def _ReadArithExpr(self):
# type: () -> arith_expr_t
"""Read and parse an arithmetic expression in various contexts.
$(( 1+2 ))
(( a=1+2 ))
${a[ 1+2 ]}
${a : 1+2 : 1+2}
See tests/arith-context.test.sh for ambiguous cases.
${a[a[0]]} is valid # VS_RBRACKET vs Id.Arith_RBracket
${s : a<b?0:1 : 1} # VS_COLON vs Id.Arith_Colon
TODO: Instead of having an eof_type. I think we should use just run the
arith parser until it's done. That will take care of both : and ]. We
switch the state back.
See the assertion in ArithParser.Parse() -- unexpected extra input.
"""
# calls self.ReadWord(lex_mode_e.Arith)
a_parser = tdop.TdopParser(arith_parse.Spec(), self, self.parse_opts)
anode = a_parser.Parse()
return anode
def MakeArithParser(self, code_str): # type: (str) -> TdopParser """Used for a[x+1]=foo in the CommandParser.""" line_reader = reader.StringLineReader(code_str, self.arena) lx = self._MakeLexer(line_reader) w_parser = word_parse.WordParser(self, lx, line_reader) w_parser.Init(lex_mode_e.Arith) # Special initialization a_parser = tdop.TdopParser(arith_parse.Spec(), w_parser, self.parse_opts) return a_parser
def main(argv):
spec = arith_parse.Spec()
print("""\
#include "osh_arith_parse.h"
using syntax_asdl::arith_expr_t;
using syntax_asdl::word_t;
using tdop::TdopParser;
""")
to_declare = collections.defaultdict(set)
for row in spec.nud_lookup.itervalues():
mod_name, func_name = row.ModuleAndFuncName()
to_declare[mod_name].add(('N', func_name))
log('')
log('')
# TODO: namespace are arith_parse or tdop
for row in spec.led_lookup.itervalues():
mod_name, func_name = row.ModuleAndFuncName()
to_declare[mod_name].add(('L', func_name))
# main program has no headers, so here are prototypes
for mod_name in to_declare:
print('namespace %s { ' % mod_name)
for typ, func in sorted(to_declare[mod_name]):
if typ == 'N':
# tdop::NullFunc
fmt = 'arith_expr_t* %s(TdopParser*, word_t*, int);'
else:
# tdop::LeftFunc
fmt = 'arith_expr_t* %s(TdopParser*, word_t*, arith_expr_t*, int);'
print(fmt % func)
print('}')
print('')
print("""\
namespace arith_parse {
tdop::LeftInfo kLeftLookup[] = {
{ nullptr, 0, 0 }, // empty
""",
end='')
n = max(spec.led_lookup)
m = max(spec.nud_lookup)
assert n == m
log('arith_parse_gen.py: precedence table has %d entries', n)
for i in xrange(1, n):
row = spec.led_lookup.get(i)
if row is None:
assert False, 'No empty rows anymore'
print(' { nullptr, 0, 0 }, // empty')
else:
print(' %s' % row)
print("""\
};
tdop::NullInfo kNullLookup[] = {
{ nullptr, 0 }, // empty
""",
end='')
for i in xrange(1, n):
row = spec.nud_lookup.get(i)
if row is None:
assert False, 'No empty rows anymore'
print(' { nullptr, 0 }, // empty')
else:
print(' %s' % row)
print("""\
};
};
""")