mirror of https://github.com/japl-lang/japl.git
57 lines
1.7 KiB
Nim
57 lines
1.7 KiB
Nim
# Copyright 2020 Mattia Giambirtone
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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## Implementation of JAPL call frames. A call frame
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## is a subset of the VM's stack that represent
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## functions' local space
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import ../types/jobject
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type
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CallFrame* = ref object # FIXME: Call frames are broken (end indexes are likely wrong)
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function*: ptr Function
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ip*: int
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slot*: int
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endSlot*: int
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stack*: seq[ptr Obj]
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proc getView*(self: CallFrame): seq[ptr Obj] =
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result = self.stack[self.slot..self.endSlot - 1]
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proc getAbsIndex(self: CallFrame, idx: int): int =
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return idx + len(self.getView()) - 1 # TODO: Inspect this code (locals, functions)
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proc len*(self: CallFrame): int =
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result = len(self.getView())
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proc `[]`*(self: CallFrame, idx: int): ptr Obj =
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result = self.stack[self.getAbsIndex(idx)]
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proc `[]=`*(self: CallFrame, idx: int, val: ptr Obj) =
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if idx < self.slot:
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raise newException(IndexError, "CallFrame index out of range")
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self.stack[self.getAbsIndex(idx)] = val
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proc delete*(self: CallFrame, idx: int) =
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if idx < self.slot or idx > self.endSlot:
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raise newException(IndexError, "CallFrame index out of range")
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self.stack.delete(idx)
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