mylisp

My lisp interpreter in Go. Inspired by scheme syntax. See :

• https://web.mit.edu/scheme/scheme_v9.2/doc/mit-scheme-ref/index.html (prefered)
• https://www.gnu.org/software/guile/manual/guile.html#SEC_Contents
• https://www.scheme.com/tspl4/

Examples

Examples lisp/scheme files are in the examples folder.

You can run an example directly from the command line with :

go run . -l "examples/counter.scm"

Builtins and help

You can list the available keywords built-in with * (keywords )*.

You can display help on one or more keywoards ( kw1, kw2 ...) by evaluationg ( help kw1 kw2 )

Non standard keywords :

New keywords :

• ( debug value ) sets the debug/trace level
• ( join-path p1 p2 ... ) constructs a path from path components, using system file separator
• ( load fullPathName ) loads and evaluate a file
• ( file-sep ) retuns the system file separator
• ( version ) gets the current version of the interpreter
• ( help keyword ) : display online help for keyword

Extended behaviour vs standard :

• ( display x1 x2 ... ) : display can display zero, one or more Terms.

Numbers

• Numbers are integer or rationnal.
• The decimal point is not accepted.
• Rational are written 8/3. ( no space ! )
• Rational are immutable and always normalized, with a positive denominator.
• Zero is 0/1, while 1/0 represents NaN.

Strings

• string litterlas are quoted with double quotes (")
• there is no escaping, string litteral may contain newline directly

Errors

Error is a specific type that can be returned from evaluation.