def GetVar(self, name, lookup_mode=scope_e.Dynamic):
assert isinstance(name, str), name
# Do lookup of system globals before looking at user variables. Note: we
# could optimize this at compile-time like $?. That would break
# ${!varref}, but it's already broken for $?.
if name == 'FUNCNAME':
# bash wants it in reverse order. This is a little inefficient but we're
# not depending on deque().
strs = list(reversed(self.func_name_stack))
# TODO: Reuse this object too?
return runtime.StrArray(strs)
if name == 'LINENO':
return self.line_num
# Instead of BASH_SOURCE. Using Oil _ convnetion.
if name == 'SOURCE_NAME':
return self.source_name
cell, _ = self._FindCellAndNamespace(name, lookup_mode, is_read=True)
if cell:
return cell.val
return runtime.Undef()
def testGetVar(self):
mem = _InitMem()
# readonly a=x
mem.SetVar(runtime.LhsName('a'), runtime.Str('x'),
(var_flags_e.ReadOnly, ), scope_e.Dynamic)
val = mem.GetVar('a', scope_e.Dynamic)
test_lib.AssertAsdlEqual(self, runtime.Str('x'), val)
val = mem.GetVar('undef', scope_e.Dynamic)
test_lib.AssertAsdlEqual(self, runtime.Undef(), val)
def GetSpecialVar(self, op_id):
if op_id == Id.VSub_Bang: # $!
n = self.last_job_id
if n == -1:
return runtime.Undef() # could be an error
elif op_id == Id.VSub_QMark: # $?
# TODO: Have to parse status somewhere.
# External commands need WIFEXITED test. What about subshells?
n = self.last_status
elif op_id == Id.VSub_Pound: # $#
n = self.argv_stack[-1].GetNumArgs()
elif op_id == Id.VSub_Dollar: # $$
n = self.root_pid
else:
raise NotImplementedError(op_id)
return runtime.Str(str(n))
def _EvalBracedVarSub(self, part, part_vals, quoted):
"""
Args:
part_vals: output param to append to.
"""
# We have four types of operator that interact.
#
# 1. Bracket: value -> (value, bool maybe_decay_array)
#
# 2. Then these four cases are mutually exclusive:
#
# a. Prefix length: value -> value
# b. Test: value -> part_value[]
# c. Other Suffix: value -> value
# d. no operator: you have a value
#
# That is, we don't have both prefix and suffix operators.
#
# 3. Process maybe_decay_array here before returning.
maybe_decay_array = False # for $*, ${a[*]}, etc.
var_name = None # For ${foo=default}
# 1. Evaluate from (var_name, var_num, token Id) -> value
if part.token.id == Id.VSub_Name:
var_name = part.token.val
val = self.mem.GetVar(var_name)
#log('EVAL NAME %s -> %s', var_name, val)
elif part.token.id == Id.VSub_Number:
var_num = int(part.token.val)
val = self._EvalVarNum(var_num)
else:
# $* decays
val, maybe_decay_array = self._EvalSpecialVar(
part.token.id, quoted)
# 2. Bracket: value -> (value v, bool maybe_decay_array)
# maybe_decay_array is for joining ${a[*]} and unquoted ${a[@]} AFTER
# suffix ops are applied. If we take the length with a prefix op, the
# distinction is ignored.
if part.bracket_op:
if part.bracket_op.tag == bracket_op_e.WholeArray:
op_id = part.bracket_op.op_id
if op_id == Id.Lit_At:
if not quoted:
maybe_decay_array = True # ${a[@]} decays but "${a[@]}" doesn't
if val.tag == value_e.Undef:
val = self._EmptyStrArrayOrError(part.token)
elif val.tag == value_e.Str:
e_die("Can't index string with @: %r", val, part=part)
elif val.tag == value_e.StrArray:
# TODO: Is this a no-op? Just leave 'val' alone.
val = runtime.StrArray(val.strs)
elif op_id == Id.Arith_Star:
maybe_decay_array = True # both ${a[*]} and "${a[*]}" decay
if val.tag == value_e.Undef:
val = self._EmptyStrArrayOrError(part.token)
elif val.tag == value_e.Str:
e_die("Can't index string with *: %r", val, part=part)
elif val.tag == value_e.StrArray:
# TODO: Is this a no-op? Just leave 'val' alone.
# ${a[*]} or "${a[*]}" : maybe_decay_array is always true
val = runtime.StrArray(val.strs)
else:
raise AssertionError(op_id) # unknown
elif part.bracket_op.tag == bracket_op_e.ArrayIndex:
anode = part.bracket_op.expr
if val.tag == value_e.Undef:
pass # it will be checked later
elif val.tag == value_e.Str:
# Bash treats any string as an array, so we can't add our own
# behavior here without making valid OSH invalid bash.
e_die("Can't index string %r with integer",
part.token.val,
token=part.token)
elif val.tag == value_e.StrArray:
index = self.arith_ev.Eval(anode)
try:
# could be None because representation is sparse
s = val.strs[index]
except IndexError:
s = None
if s is None:
val = runtime.Undef()
else:
val = runtime.Str(s)
elif val.tag == value_e.AssocArray:
key = self.arith_ev.Eval(anode, int_coerce=False)
try:
val = runtime.Str(val.d[key])
except KeyError:
val = runtime.Undef()
else:
raise AssertionError(val.__class__.__name__)
else:
raise AssertionError(part.bracket_op.tag)
if part.prefix_op:
val = self._EmptyStrOrError(val) # maybe error
val = self._ApplyPrefixOp(val, part.prefix_op)
# NOTE: When applying the length operator, we can't have a test or
# suffix afterward. And we don't want to decay the array
elif part.suffix_op:
op = part.suffix_op
if op.tag == suffix_op_e.StringNullary:
if op.op_id == Id.VOp0_P:
# TODO: Use dependency injection
#val = self.prompt._EvalPS1(val)
prompt = ui.PROMPT.EvalPrompt(val)
val = runtime.Str(prompt)
else:
raise NotImplementedError(op.op_id)
elif op.tag == suffix_op_e.StringUnary:
if LookupKind(part.suffix_op.op_id) == Kind.VTest:
# TODO: Change style to:
# if self._ApplyTestOp(...)
# return
# It should return whether anything was done. If not, we continue to
# the end, where we might throw an error.
assign_part_vals, effect = self._ApplyTestOp(
val, part.suffix_op, quoted, part_vals)
# NOTE: Splicing part_values is necessary because of code like
# ${undef:-'a b' c 'd # e'}. Each part_value can have a different
# do_glob/do_elide setting.
if effect == effect_e.SpliceParts:
return # EARLY RETURN, part_vals mutated
elif effect == effect_e.SpliceAndAssign:
if var_name is None:
# TODO: error context
e_die("Can't assign to special variable")
else:
# NOTE: This decays arrays too! 'set -o strict_array' could
# avoid it.
rhs_str = _DecayPartValuesToString(
assign_part_vals, self.splitter.GetJoinChar())
state.SetLocalString(self.mem, var_name, rhs_str)
return # EARLY RETURN, part_vals mutated
elif effect == effect_e.Error:
raise NotImplementedError
else:
# The old one
#val = self._EmptyStringPartOrError(part_val, quoted)
pass # do nothing, may still be undefined
else:
val = self._EmptyStrOrError(val) # maybe error
# Other suffix: value -> value
val = self._ApplyUnarySuffixOp(val, part.suffix_op)
elif op.tag == suffix_op_e.PatSub: # PatSub, vectorized
val = self._EmptyStrOrError(val) # ${undef//x/y}
pat_val = self.EvalWordToString(op.pat, do_fnmatch=True)
assert pat_val.tag == value_e.Str, pat_val
if op.replace:
replace_val = self.EvalWordToString(op.replace,
do_fnmatch=True)
assert replace_val.tag == value_e.Str, replace_val
replace_str = replace_val.s
else:
replace_str = ''
# Either GlobReplacer or ConstStringReplacer
replacer = libstr.MakeReplacer(pat_val.s, replace_str,
op.spids[0])
if val.tag == value_e.Str:
s = replacer.Replace(val.s, op)
val = runtime.Str(s)
elif val.tag == value_e.StrArray:
strs = []
for s in val.strs:
if s is not None:
strs.append(replacer.Replace(s, op))
val = runtime.StrArray(strs)
else:
raise AssertionError(val.__class__.__name__)
elif op.tag == suffix_op_e.Slice:
val = self._EmptyStrOrError(val) # ${undef:3:1}
if op.begin:
begin = self.arith_ev.Eval(op.begin)
else:
begin = 0
if op.length:
length = self.arith_ev.Eval(op.length)
else:
length = None
if val.tag == value_e.Str: # Slice UTF-8 characters in a string.
s = val.s
try:
if begin < 0:
# It could be negative if we compute unicode length, but that's
# confusing.
# TODO: Instead of attributing it to the word part, it would be
# better if we attributed it to arith_expr begin.
raise util.InvalidSlice(
"The start index of a string slice can't be negative: %d",
begin,
part=part)
byte_begin = libstr.AdvanceUtf8Chars(s, begin, 0)
if length is None:
byte_end = len(s)
else:
if length < 0:
# TODO: Instead of attributing it to the word part, it would be
# better if we attributed it to arith_expr begin.
raise util.InvalidSlice(
"The length of a string slice can't be negative: %d",
length,
part=part)
byte_end = libstr.AdvanceUtf8Chars(
s, length, byte_begin)
except (util.InvalidSlice, util.InvalidUtf8) as e:
if self.exec_opts.strict_word_eval:
raise
else:
# TODO:
# - We don't see the error location here, but we see it when set
# -o strict-word-eval.
# - Doesn't make the command exit with 1. It just sets the word
# to empty string.
util.warn(e.UserErrorString())
substr = '' # error condition
else:
substr = s[byte_begin:byte_end]
val = runtime.Str(substr)
elif val.tag == value_e.StrArray: # Slice array entries.
# NOTE: unset elements don't count towards the length.
strs = []
for s in val.strs[begin:]:
if s is not None:
strs.append(s)
if len(
strs
) == length: # never true for unspecified length
break
val = runtime.StrArray(strs)
else:
raise AssertionError(
val.__class__.__name__) # Not possible
# After applying suffixes, process maybe_decay_array here.
if maybe_decay_array and val.tag == value_e.StrArray:
val = self._DecayArray(val)
# For the case where there are no prefix or suffix ops.
val = self._EmptyStrOrError(val)
# For example, ${a} evaluates to value_t.Str(), but we want a
# part_value.StringPartValue.
part_val = _ValueToPartValue(val, quoted)
part_vals.append(part_val)
def SetVar(self, lval, value, new_flags, lookup_mode):
"""
Args:
lval: lvalue
val: value, or None if only changing flags
new_flags: tuple of flags to set: ReadOnly | Exported
() means no flags to start with
None means unchanged?
scope:
Local | Global | Dynamic - for builtins, PWD, etc.
NOTE: in bash, PWD=/ changes the directory. But not in dash.
"""
# STRICTNESS / SANENESS:
#
# 1) Don't create arrays automatically, e.g. a[1000]=x
# 2) Never change types? yeah I think that's a good idea, at least for oil
# (not sh, for compatibility). set -o strict-types or something. That
# means arrays have to be initialized with let arr = [], which is fine.
# This helps with stuff like IFS. It starts off as a string, and assigning
# it to a list is en error. I guess you will have to turn this no for
# bash?
assert new_flags is not None
if lval.tag == lvalue_e.LhsName:
#if lval.name == 'ldflags':
# TODO: Turn this into a tracing feature. Like osh --tracevar ldflags
# --tracevar foo. Has to respect environment variables too.
if 0:
util.log('--- SETTING ldflags to %s', value)
if lval.spids:
span_id = lval.spids[0]
line_span = self.arena.GetLineSpan(span_id)
line_id = line_span.line_id
#line = arena.GetLine(line_id)
path, line_num = self.arena.GetDebugInfo(line_id)
col = line_span.col
#length = line_span.length
util.log('--- spid %s: %s, line %d, col %d', span_id, path,
line_num + 1, col)
# TODO: Need the arena to look it up the line spid and line number.
# Maybe this should return one of (cell, scope). existing cell, or the
# scope to put it in?
# _FindCellOrScope
cell, namespace = self._FindCellAndNamespace(
lval.name, lookup_mode)
if cell:
if value is not None:
if cell.readonly:
# TODO: error context
e_die("Can't assign to readonly value %r", lval.name)
cell.val = value
if var_flags_e.Exported in new_flags:
cell.exported = True
if var_flags_e.ReadOnly in new_flags:
cell.readonly = True
else:
if value is None:
value = runtime.Undef() # export foo, readonly foo
cell = runtime.cell(value, var_flags_e.Exported in new_flags,
var_flags_e.ReadOnly in new_flags)
namespace[lval.name] = cell
if (cell.val is not None and cell.val.tag == value_e.StrArray
and cell.exported):
e_die("Can't export array") # TODO: error context
elif lval.tag == lvalue_e.LhsIndexedName:
# a[1]=(1 2 3)
if value.tag == value_e.StrArray:
e_die("Can't assign array to array member"
) # TODO: error context
cell, namespace = self._FindCellAndNamespace(
lval.name, lookup_mode)
if cell:
if cell.val.tag != value_e.StrArray:
# s=x
# s[1]=y
e_die("Can't index non-array") # TODO: error context
if cell.readonly:
e_die("Can't assign to readonly value")
strs = cell.val.strs
try:
strs[lval.index] = value.s
except IndexError:
# Fill it in with None. It could look like this:
# ['1', 2, 3, None, None, '4', None]
# Then ${#a[@]} counts the entries that are not None.
#
# TODO: strict-array for Oil arrays won't auto-fill.
n = lval.index - len(strs) + 1
strs.extend([None] * n)
strs[lval.index] = value.s
else:
# When the array doesn't exist yet, it is created filled with None.
# Access to the array needs to explicitly filter those sentinel values.
# It also wastes memory. But indexed access is fast.
# What should be optimized for? Bash uses a linked list. Random access
# takes linear time, but iteration skips unset entries automatically.
# - Maybe represent as hash table? Then it's not an ASDL type?
# representations:
# - array_item.Str array_item.Undef
# - parallel array: val.strs, val.undefs
# - or change ASDL type checking
# - ASDL language does not allow: StrArray(string?* strs)
# - or add dict to ASDL? Didn't it support obj?
# - finding the max index is linear time?
# - also you have to sort the indices
#
# array ops:
# a=(1 2)
# a[1]=x
# a+=(1 2)
# ${a[@]} - get all
# ${#a[@]} - length
# ${!a[@]} - keys
# That seems pretty minimal.
items = [None] * lval.index
items.append(value.s)
new_value = runtime.StrArray(items)
# arrays can't be exported
cell = runtime.cell(new_value, False, var_flags_e.ReadOnly
in new_flags)
namespace[lval.name] = cell
else:
raise AssertionError
def GetArgNum(self, arg_num):
index = self.num_shifted + arg_num - 1
if index >= len(self.argv):
return runtime.Undef()
return runtime.Str(str(self.argv[index]))
def GetVar(self, name, lookup_mode=scope_e.Dynamic):
assert isinstance(name, str), name
# Do lookup of system globals before looking at user variables. Note: we
# could optimize this at compile-time like $?. That would break
# ${!varref}, but it's already broken for $?.
if name == 'FUNCNAME':
# bash wants it in reverse order. This is a little inefficient but we're
# not depending on deque().
strs = []
for func_name, source_name, _, _, _ in reversed(self.debug_stack):
if func_name:
strs.append(func_name)
if source_name:
strs.append('source') # bash doesn't give name
# Temp stacks are ignored
if self.has_main:
strs.append('main') # bash does this
return runtime.StrArray(strs) # TODO: Reuse this object too?
# This isn't the call source, it's the source of the function DEFINITION
# (or the sourced # file itself).
if name == 'BASH_SOURCE':
return runtime.StrArray(list(reversed(self.bash_source)))
# This is how bash source SHOULD be defined, but it's not!
if name == 'CALL_SOURCE':
strs = []
for func_name, source_name, call_spid, _, _ in reversed(
self.debug_stack):
# should only happen for the first entry
if call_spid == const.NO_INTEGER:
continue
span = self.arena.GetLineSpan(call_spid)
path, _ = self.arena.GetDebugInfo(span.line_id)
strs.append(path)
if self.has_main:
strs.append('-') # Bash does this to line up with main?
return runtime.StrArray(strs) # TODO: Reuse this object too?
if name == 'BASH_LINENO':
strs = []
for func_name, source_name, call_spid, _, _ in reversed(
self.debug_stack):
# should only happen for the first entry
if call_spid == const.NO_INTEGER:
continue
span = self.arena.GetLineSpan(call_spid)
_, line_num = self.arena.GetDebugInfo(span.line_id)
strs.append(str(line_num))
if self.has_main:
strs.append('0') # Bash does this to line up with main?
return runtime.StrArray(strs) # TODO: Reuse this object too?
if name == 'LINENO':
return self.line_num
# This is OSH-specific. Get rid of it in favor of ${BASH_SOURCE[0]} ?
if name == 'SOURCE_NAME':
return self.source_name
cell, _ = self._FindCellAndNamespace(name, lookup_mode, writing=False)
if cell:
return cell.val
return runtime.Undef()
def SetVar(self, lval, value, new_flags, lookup_mode, strict_array=False):
"""
Args:
lval: lvalue
val: value, or None if only changing flags
new_flags: tuple of flags to set: ReadOnly | Exported
() means no flags to start with
None means unchanged?
scope:
Local | Global | Dynamic - for builtins, PWD, etc.
NOTE: in bash, PWD=/ changes the directory. But not in dash.
"""
# STRICTNESS / SANENESS:
#
# 1) Don't create arrays automatically, e.g. a[1000]=x
# 2) Never change types? yeah I think that's a good idea, at least for oil
# (not sh, for compatibility). set -o strict-types or something. That
# means arrays have to be initialized with let arr = [], which is fine.
# This helps with stuff like IFS. It starts off as a string, and assigning
# it to a list is en error. I guess you will have to turn this no for
# bash?
assert new_flags is not None
if lval.tag == lvalue_e.LhsName:
#if lval.name == 'ldflags':
# TODO: Turn this into a tracing feature. Like osh --tracevar ldflags
# --tracevar foo. Has to respect environment variables too.
if 0:
util.log('--- SETTING ldflags to %s', value)
if lval.spids:
span_id = lval.spids[0]
line_span = self.arena.GetLineSpan(span_id)
line_id = line_span.line_id
#line = arena.GetLine(line_id)
path, line_num = self.arena.GetDebugInfo(line_id)
col = line_span.col
#length = line_span.length
util.log('--- spid %s: %s, line %d, col %d', span_id, path,
line_num + 1, col)
# TODO: Need the arena to look it up the line spid and line number.
# Maybe this should return one of (cell, scope). existing cell, or the
# scope to put it in?
# _FindCellOrScope
cell, namespace = self._FindCellAndNamespace(
lval.name, lookup_mode)
if cell:
if value is not None:
if cell.readonly:
# TODO: error context
e_die("Can't assign to readonly value %r", lval.name)
cell.val = value
if var_flags_e.Exported in new_flags:
cell.exported = True
if var_flags_e.ReadOnly in new_flags:
cell.readonly = True
if var_flags_e.AssocArray in new_flags:
cell.is_assoc_array = True
else:
if value is None:
# set -o nounset; local foo; echo $foo # It's still undefined!
value = runtime.Undef() # export foo, readonly foo
cell = runtime.cell(value, var_flags_e.Exported in new_flags,
var_flags_e.ReadOnly in new_flags,
var_flags_e.AssocArray in new_flags)
namespace[lval.name] = cell
if (cell.val is not None and cell.val.tag == value_e.StrArray
and cell.exported):
e_die("Can't export array") # TODO: error context
elif lval.tag == lvalue_e.LhsIndexedName:
# TODO: All paths should have this? We can get here by a[x]=1 or
# (( a[ x ] = 1 )). Maybe we should make them different?
if lval.spids:
left_spid = lval.spids[0]
else:
left_spid = const.NO_INTEGER
# TODO: This is a parse error!
# a[1]=(1 2 3)
if value.tag == value_e.StrArray:
e_die("Can't assign array to array member", span_id=left_spid)
cell, namespace = self._FindCellAndNamespace(
lval.name, lookup_mode)
if not cell:
self._BindNewArrayWithEntry(namespace, lval, value, new_flags)
return
# bash/mksh have annoying behavior of letting you do LHS assignment to
# Undef, which then turns into an array. (Undef means that set -o
# nounset fails.)
cell_tag = cell.val.tag
if (cell_tag == value_e.Str
or (cell_tag == value_e.Undef and strict_array)):
# s=x
# s[1]=y # invalid
e_die("Entries in value of type %s can't be assigned to",
cell.val.__class__.__name__,
span_id=left_spid)
if cell.readonly:
e_die("Can't assign to readonly value", span_id=left_spid)
if cell_tag == value_e.Undef:
if cell.is_assoc_array:
self._BindNewAssocArrayWithEntry(namespace, lval, value,
new_flags)
else:
self._BindNewArrayWithEntry(namespace, lval, value,
new_flags)
return
if cell_tag == value_e.StrArray:
strs = cell.val.strs
try:
strs[lval.index] = value.s
except IndexError:
# Fill it in with None. It could look like this:
# ['1', 2, 3, None, None, '4', None]
# Then ${#a[@]} counts the entries that are not None.
#
# TODO: strict-array for Oil arrays won't auto-fill.
n = lval.index - len(strs) + 1
strs.extend([None] * n)
strs[lval.index] = value.s
return
if cell_tag == value_e.AssocArray:
cell.val.d[lval.index] = value.s
return
else:
raise AssertionError(lval.__class__.__name__)
def _EvalBracedVarSub(self, part, part_vals, quoted):
"""
Args:
part_vals: output param to append to.
"""
# We have four types of operator that interact.
#
# 1. Bracket: value -> (value, bool maybe_decay_array)
#
# 2. Then these four cases are mutually exclusive:
#
# a. Prefix length: value -> value
# b. Test: value -> part_value[]
# c. Other Suffix: value -> value
# d. no operator: you have a value
#
# That is, we don't have both prefix and suffix operators.
#
# 3. Process maybe_decay_array here before returning.
maybe_decay_array = False # for $*, ${a[*]}, etc.
var_name = None # For ${foo=default}
# 1. Evaluate from (var_name, var_num, token Id) -> value
if part.token.id == Id.VSub_Name:
var_name = part.token.val
val = self.mem.GetVar(var_name)
#log('EVAL NAME %s -> %s', var_name, val)
elif part.token.id == Id.VSub_Number:
var_num = int(part.token.val)
val = self._EvalVarNum(var_num)
else:
# $* decays
val, maybe_decay_array = self._EvalSpecialVar(part.token.id, quoted)
# 2. Bracket: value -> (value v, bool maybe_decay_array)
# maybe_decay_array is for joining ${a[*]} and unquoted ${a[@]} AFTER suffix ops
# are applied. If we take the length with a prefix op, the distinction is
# ignored.
if part.bracket_op:
if part.bracket_op.tag == bracket_op_e.WholeArray:
op_id = part.bracket_op.op_id
if op_id == Id.Lit_At:
if not quoted:
maybe_decay_array = True # ${a[@]} decays but "${a[@]}" doesn't
if val.tag == value_e.Undef:
val = self._EmptyStrArrayOrError(part.token)
elif val.tag == value_e.Str:
e_die("Can't index string with @: %r", val, part=part)
elif val.tag == value_e.StrArray:
val = runtime.StrArray(val.strs)
elif op_id == Id.Arith_Star:
maybe_decay_array = True # both ${a[*]} and "${a[*]}" decay
if val.tag == value_e.Undef:
val = self._EmptyStrArrayOrError(part.token)
elif val.tag == value_e.Str:
e_die("Can't index string with *: %r", val, part=part)
elif val.tag == value_e.StrArray:
# Always maybe_decay_array with ${a[*]} or "${a[*]}"
val = runtime.StrArray(val.strs)
else:
raise AssertionError(op_id) # unknown
elif part.bracket_op.tag == bracket_op_e.ArrayIndex:
anode = part.bracket_op.expr
index = self.arith_ev.Eval(anode)
if val.tag == value_e.Undef:
pass # it will be checked later
elif val.tag == value_e.Str:
# TODO: Implement this as an extension. Requires unicode support.
# Bash treats it as an array.
e_die("Can't index string %r with integer", part.token.val)
elif val.tag == value_e.StrArray:
try:
s = val.strs[index]
except IndexError:
s = None
if s is None:
val = runtime.Undef()
else:
val = runtime.Str(s)
else:
raise AssertionError(part.bracket_op.tag)
if part.prefix_op:
val = self._EmptyStrOrError(val) # maybe error
val = self._ApplyPrefixOp(val, part.prefix_op)
# NOTE: When applying the length operator, we can't have a test or
# suffix afterward. And we don't want to decay the array
elif part.suffix_op:
op = part.suffix_op
if op.tag == suffix_op_e.StringUnary:
if LookupKind(part.suffix_op.op_id) == Kind.VTest:
# TODO: Change style to:
# if self._ApplyTestOp(...)
# return
# It should return whether anything was done. If not, we continue to
# the end, where we might throw an error.
assign_part_vals, effect = self._ApplyTestOp(val, part.suffix_op,
quoted, part_vals)
# NOTE: Splicing part_values is necessary because of code like
# ${undef:-'a b' c 'd # e'}. Each part_value can have a different
# do_glob/do_elide setting.
if effect == effect_e.SpliceParts:
return # EARLY RETURN, part_vals mutated
elif effect == effect_e.SpliceAndAssign:
if var_name is None:
# TODO: error context
e_die("Can't assign to special variable")
else:
# NOTE: This decays arrays too! 'set -o strict_array' could
# avoid it.
rhs_str = _DecayPartValuesToString(assign_part_vals,
self.splitter.GetJoinChar())
state.SetLocalString(self.mem, var_name, rhs_str)
return # EARLY RETURN, part_vals mutated
elif effect == effect_e.Error:
raise NotImplementedError
else:
# The old one
#val = self._EmptyStringPartOrError(part_val, quoted)
pass # do nothing, may still be undefined
else:
val = self._EmptyStrOrError(val) # maybe error
# Other suffix: value -> value
val = self._ApplyUnarySuffixOp(val, part.suffix_op)
elif op.tag == suffix_op_e.PatSub: # PatSub, vectorized
val = self._EmptyStrOrError(val)
pat_val = self.EvalWordToString(op.pat, do_fnmatch=True)
assert pat_val.tag == value_e.Str, pat_val
if op.replace:
replace_val = self.EvalWordToString(op.replace, do_fnmatch=True)
assert replace_val.tag == value_e.Str, replace_val
replace_str = replace_val.s
else:
replace_str = ''
pat = pat_val.s
if val.tag == value_e.Str:
s = libstr.PatSub(val.s, op, pat, replace_str)
val = runtime.Str(s)
elif val.tag == value_e.StrArray:
strs = []
for s in val.strs:
if s is not None:
strs.append(libstr.PatSub(s, op, pat, replace_str))
val = runtime.StrArray(strs)
else:
raise AssertionError(val.__class__.__name__)
elif op.tag == suffix_op_e.Slice:
# NOTE: The beginning can be negative, but Python handles this. Might
# want to make it explicit.
# TODO: Check out of bounds errors? begin > end?
if op.begin:
begin = self.arith_ev.Eval(op.begin)
else:
begin = 0
if op.length:
length = self.arith_ev.Eval(op.length)
end = begin + length
else:
length = None
end = None # Python supports None as the end
if val.tag == value_e.Str: # Slice characters in a string.
# TODO: Need to support unicode? Write spec # tests.
val = runtime.Str(val.s[begin : end])
elif val.tag == value_e.StrArray: # Slice array entries.
# NOTE: unset elements don't count towards the length
strs = []
for s in val.strs[begin:]:
if s is not None:
strs.append(s)
if len(strs) == length: # never true for unspecified length
break
val = runtime.StrArray(strs)
else:
raise AssertionError(val.__class__.__name__)
# After applying suffixes, process maybe_decay_array here.
if maybe_decay_array and val.tag == value_e.StrArray:
val = self._DecayArray(val)
# No prefix or suffix ops
val = self._EmptyStrOrError(val)
# For example, ${a} evaluates to value_t.Str(), but we want a
# part_value.StringPartValue.
part_val = _ValueToPartValue(val, quoted)
part_vals.append(part_val)
