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# Copyright 2022 Jeffrey Kegler
# This file is part of Marpa::R2. Marpa::R2 is free software: you can
# redistribute it and/or modify it under the terms of the GNU Lesser
# General Public License as published by the Free Software Foundation,
# either version 3 of the License, or (at your option) any later version.
#
# Marpa::R2 is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser
# General Public License along with Marpa::R2. If not, see
# http://www.gnu.org/licenses/.
package Marpa::R2::Stuifzand;
use 5.010001;
use strict;
use warnings;
use vars qw($VERSION $STRING_VERSION);
$VERSION = '12.000000';
$STRING_VERSION = $VERSION;
## no critic(BuiltinFunctions::ProhibitStringyEval)
$VERSION = eval $VERSION;
## use critic
package Marpa::R2::Internal::Stuifzand;
use English qw( -no_match_vars );
# Internal names end in ']' and are distinguished by prefix.
#
# Suffixed with '[prec%d]' --
# a symbol created to implement precedence.
# Suffix is removed to restore 'original'.
#
# Prefixed with '[[' -- a character class
# These are their own 'original'.
#
# Prefixed with '[:' -- a reserved symbol, one which in the
# grammars start with a colon.
# These are their own 'original'.
#
# Of the form '[Lex-42]' - where for '42' any other
# decimal number can be subsituted. Anonymous lexicals.
# These symbols are their own originals.
#
# Prefixed with '[SYMBOL#' - a unnamed internal symbol.
# Seeing these
# indicates some sort of internal error. If seen,
# they will be treated as their own original.
#
# Suffixed with '[Sep]' indicates an internal version
# of a sequence separator. These are their own
# original, because otherwise the "original" name
# would conflict with the LHS of the sequence.
#
my %node_status =
map { ; ($_ , q{} ) }
qw(
action
action_name
adverb_item
adverb_list
adverb_list_items
alternative
alternatives
array_descriptor
bare_name
blessing
blessing_name
boolean
bracketed_name
default_rule
empty_rule
group_association
left_association
lhs
op_declare
op_declare_bnf
parenthesized_rhs_primary_list
Perl_name
priorities
priority_rule
proper_specification
quantified_rule
quantifier
reserved_action_name
reserved_blessing_name
rhs
rhs_primary
rhs_primary_list
right_association
separator_specification
single_symbol
standard_name
start_rule
statement
statements
symbol
symbol_name
);
$node_status{'Marpa::R2::Internal::MetaAST'} = q{};
$node_status{array_descriptor} = "Actions in the form of array descriptors are not allowed";
$node_status{character_class} = "Character classes are not allowed";
$node_status{completion_event_declaration} = "Completion events are not allowed";
$node_status{discard_rule} = ":discard rules are not allowed";
$node_status{event_specification} = qq{The "event" adverb is not allowed};
$node_status{latm_specification} = qq{The "latm" adverb is not allowed};
$node_status{lexeme_default_statement} = "The lexeme default statement is not allowed";
$node_status{lexeme_rule} = "Lexeme statements are not allowed";
$node_status{nulled_event_declaration} = "Nulled events are not allowed";
$node_status{op_declare_match} = "lexical rules are not allowed";
$node_status{pause_specification} = "The pause adverb is not allowed";
$node_status{prediction_event_declaration} = "Prediction events are not allowed";
$node_status{priority_specification} = "The priority adverb is not allowed";
$node_status{single_quoted_string} = "Quoted strings are not allowed";
$node_status{alternative_name} = "Alternative naming is not allowed";
$node_status{naming} = "Alternative naming is not allowed";
my %catch_error_node =
map { ; ($_ , 1 ) }
qw( alternative statement );
# This code goes to some trouble to report errors with a large enough contet
# to be meaningful -- rules or alternatives
sub Marpa::R2::Internal::Stuifzand::check_ast_node {
my ($node) = @_;
my $ref_type = ref $node;
return if not $ref_type;
$ref_type =~ s/\A Marpa::R2::Internal::MetaAST_Nodes:: //xms;
my $report_error = 0;
my $problem = $node_status{$ref_type};
my $catch_error = $catch_error_node{$ref_type};
return qq{Internal error: Unknown AST node (type "$ref_type") in Stuifzand grammar}
if not defined $problem;
# "Normal" meaning other than catching errors
NORMAL_PROCESSING: {
if ($problem) {
return $problem if not $catch_error_node{$ref_type};
last NORMAL_PROCESSING;
}
for my $sub_node ( @{$node} ) {
$problem = Marpa::R2::Internal::Stuifzand::check_ast_node($sub_node);
if ($problem) {
return $problem if not $catch_error;
last NORMAL_PROCESSING;
}
} ## end for my $sub_node ( @{$node} )
return;
} ## end NORMAL_PROCESSING:
# If we are here, we are catching an error
my ( $start, $end ) = @{$node};
my $problem_was_here = substr ${$Marpa::R2::Internal::P_SOURCE}, $start,
($end-$start+1);
chomp $problem_was_here;
chomp $problem;
Marpa::R2::exception(
"Stuifzand (BNF) interface grammar is using a disallowed feature\n",
q{ } . $problem . "\n",
" Problem was in the following text:\n",
$problem_was_here,
"\n"
);
} ## end sub Marpa::R2::Internal::Stuifzand::check_ast_node
sub parse_rules {
my ($p_rules_source) = @_;
my $self = {};
my $ast = Marpa::R2::Internal::MetaAST->new($p_rules_source);
{
local $Marpa::R2::Internal::P_SOURCE = $p_rules_source;
my $problem = Marpa::R2::Internal::Stuifzand::check_ast_node(
$ast->{top_node} );
## Uncaught problem -- should not happen
if ($problem) {
Marpa::R2::exception(
"Stuifzand (BNF) interface grammar has a problem\n",
q{ } . $problem . "\n",
);
} ## end if ($problem)
}
my $hashed_ast = $ast->ast_to_hash();
my $start_lhs = $hashed_ast->{'start_lhs'} // $hashed_ast->{'first_lhs'};
Marpa::R2::exception( 'No rules in Stuifzand grammar', )
if not defined $start_lhs;
my $internal_start_lhs = '[:start]';
$hashed_ast->{'default_g1_start_action'} =
$hashed_ast->{'default_adverbs'}->{'G1'}->{'action'};
$hashed_ast->{'symbols'}->{'G1'}->{$internal_start_lhs} = {
display_form => ':start',
description => 'Internal G1 start symbol'
};
push @{ $hashed_ast->{rules}->{G1} },
{
lhs => $internal_start_lhs,
rhs => [$start_lhs],
action => '::first'
};
$self->{rules} = $hashed_ast->{rules}->{G1};
return $self;
} ## end sub parse_rules
1;
# vim: expandtab shiftwidth=4:
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