Question

当我尝试编译这个例子时

record R where
    f: () -> {t: Type} -> t

我收到此错误：

Type mismatch between
        () -> t1 (Type of f)
and
        () -> t (Expected type)

Specifically:
        Type mismatch between
                t1
        and
                t

另一方面这个例子

record R where
    f: {t: Type} -> () -> t

工作得很好。你能告诉我第一个出了什么问题吗？

Answer 1

这是Idris中的错误：有时import random # Sentences we'll respond with if the user greeted us GREETING_KEYWORDS = ("hello", "hi", "greetings", "sup", "whats up", "You") GREETING_RESPONSES = ["sup buddy", "Hola", "Halo", "Hi back?"] def check_for_greeting(sentence): """If any of the words in the user's input was a greeting, return a greeting response""" if sentence is not None: for word in sentence: if word.lower() in GREETING_KEYWORDS: return random.choice(GREETING_RESPONSES) else: pass elif sentence is None: return "You got to say something if you want me to do the same." else: return "Something is wrong..." def chat_input(): x = input("") print(check_for_greeting(x)) # Run print("chat with me...") chat_input()运算符不是右关联的：issue #4077。

要看到它，我们可以去掉记录语法：

->

现在我们需要手动实施data R : Type where MkR : (() -> {t : Type} -> t) -> R投影。事实证明

不类型检查，但是

f : R -> (() -> {t : Type} -> t)
f (MkR g) = g

确实

在我看来，Idris使用第一个变体将f : R -> () -> {t : Type} -> t f (MkR g) = g变为record，因此出现了错误。

Idris：记录中的隐含参数

1 个答案: