calc

A stack machine capable of adding, subtracting, multiplying, and dividing.

Operations

A | indicates the program is waiting for an operation. Operations are defined by a single character, possibly with one integer parameter separated by a space.

help

Print a help message.

| h

exit

Exit the program.

| .

push

Push a value onto the stack.

| < 123

pop

Print the value at the top of the stack and pop it.

| >

op

Pop the two values on top of the stack, execute an operation, and push the result back onto the stack.

3 * (1 + 4)

| < 1
| < 4
| +
| < 3
| *
| >

Outputs

Values printed without a | are outputs.

number

The result of a pop.

“nil”

There is nothing on the stack.

“err”

Error executing the last command. The stack was not changed.

“full”

The stack is full.