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from tokens import *
def std_print(arg):
print(arg.value)
#return [] # TODO this should return empty list
return NebLiteral(NebType.BOOL, True)
std = {
"print": {
"func": NebFunction("print", [NebType.STRING], NebType.BOOL),
"impl": std_print }
}
def peek(inp):
if len(inp) == 0:
return None
return inp[0]
def evaluate(items, pop):
nxt = peek(items)
if nxt is None:
return pop
elif isinstance(nxt, NebLiteral):
pop = nxt.value
return evaluate(items[1:], pop)
elif isinstance(nxt, NebSymbol):
if not nxt.name in std:
raise Exception(f"no such symbol: '{nxt.name}'")
this_func = std[nxt.name]
return evaluate(items[1:], this_func["impl"])
elif isinstance(nxt, NebExpression):
if not nxt.symbol.name in std:
raise Exception(f"no such symbol: {nxt.symbol.name}")
this_func = std[nxt.symbol.name]
#expected_sig = " ".join(x.type_.name for x in nxt.args)
#if this_func["func"].in_sig() != expected_sig:
if this_func["func"].in_sig() != nxt.maybe_sig():
raise Exception(f"{nxt.symbol.name} expects '{this_func['func'].in_sig()}', got '{nxt.maybe_sig()}'")
ret = this_func["impl"](*(nxt.args))
return evaluate(items[1:], ret)
else:
raise Exception("expected a literal or an expression")
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