Merge pull request #442 from codecrafters-io/andy/hints

Add Rust and Go hints to stage 2

Author: andy1li

solutions/go/02-rg2/config.yml

@@ -0,0 +1,25 @@
+hints:
+  - title_markdown: "How do I access the client's TCP connection?"
+    body_markdown: |-
+      This is returned by the [`Accept()`](https://pkg.go.dev/net#Listener.Accept) method.
+
+      ```go
+      # The return value value includes:
+      # 1. the client's connection (a `net.Conn` object)
+      # 2. an error (if any)
+      conn, err := listener.Accept()
+      ```
+
+      Each [`net.Conn`](https://pkg.go.dev/net#Conn) represents an active connection from a client.
+
+  - title_markdown: "How do I send a response to the client?"
+    body_markdown: |-
+      Use the [`Write()`](https://pkg.go.dev/net#Conn.Write) method on the client's connection:
+
+      ```go
+      # Send the response to the client
+      conn.Write([]byte("+PONG\r\n"))
+      ```
+
+      - The above code uses `[]byte()` to convert the string to a [byte slice](https://go.dev/blog/slices-intro#slices).
+      - `+PONG\r\n` is the string "PONG" encoded as a [RESP simple string](https://redis.io/docs/latest/develop/reference/protocol-spec/#simple-strings).

solutions/python/02-rg2/config.yml

@@ -14,12 +14,12 @@ hints:
 
   - title_markdown: "How do I send a response to the client?"
     body_markdown: |-
-      Use the [`sendall()`](https://docs.python.org/3/library/socket.html#socket.socket.sendall) method on the client's connection for this:
+      Use the [`sendall()`](https://docs.python.org/3/library/socket.html#socket.socket.sendall) method on the client's connection:
 
       ```python
       # Send the response to the client
       connection.sendall(b"+PONG\r\n")
       ```
 
-      - The above code uses `b` to convert the string to a [bytes object](https://docs.python.org/3/library/stdtypes.html#bytes).
+      - The above code uses `b` to create a [bytes object](https://docs.python.org/3/library/stdtypes.html#bytes).
       - `+PONG\r\n` is the string "PONG" encoded as a [RESP simple string](https://redis.io/docs/latest/develop/reference/protocol-spec/#simple-strings).

solutions/rust/02-rg2/config.yml

@@ -0,0 +1,24 @@
+hints:
+  - title_markdown: "How do I access the client's TCP connection?"
+    body_markdown: |-
+      This is returned by the [`incoming()`](https://doc.rust-lang.org/std/net/struct.TcpListener.html#method.into_incoming) method.
+
+      ```rust
+      # The return value is an iterator that provides a sequence of `TcpStream` objects.
+      for stream in listener.incoming()
+      ```
+
+      Each [`TcpStream`](https://doc.rust-lang.org/std/net/struct.TcpStream.html) represents an active connection from a client.
+
+  - title_markdown: "How do I send a response to the client?"
+    body_markdown: |-
+      Use the [`write_all()`](https://doc.rust-lang.org/std/io/trait.Write.html#method.write_all) method on the client's connection:
+
+      ```rust
+      # Send the response to the client
+      stream.write_all(b"+PONG\r\n").unwrap();
+      ```
+
+      - The above code uses `b` to create a [byte string literal](https://doc.rust-lang.org/reference/tokens.html#byte-string-literals).
+      - `+PONG\r\n` is the string "PONG" encoded as a [RESP simple string](https://redis.io/docs/latest/develop/reference/protocol-spec/#simple-strings).
+      - To satisfy the Rust compiler, you also need to import the [Write](https://doc.rust-lang.org/std/io/trait.Write.html) trait and mark the TcpStream as [mutable](https://doc.rust-lang.org/book/ch03-01-variables-and-mutability.html) in order to use `write_all()`.