Perl: add readline interface and step0_repl

1 files changed, 33 insertions, 0 deletions

diff --git a/perl/step0_repl.pl b/perl/step0_repl.pl
new file mode 100644
index 0000000..8295cc0
--- /dev/null
+++ b/perl/step0_repl.pl
@@ -0,0 +1,33 @@
+use strict;
+use warnings;
+use readline qw(readline);
+
+# read
+sub READ {
+    my $str = shift;
+    return $str;
+}
+
+# eval
+sub EVAL {
+    my($ast, $env) = @_;
+    return $ast;
+}
+
+# print
+sub PRINT {
+    my $exp = shift;
+    return $exp;
+}
+
+# repl
+sub REP {
+    my $str = shift;
+    return PRINT(EVAL(READ($str), {}));
+}
+
+while (1) {
+    my $line = readline("user> ");
+    if (! defined $line) { last; }
+    print(REP($line), "\n");
+}