Implementation a programming language named Tea. Exercise related to this topics:

• Recursive Programming
• C++ (as language)
• 2 Dimensional Arrays
• Struct Templates
• Stack Implementation
• Data Structures

A company's engineers decided to write simple programming language. That language would be easy to write, so has simple rules. Tea programs consist of subsequent lines of statements. Each statement has a simple job. There are 7 statements and 5 variables.

inc

Increments arg1 by arg2

dec

Decrements arg2 by arg2

mul

Multiplies arg1 by arg2

div

Divides arg1 by arg2

function

Defines a function named arg1

call

Calls arg1 with argument arg2

return

returns arg1

Engineers of the company all hated local variable declerations. So, Tea does not allow define variables. There are 5 predefined variables: [a,b,c,d,e]. A function can use these variables by accessing and operating on them. They all specific to a function. Every function uses different [a,b,c,d,e] variables. They are all 0 at initialization.

Functions are defined like;

  function foo
  //operations with call, mul, inc, div, dec
  return a  // or any variable 

This function call initializes all variables for this call except e. e is taken by parent functions variable. (But it initializes again for new function, changes on it does not change parent's e). Due to return a statement, function finally assigns its a to the parent's a variable. Each Tea program has a main function and starts from this function. It is not necessity to place functions in certain order. A function can be defined and called before or after another functions including main.

  function main
  inc a 2
  inc b 3
  call foo a
  call bar b
  inc d a
  inc d c
  return d
  function foo
  inc a 4
  div a 2
  return a
  function bar
  inc c 7
  dec c b
  return c

Lines are 0-indexed

compile:

g++ tea.cpp -o tea.exe

run:

tea.exe example_code

As I code this program, there is a problem with variables. They should initialize at start but every function uses new set of variables. Also functions can call functions, so i cannot use just one set of inputs for main, one for called functions. I needed segmentated memory. But I had limitation which is set by my instructor. In this limits:

I implemented variables as 2D array: T variables[LANGUAGE_DEPTH][5]; . Which means I have LANGUAGE_DEPTH times array of 5 variables. Variables[0] is set of variables of main function. If main calls a function i use Variables[1] for it. If it calls another, program uses Variables[2]. I say this k number in Variables[k] depth or degree of function. I use LANGUAGE_DEPTH property to scale power of Tea programming language. In other words, capability to work with nested functions. You can have more powerfull tea engine with increasing it. (Default: 5).