mirror of https://github.com/japl-lang/japl.git
57 lines
1.6 KiB
Nim
57 lines
1.6 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 represents
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## function-local space
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import ../types/function
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import ../types/baseObject
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import ../types/arraylist
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{.experimental: "implicitDeref".}
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type
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CallFrame* = ref object
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function*: ptr Function
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ip*: int
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slot*: int
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stack*: ptr ArrayList[ptr Obj]
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proc clear*(self: CallFrame): int =
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## Returns how much to clear, and clears that many
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while self.stack.len() > self.slot:
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discard self.stack.pop()
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inc result
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proc getView*(self: CallFrame): ptr ArrayList[ptr Obj] =
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result = self.stack[self.slot..self.stack.len()]
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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[idx + self.slot]
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proc `[]=`*(self: CallFrame, idx: int, val: ptr Obj) =
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self.stack[idx + self.slot] = val
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proc delete*(self: CallFrame, idx: int) =
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self.stack.delete(idx + self.slot)
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