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|
use strict;
use warnings FATAL => qw(all);
no if $] >= 5.018, warnings => "experimental::smartmatch";
use File::Basename;
use lib dirname (__FILE__);
use readline qw(mal_readline set_rl_mode);
use feature qw(switch);
use Data::Dumper;
use types qw($nil $true $false _list_Q);
use reader;
use printer;
use env;
use core qw($core_ns);
# read
sub READ {
my $str = shift;
return reader::read_str($str);
}
# eval
sub eval_ast {
my($ast, $env) = @_;
given (ref $ast) {
when (/^Symbol/) {
$env->get($ast);
}
when (/^List/) {
my @lst = map {EVAL($_, $env)} @{$ast->{val}};
return List->new(\@lst);
}
when (/^Vector/) {
my @lst = map {EVAL($_, $env)} @{$ast->{val}};
return Vector->new(\@lst);
}
when (/^HashMap/) {
my $new_hm = {};
foreach my $k (keys($ast->{val})) {
$new_hm->{$k} = EVAL($ast->get($k), $env);
}
return HashMap->new($new_hm);
}
default {
return $ast;
}
}
}
sub EVAL {
my($ast, $env) = @_;
while (1) {
#print "EVAL: " . printer::_pr_str($ast) . "\n";
if (! _list_Q($ast)) {
return eval_ast($ast, $env);
}
# apply list
my ($a0, $a1, $a2, $a3) = @{$ast->{val}};
given ((ref $a0) =~ /^Symbol/ ? $$a0 : $a0) {
when (/^def!$/) {
my $res = EVAL($a2, $env);
return $env->set($a1, $res);
}
when (/^let\*$/) {
my $let_env = Env->new($env);
for(my $i=0; $i < scalar(@{$a1->{val}}); $i+=2) {
$let_env->set($a1->nth($i), EVAL($a1->nth($i+1), $let_env));
}
$ast = $a2;
$env = $let_env;
# Continue loop (TCO)
}
when (/^do$/) {
eval_ast($ast->slice(1, $#{$ast->{val}}-1), $env);
$ast = $ast->nth($#{$ast->{val}});
# Continue loop (TCO)
}
when (/^if$/) {
my $cond = EVAL($a1, $env);
if ($cond eq $nil || $cond eq $false) {
$ast = $a3 ? $a3 : $nil;
} else {
$ast = $a2;
}
# Continue loop (TCO)
}
when (/^fn\*$/) {
return Function->new(\&EVAL, $a2, $env, $a1);
}
default {
my $el = eval_ast($ast, $env);
my $f = $el->nth(0);
if ((ref $f) =~ /^Function/) {
$ast = $f->{ast};
$env = $f->gen_env($el->rest());
# Continue loop (TCO)
} else {
return &{ $f }($el->rest());
}
}
}
} # TCO while loop
}
# print
sub PRINT {
my $exp = shift;
return printer::_pr_str($exp);
}
# repl
my $repl_env = Env->new();
sub REP {
my $str = shift;
return PRINT(EVAL(READ($str), $repl_env));
}
# core.pl: defined using perl
foreach my $n (%$core_ns) {
$repl_env->set(Symbol->new($n), $core_ns->{$n});
}
$repl_env->set(Symbol->new('eval'), sub { EVAL($_[0]->nth(0), $repl_env); });
my @_argv = map {String->new($_)} @ARGV[1..$#ARGV];
$repl_env->set(Symbol->new('*ARGV*'), List->new(\@_argv));
# core.mal: defined using the language itself
REP("(def! not (fn* (a) (if a false true)))");
REP("(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))");
if (scalar(@ARGV) > 0 && $ARGV[0] eq "--raw") {
set_rl_mode("raw");
shift @ARGV;
}
if (scalar(@ARGV) > 0) {
REP("(load-file \"" . $ARGV[0] . "\")");
exit 0;
}
while (1) {
my $line = mal_readline("user> ");
if (! defined $line) { last; }
do {
local $@;
my $ret;
eval {
use autodie; # always "throw" errors
print(REP($line), "\n");
1;
} or do {
my $err = $@;
given (ref $err) {
when (/^BlankException/) {
# ignore and continue
}
default {
chomp $err;
print "Error: $err\n";
}
}
};
};
}
|
