def sig(var, codom):
"""Create the term
Sig x:A.B from its constituents
Arguments:
- `var`: a constant expr
- `codom`: an expression possibly containing var
"""
if var.is_const():
codom_abs = e.abstract_expr([var.name], codom)
return e.Bound(e.Sig(var.name), var.type, codom_abs)
else:
mess = "Expected {0!s} to be a constant".format(var)
raise e.ExprError(mess, var)
def exists(var, prop):
"""Create the term
exists x:A.t from its constituents
Arguments:
- `var`: a constant expr
- `prop`: an expression possibly containing var
"""
if var.is_const():
prop_abs = e.abstract_expr([var.name], prop)
return e.Bound(e.Exists(var.name), var.type, prop_abs)
else:
mess = "Expected {0!s} to be a constant".format(var)
raise e.ExprError(mess, var)
def pi(var, codom, impl=None):
"""Create the term
Pi x:A.B from its constituents
Arguments:
- `var`: a constant expr
- `codom`: an expression possibly containing var
- `impl`: a flag which notes if the argument is implicit.
"""
if var.is_const():
codom_abs = e.abstract_expr([var.name], codom)
ret = e.Bound(e.Pi(var.name), var.type, codom_abs)
if impl:
ret.info['implicit'] = True
return ret
else:
mess = "Expected {0!s} to be a constant".format(var)
raise e.ExprError(mess, var)
def abst(var, body):
"""Create the term
lambda x:A.t from its constituents
Arguments:
- `var`: a constant expr
- `body`: an expression possibly containing var
"""
if var.is_const():
ty, _ = mvar_infer(var.type)
if ty.equals(e.Bool()):
body = enrich(var.name, var.type, body)
else:
pass
body_abs = e.abstract_expr([var.name], body)
return e.Bound(e.Abst(var.name), var.type, body_abs)
else:
print var.__class__
mess = "Expected {0!s} to be a constant".format(var)
raise e.ExprError(mess, var)
def visit_bound(self, expr, *args, **kwargs):
var, open_expr = self.open_fresh(expr)
new_open_expr = self.visit(open_expr)
dom = self.visit(expr.dom)
return e.Bound(expr.binder, dom, self.abst([var], new_open_expr))
def visit_bound(self, expr):
dom = self.visit(expr.dom)
body = self.visit(expr.body)
return e.Bound(expr.binder, dom, body)