haskeme

Compiler from I- to S-Expressions for the Scheme Programming Language

Monthly Downloads: 6

Programming language: Haskell

License: BSD 3-clause "New" or "Revised" License

Tags: Language    

Latest version: v0.1.0.4

README

haskeme

This compiler translates Scheme source code written with I-Expressions (indented expressions) into S-Expressions (symbolic expressions).

Usage

Haskeme can read and write files:

haskeme --input "program.hss" --output "program.ss"

Haskeme can also use StdIn and StdOut:

cat "program.hss" | haskeme > "program.ss"

Options

• -i or --input to specify input file
• -o or --output to specify output file

I-Expressions

I-Expressions are indented expressions and are translated by few simple rules:

• a new line translates to a new S-Expression
• same indentation as the expression above translates to a new S-Expression following the prior one
• more indentation as the expression above translates to a new S-Expression as an argument to the prior one
• less indentation as the expression above, but still more indentation as another expression above translates to a new S-Expression, while the prior and further indented block gets wrapped in extra parentheses (look at the let-example)
• S-Expression can be mixed in while staying in a single line (look at the example for mixed expressions)
• full line comments starting with ; are ignored
• a new line can be prevented from being turned into an S-Expression by prepending it with : after the indent (look at the example for prevented expressions)

Example

• I-Expressions:

  define f
    lambda
      x
      let
          y
            * x x
        if
          > x 0
          + y 1
          : #f
  

• S-Expressions:

  (define f
    (lambda (x)
      (let ((y (* x x)))
        (if (> x 0)
            (+ y 1)
            #f))))
  

• mixed I- and S-Expressions:

  define f
    lambda (x)
      let
          y (* x x)
        if (> x 0)
           + y 1
           : #f
  

Install

• install from Hackage with cabal:

  cabal install haskeme
  

• clone from GitHub and compile with cabal:

  git clone https://github.com/jumper149/haskeme.git
  cd haskeme
  cabal build
  

• clone from GitHub and compile with ghc (not recommended, use this PKGBUILD as a template)

• install from AUR (only ArchLinux-Users)

Dependencies

• ghc (make)
• cabal (opt. make)