wrote some libraries for the new powerful macro system

docs/opcodes.md

@@ -127,7 +127,8 @@ opcode | symbol | stack changes | comment
 132 | nil |  -- []        | this is the root of a list.
 134 | ++  |  X Y -- Z     | appends 2 lists or 2 binaries. Cannot append a list to a binary. Also works on pairs of lists.
 135 | split |  N Binary -- BinaryA BinaryB  | Binary A has N*8 many bits. BinaryA appended to BinaryB makes Binary.
-    136 | reverse |   F -- G | only works on lists
+136 | reverse |  	 F -- G | only works on lists
+137 | is_list | L -- L B | checks if the thing on the top of the stack is a list or not. Does not drop it.
 
 
 The following are compiler macros that make it easier to program:

examples/cond_macro.scm

@@ -0,0 +1,14 @@
+(macro = (A B)
+       '(nop A B === swap drop swap drop))
+(macro cond (X)%this cond is a macro. it generates byte code.
+       (cond (((= X ()) '(nop))%this cond is part of the pre-processor. It cannot generate byte code.
+	      (true '(nop
+		      `(car (car X))
+		      if
+		      `(car (cdr (car X)))
+		      else
+		      (cond `(cdr X))
+		      then)))))
+(cond (((= 4 5) 3)
+       (false 2)
+       (true 1)))

examples/first_macro.scm

@@ -0,0 +1,11 @@
+(macro = (A B)
+       (quote nop A B === swap drop swap drop))
+(macro twos (X)
+       (cond (((= X 0) '(nil))
+       	      (true '(cons 2 (twos (- X 1)))))))
+(macro things (X Y)
+       (cond (((= X 0) '(nil))
+       	      (true '(cons Y (things (- X 1) Y))))))
+
+
+(= (things 3 5) (cons 5 (cons 5 (cons 5 nil))))

examples/square_each_macro.scm

@@ -0,0 +1,23 @@
+(macro square (X) (* X X))
+(macro = (A B)
+       '(nop A B === swap drop swap drop))
+
+
+(macro sqr (X)
+       (cond (((= X ()) '(nil))
+	      ((is_list X) '(cons (square `(car X))
+				  (sqr `(cdr X))))
+	      (true X))))
+(macro tree (X)
+       (cond (((= X ()) '(nil))
+	      ((not (is_list X)) X)
+	      ((is_list (car X)) '(cons `(tree (car X))
+					`(tree (cdr X))))
+	     (true '(cons `(car X)
+			  `(tree (cdr X)))))))
+
+(and
+ (= (sqr (2 3))
+    (cons 4 (cons 9 nil)))
+ (= (tree (4 9))
+    (cons 4 (cons 9 nil))))

src/chalang.erl

@@ -70,6 +70,7 @@ new_state(TotalCoins, Height, Slash, Oracle, Accounts, Channels) ->
 -define(append, 134).
 -define(split, 135).
 -define(reverse, 136).
+-define(is_list, 137).
 -define(int_bits, 32).
 
 %op_gas limits our program in time.
@@ -496,6 +497,15 @@ run3(?reverse, D) ->
     [H|T] = D#d.stack,
     D#d{op_gas = D#d.op_gas - length(H),
 	stack = [lists:reverse(H)|T]};
+run3(?is_list, D) ->
+    [H|T] = D#d.stack,
+    G = if
+	    is_list(H) -> <<1:?int_bits>>;
+	    true -> <<0:?int_bits>>
+	end,
+    D#d{op_gas = D#d.op_gas - 1,
+	stack = [G|[H|T]],
+	ram_current = D#d.ram_current - 1};
 run3(?nop, D) -> D.
 
 

src/compiler_chalang.erl

@@ -254,6 +254,7 @@ w2o(<<"nil">>) -> 132;
 w2o(<<"++">>) -> 134;
 w2o(<<"split">>) -> 135;
 w2o(<<"reverse">>) -> 136;
+w2o(<<"is_list">>) -> 137;
 w2o(_) -> not_op.
 %to_opcodes([<<"or_die">>|R], F, Out) ->
     %( bool -- )