OILS / builtin / pure_ysh.py View on Github | oils.pub

229 lines, 144 significant
1"""
2builtin/pure_ysh.py - YSH builtins that don't do I/O.
3"""
4from __future__ import print_function
5
6from _devbuild.gen.runtime_asdl import cmd_value
7from _devbuild.gen.syntax_asdl import command_t, loc, loc_t
8from _devbuild.gen.value_asdl import value, value_e, value_t
9from core import bash_impl
10from core import error
11from core import state
12from core import vm
13from frontend import flag_util
14from frontend import typed_args
15from mycpp import mylib
16from mycpp.mylib import tagswitch, NewDict
17
18from typing import TYPE_CHECKING, cast, Any, Dict, List
19
20if TYPE_CHECKING:
21 from core import executor
22 from display import ui
23 from osh.cmd_eval import CommandEvaluator
24
25
26class Shvar(vm._Builtin):
27
28 def __init__(self, mem, search_path, cmd_ev):
29 # type: (state.Mem, executor.SearchPath, CommandEvaluator) -> None
30 self.mem = mem
31 self.search_path = search_path # to clear PATH
32 self.cmd_ev = cmd_ev # To run blocks
33
34 def Run(self, cmd_val):
35 # type: (cmd_value.Argv) -> int
36 _, arg_r = flag_util.ParseCmdVal('shvar',
37 cmd_val,
38 accept_typed_args=True)
39
40 # TODO: I think shvar LANG=C should just mutate
41 # But should there be a whitelist?
42 cmd_frag = typed_args.RequiredBlockAsFrag(cmd_val)
43
44 vars = NewDict() # type: Dict[str, value_t]
45 args, arg_locs = arg_r.Rest2()
46 if len(args) == 0:
47 raise error.Usage('Expected name=value', loc.Missing)
48
49 for i, arg in enumerate(args):
50 name, s = mylib.split_once(arg, '=')
51 if s is None:
52 raise error.Usage('Expected name=value', arg_locs[i])
53 v = value.Str(s) # type: value_t
54 vars[name] = v
55
56 # Important fix: shvar PATH='' { } must make all binaries invisible
57 if name == 'PATH':
58 self.search_path.ClearCache()
59
60 with state.ctx_Eval(self.mem, None, None, vars):
61 unused = self.cmd_ev.EvalCommandFrag(cmd_frag)
62
63 return 0
64
65
66class ctx_Context(object):
67 """For ctx push (context) { ... }"""
68
69 def __init__(self, mem, context):
70 # type: (state.Mem, Dict[str, value_t]) -> None
71 self.mem = mem
72 self.mem.PushContextStack(context)
73
74 def __enter__(self):
75 # type: () -> None
76 pass
77
78 def __exit__(self, type, value, traceback):
79 # type: (Any, Any, Any) -> None
80 self.mem.PopContextStack()
81
82
83class Ctx(vm._Builtin):
84
85 def __init__(self, mem, cmd_ev):
86 # type: (state.Mem, CommandEvaluator) -> None
87 self.mem = mem
88 self.cmd_ev = cmd_ev # To run blocks
89
90 def _GetContext(self):
91 # type: () -> Dict[str, value_t]
92 ctx = self.mem.GetContext()
93 if ctx is None:
94 raise error.Expr(
95 "Could not find a context. Did you forget to 'ctx push'?",
96 loc.Missing)
97 return ctx
98
99 def _Push(self, context, block):
100 # type: (Dict[str, value_t], command_t) -> int
101 with ctx_Context(self.mem, context):
102 return self.cmd_ev.EvalCommandFrag(block)
103
104 def _Set(self, updates):
105 # type: (Dict[str, value_t]) -> int
106 ctx = self._GetContext()
107 ctx.update(updates)
108 return 0
109
110 def _Emit(self, field, item, blame):
111 # type: (str, value_t, loc_t) -> int
112 ctx = self._GetContext()
113
114 if field not in ctx:
115 ctx[field] = value.List([])
116
117 UP_arr = ctx[field]
118 if UP_arr.tag() != value_e.List:
119 raise error.TypeErr(
120 UP_arr,
121 "Expected the context item '%s' to be a List" % (field), blame)
122
123 arr = cast(value.List, UP_arr)
124 arr.items.append(item)
125
126 return 0
127
128 def Run(self, cmd_val):
129 # type: (cmd_value.Argv) -> int
130 rd = typed_args.ReaderForProc(cmd_val)
131 _, arg_r = flag_util.ParseCmdVal('ctx',
132 cmd_val,
133 accept_typed_args=True)
134
135 verb, verb_loc = arg_r.ReadRequired2(
136 'Expected a verb (push, set, emit)')
137
138 if verb == "push":
139 context = rd.PosDict()
140 block = rd.RequiredBlockAsFrag()
141 rd.Done()
142 arg_r.AtEnd()
143
144 return self._Push(context, block)
145
146 elif verb == "set":
147 updates = rd.RestNamed()
148 rd.Done()
149 arg_r.AtEnd()
150
151 return self._Set(updates)
152
153 elif verb == "emit":
154 field, field_loc = arg_r.ReadRequired2(
155 "A target field is required")
156 item = rd.PosValue()
157 rd.Done()
158 arg_r.AtEnd()
159
160 return self._Emit(field, item, field_loc)
161
162 else:
163 raise error.Usage("Unknown verb '%s'" % verb, verb_loc)
164
165
166class PushRegisters(vm._Builtin):
167
168 def __init__(self, mem, cmd_ev):
169 # type: (state.Mem, CommandEvaluator) -> None
170 self.mem = mem
171 self.cmd_ev = cmd_ev # To run blocks
172
173 def Run(self, cmd_val):
174 # type: (cmd_value.Argv) -> int
175 _, arg_r = flag_util.ParseCmdVal('push-registers',
176 cmd_val,
177 accept_typed_args=True)
178
179 cmd_frag = typed_args.RequiredBlockAsFrag(cmd_val)
180
181 with state.ctx_Registers(self.mem):
182 unused = self.cmd_ev.EvalCommandFrag(cmd_frag)
183
184 # make it "SILENT" in terms of not mutating $?
185 # TODO: Revisit this. It might be better to provide the headless shell
186 # with a way to SET $? instead. Needs to be tested/prototyped.
187 return self.mem.last_status[-1]
188
189
190class Append(vm._Builtin):
191 """Push word args onto an List.
192
193 Not doing typed args since you can do
194
195 :: mylist->append(42)
196 """
197
198 def __init__(self, mem, errfmt):
199 # type: (state.Mem, ui.ErrorFormatter) -> None
200 self.mem = mem
201 self.errfmt = errfmt
202
203 def Run(self, cmd_val):
204 # type: (cmd_value.Argv) -> int
205
206 # This means we ignore -- , which is consistent
207 _, arg_r = flag_util.ParseCmdVal('append',
208 cmd_val,
209 accept_typed_args=True)
210
211 rd = typed_args.ReaderForProc(cmd_val)
212 val = rd.PosValue()
213 rd.Done()
214
215 UP_val = val
216 with tagswitch(val) as case:
217 if case(value_e.BashArray):
218 val = cast(value.BashArray, UP_val)
219 bash_impl.BashArray_AppendValues(val, arg_r.Rest())
220 elif case(value_e.List):
221 val = cast(value.List, UP_val)
222 typed = [value.Str(s)
223 for s in arg_r.Rest()] # type: List[value_t]
224 val.items.extend(typed)
225 else:
226 raise error.TypeErr(val, 'expected List or BashArray',
227 loc.Missing)
228
229 return 0