OILS / ysh / expr_eval.py View on Github | oils.pub

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1#!/usr/bin/env python2
2"""expr_eval.py."""
3from __future__ import print_function
4
5from _devbuild.gen.id_kind_asdl import Id
6from _devbuild.gen.syntax_asdl import (
7 ExprSub,
8 loc,
9 loc_t,
10 re,
11 re_e,
12 re_t,
13 Token,
14 SimpleVarSub,
15 word_part,
16 SingleQuoted,
17 DoubleQuoted,
18 BracedVarSub,
19 YshArrayLiteral,
20 CommandSub,
21 expr,
22 expr_e,
23 expr_t,
24 y_lhs_e,
25 y_lhs_t,
26 Attribute,
27 Subscript,
28 class_literal_term,
29 class_literal_term_e,
30 class_literal_term_t,
31 char_class_term_t,
32 PosixClass,
33 PerlClass,
34 CharCode,
35 CharRange,
36 ArgList,
37 Eggex,
38 cmd_frag,
39)
40from _devbuild.gen.runtime_asdl import (
41 coerced_e,
42 coerced_t,
43 scope_e,
44 scope_t,
45 part_value,
46 part_value_t,
47)
48from _devbuild.gen.value_asdl import (value, value_e, value_t, y_lvalue,
49 y_lvalue_e, y_lvalue_t, IntBox, LeftName,
50 Obj)
51from core import error
52from core.error import e_die, e_die_status
53from core import num
54from core import pyutil
55from core import state
56from core import vm
57from display import ui
58from data_lang import j8
59from frontend import lexer
60from frontend import match
61from frontend import typed_args
62from osh import braces
63from osh import word_
64from mycpp import mops
65from mycpp.mylib import log, NewDict, switch, tagswitch, print_stderr
66from ysh import func_proc
67from ysh import val_ops
68
69import libc
70
71from typing import cast, Optional, Dict, List, Tuple, TYPE_CHECKING
72
73if TYPE_CHECKING:
74 from osh import cmd_eval
75 from osh import word_eval
76 from osh import split
77
78_ = log
79
80
81def LookupVar(mem, var_name, which_scopes, var_loc):
82 # type: (state.Mem, str, scope_t, loc_t) -> value_t
83
84 # Lookup WITHOUT dynamic scope.
85 val = mem.GetValue(var_name, which_scopes=which_scopes)
86 if val.tag() == value_e.Undef:
87 e_die('Undefined variable %r' % var_name, var_loc)
88
89 return val
90
91
92def _ConvertToInt(val, msg, blame_loc):
93 # type: (value_t, str, loc_t) -> mops.BigInt
94 UP_val = val
95 with tagswitch(val) as case:
96 if case(value_e.Int):
97 val = cast(value.Int, UP_val)
98 return val.i
99
100 elif case(value_e.Str):
101 val = cast(value.Str, UP_val)
102 if match.LooksLikeYshInt(val.s):
103 s = val.s.replace('_', '')
104 ok, i = mops.FromStr2(s)
105 if not ok:
106 e_die("Integer too big: %s" % s, blame_loc)
107 return i
108
109 raise error.TypeErr(val, msg, blame_loc)
110
111
112def _ConvertToNumber(val):
113 # type: (value_t) -> Tuple[coerced_t, mops.BigInt, float]
114 UP_val = val
115 with tagswitch(val) as case:
116 if case(value_e.Int):
117 val = cast(value.Int, UP_val)
118 return coerced_e.Int, val.i, -1.0
119
120 elif case(value_e.Float):
121 val = cast(value.Float, UP_val)
122 return coerced_e.Float, mops.MINUS_ONE, val.f
123
124 elif case(value_e.Str):
125 val = cast(value.Str, UP_val)
126
127 if match.LooksLikeYshInt(val.s):
128 s = val.s.replace('_', '')
129 ok, i = mops.FromStr2(s)
130 if not ok:
131 e_die("Integer too big: %s" % s, loc.Missing)
132 return coerced_e.Int, i, -1.0
133
134 if match.LooksLikeYshFloat(val.s):
135 s = val.s.replace('_', '')
136 return coerced_e.Float, mops.MINUS_ONE, float(s)
137
138 return coerced_e.Neither, mops.MINUS_ONE, -1.0
139
140
141def ConvertForBinaryOp(left, right):
142 # type: (value_t, value_t) -> Tuple[coerced_t, mops.BigInt, mops.BigInt, float, float]
143 """
144 Returns one of
145 value_e.Int or value_e.Float
146 2 ints or 2 floats
147
148 To indicate which values the operation should be done on
149 """
150 c1, i1, f1 = _ConvertToNumber(left)
151 c2, i2, f2 = _ConvertToNumber(right)
152
153 nope = mops.MINUS_ONE
154
155 if c1 == coerced_e.Int and c2 == coerced_e.Int:
156 return coerced_e.Int, i1, i2, -1.0, -1.0
157
158 elif c1 == coerced_e.Int and c2 == coerced_e.Float:
159 return coerced_e.Float, nope, nope, mops.ToFloat(i1), f2
160
161 elif c1 == coerced_e.Float and c2 == coerced_e.Int:
162 return coerced_e.Float, nope, nope, f1, mops.ToFloat(i2)
163
164 elif c1 == coerced_e.Float and c2 == coerced_e.Float:
165 return coerced_e.Float, nope, nope, f1, f2
166
167 else:
168 # No operation is valid
169 return coerced_e.Neither, nope, nope, -1.0, -1.0
170
171
172class ExprEvaluator(object):
173 """Shared between arith and bool evaluators.
174
175 They both:
176
177 1. Convert strings to integers, respecting shopt -s strict_arith.
178 2. Look up variables and evaluate words.
179 """
180
181 def __init__(
182 self,
183 mem, # type: state.Mem
184 mutable_opts, # type: state.MutableOpts
185 methods, # type: Dict[int, Dict[str, vm._Callable]]
186 splitter, # type: split.SplitContext
187 errfmt, # type: ui.ErrorFormatter
188 ):
189 # type: (...) -> None
190 self.shell_ex = None # type: vm._Executor
191 self.cmd_ev = None # type: cmd_eval.CommandEvaluator
192 self.word_ev = None # type: word_eval.AbstractWordEvaluator
193
194 self.mem = mem
195 self.mutable_opts = mutable_opts
196 self.methods = methods
197 self.splitter = splitter
198 self.errfmt = errfmt
199
200 def CheckCircularDeps(self):
201 # type: () -> None
202 assert self.shell_ex is not None
203 assert self.word_ev is not None
204
205 def _LookupVar(self, name, var_loc):
206 # type: (str, loc_t) -> value_t
207 return LookupVar(self.mem, name, scope_e.LocalOrGlobal, var_loc)
208
209 def EvalAugmented(self, lval, rhs_val, op, which_scopes):
210 # type: (y_lvalue_t, value_t, Token, scope_t) -> None
211 """ setvar x += 1, setvar L[0] -= 1
212
213 Called by CommandEvaluator
214 """
215 UP_lval = lval
216 with tagswitch(lval) as case:
217 if case(y_lvalue_e.Local): # setvar x += 1
218 lval = cast(LeftName, UP_lval)
219 lhs_val = self._LookupVar(lval.name, lval.blame_loc)
220 if op.id in (Id.Arith_PlusEqual, Id.Arith_MinusEqual,
221 Id.Arith_StarEqual, Id.Arith_SlashEqual):
222 new_val = self._ArithIntFloat(lhs_val, rhs_val, op)
223 else:
224 new_val = self._ArithIntOnly(lhs_val, rhs_val, op)
225
226 self.mem.SetNamed(lval, new_val, which_scopes)
227
228 elif case(y_lvalue_e.Container): # setvar d.key += 1
229 lval = cast(y_lvalue.Container, UP_lval)
230
231 obj = lval.obj
232 UP_obj = obj
233
234 lhs_val_ = None # type: value_t
235 # Similar to command_e.Mutation
236 with tagswitch(obj) as case:
237 if case(value_e.List):
238 obj = cast(value.List, UP_obj)
239 i1 = _ConvertToInt(lval.index,
240 'List index should be Int',
241 loc.Missing)
242 # TODO: don't truncate
243 index = mops.BigTruncate(i1)
244 try:
245 lhs_val_ = obj.items[index]
246 except IndexError:
247 raise error.Expr(
248 'List index out of range: %d' % index,
249 loc.Missing)
250
251 elif case(value_e.Dict):
252 obj = cast(value.Dict, UP_obj)
253 index = -1 # silence C++ warning
254 key = val_ops.ToStr(lval.index,
255 'Dict key should be Str',
256 loc.Missing)
257 try:
258 lhs_val_ = obj.d[key]
259 except KeyError:
260 raise error.Expr('Dict key not found: %r' % key,
261 loc.Missing)
262
263 elif case(value_e.Obj):
264 obj = cast(Obj, UP_obj)
265 index = -1 # silence C++ warning
266 key = val_ops.ToStr(lval.index,
267 'Obj attribute should be Str',
268 loc.Missing)
269 try:
270 lhs_val_ = obj.d[key]
271 except KeyError:
272 raise error.Expr(
273 'Obj attribute not found: %r' % key,
274 loc.Missing)
275
276 else:
277 raise error.TypeErr(
278 obj, "obj[index] expected List or Dict",
279 loc.Missing)
280
281 if op.id in (Id.Arith_PlusEqual, Id.Arith_MinusEqual,
282 Id.Arith_StarEqual, Id.Arith_SlashEqual):
283 new_val_ = self._ArithIntFloat(lhs_val_, rhs_val, op)
284 else:
285 new_val_ = self._ArithIntOnly(lhs_val_, rhs_val, op)
286
287 with tagswitch(obj) as case:
288 if case(value_e.List):
289 obj = cast(value.List, UP_obj)
290 assert index != -1, 'Should have been initialized'
291 obj.items[index] = new_val_
292
293 elif case(value_e.Dict):
294 obj = cast(value.Dict, UP_obj)
295 obj.d[key] = new_val_
296
297 elif case(value_e.Obj):
298 obj = cast(Obj, UP_obj)
299 obj.d[key] = new_val_
300
301 else:
302 raise AssertionError()
303
304 else:
305 raise AssertionError()
306
307 def _EvalLeftLocalOrGlobal(self, lhs, which_scopes):
308 # type: (expr_t, scope_t) -> value_t
309 """Evaluate the LEFT MOST part, respecting setvar/setglobal.
310
311 Consider this statement:
312
313 setglobal g[a[i]] = 42
314
315 - The g is always global, never local. It's the thing to be mutated.
316 - The a can be local or global
317 """
318 UP_lhs = lhs
319 with tagswitch(lhs) as case:
320 if case(expr_e.Var):
321 lhs = cast(expr.Var, UP_lhs)
322
323 # respect setvar/setglobal with which_scopes
324 return LookupVar(self.mem, lhs.name, which_scopes, lhs.left)
325
326 elif case(expr_e.Subscript):
327 lhs = cast(Subscript, UP_lhs)
328
329 # recursive call
330 obj = self._EvalLeftLocalOrGlobal(lhs.obj, which_scopes)
331 index = self._EvalExpr(lhs.index)
332
333 return self._EvalSubscript(obj, index, lhs.left)
334
335 elif case(expr_e.Attribute):
336 lhs = cast(Attribute, UP_lhs)
337 assert lhs.op.id == Id.Expr_Dot
338
339 # recursive call
340 obj = self._EvalLeftLocalOrGlobal(lhs.obj, which_scopes)
341 return self._EvalDot(lhs, obj)
342
343 else:
344 # Shouldn't happen because of Transformer._CheckLhs
345 raise AssertionError()
346
347 def _EvalLhsExpr(self, lhs, which_scopes):
348 # type: (y_lhs_t, scope_t) -> y_lvalue_t
349 """
350 Handle setvar x, setvar a[i], ... setglobal x, setglobal a[i]
351 """
352 UP_lhs = lhs
353 with tagswitch(lhs) as case:
354 if case(y_lhs_e.Var):
355 lhs = cast(Token, UP_lhs)
356 return LeftName(lexer.LazyStr(lhs), lhs)
357
358 elif case(y_lhs_e.Subscript):
359 lhs = cast(Subscript, UP_lhs)
360 # setvar mylist[0] = 42
361 # setvar mydict['key'] = 42
362
363 lval = self._EvalLeftLocalOrGlobal(lhs.obj, which_scopes)
364 index = self._EvalExpr(lhs.index)
365 return y_lvalue.Container(lval, index)
366
367 elif case(y_lhs_e.Attribute):
368 lhs = cast(Attribute, UP_lhs)
369 assert lhs.op.id == Id.Expr_Dot
370
371 # setvar mydict.key = 42
372 lval = self._EvalLeftLocalOrGlobal(lhs.obj, which_scopes)
373
374 attr = value.Str(lhs.attr_name)
375 return y_lvalue.Container(lval, attr)
376
377 else:
378 raise AssertionError()
379
380 def EvalExprClosure(self, expr_val, blame_loc):
381 # type: (value.Expr, loc_t) -> value_t
382 """
383 Used by user-facing APIs that take value.Expr closures:
384
385 var i = 42
386 var x = io->evalExpr(^[i + 1])
387 var x = s.replace(pat, ^"- $0 $i -")
388 """
389 with state.ctx_EnclosedFrame(self.mem, expr_val.captured_frame,
390 expr_val.module_frame, None):
391 return self.EvalExpr(expr_val.e, blame_loc)
392
393 def EvalExpr(self, node, blame_loc):
394 # type: (expr_t, loc_t) -> value_t
395 """Public API for _EvalExpr to ensure command_sub_errexit"""
396 self.mem.SetLocationForExpr(blame_loc)
397 # Pure C++ won't need to catch exceptions
398 with state.ctx_YshExpr(self.mutable_opts):
399 val = self._EvalExpr(node)
400 return val
401
402 def EvalLhsExpr(self, lhs, which_scopes):
403 # type: (y_lhs_t, scope_t) -> y_lvalue_t
404 """Public API for _EvalLhsExpr to ensure command_sub_errexit"""
405 with state.ctx_YshExpr(self.mutable_opts):
406 lval = self._EvalLhsExpr(lhs, which_scopes)
407 return lval
408
409 def EvalExprSub(self, part):
410 # type: (ExprSub) -> part_value_t
411 """Evaluate $[] and @[] that come from commands; return part_value_t """
412
413 val = self.EvalExpr(part.child, part.left)
414
415 with switch(part.left.id) as case:
416 if case(Id.Left_DollarBracket): # $[join(x)]
417 s = val_ops.Stringify(val, loc.WordPart(part), 'Expr sub ')
418 return word_.PieceQuoted(s)
419
420 elif case(Id.Lit_AtLBracket): # @[split(x)]
421 strs = val_ops.ToShellArray(val, loc.WordPart(part),
422 'Expr splice ')
423 return part_value.Array(strs, True)
424
425 else:
426 raise AssertionError(part.left)
427
428 def _EvalExprSub(self, part):
429 # type: (ExprSub) -> value_t
430 """Evaluate $[] and @[] that come from INTERIOR expressions
431
432 Returns value_t
433 """
434 val = self._EvalExpr(part.child)
435
436 with switch(part.left.id) as case:
437 if case(Id.Left_DollarBracket): # $[join(x)]
438 s = val_ops.Stringify(val, loc.WordPart(part), 'Expr sub ')
439 return value.Str(s)
440
441 elif case(Id.Left_AtBracket): # @[split(x)]
442 strs = val_ops.ToShellArray(val, loc.WordPart(part),
443 'Expr splice ')
444 items = [value.Str(s) for s in strs] # type: List[value_t]
445 return value.List(items)
446
447 else:
448 raise AssertionError(part.left)
449
450 def PluginCall(self, func_val, pos_args):
451 # type: (value.Func, List[value_t]) -> value_t
452 """For renderPrompt()
453
454 Similar to
455 - WordEvaluator.EvalForPlugin(), which evaluates $PS1 outside main loop
456 - ReadlineCallback.__call__, which executes shell outside main loop
457 """
458 with state.ctx_YshExpr(self.mutable_opts):
459 with state.ctx_Registers(self.mem): # to sandbox globals
460 named_args = NewDict() # type: Dict[str, value_t]
461 arg_list = ArgList.CreateNull() # There's no call site
462 rd = typed_args.Reader(pos_args, named_args, None, arg_list)
463
464 try:
465 val = func_proc.CallUserFunc(func_val, rd, self.mem,
466 self.cmd_ev)
467 except error.FatalRuntime as e:
468 val = value.Str('<Runtime error: %s>' %
469 e.UserErrorString())
470
471 except (IOError, OSError) as e:
472 val = value.Str('<I/O error: %s>' % pyutil.strerror(e))
473
474 except KeyboardInterrupt:
475 val = value.Str('<Ctrl-C>')
476
477 return val
478
479 def CallConvertFunc(self, func_val, arg, convert_tok, call_loc):
480 # type: (value_t, value_t, Token, loc_t) -> value_t
481 """ For Eggex captures """
482 with state.ctx_YshExpr(self.mutable_opts):
483 pos_args = [arg]
484 named_args = NewDict() # type: Dict[str, value_t]
485 arg_list = ArgList.CreateNull() # There's no call site
486 rd = typed_args.Reader(pos_args, named_args, None, arg_list)
487 rd.SetFallbackLocation(convert_tok)
488 try:
489 val = self._CallFunc(func_val, rd)
490 except error.FatalRuntime as e:
491 func_name = lexer.TokenVal(convert_tok)
492 self.errfmt.Print_(
493 'Fatal error calling Eggex conversion func %r from this Match accessor'
494 % func_name, call_loc)
495 print_stderr('')
496 raise
497
498 return val
499
500 def _CallMetaMethod(self, func_val, pos_args, blame_loc):
501 # type: (value_t, List[value_t], loc_t) -> value_t
502
503 named_args = NewDict() # type: Dict[str, value_t]
504 arg_list = ArgList.CreateNull() # There's no call site
505 rd = typed_args.Reader(pos_args, named_args, None, arg_list)
506 rd.SetFallbackLocation(blame_loc)
507 # errors propagate
508 return self._CallFunc(func_val, rd)
509
510 def SpliceValue(self, val, part):
511 # type: (value_t, word_part.Splice) -> List[str]
512 """ write -- @myvar """
513 return val_ops.ToShellArray(val, loc.WordPart(part), prefix='Splice ')
514
515 def _EvalConst(self, node):
516 # type: (expr.Const) -> value_t
517 return node.val
518
519 def _EvalUnary(self, node):
520 # type: (expr.Unary) -> value_t
521
522 val = self._EvalExpr(node.child)
523
524 with switch(node.op.id) as case:
525 if case(Id.Arith_Plus):
526 # Unary plus: coerce to number but don't change the value
527 c1, i1, f1 = _ConvertToNumber(val)
528 if c1 == coerced_e.Int:
529 return value.Int(i1)
530 if c1 == coerced_e.Float:
531 return value.Float(f1)
532 raise error.TypeErr(val, 'Unary + expected Int or Float',
533 node.op)
534
535 elif case(Id.Arith_Minus):
536 c1, i1, f1 = _ConvertToNumber(val)
537 if c1 == coerced_e.Int:
538 return value.Int(mops.Negate(i1))
539 if c1 == coerced_e.Float:
540 return value.Float(-f1)
541 raise error.TypeErr(val, 'Negation expected Int or Float',
542 node.op)
543
544 elif case(Id.Arith_Tilde):
545 i = _ConvertToInt(val, '~ expected Int', node.op)
546 return value.Int(mops.BitNot(i))
547
548 elif case(Id.Expr_Not):
549 b = val_ops.ToBool(val)
550 return value.Bool(False if b else True)
551
552 # &s &a[0] &d.key &d.nested.other
553 elif case(Id.Arith_Amp):
554 # Only 3 possibilities:
555 # - expr.Var
556 # - expr.Attribute with `.` operator (d.key)
557 # - expr.SubScript
558 #
559 # See _EvalLhsExpr, which gives you y_lvalue
560
561 # TODO: &x, &a[0], &d.key, creates a value.Place?
562 # If it's Attribute or SubScript, you don't evaluate them.
563 # y_lvalue_t -> place_t
564
565 raise NotImplementedError(node.op)
566
567 else:
568 raise AssertionError(node.op)
569
570 raise AssertionError('for C++ compiler')
571
572 def _ArithIntFloat(self, left, right, op):
573 # type: (value_t, value_t, Token) -> value_t
574 """
575 Note: may be replaced with arithmetic on tagged integers, e.g. 60 bit
576 with overflow detection
577 """
578 c, i1, i2, f1, f2 = ConvertForBinaryOp(left, right)
579
580 op_id = op.id
581
582 if c == coerced_e.Int:
583 with switch(op_id) as case:
584 if case(Id.Arith_Plus, Id.Arith_PlusEqual):
585 return value.Int(mops.Add(i1, i2))
586 elif case(Id.Arith_Minus, Id.Arith_MinusEqual):
587 return value.Int(mops.Sub(i1, i2))
588 elif case(Id.Arith_Star, Id.Arith_StarEqual):
589 return value.Int(mops.Mul(i1, i2))
590 elif case(Id.Arith_Slash, Id.Arith_SlashEqual):
591 if mops.Equal(i2, mops.ZERO):
592 raise error.Expr('Divide by zero', op)
593 return value.Float(mops.ToFloat(i1) / mops.ToFloat(i2))
594 else:
595 raise AssertionError()
596
597 elif c == coerced_e.Float:
598 with switch(op_id) as case:
599 if case(Id.Arith_Plus, Id.Arith_PlusEqual):
600 return value.Float(f1 + f2)
601 elif case(Id.Arith_Minus, Id.Arith_MinusEqual):
602 return value.Float(f1 - f2)
603 elif case(Id.Arith_Star, Id.Arith_StarEqual):
604 return value.Float(f1 * f2)
605 elif case(Id.Arith_Slash, Id.Arith_SlashEqual):
606 if f2 == 0.0:
607 raise error.Expr('Divide by zero', op)
608 return value.Float(f1 / f2)
609 else:
610 raise AssertionError()
611
612 else:
613 raise error.TypeErrVerbose(
614 'Binary operator expected numbers, got %s and %s (OILS-ERR-201)'
615 % (ui.ValType(left), ui.ValType(right)), op)
616
617 def _ArithIntOnly(self, left, right, op):
618 # type: (value_t, value_t, Token) -> value_t
619
620 i1 = _ConvertToInt(left, 'Left operand should be Int', op)
621 i2 = _ConvertToInt(right, 'Right operand should be Int', op)
622
623 with switch(op.id) as case:
624
625 # a % b setvar a %= b
626 if case(Id.Arith_Percent, Id.Arith_PercentEqual):
627 if mops.Equal(i2, mops.ZERO):
628 raise error.Expr('Divide by zero', op)
629 if mops.Greater(mops.ZERO, i2):
630 # Disallow this to remove confusion between modulus and remainder
631 raise error.Expr("Divisor can't be negative", op)
632
633 return value.Int(mops.Rem(i1, i2))
634
635 # a // b setvar a //= b
636 elif case(Id.Expr_DSlash, Id.Expr_DSlashEqual):
637 if mops.Equal(i2, mops.ZERO):
638 raise error.Expr('Divide by zero', op)
639 return value.Int(mops.Div(i1, i2))
640
641 # a ** b setvar a **= b (ysh only)
642 elif case(Id.Arith_DStar, Id.Expr_DStarEqual):
643 # Same as sh_expr_eval.py
644 if mops.Greater(mops.ZERO, i2):
645 raise error.Expr("Exponent can't be a negative number", op)
646 return value.Int(num.Exponent(i1, i2))
647
648 # Bitwise
649 elif case(Id.Arith_Amp, Id.Arith_AmpEqual): # &
650 return value.Int(mops.BitAnd(i1, i2))
651
652 elif case(Id.Arith_Pipe, Id.Arith_PipeEqual): # |
653 return value.Int(mops.BitOr(i1, i2))
654
655 elif case(Id.Arith_Caret, Id.Arith_CaretEqual): # ^
656 return value.Int(mops.BitXor(i1, i2))
657
658 elif case(Id.Arith_DGreat, Id.Arith_DGreatEqual): # >>
659 if mops.Greater(mops.ZERO, i2): # i2 < 0
660 raise error.Expr("Can't right shift by negative number",
661 op)
662 return value.Int(mops.RShift(i1, i2))
663
664 elif case(Id.Arith_DLess, Id.Arith_DLessEqual): # <<
665 if mops.Greater(mops.ZERO, i2): # i2 < 0
666 raise error.Expr("Can't left shift by negative number", op)
667 return value.Int(mops.LShift(i1, i2))
668
669 else:
670 raise AssertionError(op.id)
671
672 def _Concat(self, left, right, op):
673 # type: (value_t, value_t, Token) -> value_t
674 UP_left = left
675 UP_right = right
676
677 if left.tag() == value_e.Str and right.tag() == value_e.Str:
678 left = cast(value.Str, UP_left)
679 right = cast(value.Str, UP_right)
680
681 return value.Str(left.s + right.s)
682
683 elif left.tag() == value_e.List and right.tag() == value_e.List:
684 left = cast(value.List, UP_left)
685 right = cast(value.List, UP_right)
686
687 c = list(left.items) # mycpp rewrite of L1 + L2
688 c.extend(right.items)
689 return value.List(c)
690
691 elif left.tag() == value_e.Dict and right.tag() == value_e.Dict:
692 left = cast(value.Dict, UP_left)
693 right = cast(value.Dict, UP_right)
694
695 res = left.d.copy()
696 res.update(right.d)
697 return value.Dict(res)
698
699 else:
700 raise error.TypeErrVerbose(
701 'Expected Str ++ Str, List ++ List, or Dict ++ Dict, got %s ++ %s'
702 % (ui.ValType(left), ui.ValType(right)), op)
703
704 def _EvalBinary(self, node):
705 # type: (expr.Binary) -> value_t
706
707 left = self._EvalExpr(node.left)
708
709 # Logical and/or lazily evaluate
710 with switch(node.op.id) as case:
711 if case(Id.Expr_And):
712 if val_ops.ToBool(left): # no errors
713 return self._EvalExpr(node.right)
714 else:
715 return left
716
717 elif case(Id.Expr_Or):
718 if val_ops.ToBool(left):
719 return left
720 else:
721 return self._EvalExpr(node.right)
722
723 # These operators all eagerly evaluate
724 right = self._EvalExpr(node.right)
725
726 with switch(node.op.id) as case:
727 if case(Id.Arith_DPlus): # a ++ b to concat Str or List
728 return self._Concat(left, right, node.op)
729
730 elif case(Id.Arith_Plus, Id.Arith_Minus, Id.Arith_Star,
731 Id.Arith_Slash):
732 return self._ArithIntFloat(left, right, node.op)
733
734 else:
735 return self._ArithIntOnly(left, right, node.op)
736
737 def _CompareNumeric(self, left, right, op):
738 # type: (value_t, value_t, Token) -> bool
739 c, i1, i2, f1, f2 = ConvertForBinaryOp(left, right)
740
741 if c == coerced_e.Int:
742 with switch(op.id) as case:
743 if case(Id.Arith_Less):
744 return mops.Greater(i2, i1)
745 elif case(Id.Arith_Great):
746 return mops.Greater(i1, i2)
747 elif case(Id.Arith_LessEqual):
748 return mops.Greater(i2, i1) or mops.Equal(i1, i2)
749 elif case(Id.Arith_GreatEqual):
750 return mops.Greater(i1, i2) or mops.Equal(i1, i2)
751 else:
752 raise AssertionError()
753
754 elif c == coerced_e.Float:
755 with switch(op.id) as case:
756 if case(Id.Arith_Less):
757 return f1 < f2
758 elif case(Id.Arith_Great):
759 return f1 > f2
760 elif case(Id.Arith_LessEqual):
761 return f1 <= f2
762 elif case(Id.Arith_GreatEqual):
763 return f1 >= f2
764 else:
765 raise AssertionError()
766
767 else:
768 raise error.TypeErrVerbose(
769 'Comparison operator expected numbers, got %s and %s' %
770 (ui.ValType(left), ui.ValType(right)), op)
771
772 def _EvalCompare(self, node):
773 # type: (expr.Compare) -> value_t
774
775 left = self._EvalExpr(node.left)
776 result = True # Implicit and
777 for i, op in enumerate(node.ops):
778 right_expr = node.comparators[i]
779
780 right = self._EvalExpr(right_expr)
781
782 if op.id in (Id.Arith_Less, Id.Arith_Great, Id.Arith_LessEqual,
783 Id.Arith_GreatEqual):
784 result = self._CompareNumeric(left, right, op)
785
786 elif op.id == Id.Expr_TEqual:
787 result = val_ops.ExactlyEqual(left, right, op)
788 elif op.id == Id.Expr_NotDEqual:
789 result = not val_ops.ExactlyEqual(left, right, op)
790
791 elif op.id == Id.Expr_In:
792 result = val_ops.Contains(left, right)
793 elif op.id == Id.Node_NotIn:
794 result = not val_ops.Contains(left, right)
795
796 elif op.id == Id.Expr_Is:
797 result = left is right
798
799 elif op.id == Id.Node_IsNot:
800 result = left is not right
801
802 elif op.id == Id.Expr_DTilde:
803 # no extglob in YSH; use eggex
804 if left.tag() != value_e.Str:
805 raise error.TypeErrVerbose('LHS must be Str', op)
806
807 if right.tag() != value_e.Str:
808 raise error.TypeErrVerbose('RHS must be Str', op)
809
810 UP_left = left
811 UP_right = right
812 left = cast(value.Str, UP_left)
813 right = cast(value.Str, UP_right)
814 return value.Bool(libc.fnmatch(right.s, left.s))
815
816 elif op.id == Id.Expr_NotDTilde:
817 if left.tag() != value_e.Str:
818 raise error.TypeErrVerbose('LHS must be Str', op)
819
820 if right.tag() != value_e.Str:
821 raise error.TypeErrVerbose('RHS must be Str', op)
822
823 UP_left = left
824 UP_right = right
825 left = cast(value.Str, UP_left)
826 right = cast(value.Str, UP_right)
827 return value.Bool(not libc.fnmatch(right.s, left.s))
828
829 elif op.id == Id.Expr_TildeDEqual:
830 # Approximate equality
831 UP_left = left
832 if left.tag() != value_e.Str:
833 e_die('~== expects a string on the left', op)
834
835 left = cast(value.Str, UP_left)
836 left2 = left.s.strip()
837
838 UP_right = right
839 with tagswitch(right) as case:
840 if case(value_e.Str):
841 right = cast(value.Str, UP_right)
842 return value.Bool(left2 == right.s)
843
844 elif case(value_e.Bool):
845 right = cast(value.Bool, UP_right)
846 left2 = left2.lower()
847 lb = False
848 if left2 == 'true':
849 lb = True
850 elif left2 == 'false':
851 lb = False
852 else:
853 return value.Bool(False)
854
855 #log('left %r left2 %r', left, left2)
856 return value.Bool(lb == right.b)
857
858 elif case(value_e.Int):
859 right = cast(value.Int, UP_right)
860
861 # Note: this logic is similar to _ConvertToInt(left2)
862 if not match.LooksLikeYshInt(left2):
863 return value.Bool(False)
864
865 left2 = left2.replace('_', '')
866 ok, left_i = mops.FromStr2(left2)
867 if not ok:
868 e_die('Integer too big: %s' % left2, op)
869
870 eq = mops.Equal(left_i, right.i)
871 return value.Bool(eq)
872
873 e_die('~== expects Str, Int, or Bool on the right', op)
874
875 else:
876 try:
877 if op.id == Id.Arith_Tilde:
878 result = val_ops.MatchRegex(left, right, self.mem)
879
880 elif op.id == Id.Expr_NotTilde:
881 # don't pass self.mem to not set a match
882 result = not val_ops.MatchRegex(left, right, None)
883
884 else:
885 raise AssertionError(op)
886 except ValueError as e:
887 # Status 2 indicates a regex parse error, as with [[ in OSH
888 e_die_status(2, e.message, op)
889
890 if not result:
891 return value.Bool(result)
892
893 left = right
894
895 return value.Bool(result)
896
897 def _CallFunc(self, to_call, rd):
898 # type: (value_t, typed_args.Reader) -> value_t
899
900 # Now apply args to either builtin or user-defined function
901 UP_to_call = to_call
902 with tagswitch(to_call) as case:
903 if case(value_e.Func):
904 to_call = cast(value.Func, UP_to_call)
905
906 return func_proc.CallUserFunc(to_call, rd, self.mem,
907 self.cmd_ev)
908
909 elif case(value_e.BuiltinFunc):
910 to_call = cast(value.BuiltinFunc, UP_to_call)
911
912 # C++ cast to work around ASDL 'any'
913 f = cast(vm._Callable, to_call.callable)
914 return f.Call(rd)
915 else:
916 raise AssertionError("Shouldn't have been bound")
917
918 def _EvalFuncCall(self, node):
919 # type: (expr.FuncCall) -> value_t
920
921 func = self._EvalExpr(node.func)
922 UP_func = func
923
924 # The () operator has a 2x2 matrix of
925 # (free, bound) x (builtin, user-defined)
926
927 # Eval args first
928 with tagswitch(func) as case:
929 if case(value_e.Func, value_e.BuiltinFunc):
930 to_call = func
931 pos_args, named_args = func_proc._EvalArgList(self, node.args)
932 rd = typed_args.Reader(pos_args, named_args, None, node.args)
933
934 elif case(value_e.BoundFunc):
935 func = cast(value.BoundFunc, UP_func)
936
937 to_call = func.func
938 pos_args, named_args = func_proc._EvalArgList(self,
939 node.args,
940 self_val=func.me)
941 rd = typed_args.Reader(pos_args,
942 named_args,
943 None,
944 node.args,
945 is_bound=True)
946 else:
947 raise error.TypeErr(func, 'Expected a function or method',
948 node.args.left)
949
950 return self._CallFunc(to_call, rd)
951
952 def _EvalSubscript(self, obj, index, blame_loc):
953 # type: (value_t, value_t, loc_t) -> value_t
954
955 UP_obj = obj
956 UP_index = index
957
958 with tagswitch(obj) as case:
959 if case(value_e.Str):
960 # Note: s[i] and s[i:j] are like Go, on bytes. We may provide
961 # s->numBytes(), s->countRunes(), and iteration over runes.
962 obj = cast(value.Str, UP_obj)
963 with tagswitch(index) as case2:
964 if case2(value_e.Slice):
965 index = cast(value.Slice, UP_index)
966
967 lower = index.lower.i if index.lower else 0
968 upper = index.upper.i if index.upper else len(obj.s)
969 return value.Str(obj.s[lower:upper])
970
971 elif case2(value_e.Int):
972 index = cast(value.Int, UP_index)
973 i = mops.BigTruncate(index.i)
974 try:
975 return value.Str(obj.s[i])
976 except IndexError:
977 raise error.Expr('index out of range', blame_loc)
978
979 else:
980 raise error.TypeErr(index,
981 'Str index expected Int or Slice',
982 blame_loc)
983
984 elif case(value_e.List):
985 obj = cast(value.List, UP_obj)
986
987 big_i = mops.ZERO
988 with tagswitch(index) as case2:
989 if case2(value_e.Slice):
990 index = cast(value.Slice, UP_index)
991
992 lower = (index.lower.i if index.lower else 0)
993 upper = (index.upper.i
994 if index.upper else len(obj.items))
995 return value.List(obj.items[lower:upper])
996
997 elif case2(value_e.Int):
998 index = cast(value.Int, UP_index)
999 big_i = index.i
1000
1001 elif case2(value_e.Str):
1002 index = cast(value.Str, UP_index)
1003 big_i = _ConvertToInt(index, 'List index expected Int',
1004 blame_loc)
1005
1006 else:
1007 raise error.TypeErr(
1008 index, 'List index expected Int, Str, or Slice',
1009 blame_loc)
1010
1011 i = mops.BigTruncate(big_i) # TODO: don't truncate
1012 try:
1013 return obj.items[i]
1014 except IndexError:
1015 raise error.Expr('List index out of range: %d' % i,
1016 blame_loc)
1017
1018 elif case(value_e.Dict):
1019 obj = cast(value.Dict, UP_obj)
1020 if index.tag() != value_e.Str:
1021 raise error.TypeErr(index, 'Dict index expected Str',
1022 blame_loc)
1023
1024 index = cast(value.Str, UP_index)
1025 try:
1026 return obj.d[index.s]
1027 except KeyError:
1028 # TODO: expr.Subscript has no error location
1029 raise error.Expr('Dict entry not found: %r' % index.s,
1030 blame_loc)
1031
1032 elif case(value_e.Obj):
1033 obj = cast(Obj, UP_obj)
1034
1035 index_method = val_ops.IndexMetaMethod(obj)
1036 if index_method is not None:
1037 pos_args = [obj, index]
1038 return self._CallMetaMethod(index_method, pos_args,
1039 blame_loc)
1040
1041 raise error.TypeErr(
1042 obj, 'Subscript expected one of (Str List Dict, indexable Obj)',
1043 blame_loc)
1044
1045 def _ChainedLookup(self, obj, current, attr_name):
1046 # type: (Obj, Obj, str) -> Optional[value_t]
1047 """Prototype chain lookup.
1048
1049 Args:
1050 obj: properties we might bind to
1051 current: our location in the prototype chain
1052 """
1053 val = current.d.get(attr_name)
1054 if val is not None:
1055 # Special bound method logic for objects, but NOT modules
1056 if val.tag() in (value_e.Func, value_e.BuiltinFunc):
1057 return value.BoundFunc(obj, val)
1058 else:
1059 return val
1060
1061 if current.prototype is not None:
1062 return self._ChainedLookup(obj, current.prototype, attr_name)
1063
1064 return None
1065
1066 def _EvalDot(self, node, val):
1067 # type: (Attribute, value_t) -> value_t
1068 """ foo.attr on RHS or LHS
1069
1070 setvar x = foo.attr
1071 setglobal g[foo.attr] = 42
1072 """
1073 UP_val = val
1074 with tagswitch(val) as case:
1075 if case(value_e.Dict):
1076 val = cast(value.Dict, UP_val)
1077 attr_name = node.attr_name
1078
1079 # Dict key / normal attribute lookup
1080 result = val.d.get(attr_name)
1081 if result is not None:
1082 return result
1083
1084 raise error.Expr('Dict entry %r not found' % attr_name,
1085 node.op)
1086
1087 elif case(value_e.Obj):
1088 obj = cast(Obj, UP_val)
1089 attr_name = node.attr_name
1090
1091 # Dict key / normal attribute lookup
1092 result = obj.d.get(attr_name)
1093 if result is not None:
1094 return result
1095
1096 # Prototype lookup - with special logic for BoundMethod
1097 if obj.prototype is not None:
1098 result = self._ChainedLookup(obj, obj.prototype, attr_name)
1099 if result is not None:
1100 return result
1101
1102 raise error.Expr('Attribute %r not found on Obj' % attr_name,
1103 node.op)
1104
1105 else:
1106 # Method lookup on builtin types.
1107 # They don't have attributes or prototype chains -- we only
1108 # have a flat dict.
1109 type_methods = self.methods.get(val.tag())
1110 name = node.attr_name
1111 vm_callable = (type_methods.get(name)
1112 if type_methods is not None else None)
1113 if vm_callable:
1114 func_val = value.BuiltinFunc(vm_callable)
1115 return value.BoundFunc(val, func_val)
1116
1117 raise error.TypeErrVerbose(
1118 "Method %r not found on builtin type %s" %
1119 (name, ui.ValType(val)), node.attr)
1120
1121 raise AssertionError()
1122
1123 def _EvalRArrow(self, node, val):
1124 # type: (Attribute, value_t) -> value_t
1125 mut_name = 'M/' + node.attr_name
1126
1127 UP_val = val
1128 with tagswitch(val) as case:
1129 if case(value_e.Obj):
1130 obj = cast(Obj, UP_val)
1131
1132 if obj.prototype is not None:
1133 result = self._ChainedLookup(obj, obj.prototype, mut_name)
1134 if result is not None:
1135 return result
1136
1137 # TODO: we could have different errors for:
1138 # - no prototype
1139 # - found in the properties, not in the prototype chain (not
1140 # sure if this error is common.)
1141 raise error.Expr(
1142 "Mutating method %r not found on Obj prototype chain" %
1143 mut_name, node.attr)
1144 else:
1145 # Look up methods on builtin types
1146 # TODO: These should also be called M/append, M/erase, etc.
1147
1148 type_methods = self.methods.get(val.tag())
1149 vm_callable = (type_methods.get(mut_name)
1150 if type_methods is not None else None)
1151 if vm_callable:
1152 func_val = value.BuiltinFunc(vm_callable)
1153 return value.BoundFunc(val, func_val)
1154
1155 raise error.TypeErrVerbose(
1156 "Mutating method %r not found on builtin type %s" %
1157 (mut_name, ui.ValType(val)), node.attr)
1158 raise AssertionError()
1159
1160 def _EvalAttribute(self, node):
1161 # type: (Attribute) -> value_t
1162
1163 val = self._EvalExpr(node.obj)
1164 with switch(node.op.id) as case:
1165 if case(Id.Expr_Dot): # d.key is like d['key']
1166 return self._EvalDot(node, val)
1167
1168 elif case(Id.Expr_RArrow): # e.g. mylist->append(42)
1169 return self._EvalRArrow(node, val)
1170
1171 elif case(Id.Expr_RDArrow): # chaining s => split()
1172 name = node.attr_name
1173
1174 # Look up builtin methods, e.g.
1175 # s => strip() is like s.strip()
1176 # Note:
1177 # m => group(1) is worse than m.group(1)
1178 # This is not a transformation, but more like an attribute
1179
1180 type_methods = self.methods.get(val.tag())
1181 vm_callable = (type_methods.get(name)
1182 if type_methods is not None else None)
1183 if vm_callable:
1184 func_val = value.BuiltinFunc(vm_callable)
1185 return value.BoundFunc(val, func_val)
1186
1187 # Operator is =>, so try function chaining.
1188
1189 # Instead of str(f()) => upper()
1190 # or str(f()).upper() as in Pythohn
1191 #
1192 # It's more natural to write
1193 # f() => str() => upper()
1194
1195 # Could improve error message: may give "Undefined variable"
1196 val2 = self._LookupVar(name, node.attr)
1197
1198 with tagswitch(val2) as case2:
1199 if case2(value_e.Func, value_e.BuiltinFunc):
1200 return value.BoundFunc(val, val2)
1201 else:
1202 raise error.TypeErr(
1203 val2, 'Fat arrow => expects method or function',
1204 node.attr)
1205
1206 else:
1207 raise AssertionError(node.op)
1208 raise AssertionError()
1209
1210 def _EvalExpr(self, node):
1211 # type: (expr_t) -> value_t
1212 """Turn an expression into a value."""
1213 if 0:
1214 print('_EvalExpr()')
1215 node.PrettyPrint()
1216 print('')
1217
1218 UP_node = node
1219 with tagswitch(node) as case:
1220 if case(expr_e.Const):
1221 node = cast(expr.Const, UP_node)
1222 return self._EvalConst(node)
1223
1224 elif case(expr_e.Var):
1225 node = cast(expr.Var, UP_node)
1226 return self._LookupVar(node.name, node.left)
1227
1228 elif case(expr_e.Place):
1229 node = cast(expr.Place, UP_node)
1230 frame = self.mem.CurrentFrame()
1231 return value.Place(LeftName(node.var_name, node.blame_tok),
1232 frame)
1233
1234 elif case(expr_e.CommandSub):
1235 node = cast(CommandSub, UP_node)
1236
1237 id_ = node.left_token.id
1238 if id_ == Id.Left_CaretParen: # ^(echo block literal)
1239 # TODO: Propagate location info with ^(
1240 return value.Command(cmd_frag.Expr(node.child),
1241 self.mem.CurrentFrame(),
1242 self.mem.GlobalFrame())
1243 else:
1244 stdout_str = self.shell_ex.RunCommandSub(node)
1245 if id_ == Id.Left_AtParen: # @(seq 3)
1246 # YSH splitting algorithm: does not depend on IFS
1247 try:
1248 strs = j8.SplitJ8Lines(stdout_str)
1249 except error.Decode as e:
1250 # status code 4 is special, for encode/decode errors.
1251 raise error.Structured(4, e.Message(),
1252 node.left_token)
1253
1254 items = [value.Str(s)
1255 for s in strs] # type: List[value_t]
1256 return value.List(items)
1257 else:
1258 return value.Str(stdout_str)
1259
1260 elif case(expr_e.ExprSub):
1261 node = cast(ExprSub, UP_node)
1262 return self._EvalExprSub(node)
1263
1264 elif case(expr_e.YshArrayLiteral): # var x = :| foo *.py |
1265 node = cast(YshArrayLiteral, UP_node)
1266 words = braces.BraceExpandWords(node.words)
1267 strs = self.word_ev.EvalWordSequence(words)
1268 #log('ARRAY LITERAL EVALUATED TO -> %s', strs)
1269 #return value.InternalStringArray(strs)
1270
1271 # It's equivalent to ['foo', 'bar']
1272 items = [value.Str(s) for s in strs]
1273 return value.List(items)
1274
1275 elif case(expr_e.DoubleQuoted):
1276 node = cast(DoubleQuoted, UP_node)
1277 # In an ideal world, YSH would *statically* disallow:
1278 #
1279 # - "$@" and "${array[@]}"
1280 # - backticks like `echo hi`
1281 # - $(( 1+2 )) and $[] -- although useful for refactoring
1282 # - not sure: ${x%%} -- could disallow this
1283 # - these enters the ArgDQ state: "${a:-foo bar}" ?
1284 #
1285 # But that would complicate the parser/evaluator. So just rely
1286 # on runtime strict_array to disallow the bad parts.
1287 return value.Str(self.word_ev.EvalDoubleQuotedToString(node))
1288
1289 elif case(expr_e.SingleQuoted):
1290 node = cast(SingleQuoted, UP_node)
1291 return value.Str(node.sval)
1292
1293 elif case(expr_e.BracedVarSub):
1294 node = cast(BracedVarSub, UP_node)
1295 return value.Str(self.word_ev.EvalBracedVarSubToString(node))
1296
1297 elif case(expr_e.SimpleVarSub):
1298 node = cast(SimpleVarSub, UP_node)
1299 return value.Str(self.word_ev.EvalSimpleVarSubToString(node))
1300
1301 elif case(expr_e.Unary):
1302 node = cast(expr.Unary, UP_node)
1303 return self._EvalUnary(node)
1304
1305 elif case(expr_e.Binary):
1306 node = cast(expr.Binary, UP_node)
1307 return self._EvalBinary(node)
1308
1309 elif case(expr_e.Slice): # a[:0]
1310 node = cast(expr.Slice, UP_node)
1311
1312 lower = None # type: Optional[IntBox]
1313 upper = None # type: Optional[IntBox]
1314
1315 if node.lower:
1316 i1 = _ConvertToInt(self._EvalExpr(node.lower),
1317 'Slice begin should be Int', node.op)
1318 # TODO: don't truncate
1319 lower = IntBox(mops.BigTruncate(i1))
1320
1321 if node.upper:
1322 i1 = _ConvertToInt(self._EvalExpr(node.upper),
1323 'Slice end should be Int', node.op)
1324 # TODO: don't truncate
1325 upper = IntBox(mops.BigTruncate(i1))
1326
1327 return value.Slice(lower, upper)
1328
1329 elif case(expr_e.Range):
1330 node = cast(expr.Range, UP_node)
1331
1332 assert node.lower is not None
1333 assert node.upper is not None
1334
1335 i1 = _ConvertToInt(self._EvalExpr(node.lower),
1336 'Range begin should be Int', node.op)
1337
1338 i2 = _ConvertToInt(self._EvalExpr(node.upper),
1339 'Range end should be Int', node.op)
1340
1341 if node.op.id == Id.Expr_DDotEqual: # Closed range
1342 i2 = mops.Add(i2, mops.ONE)
1343
1344 # TODO: Don't truncate
1345 return value.Range(mops.BigTruncate(i1), mops.BigTruncate(i2))
1346
1347 elif case(expr_e.Compare):
1348 node = cast(expr.Compare, UP_node)
1349 return self._EvalCompare(node)
1350
1351 elif case(expr_e.IfExp):
1352 node = cast(expr.IfExp, UP_node)
1353 b = val_ops.ToBool(self._EvalExpr(node.test))
1354 if b:
1355 return self._EvalExpr(node.body)
1356 else:
1357 return self._EvalExpr(node.orelse)
1358
1359 elif case(expr_e.List):
1360 node = cast(expr.List, UP_node)
1361 items = [self._EvalExpr(e) for e in node.elts]
1362 return value.List(items)
1363
1364 elif case(expr_e.Tuple):
1365 node = cast(expr.Tuple, UP_node)
1366 # YSH language: Tuple syntax evaluates to LIST !
1367 items = [self._EvalExpr(e) for e in node.elts]
1368 return value.List(items)
1369
1370 elif case(expr_e.Dict):
1371 node = cast(expr.Dict, UP_node)
1372
1373 kvals = [self._EvalExpr(e) for e in node.keys]
1374 values = [] # type: List[value_t]
1375
1376 for i, value_expr in enumerate(node.values):
1377 if value_expr.tag() == expr_e.Implicit: # {key}
1378 # Enforced by parser. Key is expr.Const
1379 assert kvals[i].tag() == value_e.Str, kvals[i]
1380 key = cast(value.Str, kvals[i])
1381 v = self._LookupVar(key.s, loc.Missing)
1382 else:
1383 v = self._EvalExpr(value_expr)
1384
1385 values.append(v)
1386
1387 d = NewDict() # type: Dict[str, value_t]
1388 for i, kval in enumerate(kvals):
1389 k = val_ops.ToStr(kval, 'Dict keys must be strings',
1390 loc.Missing)
1391 d[k] = values[i]
1392
1393 return value.Dict(d)
1394
1395 elif case(expr_e.ListComp):
1396 e_die_status(
1397 2, 'List comprehension reserved but not implemented')
1398
1399 elif case(expr_e.GeneratorExp):
1400 e_die_status(
1401 2, 'Generator expression reserved but not implemented')
1402
1403 elif case(expr_e.Literal): # ^[1 + 2]
1404 node = cast(expr.Literal, UP_node)
1405 return value.Expr(node.inner, self.mem.CurrentFrame(),
1406 self.mem.GlobalFrame())
1407
1408 elif case(expr_e.Lambda): # |x| x+1 syntax is reserved
1409 # TODO: Location information for |, or func
1410 # Note: anonymous functions also evaluate to a Lambda, but they shouldn't
1411 e_die_status(2, 'Lambda reserved but not implemented')
1412
1413 elif case(expr_e.FuncCall):
1414 node = cast(expr.FuncCall, UP_node)
1415 return self._EvalFuncCall(node)
1416
1417 elif case(expr_e.Subscript):
1418 node = cast(Subscript, UP_node)
1419 obj = self._EvalExpr(node.obj)
1420 index = self._EvalExpr(node.index)
1421 return self._EvalSubscript(obj, index, node.left)
1422
1423 elif case(expr_e.Attribute): # obj->method or mydict.key
1424 node = cast(Attribute, UP_node)
1425 return self._EvalAttribute(node)
1426
1427 elif case(expr_e.Eggex):
1428 node = cast(Eggex, UP_node)
1429 return self.EvalEggex(node)
1430
1431 else:
1432 raise NotImplementedError(node.__class__.__name__)
1433
1434 def EvalEggex(self, node):
1435 # type: (Eggex) -> value.Eggex
1436
1437 # Splice, check flags consistency, and accumulate convert_funcs indexed
1438 # by capture group
1439 ev = EggexEvaluator(self.mem, node.canonical_flags)
1440 spliced = ev.EvalE(node.regex)
1441
1442 # as_ere and capture_names filled by ~ operator or Str method
1443 return value.Eggex(spliced, node.canonical_flags, ev.convert_funcs,
1444 ev.convert_toks, None, [])
1445
1446
1447class EggexEvaluator(object):
1448
1449 def __init__(self, mem, canonical_flags):
1450 # type: (state.Mem, str) -> None
1451 self.mem = mem
1452 self.canonical_flags = canonical_flags
1453 self.convert_funcs = [] # type: List[Optional[value_t]]
1454 self.convert_toks = [] # type: List[Optional[Token]]
1455
1456 def _LookupVar(self, name, var_loc):
1457 # type: (str, loc_t) -> value_t
1458 """
1459 Duplicated from ExprEvaluator
1460 """
1461 return LookupVar(self.mem, name, scope_e.LocalOrGlobal, var_loc)
1462
1463 def _EvalClassLiteralTerm(self, term, out):
1464 # type: (class_literal_term_t, List[char_class_term_t]) -> None
1465 UP_term = term
1466
1467 # These 2 vars will be initialized if we don't return early
1468 s = None # type: Optional[str]
1469 char_code_tok = None # type: Token
1470
1471 with tagswitch(term) as case:
1472
1473 if case(class_literal_term_e.CharCode):
1474 term = cast(CharCode, UP_term)
1475
1476 # What about \0? At runtime, ERE should disallow it. But we
1477 # can also disallow it here.
1478 out.append(term)
1479 return
1480
1481 elif case(class_literal_term_e.CharRange):
1482 term = cast(CharRange, UP_term)
1483 out.append(term)
1484 return
1485
1486 elif case(class_literal_term_e.PosixClass):
1487 term = cast(PosixClass, UP_term)
1488 out.append(term)
1489 return
1490
1491 elif case(class_literal_term_e.PerlClass):
1492 term = cast(PerlClass, UP_term)
1493 out.append(term)
1494 return
1495
1496 elif case(class_literal_term_e.SingleQuoted):
1497 term = cast(SingleQuoted, UP_term)
1498
1499 s = term.sval
1500 char_code_tok = term.left
1501
1502 elif case(class_literal_term_e.Splice):
1503 term = cast(class_literal_term.Splice, UP_term)
1504
1505 val = self._LookupVar(term.var_name, term.name)
1506 s = val_ops.ToStr(val, 'Eggex char class splice expected Str',
1507 term.name)
1508 char_code_tok = term.name
1509
1510 assert s is not None, term
1511 for ch in s:
1512 char_int = ord(ch)
1513 if char_int >= 128:
1514 # / [ '\x7f\xff' ] / is better written as / [ \x7f \xff ] /
1515 e_die(
1516 "Use unquoted char literal for byte %d, which is >= 128"
1517 " (avoid confusing a set of bytes with a sequence)" %
1518 char_int, char_code_tok)
1519 out.append(CharCode(char_code_tok, char_int, False))
1520
1521 def EvalE(self, node):
1522 # type: (re_t) -> re_t
1523 """Resolve references and eval constants in an Eggex
1524
1525 Rules:
1526 Splice => re_t # like Hex and @const in / Hex '.' @const /
1527 Speck/Token (syntax) => Primitive (logical)
1528 Chars and Strings => LiteralChars
1529 """
1530 UP_node = node
1531
1532 with tagswitch(node) as case:
1533 if case(re_e.Seq):
1534 node = cast(re.Seq, UP_node)
1535 new_children = [self.EvalE(child) for child in node.children]
1536 return re.Seq(new_children)
1537
1538 elif case(re_e.Alt):
1539 node = cast(re.Alt, UP_node)
1540 new_children = [self.EvalE(child) for child in node.children]
1541 return re.Alt(new_children)
1542
1543 elif case(re_e.Repeat):
1544 node = cast(re.Repeat, UP_node)
1545 return re.Repeat(self.EvalE(node.child), node.op)
1546
1547 elif case(re_e.Group):
1548 node = cast(re.Group, UP_node)
1549
1550 # placeholder for non-capturing group
1551 self.convert_funcs.append(None)
1552 self.convert_toks.append(None)
1553 return re.Group(self.EvalE(node.child))
1554
1555 elif case(re_e.Capture): # Identical to Group
1556 node = cast(re.Capture, UP_node)
1557 convert_func = None # type: Optional[value_t]
1558 convert_tok = None # type: Optional[Token]
1559 if node.func_name:
1560 func_name = lexer.LazyStr(node.func_name)
1561 func_val = self.mem.GetValue(func_name)
1562 with tagswitch(func_val) as case:
1563 if case(value_e.Func, value_e.BuiltinFunc):
1564 convert_func = func_val
1565 convert_tok = node.func_name
1566 else:
1567 raise error.TypeErr(
1568 func_val,
1569 "Expected %r to be a func" % func_name,
1570 node.func_name)
1571
1572 self.convert_funcs.append(convert_func)
1573 self.convert_toks.append(convert_tok)
1574 return re.Capture(self.EvalE(node.child), node.name,
1575 node.func_name)
1576
1577 elif case(re_e.CharClassLiteral):
1578 node = cast(re.CharClassLiteral, UP_node)
1579
1580 new_terms = [] # type: List[char_class_term_t]
1581 for t in node.terms:
1582 # can get multiple char_class_term.CharCode for a
1583 # class_literal_term_t
1584 self._EvalClassLiteralTerm(t, new_terms)
1585 return re.CharClass(node.negated, new_terms)
1586
1587 elif case(re_e.SingleQuoted):
1588 node = cast(SingleQuoted, UP_node)
1589
1590 s = node.sval
1591 return re.LiteralChars(node.left, s)
1592
1593 elif case(re_e.Splice):
1594 node = cast(re.Splice, UP_node)
1595
1596 val = self._LookupVar(node.var_name, node.name)
1597 UP_val = val
1598 with tagswitch(val) as case:
1599 if case(value_e.Str):
1600 val = cast(value.Str, UP_val)
1601 to_splice = re.LiteralChars(node.name,
1602 val.s) # type: re_t
1603
1604 elif case(value_e.Eggex):
1605 val = cast(value.Eggex, UP_val)
1606
1607 # Splicing means we get the conversion funcs too.
1608 self.convert_funcs.extend(val.convert_funcs)
1609 self.convert_toks.extend(val.convert_toks)
1610
1611 # Splicing requires flags to match. This check is
1612 # transitive.
1613 to_splice = val.spliced
1614
1615 if val.canonical_flags != self.canonical_flags:
1616 e_die(
1617 "Expected eggex flags %r, but got %r" %
1618 (self.canonical_flags, val.canonical_flags),
1619 node.name)
1620
1621 else:
1622 raise error.TypeErr(
1623 val, 'Eggex splice expected Str or Eggex',
1624 node.name)
1625 return to_splice
1626
1627 else:
1628 # These are evaluated at translation time
1629
1630 # case(re_e.Primitive)
1631 # case(re_e.PosixClass)
1632 # case(re_e.PerlClass)
1633 return node
1634
1635
1636# vim: sw=4