# Qlang

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## Do you know the one best language in this world?

#### I believe mathematics is absolutely that one.

## How can we deal something as great as mathematics in a discrete world?

#### Q-language is the answer.

Q lets you have a sense of mathematics using a keyboard, the same as you would with a pen.

```
+---Discrete world---+                    +------Mathematics-------+
|        Ruby        |                    |        axiom           |
|        TeX         |<------   Q  ------>|    Uncountable noun    |
|       Python       |                    |  real number topology  |
+--------------------+                    +------------------------+
```

## Demo

The code below is input and output for the q-lang interpreter

(you can try it by `qlang -i`)

### Differentiate

```
d/dx(cos(x))
=> ( - sin( x ) )

# You can omit parentheses

d/dx log(x)
=> ( 1 / x )

d/dy xy
=> ( x )

d/dx e^x
=> e ^ x
```

### Integrate

```
S(log(x)dx)[0..1]
=> - oo

S(sin(x)dx)[0..pi]
=> 2.0

S(cos(x)dx)[0..pi]
=> 0.0
```

### Limit

```
lim[x->oo] (1 + 1/x)^x
=> 2.7182682371744895

lim[x->0] 1/x
=> oo
```

### Sigma
```
∑[x=0,10] x
=> 55.0
```

### Matrix

```
(1 2 3; 4 5 6)
=> (1 2 3; 4 5 6)

(1 2 3; 4 5 6) + (1 2 3; 4 5 6)
=> (2 4 6; 8 10 12)

(1 2 3; 4 5 6) * (1 2 3)
=> (14 32)
```

### Function
```
f(x, y) = xy
f(1, 2)
=> 2
```


## How to use

Install qlang gem.

    $ gem install qlang

## Interpreter

    $ qlang -i
    Q:->

## Use as native language

### Compile into R

    $ qlang -r foo.q

### Compile into Ruby

    $ qlang -rb foo.q

### Compile into Python

    $ qlang -py foo.q


## Use as math template within other langs


```rb
class ExampleClass
  def example_method
    #your Ruby codes
    ......

I love mathematics.
  a = (1 3 4)
  # your Q codes
Q.E.D

  end
end
```

    $ qlang -rb example.rb


```rb
class ExampleClass
  def example_method
    #your Ruby codes
    ......

    a = Vector[1, 3, 4]

  end
end
```

## Contributing

Any PRs or issues are welcome.
You can become a commiter, even if you only commit once.