +2034,10 @@ MlValue MlEnvironment::get(const std::string &name) const {
     if (name == "thread-sleep") return MlValue("thread-sleep", builtin::thread_sleep);
 	if (name == "threads-join") return MlValue("threads-join", builtin::threads_join);
 
+	// Exceptions
+	if (name == "try") return MlValue("try", builtin::try_block);
+	if (name == "throw") return MlValue("throw", builtin::throw_exception);
+
 	std::map<std::string, MlValue>::const_iterator itr = defs.find(name);
 	if (itr != defs.end()) return itr->second;
 	else if (parent_scope != nullptr) {
@@ -2061,6 +2062,50 @@ std::vector<std::string> MlEnvironment::get_lambdas_list() const {
 	return lambdas;
 }
 
+
+void repl(MlEnvironment &env) {
+	std::string code;
+	std::string input;
+	MlValue tmp;
+	std::vector<MlValue> parsed;
+
+	setup_linenoise(env);
+
+	while (true) {
+		char *line = linenoise(">>> ");
+		if (line == nullptr) break;
+
+		linenoise_line_read(line);
+
+		input = std::string(line);
+
+		if (input == "!quit" || input == "!q")
+			break;
+		else if (input == "!env" || input == "!e")
+			std::cout << env << std::endl;
+		else if (input == "!export" || input == "!x") {
+			std::cout << "File to export to: ";
+			std::getline(std::cin, input);
+
+			write_file_contents(input, code);
+		} else if (input != "") {
+			try {
+				tmp = run(input, env);
+				std::cout << " => " << tmp.debug() << std::endl;
+				code += input + "\n";
+			} catch (MlError &e) {
+				std::cerr << e.description() << std::endl;
+				MlPerfMon::instance().clear_callstack();
+			} catch (std::exception &e) {
+				std::cerr << e.what() << std::endl;
+			}
+		}
+	}
+
+	close_linenoise();
+}
+
+
 bool cmdOptionExists(char **begin, char **end, const std::string &option) { return std::find(begin, end, option) != end; }
 
 std::vector<std::string> getCmdOption(char *argv[], int argc, const std::string &option) {
@@ -2092,7 +2137,7 @@ int main(int argc, char *argv[]) {
 		}
 		// help
 		if (cmdOptionExists(argv, argv + argc, "-h")) {
-			std::cout << "Usage:\n\t-h print this help\n\t-f source_file - executes code in file\n\t-c code - runs passed code\n\t-i runs repl\n\t-b skip stdlib loading\n\t-p prints profile info at the end\n\t-v prints version string\n\n";
+			std::cout << "Usage:\n\t-h print this help\n\t-b skip stdlib loading\n\t-c code - runs code passed on command line\n\t-f source_file - executes code in file\n\t-i runs repl\n\t-p prints profile info at the end\n\t-v prints version string\n\n";
 			return 0;
 		}
 		// version

ml.h

@@ -7,7 +7,7 @@
 #include <sstream>
 #include <exception>
 
-const std::string VERSION = "ml 0.1 (" __DATE__ " " __TIME__ ")";
+const std::string VERSION = "ml 0.2 (" __DATE__ " " __TIME__ ")";
 
 const std::string STDLIB_LOADER =
 	 R"(

ml_profiler.cpp

@@ -58,6 +58,16 @@ std::string MlPerfMon::callstack() const {
     return cs.append("\n");
 }
 
+size_t MlPerfMon::get_callstack_position() {
+    return call_stack.size();
+}
+
+void MlPerfMon::restore_callstack_position(size_t to_position) {
+    if (to_position < call_stack.size()) {
+        call_stack.resize(to_position);
+    }
+}
+
 void MlPerfMon::clear_callstack() {
     call_stack.empty();
 }

ml_profiler.h

@@ -32,8 +32,13 @@ public:
 
     void add_method_call(const std::string &method);
     void end_method_call();
+
     std::string callstack() const;
+
+    size_t get_callstack_position();
+    void restore_callstack_position(size_t to_position);
     void clear_callstack();
+    
     void print_results();
 
 private: