fixes & enhandcements

(benchmark code..) implemented
repl completion very first version
(string xx) added
some builtin renames
a bit of comments
a bit of cocumentation
(sleep interval) added

ml_util.cpp

@@ -0,0 +1,78 @@
+
+#include "ml_util.h"
+
+#include <string>
+#include <vector>
+
+
+std::string get_history_file_dir() {
+	// TODO not portable and in function
+	std::string file{"/.ml_history.txt"};
+	const char *t = std::getenv("HOME");
+
+	if (t == nullptr) return "/tmp/" + file;
+	else return std::string{t} + "/" + file;
+}	
+
+// TODO fujtajbl
+MlEnvironment * repl_env = nullptr;
+
+void setup_linenoise(const MlEnvironment &env) {
+    repl_env = (MlEnvironment*) &env;
+
+	std::string history_file = get_history_file_dir();
+
+	linenoiseHistorySetMaxLen(500);
+	linenoiseSetCompletionCallback(completion);
+	linenoiseSetHintsCallback(hints);
+	linenoiseSetMultiLine(1);
+	linenoiseHistoryLoad(history_file.c_str()); 
+}
+
+void linenoise_line_read(char *line) {
+    linenoiseHistoryAdd(line);
+}
+
+void close_linenoise() {
+    std::string history_file = get_history_file_dir();
+
+    linenoiseHistorySave(history_file.c_str());
+}
+
+size_t last_token_index( std::string str ) {
+    // remove trailing white space
+    while( !str.empty() && std::isspace( str.back() ) ) str.pop_back() ;
+
+    // locate the last white space
+    return str.find_last_of( "() \t\n" ) ;
+}
+
+void completion(const char *buf, linenoiseCompletions *lc) {
+    if (buf != nullptr) {
+        std::string str{buf};
+
+        const auto pos = last_token_index(str); 
+        if (pos == std::string::npos)
+            return;     // cannot find what to complete
+
+        std::string token = str.substr(pos+1);
+        std::string begining = str.substr(0, pos+1);
+
+        std::vector<std::string> lambdas = repl_env->get_lambdas_list();
+        for (std::vector<std::string>::iterator t = lambdas.begin(); t != lambdas.end(); ++t) {
+            if(t->find(token) == 0) {
+                std::string completion_string = begining + *t;
+                linenoiseAddCompletion(lc, completion_string.c_str());
+            }
+        }
+    }
+}
+
+char *hints(const char *buf, int *color, int *bold) {
+//     if (!strcasecmp(buf,"hello")) {
+//         *color = 35;
+//         *bold = 0;
+//         return " World";
+//     }
+    return nullptr;
+}