Skip to content

Home

Jump to bottom
natsuakane edited this page Nov 7, 2023 · 9 revisions

Welcome to the Yet wiki!

Yet is a functional language, virtual environment, and virtual machine language that has a notation similar to mathematical expressions. In Yet, functions can be defined almost in the same way as formulas, and are highly compatible. In addition, the Yet language is converted to the Yet virtual machine language by the compiler, and the Yet virtual machine language can be executed on the Yet virtual environment. Furthermore, by adding the -L option to the compiler, you can transpile to Lisp language. Yet is aimed at beginners in programming to learn a functional language and a low-level language at the same time.

Index

  • How to run Yet
  • Simple calculations
  • Function
  • Input/Output
  • Conditional branching and repetition
  • Macros, includes, and operator definitions

How to run Yet

The Yet is a compiled language, so it must first be compiled into a virtual machine language and then run in a virtual environment. Compilation can be done in the terminal. The compilation command is as follows.

yetc -o VIRTUALMACHINELANGUAGEFILENAME.ye PROGRAMFILENAME.yet

If you want to output the assembly

yetc -p -o VIRTUALMACHINELANGUAGEFILENAME.ye PROGRAMFILENAME.yet

The virtual machine language file can be executed with the following command.

yet VIRTUALMACHINELANGUAGEFILENAME.ye

Simple calculations

Yet is written in infix notation. Operators, calculations, and the order of operations are as shown in the table below.

Operators Calculations Order of operations which calculate from the left or from the right?
= Assignment 1 right
? ... : conditional operator 2 left
== equal 3 left
!= equal 3 left
< more 3 left
> less 3 left
<= more or equal 3 left
>= less or equal 3 left
+ addition 4 left
- subtraction 4 left
* multiplication 5 left
/ division 5 left
% remainder 5 left
^ exponentiation 6 right
@ array reference 7 left
$ Assignment to array 7 left

Comments are enclosed in '.

Example:

3 + 5; '-> 8'
a = 3 + 3 == 6 ? 1 : 0; '-> a = 1'
a2 = (a + 1) ^ 2 ^ 3; '-> a2 = 64'

Function

Define the function as below.

FUNCNAME(ARG1, ARG2, ...) = EXPRESSION;

or

FUNCNAME(ARG1, ARG2, ...) = {
  EXPRESSION1;
  EXPRESSION2;
  ...
};

In this case, the value is returned by the return function, and local variables are defined by passing all local variable names using the declare function in the first expression.

Call the function as below

FUNCNAME(ARG1, ARG2, ...)

Example:

f(x) = 3 * x;
f(5); '-> 15'
g(x, y) = {
  declare(a);
  a = x + y;
  return(a);
};
g(10, 15); '-> 25'

Input/Output

Use the write function to write to the console, and the read function to read. The write function passes the expression to be written as an argument. The read function returns the read value as a return value.

Example:

Program

write(3 + 5);
a = read();
write(a + 1);
write(read() * read());

Execution result

$ yet VIRTUALMACHINELANGUAGEFILENAME.ye
> 8
< 5
> 6
< 4
< 6
> 24

Conditional branching and repetition

Conditional branching is performed using conditional operators or if functions.

The format of the ternary operator is as follows.

CONDITIONALEXPRESSION ? THENEXPRESSION : FALSEEXPRESSION

The if function can be called as follows.

if(CONDITIONALEXPRESSION, THENBLOCK, FALSEBLOCK)

Iteration is done by recursion.

Example:

Program

f(x) = {
  if(x == 0, {return(0);}, {write(x); f(x - 1);});
};
f(10);

Execution result

$ yet VIRTUALMACHINELANGUAGEFILENAME.ye
> 10
> 9
> 8
> 7
> 6
> 5
> 4
> 3
> 2
> 1
Clone this wiki locally