Fix Readme examples (#389)

* Add tests for files in README

Test readme examples to make sure:
- Language is at the point where we expect it to
  be.
- And that the examples themselves are correct.

This servers as a baseline for current hotfixes.
We will also update the examples in the README
accordingly so that it conforms the current
grammar.

* Rename factorial check file

* Update some README examples

* is a logic excepts class identifier

* [ci skip] is a logic excepts class identifier

Bunch of other small modifications uncovered
while trying to fix the README examples.

* Fix handle test

* Update version numbers in README

Author: JSAbrahams

README.md

@@ -16,11 +16,10 @@
     <a href="https://github.com/JSAbrahams/mamba/blob/main/LICENSE">
     <img src="https://img.shields.io/github/license/JSAbrahams/mamba.svg?style=for-the-badge" alt="License"/>
     </a>
-    <img src="https://img.shields.io/badge/Built%20with-%E2%99%A5-red.svg?style=for-the-badge" alt="Built with Love"/>
-    <br/>
     <a href="https://github.com/JSAbrahams/mamba/milestones">
     <img src="https://img.shields.io/github/milestones/open/JSAbrahams/mamba?style=for-the-badge" alt="Active milestones"/>
     </a>
+    <img src="https://img.shields.io/badge/Built%20with-%E2%99%A5-red.svg?style=for-the-badge" alt="Built with Love"/>
 </p>
 
 <h1 align="center">Mamba</h1>
@@ -56,7 +55,7 @@ def factorial(x: Int) -> Int => match x
 
 def num := input("Compute factorial: ")
 if num.is_digit() then
-    def result := factorial(int(num))
+    def result := factorial(Int(num))
     print("Factorial {num} is: {result}.")
 else
     print("Input was not an integer.")
@@ -93,17 +92,21 @@ class MyServer(def ip_address: IPv4Address)
     def is_connected: Bool     := False
     def _last_message: String? := None
 
-    def last_sent(fin self) -> String raise ServerError => if self._last_message /= None 
-        then self._last_message
-        else raise ServerError("No last message!")
+    def last_sent(fin self) -> String raise [ServerError] =>
+        if self._last_message != None then
+            self._last_message
+        else
+            raise ServerError("No last message!")
 
     def connect(self) =>
         self.is_connected := True
         print(always_the_same_message)
 
-    def send(self, message: String) raise ServerError => if self.is_connected 
-        then self._last_message := message
-        else raise ServerError("Not connected!")
+    def send(self, message: String) raise [ServerError] =>
+        if self.is_connected then
+            self._last_message := message
+        else
+            raise ServerError("Not connected!")
 
     def disconnect(self) => self.is_connected := False
 ```
@@ -127,7 +130,7 @@ print("last message sent before disconnect: \"{my_server.last_sent()}\".")
 my_server.disconnect()
 ```
 
-### 🗃 Type refinement (🇻 0.6+)
+### 🗃 Type refinement (🇻 0.4.1+)
 
 As shown above Mamba has a type system.
 Mamba however also has type refinement features to assign additional properties to types.
@@ -152,9 +155,11 @@ class MyServer(self: DisConnMyServer, def ip_address: IPv4Address): Server
     def is_connected: Bool     := False
     def _last_message: String? := None
 
-    def last_sent(self) -> String raise ServerErr => if self.last_message /= None 
-        then self._last_message
-        else raise ServerError("No last message!")
+    def last_sent(self) -> String raise ServerErr => 
+        if self.last_message != None then 
+            self._last_message
+        else
+            raise ServerError("No last message!")
 
     def connect(self: DisConnMyServer) => self.is_connected := True
 
@@ -208,7 +213,7 @@ Type refinement allows us to do some additional things:
   that certain conditions hold. We can simply ask whether a given object is a certain state by checking whether it is a
   certain type.
 
-### 🔒 Pure functions (🇻 0.4.1)
+### 🔒 Pure functions (🇻 0.4.1+)
 
 Mamba has features to ensure that functions are pure, meaning that if `x = y`, for any `f`, `f(x) = f(y)`.
 (Except if the output of the function is say `None` or `NaN`.)
@@ -242,7 +247,7 @@ def pure sin(x: Int) =>
     ans
 ```
 
-### ⚠ Error handling (🇻 0.5+)
+### ⚠ Error handling
 
 Unlike Python, Mamba does not have `try` `except` and `finally` (or `try` `catch` as it is sometimes known).
 Instead, we aim to directly handle errors on-site so the origin of errors is more tracable.
@@ -274,15 +279,16 @@ This also prevents us from wrapping large code blocks in a `try`, where it might
 This is shown below:
 
 ```mamba
-def a := function_may_throw_err() handle
-    err: MyErr => 
-        print("We have a problem: {err.message}.")
-        return  # we return, halting execution
-    err: MyOtherErr => 
-        print("We have another problem: {err.message}.")
-        0  # ... or we assign default value 0 to a
-        
-print("a has value {a}.")
+def g() =>
+    def a := function_may_throw_err() handle
+        err: MyErr =>
+            print("We have a problem: {err.message}.")
+            return  # we return, halting execution
+        err: MyOtherErr =>
+            print("We have another problem: {err.message}.")
+            0  # ... or we assign default value 0 to a
+
+    print("a has value {a}.")
 ```
 
 If we don't want to use a `handle`, we can simply use `raise` after a statement or exception to show that its execution might result in an exception, but we don't want to handle that here.

src/check/resource/primitive/bool.py

@@ -1,5 +1,5 @@
 class bool:
-    def __init__(self, arg: bool) -> bool: pass
+    def __init__(self, arg: Union[int, str, bool]) -> bool: pass
 
     def __bool__(self) -> bool: pass
     def __str__(self) -> str: pass

tests/resource/valid/readme_example/error_handling.mamba

@@ -0,0 +1,18 @@
+from ipaddress import IPv4Address
+
+class ServerErr: Exception
+class MyServer(def ip_address: IPv4Address):
+    def send(self, message: String) =>
+        pass
+    def disconnect() => pass
+
+class ConnectedMyServer: MyServer
+
+def fin some_ip := ipaddress.ip_address("151.101.193.140")
+def my_server   := MyServer(some_ip)
+
+def message := "Hello World!"
+my_server.send(message) handle
+    err: ServerErr => print("Error while sending message: \"{message}\": {err}")
+
+if my_server isa ConnectedMyServer then my_server.disconnect()

tests/resource/valid/readme_example/error_handling_check.py

@@ -0,0 +1,18 @@
+from ipaddress import IPv4Address
+from server import MyServer
+
+class MyServer:
+    def __init__(self, ip_address: IPv4Address):
+        self.ip_address = ip_address
+
+fin some_ip = ipaddress.ip_address("151.101.193.140")
+my_server = MyServer(some_ip)
+
+def message = "Hello World!"
+try:
+    my_server.send(message)
+except ServerErr as err:
+    print(f"Error while sending message: \"{message}\": {err}")
+
+if isinstance(my_server, ConnectedMyServer):
+    my_server.disconnect()

tests/resource/valid/readme_example/factorial_dynamic.mamba

@@ -0,0 +1,6 @@
+def factorial(x: Int) -> Int => match x
+    0 => 1
+    n =>
+        def ans := 1
+        for i in 1 ..= n do ans := ans * i
+        ans

tests/resource/valid/readme_example/factorial_dynamic_check.py

@@ -0,0 +1,9 @@
+def factorial(x: int) -> int:
+    match x:
+        case 0:
+            return 1
+        case n:
+            ans = 1
+            for i in range(1, n, 1):
+                ans = ans * i
+            return ans

tests/resource/valid/readme_example/handle.mamba

@@ -0,0 +1,17 @@
+class MyErr(def message: String): Exception
+class MyOtherErr(def message: String): Exception
+
+def function_may_throw_err() -> Int raise [MyErr] => 10
+
+def g() =>
+    def a := function_may_throw_err() handle
+        err: MyErr =>
+            print("We have a problem: {err.message}.")
+            return  # we return, halting execution
+        err: MyOtherErr =>
+            print("We have another problem: {err.message}.")
+            0  # ... or we assign default value 0 to a
+
+    print("a has value {a}.")
+
+g()

tests/resource/valid/readme_example/handle_check.py

@@ -0,0 +1,27 @@
+class MyErr(Exception):
+    def __init__(self, message: str):
+        Exception.__init__(self)
+        self.message = message
+
+class MyOtherErr(Exception):
+    def __init__(self, message: str):
+        Exception.__init__(self)
+        self.message = message
+
+def function_may_throw_err() -> int:
+    return 10
+
+def g():
+    a = None
+    try:
+        a: int = function_may_throw_err()
+    except MyErr as err:
+        print(f"We have a problem: {err.message}.")
+        return None
+    except MyOtherErr as err:
+        print(f"We have another problem: {err.message}.")
+        a = 0
+
+    print(f"a has value {a}.")
+
+g()

tests/resource/valid/readme_example/pos_int.mamba

@@ -0,0 +1,6 @@
+type PosInt: Int when
+    self >= 0 else "Must be greater than 0"
+
+def factorial(x: PosInt) -> PosInt => match x
+    0 => 1
+    n => n * factorial(n - 1)

tests/resource/valid/readme_example/pure_functions.mamba

@@ -0,0 +1,9 @@
+# taylor is immutable, its value does not change during execution
+def fin taylor := 7
+
+# the sin function is pure, its output depends solely on the input
+def pure sin(x: Int) =>
+    def ans := x
+    for i in 1 ..= taylor .. 2 do
+        ans := ans + (x ^ (i + 2)) / (factorial (i + 2))
+    ans