Brainfcsk

A brainfuck-derivative virtual machine / interpreter written in C#.

Syntax

All of the core commands of brainfuck have direct equivalents to brainfcsk, but are implemented using C# overloadable operators.

Brainfcsk	Brainfuck	Description
%	.	Write a byte to the console.
/	,	Read a byte from the console.
!	>	Increment the pointer.
~	<	Decrement the pointer.
+	+	Increment the value under the pointer.
-	-	Decrement the value under the pointer.
[…]	[…]	Loop while the value under the pointer is non-zero.

However, because C# operators are either unary or binary, a programmer often needs to resort to certain tricks to satisfy the C# compiler. Here are a few handy tips:

• (F)(x => ...) converts arbitrary C# code into a program fragment; x is the VM's current state.
• A*x evaluates fragment A using x as an initial state.
• (B)A evaluates fragment A using the default state as an initial state (equivalent to A*new B()).
• F._ is a no-op fragment. It's useful as a placeholder or as an 'anchor' for operators. This may also be aliased as simply _ with F _ = F._; or using static F;.
• Operators must be 'anchored' with fragments (or the no-op fragment). e.g. !_, _%_, and _[_] are all valid brainfcsk fragments.
• The compiler can easily confuse the + and - operators for ++ and --, respectively. Use white space to force it treat them correctly.
• Tie two terminal fragments together using A|B.