upd add pattern matching examples

docs/readme.md

@@ -134,7 +134,164 @@ int my_func(int x) {
 note that compiler can optimise few comparison conditions for ```switch``` better than that in ```if .. else```.  
 
 
-### 2.4.1 pattern matching examples
+### 2.4.1 pattern matching on strings
+There are Pattern Matching on strings/binaries in Erlang, that looks like:
+```
+my_func(<<"test", Rest/binary>>) -> true;
+my_func(_) -> false.
+
+% or
+my_func("test" ++ Rest) -> true;
+my_func(_) -> false.
+```
+similar code in D - dlang:
+```
+bool my_func(string str){
+    if(str.length >= 4 && str[0..4] == "test"){
+        return true;
+    }
+    return false;
+}
+
+// also we can get rest
+
+import std.stdio;
+
+bool my_func(string str, out string rest){
+    if(str.length >= 4 && str[0..4] == "test"){
+        rest = str[4..$];
+        return true;
+    }
+    rest = str;
+    return false;
+}
+
+void main(){
+    string rest;
+    writeln(my_func("test123", rest)); // true, rest = "123"
+    writeln(rest); // "123"
+    writeln(my_func("example", rest)); // false, rest = "example"
+}
+
+// also we can to match from string ending
+bool has_end_test(string str){
+    if(str.length >= 4){
+        if(str[$-4 .. $] == "test"){
+            return true;
+        }
+    }
+    return false;
+}
+```
+In My Humble Opinion be better to make this syntax similar (laconic) as in Erlang.
+
+
+### 2.4.2 pattern matching examples
+```
+// left = function type, right = arguments type
+bool = string str
+has_begin_test "test" ++ _ = true
+has_begin_test _ = false
+
+->
+
+bool has_begin_test(string str){
+    if(str.length >= 4 && str[0..4] == "test"){
+        return true;
+    }
+    return false;
+}
+```
+
+```
+// left = function type, right = arguments type
+bool = string str, out string rest
+has_begin_test    "test" ++ rest = true
+has_begin_test    _ = false
+
+->
+
+// import std.stdio;
+
+bool has_begin_test(string str, out string rest){
+    if(str.length >= 4 && str[0..4] == "test"){
+        rest = str[4..$];
+        return true;
+    }
+    rest = str;
+    return false;
+}
+
+/*
+void main(){
+    string rest;
+    
+    writeln(has_begin_test("test123", rest)); // true, rest = "123"
+    writeln(rest); // "123"
+    
+    writeln(has_begin_test("test", rest)); // true, rest = ""
+    writeln(rest); // ""
+    
+    writeln(has_begin_test("example", rest)); // false, rest = "example"
+    writeln(rest); // "example"
+}
+*/
+```
+
+```
+// left = function type, right = arguments type
+bool = string str
+has_end_test _ ++ "test" = true
+has_end_test _ = false
+
+->
+
+// match from string ending
+bool has_end_test(string str){
+    if(str.length >= 4){
+        if(str[$-4 .. $] == "test"){
+            return true;
+        }
+    }
+    return false;
+}
+```
+
+```
+// left = function type, right = arguments type
+bool = string str, out string rest
+has_end_test rest ++ "test" = true
+has_end_test _ = false
+
+->
+
+// import std.stdio;
+
+bool has_end_test(string str, out string rest){
+    if(str.length >= 4 && str[$-4 .. $] == "test"){
+        rest = str[0 .. $-4];
+        return true;
+    }
+    rest = str;
+    return false;
+}
+
+/*
+void main() {
+    string rest;
+    
+    writeln(has_end_test("hellotest", rest)); // true, rest = "hello"
+    writeln(rest); // "hello"
+    
+    writeln(has_end_test("example", rest)); // false, rest = "example"
+    writeln(rest); // "example"
+    
+    writeln(has_end_test("test", rest)); // true, rest = ""
+    writeln(rest); // ""
+}
+*/
+```
+
 ```
 // left = function type, right = arguments type
 int = int x