Simple simulator of Random Access Machine

Compile Step Run Instruction pointer:
Step delay ms     Instruction counter
Memory (cell 0 is marked by "|"): | 5 | Program: # RAM example from textbook I := 1 Z := 1 VNEJSI: if I > [0] then halt J := 1 VNITRNI: if J > I then goto DALSI [Z] := 1 Z := Z + 1 J := J + 1 goto VNITRNI DALSI: I := I + 1 goto VNEJSI # Bubble sort, cell 0 is length of input and input is in cells 1 .. [0] C := 1 outer: if C = 0 then halt C := 0 A := 1 inner: B := A + 1 if B > [0] then goto outer if [A] <= [B] then goto next T := [A] [A] := [B] [B] := T C := 1 next: A := B goto inner

Syntax is based on lecture NTIN060. The formal definition of it is:

• A program is sequence of statements executed one at time in order they are written unless specified otherwise. There is an implicit halt instruction at the very end.
• Everything written after # is ignored.
• A statement is:
  • Simple statement
  • Conditional statement written if A ?? B then Inst where A and B are expressions, Inst is a simple statement, and ?? is equality =, non-equality <>, strict inequality <, > or non-strict inequality <=, >=.
• A simple statement is:
  • halt which stops execution of the program
  • goto LABEL which tranfers execution to given label. Labels are defined name_of_label: in front of any statement, name_of_label is C-like identifier.
  • Assignment X := W where X is an expression which is not a literal value and W is (Y and Z are expressions):
    • an expression Y,
    • arithmetic operation: Y + Z, Y - Z, Y * Z, Y / Z (integer division, result rounded to zero, Z must be non-zero), and Y % Z (remainder, Z must be positive),
    • logical operation: bitwise and Y & Z, bitwise or Y | Z, bitwise exclusive-or Y ^ Z, left shift Y << Z, right shift Y >> Z.
• An expression is:
  • a literal integer like 5 or -100,
  • directly addresssed memory cell [integer],
  • indirectly addressed memory cell [[integer]].