G.match,
G.id,
G.string_literal,
G.block_string_literal,
G.bool_literal,
G.unit_literal,
NullLiteral("null"),
G.integer,
G.anonymous_function,
Pick("(", G.expr, ")"),
G.if_then_else
),
anonymous_function=AnonymousFunction(
"(", List(G.param, empty_valid=True, sep=","), ")",
"=>", Null(G.doc_node), G.expr
),
block_expr=BlockExpr(
"{", List(G.decl, sep=";", empty_valid=False), ";", c(), G.expr,
"}"
),
val_decl=ValDecl(
Opt(G.decl_annotation),
Opt(G.doc_node),
"val", c(), G.id, "=", G.expr
),
fun_decl=FunDecl(
Opt(G.decl_annotation),
from __future__ import absolute_import, division, print_function
from langkit.dsl import ASTNode, Field
from langkit.parsers import Grammar, List, Null
from lexer_example import Token
from utils import build_and_run
class FooNode(ASTNode):
pass
class DefNode(FooNode):
name = Field()
values = Field()
class Identifier(FooNode):
token_node = True
g = Grammar('main_rule')
g.add_rules(main_rule=List(g.def_node),
def_node=DefNode('(', g.identifier, ',',
Null(DefNode.list), ')'),
identifier=Identifier(Token.Identifier))
build_and_run(g, ada_main='main.adb', generate_unparser=True)
print('Done')
discriminant_spec=DiscriminantSpec(List(A.defining_id, sep=","), ":",
A.type_expr, Opt(":=", A.expr)),
discr_spec_list=List(A.discriminant_spec, sep=";"),
discriminant_part=Or(
KnownDiscriminantPart("(", A.discr_spec_list, ")"),
UnknownDiscriminantPart("(", "<>", ")"),
),
enum_literal_decl=EnumLiteralDecl(A.defining_id
| DefiningName(A.char_literal)),
formal_discrete_type_def=FormalDiscreteTypeDef("(", "<>", ")"),
record_def=Or(
RecordDef("record", A.component_list, "end", "record"),
NullRecordDef(
"null",
"record",
ComponentList(Null(List(A.component_item)), Null(A.variant_part)),
),
),
range_spec=RangeSpec("range", A.discrete_range | A.name | A.box_expr),
real_type_def=Or(A.floating_point_def, A.decimal_fixed_point_def,
A.ordinary_fixed_point_def),
sexpr_or_box=A.simple_expr | A.box_expr,
ordinary_fixed_point_def=OrdinaryFixedPointDef(
"delta",
A.sexpr_or_box,
Opt(A.range_spec),
),
decimal_fixed_point_def=DecimalFixedPointDef("delta", A.sexpr_or_box,
"digits", A.sexpr_or_box,
Opt(A.range_spec)),
floating_point_def=FloatingPointDef("digits", A.sexpr_or_box,
class FooNode(ASTNode):
pass
class RootNode(FooNode):
ident = Field()
number = Field()
class Identifier(FooNode):
token_node = True
class Number(FooNode):
token_node = True
g = Grammar('main_rule')
g.add_rules(main_rule=List(
Or(
RootNode('def', Null(Identifier), Opt('{', Number(Token.Number), '}'),
';'),
RootNode('def', Opt('(', Identifier(Token.Identifier), ')'),
Null(Number), ';'),
)))
build_and_run(g, ada_main='main.adb', generate_unparser=True)
print('Done')
Opt(A.range_spec)),
range_constraint=RangeConstraint(A.range_spec),
constraint=Or(A.digits_constraint, A.delta_constraint, A.range_constraint,
A.index_constraint, A.discriminant_constraint),
discriminant_spec=DiscriminantSpec(List(A.identifier, sep=","), ":",
A.type_expr, Opt(":=", A.expr)),
discr_spec_list=List(A.discriminant_spec, sep=";"),
discriminant_part=Or(
KnownDiscriminantPart("(", A.discr_spec_list, ")"),
UnknownDiscriminantPart("(", "<>", ")"),
),
enum_literal_decl=EnumLiteralDecl(A.identifier | A.char_literal),
formal_discrete_type_def=FormalDiscreteTypeDef("(", "<>", ")"),
record_def=Or(
RecordDef("record", A.component_list, "end", "record"),
NullRecordDef("null", "record", Null(ComponentList)),
),
range_spec=RangeSpec("range", A.discrete_range | A.name | A.box_expr),
real_type_def=Or(A.floating_point_def, A.decimal_fixed_point_def,
A.ordinary_fixed_point_def),
sexpr_or_box=A.simple_expr | A.box_expr,
ordinary_fixed_point_def=OrdinaryFixedPointDef(
"delta",
A.sexpr_or_box,
Opt(A.range_spec),
),
decimal_fixed_point_def=DecimalFixedPointDef("delta", A.sexpr_or_box,
"digits", A.sexpr_or_box,
Opt(A.range_spec)),
floating_point_def=FloatingPointDef("digits", A.sexpr_or_box,
Opt(A.range_spec)),
KnownDiscriminantPart("(", A.discr_spec_list, ")"),
UnknownDiscriminantPart("(", "<>", ")"),
),
enum_literal_decl=EnumLiteralDecl(
A.defining_id | DefiningName(A.char_literal)
),
formal_discrete_type_def=FormalDiscreteTypeDef("(", "<>", ")"),
record_def=Or(
RecordDef("record", A.component_list, "end", "record"),
NullRecordDef(
"null", "record",
ComponentList(
Null(List(A.component_item)),
Null(A.variant_part)
),
),
),
range_spec=RangeSpec("range", A.discrete_range | A.name | A.box_expr),
real_type_def=Or(A.floating_point_def, A.decimal_fixed_point_def,
A.ordinary_fixed_point_def),
sexpr_or_box=A.simple_expr | A.box_expr,
ordinary_fixed_point_def=OrdinaryFixedPointDef(
"delta", A.sexpr_or_box, Opt(A.range_spec),
),
G.string_literal,
G.block_string_literal,
G.bool_literal,
G.unit_literal,
NullLiteral("null"),
G.integer,
G.anonymous_function,
Pick("(", G.expr, ")"),
G.if_then_else,
G.block_expr,
G.tuple_expr,
),
tuple_expr=Tuple("(", List(G.expr, sep=","), ")"),
anonymous_function=AnonymousFunction(
"(", List(G.param, empty_valid=True, sep=","), ")", "=>",
Null(G.doc_node), G.expr),
block_expr=BlockExpr("{", List(G.decl, sep=";", empty_valid=False), ";",
c(), G.expr, "}"),
val_decl=ValDecl(Opt(G.decl_annotation), Opt(G.doc_node), "val", c(), G.id,
"=", G.expr),
fun_decl=FunDecl(
Opt(G.decl_annotation), "fun", c(), G.id,
NamedFunction("(", List(G.param, empty_valid=True, sep=","), ")", "=",
Opt(G.doc_node), G.expr)),
fun_call=FunCall(G.id, Safe("?"), "(", c(), G.arg_list, ")"),
arg_list=List(G.arg, empty_valid=True, sep=","),
selector_decl=SelectorDecl(Opt(G.decl_annotation), "selector", c(), G.id,
Opt(G.doc_node),
List(G.selector_arm, empty_valid=False)),
selector_arm=SelectorArm(
"|", G.pattern, "=>", List(G.selector_expr,
from __future__ import absolute_import, division, print_function
from langkit.parsers import Grammar, List, Or, Pick, Null
from language.lexer import dependz_lexer as L
from language.ast import (Program, Introduction, Definition, Abstraction,
Apply, SourceId, Arrow, Term)
dependz_grammar = Grammar('main_rule')
D = dependz_grammar
dependz_grammar.add_rules(main_rule=List(D.toplevel,
empty_valid=True,
list_cls=Program),
toplevel=Or(D.intro, D.definition),
intro=Introduction(D.ident, ':', D.defterm,
L.Newlines),
definition=Definition(D.ident, '=', D.defterm,
L.Newlines),
ident=SourceId(L.Ident),
defterm=Or(
Or(Arrow(Null(Term), D.term, '->', D.defterm),
Arrow(D.term, ':', D.term, '->', D.defterm)),
D.term),
term=Or(Apply(D.term, D.term1), D.term1),
term1=Or(D.ident, D.term2),
term2=Or(Abstraction('\\', D.ident, '.', D.term),
D.term3),
term3=Pick('(', D.defterm, ')'))
def lower(rule):
"""
Helper to lower one parser.
:param liblktlang.GrammarExpr rule: Grammar rule to lower.
:rtype: Parser
"""
# For convenience, accept null input rules, as we generally want to
# forward them as-is to the lower level parsing machinery.
if rule is None:
return None
loc = ctx.lkt_loc(rule)
with ctx.lkt_context(rule):
if isinstance(rule, liblktlang.ParseNodeExpr):
node = resolve_node_ref(rule.f_node_name)
# Lower the subparsers
subparsers = [
lower(subparser) for subparser in rule.f_sub_exprs
]
# Qualifier nodes are a special case: we produce one subclass
# or the other depending on whether the subparsers accept the
# input.
if node._type.is_bool_node:
return Opt(*subparsers, location=loc).as_bool(node)
# Likewise for enum nodes
elif node._type.base and node._type.base.is_enum_node:
return _Transform(_Row(*subparsers, location=loc),
node.type_ref,
location=loc)
# For other nodes, always create the node when the subparsers
# accept the input.
else:
return _Transform(parser=_Row(*subparsers),
typ=node,
location=loc)
elif isinstance(rule, liblktlang.GrammarToken):
token_name = rule.f_token_name.text
try:
val = tokens[token_name]
except KeyError:
check_source_language(
False, 'Unknown token: {}'.format(token_name))
match_text = ''
if rule.f_expr:
# The grammar is supposed to mainain this invariant
assert isinstance(rule.f_expr, liblktlang.TokenLit)
match_text = denoted_string_literal(rule.f_expr)
return _Token(val=val, match_text=match_text, location=loc)
elif isinstance(rule, liblktlang.TokenLit):
return _Token(denoted_string_literal(rule), location=loc)
elif isinstance(rule, liblktlang.GrammarList):
return List(lower(rule.f_expr),
empty_valid=rule.f_kind.text == '*',
list_cls=resolve_node_ref(rule.f_list_type),
sep=lower(rule.f_sep),
location=loc)
elif isinstance(
rule,
(liblktlang.GrammarImplicitPick, liblktlang.GrammarPick)):
return Pick(*[lower(subparser) for subparser in rule.f_exprs],
location=loc)
elif isinstance(rule, liblktlang.GrammarRuleRef):
return getattr(grammar, rule.f_node_name.text)
elif isinstance(rule, liblktlang.GrammarOrExpr):
return Or(
*[lower(subparser) for subparser in rule.f_sub_exprs],
location=loc)
elif isinstance(rule, liblktlang.GrammarOpt):
return Opt(lower(rule.f_expr), location=loc)
elif isinstance(rule, liblktlang.GrammarOptGroup):
return Opt(*[lower(subparser) for subparser in rule.f_expr],
location=loc)
elif isinstance(rule, liblktlang.GrammarExprList):
return Pick(*[lower(subparser) for subparser in rule],
location=loc)
elif isinstance(rule, liblktlang.GrammarDiscard):
return Discard(lower(rule.f_expr), location=loc)
elif isinstance(rule, liblktlang.GrammarNull):
return Null(resolve_node_ref(rule.f_name), location=loc)
elif isinstance(rule, liblktlang.GrammarSkip):
return Skip(resolve_node_ref(rule.f_name), location=loc)
elif isinstance(rule, liblktlang.GrammarDontSkip):
return DontSkip(lower(rule.f_expr),
lower(rule.f_dont_skip),
location=loc)
elif isinstance(rule, liblktlang.GrammarPredicate):
check_source_language(
isinstance(rule.f_prop_ref, liblktlang.DotExpr),
'Invalid property reference')
node = resolve_node_ref(rule.f_prop_ref.f_prefix)
prop_name = rule.f_prop_ref.f_suffix.text
try:
prop = getattr(node, prop_name)
except AttributeError:
check_source_language(
False, '{} has no {} property'.format(
node._name.camel_with_underscores, prop_name))
return Predicate(lower(rule.f_expr), prop, location=loc)
else:
raise NotImplementedError('unhandled parser: {}'.format(rule))
# Non optional fields
field_opt_bool = Field()
field_transform = Field()
class HasExample(FooNode):
enum_node = True
qualifier = True
foo_grammar = Grammar('main_rule')
foo_grammar.add_rules(main_rule=Or(foo_grammar.rule_1, foo_grammar.rule_2),
rule_1=ExampleWrapper(
Opt(Example("example")),
Or(Example("example"), Null(Example)),
foo_grammar.sub_rule, Null(Example),
DontSkip(Opt(Example("example"))),
Opt(Example("example")).as_bool(HasExample),
Example("example")),
rule_2=ExampleWrapper(Example("example"),
Example("example"),
Example("example"),
Example("example"),
Example("example"),
HasExample("example"),
Example("example")),
sub_rule=Opt(Example("example")))
emit_and_print_errors(foo_grammar)
print('== {} =='.format(label))
@has_abstract_list
class FooNode(ASTNode):
pass
class Example(FooNode):
f = Field(FooNode)
@synthetic
class SynthExample(FooNode):
pass
@synthetic
class ListSynthExample(FooNode.list):
pass
foo_grammar = Grammar('main_rule')
foo_grammar.add_rules(main_rule=Example(
'example', parser_constructor(SynthExample, ListSynthExample)))
emit_and_print_errors(foo_grammar)
print('')
run('List', lambda _, cls: List('example', list_cls=cls))
run('Null', lambda cls, _: Null(cls))
run('Skip', lambda cls, _: Skip(cls))
run('Transform', lambda cls, _: cls())
print('Done')
),
discr_spec_list=List(A.discriminant_spec, sep=";"),
discriminant_part=Or(
KnownDiscriminantPart("(", A.discr_spec_list, ")"),
UnknownDiscriminantPart("(", "<>", ")"),
),
enum_literal_decl=EnumLiteralDecl(A.identifier | A.char_literal),
formal_discrete_type_def=FormalDiscreteTypeDef("(", "<>", ")"),
record_def=Or(
RecordDef("record", A.component_list, "end", "record"),
NullRecordDef("null", "record", Null(ComponentList)),
),
range_spec=RangeSpec("range", A.discrete_range | A.name | A.box_expr),
real_type_def=Or(A.floating_point_def, A.decimal_fixed_point_def,
A.ordinary_fixed_point_def),
sexpr_or_box=A.simple_expr | A.box_expr,
ordinary_fixed_point_def=OrdinaryFixedPointDef(
"delta", A.sexpr_or_box, Opt(A.range_spec),
),
decimal_fixed_point_def=DecimalFixedPointDef(
"delta", A.sexpr_or_box, "digits",
field_opt_bool = Field()
field_transform = Field()
class HasExample(FooNode):
enum_node = True
qualifier = True
foo_grammar = Grammar('main_rule')
foo_grammar.add_rules(
main_rule=Or(foo_grammar.rule_1, foo_grammar.rule_2),
rule_1=ExampleWrapper(
Opt(Example("example")),
Or(Example("example"), Null(Example)),
foo_grammar.sub_rule,
Null(Example),
DontSkip(Opt(Example("example"))),
Opt(Example("example")).as_bool(HasExample),
Example("example")
),
rule_2=ExampleWrapper(
Example("example"),
Example("example"),
Example("example"),
Example("example"),
Example("example"),
HasExample("example"),
