The general idea seems to be working.

I also went with "{}" syntax.

Now to see about pre-parsing ints for speed?

js4g/StackMachine.cc

@@ -10,7 +10,7 @@ namespace
 
 	namespace C
 	{
-		constexpr bool debug= false or true;
+		constexpr bool debug= false;
 	}
 }
 
@@ -52,11 +52,12 @@ namespace Dillo::Hydrogen::JavaScriptForge	::detail::  StackMachine_m
 	StackMachine::runWord( const std::string_view word )
 	{
 		if( C::debug ) std::cerr << "Processing token: " << word << std::endl;
+		if( C::debug ) std::cerr << "Conditional depth is: " << conditionals.size() << std::endl;
 		const bool inConditional= not conditionals.empty();
 
 		if( false );
 		else if( word.empty() );
-		else if( word == "@enddef" )
+		else if( word == "}" )
 		{
 			if( not definition.has_value() )
 			{
@@ -85,7 +86,7 @@ namespace Dillo::Hydrogen::JavaScriptForge	::detail::  StackMachine_m
 		}
 		else if( inConditional and currentState != conditionals.back() )
 		{
-			if( word != "@if" )
+			if( word == "@if" )
 			{
 				conditionals.push_back( Skipped );
 				resumeConditionals.push_back( currentState );
@@ -169,11 +170,11 @@ namespace Dillo::Hydrogen::JavaScriptForge	::detail::  StackMachine_m
 			resumeConditionals.push_back( currentState );
 			currentState= If;
 		}
-		else if( word == "@define" )
+		else if( word == "{" )
 		{
 			if( definition.has_value() ) throw std::runtime_error{ "Nested definitions not supported." };
 
-			definition= next();
+			definition= pop();
 
 			if( C::debug ) std::cerr << "Starting function definition for " << definition.value() << std::endl;
 		}

js4g/factorial.js4

@@ -1,4 +1,5 @@
-@define factorial
+factorial
+{
 	@dup
 	@if
 		@dup @i_dec
@@ -7,37 +8,19 @@
 	@else
 		@i_inc
 	@endif
-@enddef
+}
 
 6 @factorial
 @print
 
+5 @factorial
+@print
 
-@define fib
-	@dup
-	@not
-	@if
-		@drop 1
-	@else
-		@dup
-		@i_dec
-		@not
-		@if
-			@drop 1
-		@else
-			@i_dec
-			@dup
-			@i_dec
-			@fib
-			@swap
-			@fib
-			@i_add
-		@endif
-	@endif
-@enddef
+junk
+{
+	@print
+}
 
 
-8 @fib @print
-
 10 @factorial
 @print

js4g/fib.js4

@@ -1,4 +1,5 @@
-@define fib
+fib
+{
 	@dup
 	@not
 	@if
@@ -19,8 +20,28 @@
 			@i_add
 		@endif
 	@endif
-@enddef
+}
+
+do_fibs
+{
+	@dup
+	@if
+		@dup
+		@i_dec
+		@do_fibs
+		@print
+		@fib
+	@else
+		0
+	@endif
+}
+
+junk
+{
+	12 @dup @print @fib @print
+}
 
 
-9 @dup @print @fib @print
+37 @do_fibs
+
 

js4g/fib.py

@@ -0,0 +1,15 @@
+def fib( a ):
+	if a == 0:
+		return 1
+	elif a == 1:
+		return 1
+	else:
+		return fib( a - 1 ) + fib( a - 2 )
+
+def do_fibs( cnt ):
+	if cnt != 0:
+		do_fibs( cnt - 1 )
+		print( fib( cnt ) )
+
+
+do_fibs( 35 )

js4g/funcs.js4

@@ -0,0 +1,9 @@
+alpha
+{
+	@print
+}
+
+bravo
+{
+	@print
+}