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|
module Treetop
module Compiler
grammar Metagrammar
rule treetop_file
requires:(space? require_statement)* prefix:space? module_or_grammar suffix:space? {
def compile
requires.text_value + prefix.text_value + module_or_grammar.compile + suffix.text_value
end
}
end
rule require_statement
prefix:space? "require" [ \t]+ [^\n\r]+ [\n\r]
end
rule module_or_grammar
module_declaration / grammar
end
rule module_declaration
prefix:('module' space name:([A-Z] alphanumeric_char* ('::' [A-Z] alphanumeric_char*)*) space) module_contents:(module_declaration / grammar) suffix:(space 'end') {
def compile
prefix.text_value + module_contents.compile + suffix.text_value
end
def parser_name
prefix.name.text_value+'::'+module_contents.parser_name
end
}
end
rule grammar
'grammar' space grammar_name space ('do' space)? declaration_sequence space? 'end' <Grammar>
end
rule grammar_name
([A-Z] alphanumeric_char*)
end
rule declaration_sequence
head:declaration tail:(space declaration)* <DeclarationSequence> {
def declarations
[head] + tail
end
def tail
super.elements.map { |elt| elt.declaration }
end
}
/
'' {
def compile(builder)
end
}
end
rule declaration
parsing_rule / include_declaration
end
rule include_declaration
'include' space [A-Z] (alphanumeric_char / '::')* {
def compile(builder)
builder << text_value
end
}
end
rule parsing_rule
'rule' space nonterminal space ('do' space)? parsing_expression space 'end' <ParsingRule>
end
rule parsing_expression
choice / sequence / primary
end
rule choice
head:alternative tail:(space? '/' space? alternative)+ <Choice> {
def alternatives
[head] + tail
end
def tail
super.elements.map {|elt| elt.alternative}
end
def inline_modules
(alternatives.map {|alt| alt.inline_modules }).flatten
end
}
end
rule sequence
head:labeled_sequence_primary tail:(space labeled_sequence_primary)+ node_class_declarations <Sequence> {
def sequence_elements
[head] + tail
end
def tail
super.elements.map {|elt| elt.labeled_sequence_primary }
end
def inline_modules
(sequence_elements.map {|elt| elt.inline_modules}).flatten +
[sequence_element_accessor_module] +
node_class_declarations.inline_modules
end
def inline_module_name
node_class_declarations.inline_module_name
end
}
end
rule alternative
sequence / primary
end
rule primary
prefix atomic {
def compile(address, builder, parent_expression=nil)
prefix.compile(address, builder, self)
end
def prefixed_expression
atomic
end
def inline_modules
atomic.inline_modules
end
def inline_module_name
nil
end
}
/
prefix space? predicate_block {
def compile(address, builder, parent_expression=nil)
prefix.compile(address, builder, self)
end
def prefixed_expression
predicate_block
end
def inline_modules
[]
end
}
/
atomic suffix node_class_declarations {
def compile(address, builder, parent_expression=nil)
suffix.compile(address, builder, self)
end
def optional_expression
atomic
end
def node_class_name
node_class_declarations.node_class_name
end
def inline_modules
atomic.inline_modules + node_class_declarations.inline_modules
end
def inline_module_name
node_class_declarations.inline_module_name
end
}
/
atomic node_class_declarations {
def compile(address, builder, parent_expression=nil)
atomic.compile(address, builder, self)
end
def node_class_name
node_class_declarations.node_class_name
end
def inline_modules
atomic.inline_modules + node_class_declarations.inline_modules
end
def inline_module_name
node_class_declarations.inline_module_name
end
}
end
rule labeled_sequence_primary
label sequence_primary {
def compile(lexical_address, builder)
sequence_primary.compile(lexical_address, builder)
end
def inline_modules
sequence_primary.inline_modules
end
def label_name
if label.name
label.name
elsif sequence_primary.instance_of?(Nonterminal)
sequence_primary.text_value
else
nil
end
end
}
end
rule label
(alpha_char alphanumeric_char*) ':' {
def name
elements[0].text_value
end
}
/
'' {
def name
nil
end
}
end
rule sequence_primary
prefix atomic {
def compile(lexical_address, builder)
prefix.compile(lexical_address, builder, self)
end
def prefixed_expression
elements[1]
end
def inline_modules
atomic.inline_modules
end
def inline_module_name
nil
end
}
/
prefix space? predicate_block {
def compile(address, builder, parent_expression=nil)
prefix.compile(address, builder, self)
end
def prefixed_expression
predicate_block
end
def inline_modules
[]
end
}
/
atomic suffix {
def compile(lexical_address, builder)
suffix.compile(lexical_address, builder, self)
end
def node_class_name
nil
end
def inline_modules
atomic.inline_modules
end
def inline_module_name
nil
end
}
/
atomic
end
rule suffix
repetition_suffix / optional_suffix
end
rule optional_suffix
'?' <Optional>
end
rule node_class_declarations
node_class_expression trailing_inline_module {
def node_class_name
node_class_expression.node_class_name
end
def inline_modules
trailing_inline_module.inline_modules
end
def inline_module
trailing_inline_module.inline_module
end
def inline_module_name
inline_module.module_name if inline_module
end
}
end
rule repetition_suffix
'+' <OneOrMore> / '*' <ZeroOrMore> / occurrence_range
end
rule occurrence_range
space? min:([0-9])* '..' max:([0-9])* <OccurrenceRange>
end
rule prefix
'&' <AndPredicate> / '!' <NotPredicate> / '~' <TransientPrefix>
end
rule atomic
terminal
/
nonterminal
/
parenthesized_expression
end
rule parenthesized_expression
'(' space? parsing_expression space? ')' <ParenthesizedExpression> {
def inline_modules
parsing_expression.inline_modules
end
}
end
rule nonterminal
!keyword_inside_grammar (alpha_char alphanumeric_char*) <Nonterminal>
end
rule terminal
quoted_string / character_class / anything_symbol
end
rule quoted_string
(single_quoted_string / double_quoted_string) {
def string
super.text_value
end
}
end
rule double_quoted_string
'"' string:(!'"' ("\\\\" / '\"' / .))* '"' <Terminal>
end
rule single_quoted_string
"'" string:(!"'" ("\\\\" / "\\'" / .))* "'" <Terminal>
end
rule character_class
'[' characters:(!']' ('\\' . / bracket_expression / !'\\' .))+ ']' <CharacterClass> {
def characters
super.text_value
end
}
end
rule bracket_expression
'[:' '^'? (
'alnum' / 'alpha' / 'blank' / 'cntrl' / 'digit' / 'graph' / 'lower' /
'print' / 'punct' / 'space' / 'upper' / 'xdigit' / 'word'
) ':]'
end
rule anything_symbol
'.' <AnythingSymbol>
end
rule node_class_expression
space '<' (!'>' .)+ '>' {
def node_class_name
elements[2].text_value
end
}
/
'' {
def node_class_name
nil
end
}
end
rule trailing_inline_module
space inline_module {
def inline_modules
[inline_module]
end
def inline_module_name
inline_module.module_name
end
}
/
'' {
def inline_modules
[]
end
def inline_module
nil
end
def inline_module_name
nil
end
}
end
rule predicate_block
'' inline_module <PredicateBlock>
end
rule inline_module
'{' (inline_module / ![{}] .)* '}' <InlineModule>
end
rule keyword_inside_grammar
('rule' / 'end') !non_space_char
end
rule non_space_char
!space .
end
rule alpha_char
[A-Za-z_]
end
rule alphanumeric_char
alpha_char / [0-9]
end
rule space
(white / comment_to_eol)+
end
rule comment_to_eol
'#' (!"\n" .)*
end
rule white
[ \t\n\r]
end
end
end
end
|