Random Access Machine

Manual

1. Set up CMakeLists.txt

add_executable(exec *.cpp)

add_subdirectory(ram)
target_link_libraries(exec PUBLIC ram)

2. Include the library and create an instance of RAM

#include "RAM.h"
using namespace RAM;
...
Machine m;

3. For further identification, give it a name

m.set_name("super-machine"); // optional

4. Give the machine a stream to write to. Specify the logging mode

ofstream ls("log.txt");
m.set_log_stream(ls); // default -> cout
m.be_verbose(true); // default -> false

5. Provide it with the input stream to take the RAM source code from

ifstream ss("source.txt");
m.set_code(ss);

6. In order to set the input pick one of the following options

ifstream is("input.txt");
m.set_input(is);

m.set_input({ 6, 1, 0, 1, 0, 0, 1 });

7. Run the code

auto output = m.run();

8. Check the logs or print the out tape

cout << output;

Notes

• The machine does not control any uninitialized cells access. In case of reaching such, random value is generated as its content. Logs disclose these occurrences with the corresponding messages
• There are no any prompts or tips on the emerged issue with the source code correctness. Error message is the only sign of the ill-formed source code
• All the functions are to be in capitals with mandatory parentheses following (even for HALT())

Example

Task: The program receives n + 1 values. The first value is n. Among other values, every single one is either 0 or 1. Tell the value that prevails among the given n values. In case, there are more 1s than 0s, print 1. If 0s - print 0. If the values occur the same number of times, the output is to be two-character 1,0.

Note: It is forbidden to use negative values everywhere

Solution sample

LOAD(=0)
STORE(2)
STORE(3)
READ(1)
LOAD(1)
JZERO(EQ)

JZERO(A) R
READ(0)
JGTZ(U)
JUMP(Z)

LOAD(3) U
ADD(=1)
STORE(3)
JUMP(N)

LOAD(2) Z
ADD(=1)
STORE(2)
JUMP(N)

LOAD(1) N
SUB(=1)
STORE(1)
JUMP(R)

WRITE(=1) EQ
WRITE(=0)
HALT()

LOAD(2) A
JZERO(FU)
LOAD(3)
JZERO(FZ)
DIV(2)
JZERO(FZ)
LOAD(2)
DIV(3)
JZERO(FU)
JUMP(EQ)

WRITE(=1) FU
HALT()

WRITE(=0) FZ

Outputs

m.set_input({3, 1, 0, 1});
Output: { 1 }

m.set_input({ 6, 1, 0, 1, 0, 0, 0 });
Output: { 0 }

m.set_input({6, 1, 0, 1, 0, 0, 1});
Output: { 1, 0 }

m.set_input({0});
Output: { 1, 0 }

Detailed logs are in demo_tasks\<task-name>\log.txt

Copyright 2022, Sergey Lagov