https://github.com/aneeshdurg/lambda

A simple lambda calculus interpreter
https://github.com/aneeshdurg/lambda

haskell interpreter lambda-calculus parsec

Last synced: 19 days ago
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A simple lambda calculus interpreter

• Host: GitHub
• URL: https://github.com/aneeshdurg/lambda
• Owner: aneeshdurg
• Created: 2017-05-29T16:59:02.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2017-06-08T22:15:32.000Z (over 7 years ago)
• Last Synced: 2024-11-29T02:34:38.294Z (3 months ago)
• Topics: haskell, interpreter, lambda-calculus, parsec
• Language: Haskell
• Size: 21.5 KB
• Stars: 2
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# lambda

A simple lambda calculus interpreter

In the interest of saving time and effort I lifted a lot of template code from MP6 of cs421 - write a scheme interpreter. You might find a lot of comments pertaining to the assignment, that are irrelevent to this project. I am working on removing those, but am more interesting in getting this to work well first.

### Usage

If you haven't installed stack:

```bash

curl -sSL https://get.haskellstack.org/ | sh

```

After you have stack,

```bash

stack init

```

To run either use `stack build` to generate binaries or `stack repl` and type `main`.

### Syntax

#### Function application:

* function and arugments seperated by a space.

* functions will assume that all items to the left are arguments unless they are specified with parens or it encounters an infix binary operation (+*-/><) 

```haskell

f x

g (f x) y

f x + 1 

  == (f x) + 1

```

#### Lambda functions:

* denoted by a \, arguments are seperated by spaces

* body and arguments delimited by a .

```haskell

\x y.x + y

\x.\y.y x

(\x.x x) (\x.x x)

```

#### Variable assignment:

* Variables can only be assigned as a top level expression

```haskell

y = 1

x = (\x.x+y)

y = 3

x 2 

  == 3

y 

  == 3

```

#### Numbers and Booleans

* Currently only integers are supported

```haskell

1, 2, #t, #f

(\x . 3 > x) 2

  == #f

```

#### Binary Operators

```haskell

1+2

  == 3

5/3

 == 1

1*1

  == 1

1-1

  == 0

1 > 1

  == #t

1 < 1

  == #t

```

### TODO:

* ~~Implement logical operators~~

* ~~Implement equality operator~~

* Better show instances for types

* Tuples

* Pattern matching

* User-defined data types

* Various other things