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[refactor] Extract long _EvalPlaceMutation() method
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Andy C committed Aug 27, 2023
1 parent 0572cb6 commit 00f2e0a
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Showing 2 changed files with 118 additions and 107 deletions.
208 changes: 103 additions & 105 deletions osh/cmd_eval.py
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Original file line number Diff line number Diff line change
Expand Up @@ -720,6 +720,107 @@ def _EvalCaseArg(self, arg, blame):
else:
raise NotImplementedError()

def _EvalPlaceMutation(self, node):
# type: (command.PlaceMutation) -> None

with switch(node.keyword.id) as case2:
if case2(Id.KW_SetVar):
which_scopes = scope_e.LocalOnly
elif case2(Id.KW_SetGlobal):
which_scopes = scope_e.GlobalOnly
elif case2(Id.KW_SetRef):
# The out param is LOCAL, but the nameref lookup is dynamic
which_scopes = scope_e.LocalOnly
else:
raise AssertionError(node.keyword.id)

if node.op.id == Id.Arith_Equal:
right_val = self.expr_ev.EvalExpr(node.rhs, loc.Missing)
UP_right_val = right_val

places = None # type: List[lvalue_t]
rhs_vals = None # type: List[value_t]

num_lhs = len(node.lhs)
if num_lhs == 1:
places = [self.expr_ev.EvalPlaceExpr(node.lhs[0])]
rhs_vals = [right_val]
else:
items = val_ops.ToList(
right_val, 'Destructuring assignment expected List',
node.keyword)

num_rhs = len(items)
if num_lhs != num_rhs:
raise error.Expr('%d != %d' % (num_lhs, num_rhs),
loc.Missing)

places = []
rhs_vals = []
for i, lhs_val in enumerate(node.lhs):
places.append(self.expr_ev.EvalPlaceExpr(lhs_val))
rhs_vals.append(items[i])

for i, place in enumerate(places):
rval = rhs_vals[i]
UP_place = place

# setvar mylist[0] = 42
# setvar mydict['key'] = 42
if place.tag() == lvalue_e.ObjIndex:
place = cast(lvalue.ObjIndex, UP_place)

obj = place.obj
UP_obj = obj
with tagswitch(obj) as case:
if case(value_e.List):
obj = cast(value.List, UP_obj)
index = val_ops.ToInt(place.index,
'List index should be Int',
loc.Missing)
obj.items[index] = rval

elif case(value_e.Dict):
obj = cast(value.Dict, UP_obj)
key = val_ops.ToStr(place.index,
'Dict index should be Str',
loc.Missing)
obj.d[key] = rval

else:
raise error.TypeErr(
obj, "obj[index] expected List or Dict",
loc.Missing)

if node.keyword.id == Id.KW_SetRef:
e_die('setref obj[index] not implemented')

else:
# top level variable
self.mem.SetValue(place,
rval,
which_scopes,
flags=_PackFlags(node.keyword.id))

# TODO: Eval other augmented assignments. Do we need "kind"
# here?
elif node.op.id == Id.Arith_PlusEqual:
# Checked in the parser
assert len(node.lhs) == 1

aug_lval = self.expr_ev.EvalPlaceExpr(node.lhs[0])
val = self.expr_ev.EvalExpr(node.rhs, loc.Missing)

new_val = self.expr_ev.EvalPlusEquals(aug_lval, val, node.op)

self.mem.SetValue(aug_lval,
new_val,
which_scopes,
flags=_PackFlags(node.keyword.id))

else:
raise NotImplementedError(Id_str(node.op.id))

def _Dispatch(self, node, cmd_st):
# type: (command_t, CommandStatus) -> int
"""Switch on the command_t variants and execute them."""
Expand Down Expand Up @@ -943,111 +1044,8 @@ def _Dispatch(self, node, cmd_st):
node = cast(command.PlaceMutation, UP_node)
self.mem.SetTokenForLine(node.keyword) # point to setvar/set

with switch(node.keyword.id) as case2:
if case2(Id.KW_SetVar):
which_scopes = scope_e.LocalOnly
elif case2(Id.KW_SetGlobal):
which_scopes = scope_e.GlobalOnly
elif case2(Id.KW_SetRef):
# The out param is LOCAL, but the nameref lookup is dynamic
which_scopes = scope_e.LocalOnly
else:
raise AssertionError(node.keyword.id)

if node.op.id == Id.Arith_Equal:
right_val = self.expr_ev.EvalExpr(node.rhs, loc.Missing)
UP_right_val = right_val

places = None # type: List[lvalue_t]
rhs_vals = None # type: List[value_t]

num_lhs = len(node.lhs)
if num_lhs == 1:
places = [self.expr_ev.EvalPlaceExpr(node.lhs[0])]
rhs_vals = [right_val]
else:
if right_val.tag() != value_e.List:
raise error.TypeErr(right_val, 'expected a List',
loc.Missing)
right_val = cast(value.List, UP_right_val)

num_rhs = len(right_val.items)
if num_lhs != num_rhs:
raise error.Expr('%d != %d' % (num_lhs, num_rhs),
loc.Missing)

places = []
rhs_vals = []
for i, lhs_val in enumerate(node.lhs):
places.append(self.expr_ev.EvalPlaceExpr(lhs_val))
rhs_vals.append(right_val.items[i])

for i, place in enumerate(places):
rval = rhs_vals[i]
UP_place = place

# setvar mylist[0] = 42
# setvar mydict['key'] = 42
if place.tag() == lvalue_e.ObjIndex:
place = cast(lvalue.ObjIndex, UP_place)

obj = place.obj
UP_obj = obj
with tagswitch(obj) as case:
if case(value_e.List):
obj = cast(value.List, UP_obj)
index = val_ops.ToInt(
place.index,
'List index should be Int',
loc.Missing)
obj.items[index] = rval

elif case(value_e.Dict):
obj = cast(value.Dict, UP_obj)
key = val_ops.ToStr(
place.index,
'Dict index should be Str',
loc.Missing)
obj.d[key] = rval

else:
raise error.TypeErr(
obj,
"obj[index] expected List or Dict",
loc.Missing)

if node.keyword.id == Id.KW_SetRef:
e_die('setref obj[index] not implemented')

else:
# top level variable
self.mem.SetValue(place,
rval,
which_scopes,
flags=_PackFlags(
node.keyword.id))

# TODO: Eval other augmented assignments. Do we need "kind"
# here?
elif node.op.id == Id.Arith_PlusEqual:
# Checked in the parser
assert len(node.lhs) == 1

aug_lval = self.expr_ev.EvalPlaceExpr(node.lhs[0])
val = self.expr_ev.EvalExpr(node.rhs, loc.Missing)

new_val = self.expr_ev.EvalPlusEquals(
aug_lval, val, node.op)

self.mem.SetValue(aug_lval,
new_val,
which_scopes,
flags=_PackFlags(node.keyword.id))

else:
raise NotImplementedError(Id_str(node.op.id))

status = 0 # TODO: what should status be?
self._EvalPlaceMutation(node)
status = 0 # if no exception is thrown, it succeeds

elif case(command_e.ShAssignment): # Only unqualified assignment
node = cast(command.ShAssignment, UP_node)
Expand Down
17 changes: 15 additions & 2 deletions spec/ysh-assign.test.sh
View file
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
# Test var / setvar / etc.

## our_shell: ysh
## oils_failures_allowed: 3
## oils_failures_allowed: 4


# TODO: GetVar needs a mode where Obj[str] gets translated to value.Str?
Expand Down Expand Up @@ -93,7 +93,7 @@ echo $x
48.0
## END

#### Augmented assignment of dict entries
#### Augmented assignment of List and Dict entries

var d = {x: 42}

Expand All @@ -112,6 +112,19 @@ echo $[d.x]
48.0
## END

#### -= and other augmented assignment

var x = 5
setvar x -= 3
echo x=$x

setvar x *= 3
echo x=$x
## STDOUT:
x=3
## END


#### Augmented assignment doesn't work with multiple LHS

var x = 3
Expand Down

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