lean4-htt/tests/lean/defInst.lean
Leonardo de Moura 272dd5533f chore: style use · instead of . for lambda dot notation
We are considering removing `.` as an alternative for `·` in the
lambda dot notation (e.g., `(·+·)`).
Reasons:
- `.` is not a perfect replacement for `·` (e.g., `(·.insert ·)`)
- `.` is too overloaded: `(f.x)` and `(f .x)` and `(f . x)`. We want to keep the first two.
2022-03-11 07:49:03 -08:00

35 lines
633 B
Text
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

def Foo := List Nat
def test (x : Nat) : Foo :=
[x, x+1, x+2]
#eval test 4 -- Error
#check fun (x y : Foo) => x == y -- Error
deriving instance BEq, Repr for Foo
#eval test 4
#check fun (x y : Foo) => x == y
def Boo := List (String × String)
deriving BEq, Repr, DecidableEq
def mkBoo (s : String) : Boo :=
[(s, s)]
#eval mkBoo "hello"
#eval mkBoo "hell" == mkBoo "hello"
#eval mkBoo "hello" == mkBoo "hello"
#eval mkBoo "hello" = mkBoo "hello"
def M := ReaderT String (StateT Nat IO)
deriving Monad, MonadState, MonadReader
#print instMMonad
def action : M Unit := do
modify (· + 1)
dbg_trace "{← read}"