package Eval::TypeTiny::CodeAccumulator; use 5.008001; use strict; use warnings; BEGIN { if ( $] < 5.010 ) { require Devel::TypeTiny::Perl58Compat } } BEGIN { $Eval::TypeTiny::CodeAccumulator::AUTHORITY = 'cpan:TOBYINK'; $Eval::TypeTiny::CodeAccumulator::VERSION = '2.006000'; } $Eval::TypeTiny::CodeAccumulator::VERSION =~ tr/_//d; sub new { my $class = shift; my %self = @_ == 1 ? %{$_[0]} : @_; $self{env} ||= {}; $self{code} ||= []; $self{placeholders} ||= {}; $self{indent} ||= ''; bless \%self, $class; } sub code { join( "\n", @{ $_[0]{code} } ) } sub description { $_[0]{description} } sub env { $_[0]{env} } sub add_line { my $self = shift; my $indent = $self->{indent}; push @{ $self->{code} }, map { $indent . $_ } map { split /\n/ } @_; $self; } sub increase_indent { $_[0]{indent} .= "\t"; $_[0]; } sub decrease_indent { $_[0]{indent} =~ s/\t$//; $_[0]; } sub add_gap { push @{ $_[0]{code} }, ''; } sub add_placeholder { my ( $self, $for ) = ( shift, @_ ); my $indent = $self->{indent} || ''; $self->{placeholders}{$for} = [ scalar( @{ $self->{code} } ), $self->{indent}, ]; push @{ $self->{code} }, "$indent# placeholder [ $for ]"; if ( defined wantarray ) { return sub { $self->fill_placeholder( $for, @_ ) }; } } sub fill_placeholder { my ( $self, $for, @lines ) = ( shift, @_ ); my ( $line_number, $indent ) = @{ delete $self->{placeholders}{$for} or die }; my @indented_lines = map { $indent . $_ } map { split /\n/ } @lines; splice( @{ $self->{code} }, $line_number, 1, @indented_lines ); $self; } sub add_variable { my ( $self, $suggested_name, $reference ) = ( shift, @_ ); my $actual_name = $suggested_name; my $i = 1; while ( exists $self->{env}{$actual_name} ) { $actual_name = sprintf '%s_%d', $suggested_name, ++$i; } $self->{env}{$actual_name} = $reference; $actual_name; } sub finalize { my $self = shift; for my $p ( values %{ $self->{placeholders} } ) { splice( @{ $self->{code} }, $p->[0], 1 ); } $self; } sub compile { my ( $self, %opts ) = ( shift, @_ ); $self->{finalized}++ or $self->finalize(); require Eval::TypeTiny; return Eval::TypeTiny::eval_closure( description => $self->description, %opts, source => $self->code, environment => $self->env, ); } 1; __END__ =pod =encoding utf-8 =for stopwords pragmas coderefs =head1 NAME Eval::TypeTiny::CodeAccumulator - alternative API for Eval::TypeTiny =head1 SYNOPSIS my $make_adder = 'Eval::TypeTiny::CodeAccumulator'->new( description => 'adder', ); my $n = 40; my $varname = $make_adder->add_variable( '$addend' => \$n ); $make_adder->add_line( 'sub {' ); $make_adder->increase_indent; $make_adder->add_line( 'my $other_addend = shift;' ); $make_adder->add_gap; $make_adder->add_line( 'return ' . $varname . ' + $other_addend;' ); $make_adder->decrease_indent; $make_adder->add_line( '}' ); my $adder = $make_adder->compile; say $adder->( 2 ); ## ==> 42 =head1 STATUS This module is covered by the L. =head1 DESCRIPTION =head2 Constructor =over =item C<< new( %attrs ) >> The only currently supported attribute is C. =back =head2 Methods =over =item C<< env() >> Returns the current compilation environment, a hashref of variables to close over. =item C<< code() >> Returns the source code so far. =item C<< description() >> Returns the same description given to the constructor, if any. =item C<< add_line( @lines_of_code ) >> Adds the next line of code. =item C<< add_gap() >> Adds a blank line of code. =item C<< increase_indent() >> Increases the indentation level for subsequent lines of code. =item C<< decrease_indent() >> Decreases the indentation level for subsequent lines of code. =item C<< add_variable( $varname, $reference_to_value ) >> Adds a variable to the compilation environment so that the coderef being generated can close over it. If a variable already exists in the environment with that name, will instead add a variable with a different name and return that name. You should always continue to refer to the variable with that returned name, just in case. =item C<< add_placeholder( $placeholder_name ) >> Adds a line of code which is just a comment, but remembers its line number. =item C<< fill_placeholder( $placeholder_name, @lines_of_code ) >> Goes back to a previously inserted placeholder and replaces it with code. As an alternative, C returns a coderef, which you can call like C<< $callback->( @lines_of_code ) >>. =item C<< compile( %opts ) >> Compiles the code and returns it as a coderef. Options are passed on to C<< eval_closure >> from L, but cannot include C

 or C. C<< alias => 1 >>
is probably the option most likely to be useful, but in general
you won't need to provide any options.

=item C<< finalize() >>

This method is called by C just before compiling the code. All it
does is remove unfilled placeholder comments. It is not intended for end
users to call, but is documented as it may be a useful hook if you are
subclassing this class.

=back

=head1 BUGS

Please report any bugs to
L.

=head1 SEE ALSO

L.

=head1 AUTHOR

Toby Inkster Etobyink@cpan.orgE.

=head1 COPYRIGHT AND LICENCE

This software is copyright (c) 2022-2024 by Toby Inkster.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=head1 DISCLAIMER OF WARRANTIES

THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.