Done:

• AST of all possible constructions (Exept $EXTRN)
• Parser supports everything that is described in the AST
• Abstract Refal Mashine
• Matching by S-vars
• Add, Sub and Mul
• Tests on Factorial and Power.

TO DO:

• Matching by S-vars
• $EXTRN - importing modules
• Much more tests and nice Ci
• Exceprions
• 'Condition' expression interpretetion
• Macrodigits and sugar for many chars : 'a' 'b' ... ~ 'ab...'

1. Clone (https://github.com/SuldinVyacheslav/Refal.git)
2. Update (cabal update)
3. Build (cabal build)
4. Run (cabal v2-run Refal X)

X = test/factorial.ref or test/power.ref