Evaluate a lisp data structure and return a value for use by husk

Evaluate a lisp data structure and return the LispVal or LispError result directly

 result <- evalLisp' env $ List [Atom "/", Number 1, Number 0]
 case result of
   Left err -> putStrLn $ "Error: " ++ (show err)
   Right val -> putStrLn $ show val

Evaluate a string containing Scheme code

env <- primitiveBindings

evalString env "(+ x x x)"
"3"

evalString env "(+ x x x (* 3 9))"
"30"

evalString env "(* 3 9)"
"27"

Evaluate a string and print results to console

Call into a Scheme function

A support function for eval; eval calls into this function instead of returning values directly. continueEval then uses the continuation argument to manage program control flow.

Execute an IO action and return error or Nothing if no error was thrown.

Execute an IO action and return result or an error message. This is intended for use by a REPL, where a result is always needed regardless of type.

An empty environment with the %import function. This is presently just intended for internal use by the compiler.

Environment containing the primitive forms that are built into the Scheme language. This function only includes forms that are implemented in Haskell; derived forms implemented in Scheme (such as let, list, etc) are available in the standard library which must be pulled into the environment using (load)

For the purposes of using husk as an extension language, r5rsEnv will probably be more useful.

Load the standard r5rs environment, including libraries

Load the standard r5rs environment, including libraries, but do not create the (import) binding

Load the standard r7rs environment, including libraries

Note that the only difference between this and the r5rs equivalent is that slightly less Scheme code is loaded initially.

Load the standard r7rs environment

Load haskell bindings used for the r7rs time library

Husk version number

Attempts to find the file both in the current directory and in the husk libraries. If the file is not found in the current directory but exists as a husk library, return the full path to the file in the library. Otherwise just return the given filename.

Get the full path to a data file installed for husk

Replace a list element, by index. Taken from: http://stackoverflow.com/questions/10133361/haskell-replace-element-in-list

Register optional SRFI extensions

A utility function to display the husk console banner

This is the recommended function to use to display a lisp error, instead of just using show directly.

A helper function for the special form (string-set!)

A helper function for (list-set!)

A helper function for the special form (vector-set!)

A helper function for the special form (bytevector-u8-set!)

Retrieve the value from the hashtable for the given key. An error is thrown if the key is not found.

Note this had to be made an EvalFunc because a thunk can be passed as an optional argument to be executed if the key is not found.

Arguments:

• Current continuation
• HashTable to copy
• Object that is the key to query the table for

Returns: Object containing the key's value

Add a function to the call history

Rethrow given error with call history, if available

A wrapper for macroEval and eval