use v6; use lib IO::Path.new($?FILE).dirname; use reader; use printer; use types; use env; use core; sub read ($str) { return read_str($str); } sub eval_ast ($ast, $env) { given $ast { when MalSymbol { $env.get($ast.val) || die X::MalNotFound.new(name => $ast.val) } when MalList { MalList([$ast.map({ eval($_, $env) })]) } when MalVector { MalVector([$ast.map({ eval($_, $env) })]) } when MalHashMap { MalHashMap($ast.kv.map({ $^a => eval($^b, $env) }).Hash) } default { $ast // $NIL } } } sub eval ($ast is copy, $env is copy) { loop { return eval_ast($ast, $env) if $ast !~~ MalList; return $ast if !$ast.elems; my ($a0, $a1, $a2, $a3) = $ast.val; given $a0.val { when 'def!' { return $env.set($a1.val, eval($a2, $env)); } when 'let*' { my $new_env = MalEnv.new($env); for |$a1.val -> $key, $value { $new_env.set($key.val, eval($value, $new_env)); } $env = $new_env; $ast = $a2; } when 'do' { eval_ast(MalList([$ast[1..*-2]]), $env); $ast = $ast[*-1]; } when 'if' { if eval($a1, $env) ~~ MalNil|MalFalse { return $NIL if $a3 ~~ $NIL; $ast = $a3; } else { $ast = $a2; } } when 'fn*' { my @binds = $a1 ?? $a1.map(*.val) !! (); my &fn = -> *@args { eval($a2, MalEnv.new($env, @binds, @args)); }; return MalFunction($a2, $env, @binds, &fn); } default { my ($func, @args) = eval_ast($ast, $env).val; return $func.apply(|@args) if $func !~~ MalFunction; $ast = $func.ast; $env = MalEnv.new($func.env, $func.params, @args); } } } } sub print ($exp) { return pr_str($exp, True); } my $repl_env = MalEnv.new; sub rep ($str) { return print(eval(read($str), $repl_env)); } sub MAIN { $repl_env.set(.key, .value) for %core::ns; rep(q{(def! not (fn* (a) (if a false true)))}); while (my $line = prompt 'user> ').defined { say rep($line); CATCH { when X::MalException { .Str.say } } } }