SanyaScript

Crutched graph language compilable into Python :)

Install

First, you need to install ANTLR.

Then clone the project and install dependencies:

git clone https://github.com/ARtoriouSs/sanya-script
cd sanya-script
pip install -r requirements.txt

Generate parser with ANTLR:

antlr4 -Dlanguage=Python3 -visitor -no-listener src/grammar/SanyaScript.g4

Now you can compile SanyaScript to Python and run it with:

./sanya example.sanya result
./result

You can also do PATH=$PWD:$PATH to run it from anywhere.

Description

For better understanding of grammar structure check out the grammar file, example code file and runtime repo.

1 - Types and values:

• num - numeric, it's both ints and floats:

num n = 1
num n = 123.456

Note that variable names cannot start with number.

• logic - accepts boolean yes or no, because I can :)

logic t = yes
logic f = no

• node - accepts weight prepended with '^':

node n = ^3
node n = ^123.456

• arc - accepts two nodes separated by arc:

arc a = ^1 -> ^2
arc a = ^1 -> n

Arcs can have weight in brackets (default is 0) and be undirected:

arc a = ^1 -[3]> ^2
arc a = ^1 <-[5]-> ^2

• graph - contains arcs and nodes:

graph g = [^1, ^2, ^1 -> ^2, n, a]

Graph can destructure other graphs:

graph g = [
  ^1,
  ^2 -> ^3,
  [
    n,
    [
      a,
      []
    ]
  ]
]

Note that duplicate items will be removed as graph is a set.

1.1 - Default value

If you do not initialize variable it will store nope value (like null but not so corny).

1.2 - Arrays

Any type listed above can be an array defined like:

node{} nodes

It cannot be initialized by default, but you can push items to it using <<:

nodes << ^2

To access array elements use square brackets:

node a = nodes[0]

1.3 - Constants

Constants can be defined with const keyword, like:

const node = ^2

2 - Casts

To cast any value to different type you can use the following syntax:

graph g = (graph) ^2
node n = (node) 2
# or
node n = ^2

As you can see '#' is a comment and '^' is an alias for (node) cast.

Note that some types can't be casted to some others e.g. arc to node.

3 - Operations

You can use and, or and not with booleans, and anysimple arithmetic operations with other types:

num m = 2 + 2 * 2
node n = ^m
arc a = ^m -> ^1
graph g = [^1] + (graph) a + [n]

Note that you may need to cast values to perform some operations.

4 - Blocks

Blocks for functions, cycles and conditional statements are defined using go and end

4.1 - Conditional statements

logic a = yes
if no or a go
  node n = ^1
else
  node n = ^2
end

Any non-logical types will be casted to logical when using in if condition. Everything is true unless it's nope or no.

4.2 - Functions

Functions can be defined either with return type or without it. In the second case it will return nope:

node foo(num a, num b) go
  return (node) (a + b)
end

bar(node a) go
  puts(a)
end

To call a function simply do foo(1, 2) or so on.

4.2.1 - Builtin functions

There are some builtin functions which precompiles before the program itself:

• node{} nodes(graph) - return array of graph's nodes,
• arc{} arcs(graph) - return array of graph's arcs,
• num weight(arc) - return arc's weight,
• node source(arc) - return arc's source node,
• node target(arc) - return arc's target node,
• num value(graph) - return value of the node,
• puts(any) and put(any) - prints given structure with and without newline respectively.

It searches signatures in builtins_signatures.sanya and use their implementations from runtime builtins.py.

4.3 - Cycles

There are for and while cycles. For cycles can be defined as enumeration over array or as from-to cycle:

for num i to 10 go
  puts(i)
end

for node n in nodes(g) go
  puts(n)
end

while i < 5 go
  puts(i)
  i = i + 1
end

Any non-logical types will be casted to logical when using in while condition.

P.S.

There should be a lot of imperfections and bugs as I wrote it with 0 lines of tests, but it works in general :)