Write Yourself a Scheme in 48 Hours

Just my own implementation (and extension?) of the Write Yourself a Scheme in 48 Hours tutorial.

Build with ghc -dynamic --make Repl.hs

Exercises

Exercises 2.1

• Rewrite parseNumber without using liftM
• Parsing \" (R5RS compliance)
• Parse other escaped characters (\n, \r, \t, \\) in strings
• Parse numbers of different bases
• Parse character literals
• Parse Reals
• Parse the full numeric tower

Exercises 2.2

• Support backquote syntactic sugar
• Support vectors
• Left-factor the grammar instead of using the try combinator

Exercises 3

• Add Primitives for type-testing: symbol?, string?, number? etc.
• Remove weak typing from unpackNum, s.t. it always returns 0 if the value is not a number
• Add symbol-handling functions

Exercises 5

• Make if only accept Bool values
• Make equal? use equal? when comparing lists (instead of eqv?)
• Implement cond and case expressions
• Implement the rest of the string functions

Extra tasks

• Parse escaped characters, even when they're not part of a string
• Eval pattern for quasiquote and unquote-splicing
• Implement eqv? for vectors