init hm-inference
parent
b79c1725b3
commit
59628cfa38
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@ -0,0 +1,160 @@
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import ast
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from itertools import chain
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from nac3_types import *
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class Visitor(ast.NodeVisitor):
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def __init__(self):
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super(Visitor, self).__init__()
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self.assignments = {}
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self.calls = []
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def visit_Assign(self, node):
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self.visit(node.value)
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for target in node.targets:
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self.visit(target)
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target.type.unify(node.value.type)
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def visit_Name(self, node):
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if node.id == '_':
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node.type = TVar()
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return
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if node.id not in self.assignments:
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self.assignments[node.id] = TVar()
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ty = self.assignments[node.id]
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if isinstance(ty, TFunc):
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ty = ty.instantiate()
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node.type = ty
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def visit_Lambda(self, node):
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old = self.assignments
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self.assignments = old.copy()
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self.visit(node.args)
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self.visit(node.body)
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self.assignments = old
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node.type = TFunc(node.args.type, node.body.type, set())
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def visit_arguments(self, node):
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for arg in node.args:
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self.assignments[arg.arg] = TVar()
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arg.type = self.assignments[arg.arg]
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node.type = [FuncArg(arg.arg, arg.type, False) for arg in node.args]
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def visit_Constant(self, node):
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if isinstance(node.value, bool):
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node.type = TBool
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elif isinstance(node.value, int):
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node.type = TInt
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def visit_Call(self, node):
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self.visit(node.func)
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for arg in node.args:
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self.visit(arg)
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for keyword in node.keywords:
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self.visit(keyword.value)
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node.type = TVar()
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call = TCall([arg.type for arg in node.args],
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{keyword.arg: keyword.value.type for keyword
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in node.keywords}, node.type)
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node.func.type.unify(call)
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self.calls.append(node.func.type)
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def visit_Attribute(self, node):
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self.visit(node.value)
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node.type = TVar()
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v = TVar()
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v.type = TVarType.RECORD
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if node.attr in v.fields:
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v.fields[node.attr].unify(node.type)
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else:
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v.fields[node.attr] = node.type
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node.value.type.unify(v)
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def visit_Tuple(self, node):
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for e in node.elts:
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self.visit(e)
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node.type = TTuple([e.type for e in node.elts])
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def visit_List(self, node):
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ty = TVar()
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for e in node.elts:
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self.visit(e)
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ty.unify(e.type)
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node.type = TList(ty)
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def visit_Subscript(self, node):
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self.visit(node.value)
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if isinstance(node.slice, ast.Slice):
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node.type = node.value.type
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if isinstance(node.type, TVar):
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node.type.type = node.type.type.unifier(TVarType.LIST)
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elif not isinstance(node.type, TList):
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raise UnificationError(f'{node.type} should be a list')
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elif isinstance(node.slice, ast.ExtSlice):
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raise NotImplementedError()
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else:
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# complicated because we need to handle lists and tuples
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# differently...
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self.visit(node.slice.value)
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node.slice.value.type.unify(TInt)
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ty = node.value.type
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node.type = TVar()
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if isinstance(ty, TVar):
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index = 0
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if isinstance(node.slice.value, ast.Constant):
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seq_ty = TVarType.SEQUENCE
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if isinstance(node.ctx, (ast.AugStore, ast.Store)):
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seq_ty = TVarType.LIST
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ty.type = ty.type.unifier(seq_ty)
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index = node.slice.value.value
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else:
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ty.type = ty.type.unifier(TVarType.LIST)
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if index in ty.fields:
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ty.fields[index].unify(node.type)
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else:
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ty.fields[index] = node.type
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elif isinstance(ty, TList):
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ty.param.unify(node.type)
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elif isinstance(ty, TTuple):
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if isinstance(node.ctx, (ast.AugStore, ast.Store)):
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raise UnificationError(f'Cannot assign to tuple')
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if isinstance(node.slice.value, ast.Constant):
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index = node.slice.value.value
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if index >= len(ty.params):
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raise UnificationError('Index out of range for tuple')
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ty.params[index].unify(node.type)
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else:
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raise UnificationError('Tuple index must be a constant')
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else:
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raise UnificationError(f'Cannot use subscript for {ty}')
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def visit_For(self, node):
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self.visit(node.target)
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self.visit(node.iter)
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ty = node.iter.type
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if isinstance(ty, TVar):
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# we currently only support iterator over lists
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ty.type = ty.type.unifier(TVarType.LIST)
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if 0 in ty.fields:
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ty.fields[0].unify(node.target.type)
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else:
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ty.fields[0] = node.target.type
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elif isinstance(ty, TList):
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ty.param.unify(node.target.type)
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else:
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raise UnificationError(f'Cannot iterate over {ty}')
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for stmt in chain(node.body, node.orelse):
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self.visit(stmt)
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def visit_If(self, node):
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self.visit(node.test)
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node.test.type.unify(TBool)
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for stmt in chain(node.body, node.orelse):
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self.visit(stmt)
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def visit_While(self, node):
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self.visit(node.test)
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node.test.type.unify(TBool)
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for stmt in chain(node.body, node.orelse):
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self.visit(stmt)
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from __future__ import annotations
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from typing import Dict, Mapping, List, Set
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from enum import Enum
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from itertools import chain
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class UnificationError(Exception):
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def __init__(self, msg):
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super().__init__(msg)
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class Type:
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def find(self):
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return self
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def unify(self, _):
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raise NotImplementedError()
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def subst(self, _):
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raise NotImplementedError()
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def check(self):
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pass
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class TVarType(Enum):
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UNDETERMINED = 1
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SEQUENCE = 2
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RECORD = 5
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TUPLE = 6
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LIST = 8
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def __le__(self, other):
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if self.__class__ is other.__class__:
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return (other.value % self.value) == 0
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return NotImplemented
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def unifier(self, other):
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if self.__class__ is not other.__class__:
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raise NotImplementedError()
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if self <= other:
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return other
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elif other <= self:
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return self
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else:
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raise UnificationError(f'cannot unify {self} and {other}')
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class TVar(Type):
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next_id = 0
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def __init__(self, vrange=None):
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self.type = TVarType.UNDETERMINED
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self.rank = 0
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self.parent = self
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self.fields = {}
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self.range = vrange
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self.id = TVar.next_id
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TVar.next_id += 1
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def check(self):
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if self.range is not None:
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ty = self.find()
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# maybe we should replace this with explicit eq
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if ty not in self.range:
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raise UnificationError(
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f'{self.id} cannot be substituted by {ty}')
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def subst(self, mapping: Mapping[int, Type]):
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# user cannot specify fields...
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# so this is safe
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if self.id in mapping:
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return mapping[self.id]
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return self
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def __str__(self):
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s = self.find()
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if isinstance(s, TVar):
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if len(s.fields) > 0:
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fields = '{' + ', '.join([f'{k}: {v}' for k,
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v in s.fields.items()]) + '}'
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else:
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fields = ''
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return str(s.id) + fields
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else:
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return str(s)
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def find(self):
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root = self
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parent = self.parent
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while root is not parent and isinstance(parent, TVar):
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_, parent = root, root.parent = parent, parent.parent
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if isinstance(parent, TCall):
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parent = parent.find()
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return parent
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def unify(self, other):
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x = other.find()
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y = self.find()
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if x is y:
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return
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if isinstance(y, TVar) and isinstance(x, TVar):
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# unify field type
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x.type = x.type.unifier(y.type)
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# unify fields
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for k, v in y.fields.items():
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if k in x.fields:
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x.fields[k].unify(v)
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else:
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x.fields[k] = v
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# standard union find
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if x.rank < y.rank:
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x, y = y, x
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y.parent = x
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if x.rank == y.rank:
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x.rank += 1
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elif isinstance(y, TVar):
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# check fields
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if isinstance(x, TObj):
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if y.type not in [TVarType.UNDETERMINED, TVarType.RECORD]:
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raise UnificationError(f'Cannot unify {y} with {x}')
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for k, v in y.fields.items():
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if k not in x.fields:
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raise UnificationError(
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f'Cannot unify {y} with {x}')
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if isinstance(v, TFunc):
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v = v.instantiate()
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u = x.fields[k]
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if isinstance(u, TFunc):
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u = u.instantiate()
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v.unify(u)
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if isinstance(x, TList):
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if y.type not in [TVarType.UNDETERMINED, TVarType.SEQUENCE, TVarType.LIST]:
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raise UnificationError(f'Cannot unify {y} with {x}')
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for k, v in y.fields.items():
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assert isinstance(k, int)
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v.unify(x.param)
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if isinstance(x, TTuple):
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if y.type not in [TVarType.UNDETERMINED, TVarType.SEQUENCE, TVarType.TUPLE]:
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raise UnificationError(f'Cannot unify {y} with {x}')
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for k, v in y.fields.items():
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assert isinstance(k, int)
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if k >= len(x.params):
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raise UnificationError(f'Cannot unify {y} with {x}')
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v.unify(x.params[k])
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y.parent = x
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else:
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y.unify(x)
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class FuncArg:
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def __init__(self, name, typ, is_optional):
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self.name = name
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self.typ = typ
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self.is_optional = is_optional
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def __str__(self):
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return f'{self.name}: {self.typ}' + ('?' if self.is_optional else '')
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class TCall(Type):
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def __init__(self, posargs: List[Type], kwargs: Dict[str, Type], ret: Type):
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self.posargs = posargs
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self.kwargs = kwargs
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self.ret = ret
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self.fun = TVar()
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def check(self):
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for arg in chain(self.posargs, self.kwargs.values()):
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arg.check()
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def find(self):
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if isinstance(self.fun.find(), TVar):
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return self
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return self.fun.find()
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def unify(self, other):
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if not isinstance(self.fun.find(), TVar):
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self.fun.unify(other)
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return
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other = other.find()
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if other is self:
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return
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if isinstance(other, TCall):
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for a, b in zip(self.posargs, other.posargs):
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a.unify(b)
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for k, v in self.kwargs.items():
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if k in other.kwargs:
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other.kwargs[k].unify(v)
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else:
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other.kwargs[k] = v
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for k, v in other.kwargs.items():
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if k not in self.kwargs:
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self.kwargs[k] = v
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self.fun.unify(other.fun)
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elif isinstance(other, TFunc):
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all_args = set(arg.name for arg in other.args)
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required = set(arg.name for arg in other.args if not
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arg.is_optional)
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other.ret.unify(self.ret)
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for i, v in enumerate(self.posargs):
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arg = other.args[i]
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arg.typ.unify(v)
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if arg.name in required:
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required.remove(arg.name)
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for k, v in self.kwargs.items():
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arg = next((arg for arg in other.args if arg.name == k), None)
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if arg is None:
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raise UnificationError(f'Unknown kwarg {k}')
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if k not in all_args:
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raise UnificationError(f'Duplicated kwarg {k}')
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arg.typ.unify(v)
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if k in required:
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required.remove(k)
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all_args.remove(k)
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if len(required) > 0:
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raise UnificationError(f'Missing arguments')
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self.fun.unify(other)
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elif isinstance(other, TVar):
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other.unify(self)
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else:
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raise UnificationError(f'Cannot unify a call with {other}')
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class TFunc(Type):
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def __init__(self, args: List[FuncArg], ret: Type, vars: Set[TVar]):
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self.args = args
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self.ret = ret
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self.vars = vars
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self.instantiated = False
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def check(self):
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for arg in self.args:
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arg.typ.check()
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self.ret.check()
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def subst(self, mapping: Mapping[int, Type]):
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if len(mapping) == 0:
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return self
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return TFunc(
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[FuncArg(arg.name, arg.typ.subst(mapping), arg.is_optional)
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for arg in self.args],
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self.ret.subst(mapping),
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self.vars)
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def instantiate(self):
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mapping = {v.id: TVar(v.range) if isinstance(v, TVar)
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else TVar() for v in self.vars}
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result = self.subst(mapping)
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result.instantiated = True
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return result
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def __str__(self):
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return f'({", ".join(str(arg) for arg in self.args)}) -> {self.ret}'
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def unify(self, other):
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other = other.find()
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if other is self:
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return
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if isinstance(other, (TVar, TCall)):
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other.unify(self)
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elif isinstance(other, TFunc):
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if len(self.args) != len(other.args):
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raise UnificationError(
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f'cannot unify functions with different parameters')
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self.ret.unify(other.ret)
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for a, b in zip(self.args, other.args):
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if a.name != b.name or a.is_optional != b.is_optional:
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raise UnificationError(
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f'cannot unify functions with different parameters')
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a.typ.unify(b.typ)
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else:
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raise UnificationError(f'Cannot unify a function with {other}')
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class TObj(Type):
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def __init__(self, name: str, fields: Dict[str, Type], params: List[Type]):
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self.name = name
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self.fields = fields
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self.params = params
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def check(self):
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for arg in self.fields.values():
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arg.check()
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def subst(self, mapping: Mapping[int, Type]):
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if len(mapping) == 0:
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return self
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new_params = []
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for v in self.params:
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if isinstance(v, TVar) and v.id in mapping:
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new_params.append(mapping[v.id])
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else:
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new_params.append(v)
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return TObj(self.name, {k: v.subst(mapping) for k, v in
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self.fields.items()}, new_params)
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def unify(self, other):
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other = other.find()
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if other is self:
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return
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if isinstance(other, TObj):
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if self.name != other.name:
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raise UnificationError(f'Cannot unify {self} with {other}')
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for k in self.fields:
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self.fields[k].unify(other.fields[k])
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elif isinstance(other, TVar):
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other.unify(self)
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else:
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raise UnificationError(f'Cannot unify an object with {other}')
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def __str__(self):
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if len(self.params) > 0:
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p = '[' + ', '.join(str(p) for p in self.params) + ']'
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else:
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p = ''
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return self.name + p
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class TList(Type):
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def __init__(self, param: Type):
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self.param = param
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def unify(self, other):
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other = other.find()
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if isinstance(other, TVar):
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other.unify(self)
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elif isinstance(other, TList):
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self.param.unify(other.param)
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else:
|
||||
raise UnificationError(f'Cannot unify list with {other}')
|
||||
|
||||
def __str__(self):
|
||||
return f'List[{self.param}]'
|
||||
|
||||
|
||||
class TTuple(Type):
|
||||
def __init__(self, params: List[Type]):
|
||||
self.params = params
|
||||
|
||||
def unify(self, other):
|
||||
other = other.find()
|
||||
if isinstance(other, TVar):
|
||||
other.unify(self)
|
||||
elif isinstance(other, TTuple):
|
||||
if len(self.params) != len(other.params):
|
||||
raise UnificationError(
|
||||
'cannot unify tuples with different length')
|
||||
for a, b in zip(self.params, other.params):
|
||||
a.unify(b)
|
||||
else:
|
||||
raise UnificationError(f'Cannot unify {self} with {other}')
|
||||
|
||||
def __str__(self):
|
||||
return f'Tuple[{", ".join(str(p) for p in self.params)}]'
|
||||
|
||||
|
||||
TBool = TObj('bool', {}, [])
|
||||
TInt = TObj('int', {}, [])
|
||||
|
|
@ -0,0 +1,52 @@
|
|||
# from __future__ import annotations
|
||||
import ast
|
||||
from ast_visitor import Visitor
|
||||
from nac3_types import *
|
||||
|
||||
|
||||
var = TVar([TInt, TBool])
|
||||
var2 = TVar()
|
||||
|
||||
foo = TObj('Foo', {
|
||||
'foo': TFunc([
|
||||
FuncArg('a', var, False),
|
||||
FuncArg('b', var2, False)
|
||||
], var2, set([var2]))
|
||||
}, [var])
|
||||
|
||||
v = Visitor()
|
||||
v.assignments['get_x'] = TFunc([FuncArg('in', var, False)], TInt, set([var]))
|
||||
v.assignments['Foo'] = TFunc([FuncArg('a', var, False)], foo, set([var]))
|
||||
|
||||
prelude = set(v.assignments.keys())
|
||||
print('-----------')
|
||||
print('prelude')
|
||||
for key, value in v.assignments.items():
|
||||
print(f'{key}: {value}')
|
||||
print('-----------')
|
||||
|
||||
src = """
|
||||
a = Foo(1).foo(1, 2)
|
||||
b = Foo(1).foo(1, True)
|
||||
c = Foo(True).foo(True, 1)
|
||||
d = Foo(True).foo(True, True)
|
||||
"""
|
||||
|
||||
print(src)
|
||||
v.visit(ast.parse(src))
|
||||
|
||||
print('-----------')
|
||||
print('assignments')
|
||||
for key, value in v.assignments.items():
|
||||
if key not in prelude:
|
||||
value.check()
|
||||
print(f'{key}: {value.find()}')
|
||||
|
||||
print('-----------')
|
||||
print('calls')
|
||||
for x in v.calls:
|
||||
x.check()
|
||||
print(f'{x.find()}')
|
||||
|
||||
|
||||
# TODO: Occur check
|
||||
Loading…
Reference in New Issue