Simple S-Expr to Perl 6 compiler

gistfile1.pl

grammar Scheme {
    rule TOP { ^ <program> $ {*} }
    rule program { <s_expression>* {*} }
    rule s_expression {
        <number>
        | <ident>
        | <cons_list>
        {*}
    }
    
    rule cons_list { '(' ~ ')' <s_expression>* {*} }
                          
    token number { \d+ {*} }
}                                            

class Scheme2Perl {
    method TOP($/) { make $/<program>.ast }
    method program($/) { make $/<s_expression>>>.ast.map({ $_('$') }).join(";
\n") }
    method s_expression($/) { 
        my $expression = [//] $/<number ident cons_list>;
        make $expression.ast;
    }       
    
    method cons_list($/) {      
        my @expressions = $/<s_expression>>>.ast;
        if @expressions {   
            my $func = @expressions.shift;
            make -> $sigil { 
                "-> \{ { $func('&') } \}()( { @expressions.map({ $_('$') }).j
oin(', ') } )"
            }
        } else {
            make -> $sigil { "()" }
        }
    }

    method number($/) { make -> $sigil { +$/ } }
    method ident($/) { make -> $sigil { "$sigil$/" }; }
}
                                             
say Scheme.parse('(say 1)', :actions(Scheme2Perl.new)).ast;
eval Scheme.parse('(say 1)', :actions(Scheme2Perl.new)).ast;

my $a = 2;
eval Scheme.parse('(say a)', :actions(Scheme2Perl.new)).ast;