def Expr(self, pnode):
# type: (PNode) -> expr_t
"""Transform expressions (as opposed to statements)."""
typ = pnode.typ
tok = pnode.tok
children = pnode.children
if ISNONTERMINAL(typ):
#
# Oil Entry Points / Additions
#
if typ == grammar_nt.oil_expr: # for if/while
# oil_expr: '(' testlist ')'
return self.Expr(children[1])
if typ == grammar_nt.command_expr:
# return_expr: testlist end_stmt
return self.Expr(children[0])
#
# Python-like Expressions / Operators
#
if typ == grammar_nt.atom:
if len(children) == 1:
return self.Expr(children[0])
return self._Atom(children)
if typ == grammar_nt.testlist:
# testlist: test (',' test)* [',']
return self._Tuple(children)
if typ == grammar_nt.test:
# test: or_test ['if' or_test 'else' test] | lambdef
if len(children) == 1:
return self.Expr(children[0])
# TODO: Handle lambdef
test = self.Expr(children[2])
body = self.Expr(children[0])
orelse = self.Expr(children[4])
return expr.IfExp(test, body, orelse)
if typ == grammar_nt.lambdef:
# lambdef: '|' [name_type_list] '|' test
n = len(children)
if n == 4:
params = self._NameTypeList(children[1])
else:
params = []
body = self.Expr(children[n-1])
return expr.Lambda(params, body)
#
# Operators with Precedence
#
if typ == grammar_nt.or_test:
# or_test: and_test ('or' and_test)*
return self._AssocBinary(children)
if typ == grammar_nt.and_test:
# and_test: not_test ('and' not_test)*
return self._AssocBinary(children)
if typ == grammar_nt.not_test:
# not_test: 'not' not_test | comparison
if len(children) == 1:
return self.Expr(children[0])
op_tok = children[0].tok # not
return expr.Unary(op_tok, self.Expr(children[1]))
elif typ == grammar_nt.comparison:
if len(children) == 1:
return self.Expr(children[0])
return self._CompareChain(children)
elif typ == grammar_nt.range_expr:
n = len(children)
if n == 1:
return self.Expr(children[0])
if n == 3:
return expr.Range(
self.Expr(children[0]),
self.Expr(children[2])
)
raise AssertionError(n)
elif typ == grammar_nt.expr:
# expr: xor_expr ('|' xor_expr)*
return self._AssocBinary(children)
if typ == grammar_nt.xor_expr:
# xor_expr: and_expr ('xor' and_expr)*
return self._AssocBinary(children)
if typ == grammar_nt.and_expr: # a & b
# and_expr: shift_expr ('&' shift_expr)*
return self._AssocBinary(children)
elif typ == grammar_nt.shift_expr:
# shift_expr: arith_expr (('<<'|'>>') arith_expr)*
return self._AssocBinary(children)
elif typ == grammar_nt.arith_expr:
# arith_expr: term (('+'|'-') term)*
return self._AssocBinary(children)
elif typ == grammar_nt.term:
# term: factor (('*'|'/'|'div'|'mod') factor)*
return self._AssocBinary(children)
elif typ == grammar_nt.factor:
# factor: ('+'|'-'|'~') factor | power
# the power would have already been reduced
if len(children) == 1:
return self.Expr(children[0])
assert len(children) == 2
op = children[0]
e = children[1]
assert isinstance(op.tok, Token)
return expr.Unary(op.tok, self.Expr(e))
elif typ == grammar_nt.power:
# power: atom trailer* ['^' factor]
node = self.Expr(children[0])
if len(children) == 1: # No trailers
return node
n = len(children)
i = 1
while i < n and ISNONTERMINAL(children[i].typ):
node = self._Trailer(node, children[i])
i += 1
if i != n: # ['^' factor]
op_tok = children[i].tok
assert op_tok.id == Id.Arith_Caret, op_tok
factor = self.Expr(children[i+1])
node = expr.Binary(op_tok, node, factor)
return node
elif typ == grammar_nt.array_literal:
left_tok = children[0].tok
items = [self._ArrayItem(p) for p in children[1:-1]]
return expr.ArrayLiteral(left_tok, items)
elif typ == grammar_nt.oil_expr_sub:
return self.Expr(children[0])
#
# Oil Lexer Modes
#
elif typ == grammar_nt.sh_array_literal:
return cast(sh_array_literal, children[1].tok)
elif typ == grammar_nt.sh_command_sub:
return cast(command_sub, children[1].tok)
elif typ == grammar_nt.braced_var_sub:
return cast(braced_var_sub, children[1].tok)
elif typ == grammar_nt.dq_string:
return cast(double_quoted, children[1].tok)
elif typ == grammar_nt.sq_string:
return cast(single_quoted, children[1].tok)
elif typ == grammar_nt.simple_var_sub:
return simple_var_sub(children[0].tok)
else:
nt_name = self.number2symbol[typ]
raise AssertionError(
"PNode type %d (%s) wasn't handled" % (typ, nt_name))
else: # Terminals should have a token
id_ = tok.id
if id_ == Id.Expr_Name:
return expr.Var(tok)
if id_ in (
Id.Expr_DecInt, Id.Expr_BinInt, Id.Expr_OctInt, Id.Expr_HexInt,
Id.Expr_Float):
return expr.Const(tok)
if id_ in (Id.Expr_Null, Id.Expr_True, Id.Expr_False):
return expr.Const(tok)
raise NotImplementedError(Id_str(id_))
def Expr(self, pnode):
# type: (PNode) -> expr_t
"""Transform expressions (as opposed to statements)."""
typ = pnode.typ
tok = pnode.tok
children = pnode.children
if ISNONTERMINAL(typ):
#
# Oil Entry Points / Additions
#
if typ == grammar_nt.oil_expr: # for if/while
# oil_expr: '(' testlist ')'
return self.Expr(children[1])
if typ == grammar_nt.return_expr:
# return_expr: testlist end_stmt
return self.Expr(children[0])
if typ == grammar_nt.place_list:
return self._AssocBinary(children)
if typ == grammar_nt.place:
# place: NAME place_trailer*
if len(pnode.children) == 1:
return self.Expr(pnode.children[0])
# TODO: Called _Trailer but don't handle ( )?
# only [] . -> :: ?
raise NotImplementedError
#
# Python-like Expressions / Operators
#
if typ == grammar_nt.atom:
if len(children) == 1:
return self.Expr(children[0])
return self._Atom(children)
if typ == grammar_nt.testlist:
# testlist: test (',' test)* [',']
# We need tuples for Python's 'var a, b = x' and 'for (a, b in x) {'
return self._Tuple(children)
if typ == grammar_nt.test:
# test: or_test ['if' or_test 'else' test] | lambdef
if len(children) == 1:
return self.Expr(children[0])
# TODO: Handle lambdef
test = self.Expr(children[2])
body = self.Expr(children[0])
orelse = self.Expr(children[4])
return expr.IfExp(test, body, orelse)
if typ == grammar_nt.test_nocond:
# test_nocond: or_test | lambdef_nocond
assert len(children) == 1
return self.Expr(children[0])
if typ == grammar_nt.argument:
# argument: ( test [comp_for] |
# test '=' test |
# '**' test |
# '*' test )
if len(pnode.children) == 1:
return self.Expr(children[0])
# TODO:
raise NotImplementedError
if typ == grammar_nt.subscript:
# subscript: test | [test] ':' [test] [sliceop]
if len(pnode.children) == 1:
return self.Expr(children[0])
# TODO:
raise NotImplementedError
if typ == grammar_nt.testlist_comp:
# testlist_comp: (test|star_expr) ( comp_for | (',' (test|star_expr))* [','] )
if children[1].typ == grammar_nt.comp_for:
elt = self.Expr(children[0])
comp = self._CompFor(children[1])
return expr.ListComp(elt, [comp])
# (1,) (1, 2) etc.
if children[1].tok.id == Id.Arith_Comma:
return self._Tuple(children)
raise NotImplementedError('testlist_comp')
elif typ == grammar_nt.exprlist:
# exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
if len(children) == 1:
return self.Expr(children[0])
# used in for loop, genexpr.
# TODO: This sould be placelist? for x, *y ?
raise NotImplementedError('exprlist')
#
# Operators with Precedence
#
if typ == grammar_nt.or_test:
# or_test: and_test ('or' and_test)*
return self._AssocBinary(children)
if typ == grammar_nt.and_test:
# and_test: not_test ('and' not_test)*
return self._AssocBinary(children)
if typ == grammar_nt.not_test:
# not_test: 'not' not_test | comparison
if len(children) == 1:
return self.Expr(children[0])
op_tok = children[0].tok # not
return expr.Unary(op_tok, self.Expr(children[1]))
elif typ == grammar_nt.comparison:
if len(children) == 1:
return self.Expr(children[0])
return self._CompareChain(children)
elif typ == grammar_nt.expr:
# expr: xor_expr ('|' xor_expr)*
return self._AssocBinary(children)
if typ == grammar_nt.xor_expr:
# xor_expr: and_expr ('xor' and_expr)*
return self._AssocBinary(children)
if typ == grammar_nt.and_expr: # a & b
# and_expr: shift_expr ('&' shift_expr)*
return self._AssocBinary(children)
elif typ == grammar_nt.shift_expr:
# shift_expr: arith_expr (('<<'|'>>') arith_expr)*
return self._AssocBinary(children)
elif typ == grammar_nt.arith_expr:
# arith_expr: term (('+'|'-') term)*
return self._AssocBinary(children)
elif typ == grammar_nt.term:
# term: factor (('*'|'/'|'div'|'mod') factor)*
return self._AssocBinary(children)
elif typ == grammar_nt.factor:
# factor: ('+'|'-'|'~') factor | power
# the power would have already been reduced
if len(children) == 1:
return self.Expr(children[0])
op, e = children
assert isinstance(op.tok, token)
return expr.Unary(op.tok, self.Expr(e))
elif typ == grammar_nt.power:
# power: atom trailer* ['^' factor]
node = self.Expr(children[0])
if len(children) == 1: # No trailers
return node
n = len(children)
i = 1
while i < n and ISNONTERMINAL(children[i].typ):
node = self._Trailer(node, children[i])
i += 1
if i != n: # ['^' factor]
op_tok = children[i].tok
assert op_tok.id == Id.Arith_Caret, op_tok
factor = self.Expr(children[i+1])
node = expr.Binary(op_tok, node, factor)
return node
#
# Oil Lexer Modes
#
elif typ == grammar_nt.array_literal:
left_tok = children[0].tok
# Approximation for now.
tokens = [
pnode.tok for pnode in children[1:-1] if pnode.tok.id ==
Id.Lit_Chars
]
items = [expr.Const(t) for t in tokens] # type: List[expr_t]
return expr.ArrayLiteral(left_tok, items)
elif typ == grammar_nt.sh_array_literal:
left_tok = children[0].tok
# HACK: When typ is Id.Expr_CastedDummy, the 'tok' field ('opaque')
# actually has a list of words!
typ1 = children[1].typ
assert typ1 == Id.Expr_CastedDummy.enum_id, typ1
array_words = cast('List[word_t]', children[1].tok)
return sh_array_literal(left_tok, array_words)
elif typ == grammar_nt.sh_command_sub:
return cast(command_sub, children[1].tok)
elif typ == grammar_nt.braced_var_sub:
return cast(braced_var_sub, children[1].tok)
elif typ == grammar_nt.dq_string:
return cast(double_quoted, children[1].tok)
elif typ == grammar_nt.sq_string:
return cast(single_quoted, children[1].tok)
elif typ == grammar_nt.simple_var_sub:
return simple_var_sub(children[0].tok)
else:
nt_name = self.number2symbol[typ]
raise AssertionError(
"PNode type %d (%s) wasn't handled" % (typ, nt_name))
else: # Terminals should have a token
id_ = tok.id
if id_ == Id.Expr_Name:
return expr.Var(tok)
if id_ in (
Id.Expr_DecInt, Id.Expr_BinInt, Id.Expr_OctInt, Id.Expr_HexInt,
Id.Expr_Float):
return expr.Const(tok)
if id_ in (Id.Expr_Null, Id.Expr_True, Id.Expr_False):
return expr.Const(tok)
from core.meta import IdInstance
raise NotImplementedError(IdInstance(typ))