Deprecate _ function, Add section on postfix args to README, Add nconcat function.

README.md

@@ -10,6 +10,7 @@ func main { mega | with args ;
         { str | " " concat } swap:map
         &print swap:foreach
     "" println
+    println <{ "and with that, we're done" }
     0
 }
 ```
@@ -130,9 +131,7 @@ func main { mega | with args ;
   It sure does look like it, doesn't it? `swap` swaps the topmost two values on
   the stack. `a b -> b a`. That means we are actually calling to our iterator.
   The closure and the iterator are swapped before the call is made. `swap:map`
-  is a more concise way of writing `swap _:map`. The underscore is used as a
-  placeholder for the topmost value of the stack when making method calls,
-  because `swap :map` would try to call map on an empty expression.
+  is a more concise way of writing `swap :map`.
 
   The map function on the iterator (which is available through `:iter` on most
   collection constructs) is used to apply a function to all items in the
@@ -176,5 +175,58 @@ func main { mega | with args ;
   ```java
   for(int i = 0; i < 5; i++) { println((String) i * 5); }
   ```
+- SPL actually isn't fully concatenative. It supports postfix arguments as well:
+  ```js
+      println <{ "and with that, we're done" }
+  ```
+  This is actually not a special interpreter feature, more so is it a special
+  lexer feature. This is 100% equivalent with the non-postfix version, where the
+  string is right before the `println`.
+
+  The same can be done for object calls. Let's rewrite the previous code with
+  postfix:
+  ```js
+  Range:new <{ 0 5 }
+      :iter
+      :map <{ { | 5 * } }
+      :foreach <{ { | _str println } }
+  ```
+
+  I lied. This is now no longer 100% equivalent. Let's look at what happens
+  under the hood.
+
+  ```asm
+  call Range
+  objpush
+  const mega 0
+  const mega 5
+  objpop
+  objcall new
+  objcall iter
+  objpush
+  const func 0
+    const mega 5
+    call *
+    end
+  objpop
+  objcall map
+  objpush
+  const func 0
+    call _str
+    call println
+    end
+  objpop
+  call foreach
+  ```
+
+  You can see there are now `objpush` and `objpop` instructions. This is doing
+  the job that `swap` used to do in our previous example. However, swap can only
+  swap the topmost values, but postfix arguments allow any amount. That's why
+  there is a special instruction just for that. It can also be used through AST
+  modifications, but there is no way to get it in normal language use as it can
+  cause interpreter panics when they are used wrongly.
+
+  `objpush` and `objpop` operate on a separate stack, called the objcall stack,
+  as opposed to the main object stack.
 
 More of this tutorial to follow.

http.spl

@@ -37,24 +37,24 @@ construct net:http:Request {
         def response net:http:Response:new =response
 
         this:method:to-bytes stream:write-exact;
-        " " _:to-bytes stream:write-exact;
+        " " :to-bytes stream:write-exact;
         this:path:to-bytes stream:write-exact;
-        " HTTP/1.0\r\n" _:to-bytes stream:write-exact;
+        " HTTP/1.0\r\n" :to-bytes stream:write-exact;
 
-        "Host: " _:to-bytes stream:write-exact;
+        "Host: " :to-bytes stream:write-exact;
         this:host:to-bytes stream:write-exact;
         "\r\nConnection: Close\r\nUser-Agent: http.spl v0.1 2023-03 (spl@mail.tudbut.de)\r\n"
-            _:to-bytes stream:write-exact;
+            :to-bytes stream:write-exact;
 
         { | with header ;
             header:to-bytes stream:write-exact;
             "\r\n" stream:write-exact;
         } this:headers:foreach
 
-        "Content-Length: " _:to-bytes stream:write-exact;
+        "Content-Length: " :to-bytes stream:write-exact;
         def body this:body:to-bytes =body
         body:len _str:to-bytes stream:write-exact;
-        "\r\n\r\n" _:to-bytes stream:write-exact;
+        "\r\n\r\n" :to-bytes stream:write-exact;
         
         body stream:write-exact;
         stream:flush;

std.spl

@@ -124,14 +124,14 @@ construct List {
         array this:=array
         this
     }
-    foreach { | _:array:foreach }
-    get { any | _:array:get }
-    sget { any|null | _:array:sget }
-    len { mega | _:array:len }
-    set { any | _:array:set }
-    to-stack { .. | _:array:to-stack }
-    to-str { str | _:array:to-str }
-    sub { [any] | _:array:sub }
+    foreach { | :array:foreach }
+    get { any | :array:get }
+    sget { any|null | :array:sget }
+    len { mega | :array:len }
+    set { any | :array:set }
+    to-stack { .. | :array:to-stack }
+    to-str { str | :array:to-str }
+    sub { [any] | :array:sub }
 }
 construct _GrowingArray {
     ;
@@ -216,7 +216,7 @@ construct MicroMap {
     get-entry { [any,any]|null | with key this ;
         this:pairs:iter
             { mega | 0 swap:get key eq } swap:filter
-            _:next
+            :next
     }
     get-or-create-entry { [any,any] | with key this ;
         { [any,any] | 
@@ -227,7 +227,7 @@ construct MicroMap {
         this:pairs:iter
             { mega | 0 swap:get key eq } swap:filter
             { any | 1 swap:get } swap:map
-            _:next
+            :next
     }
     set { any | with key val this ;
         val 1 (key this:get-or-create-entry):set
@@ -235,7 +235,7 @@ construct MicroMap {
     remove { any | with key this ;
         this:pairs:iter
             { mega | 0 swap:get key eq not } swap:filter
-            _:collect
+            :collect
             List:new:from
             =pairs
     }
@@ -310,6 +310,14 @@ func concat { str | with a b ;
     a _array b _array aadd _str
 }
 
+func nconcat { str | with amt ;
+    _array
+    (amt 1 -):foreach <{ { | pop
+        swap _array swap aadd
+    } }
+    _str
+}
+
 func handle-panic { | with msg trace ;
     program-name dup if {
         program-name print " panicked at:" println
@@ -381,7 +389,13 @@ func -- { mega |
     1 -
 }
 
-func _ { | }
+def _'has-been-called 0 =_'has-been-called
+func _ { | 
+    _'has-been-called not if {
+        "WARN: The _ function is deprecated!" println
+        1 =_'has-been-called
+    }
+}
 
 func call-main-on-file { | with file ;
     catch {

test.spl

@@ -75,7 +75,7 @@ func main { int | with args ;
 
     0 5 Range:new:iter
         { | pop 10 } swap:map
-        _:sum 
+        :sum 
         _str println
 
     "" println
@@ -104,12 +104,12 @@ func main { int | with args ;
     "testing stream" println
 
     def file "test.txt" 1 StreamTypes:file:create =file 
-    "hi\n" _:to-bytes file:write-exact; 
+    "hi\n" :to-bytes file:write-exact; 
     file:close null =file
     
     "" println
     "testing split" println
-    { | println } (" " "hello how  are you" _:split):foreach
+    { | println } (" " "hello how  are you" :split):foreach
     "" println
 
     catch {