Elm 将多个信号传递给Signal.map会引发类型不匹配错误

我正在尝试使用elm-0.15打印鼠标光标与窗口中心的距离。例如，将光标放置在窗口中心必须打印（0,0）

我的密码是

import Graphics.Element exposing (show)
import Mouse
import Signal
import Window

relativeMouse : (Int, Int) -> (Int, Int)
relativeMouse (ox, oy) (x,y) = (x - ox, y - oy)

center: (Int, Int) -> (Int, Int)
center (w,h) = (w/2, h/2)

main = Signal.map show <| relativeMouse (Signal.map center Window.dimensions Mouse.position)

导入图形。元素公开（显示）
导入鼠标
输入信号
导入窗口
相对用法：（Int，Int）->（Int，Int）
相对熵（ox，oy）（x，y）=（x-ox，y-oy）
中心：（Int，Int）->（Int，Int）
中心（w，h）=（w/2，h/2）
main=Signal.map show注释是您所做的更改：

import Graphics.Element exposing (show)
import Mouse
import Signal
import Window

-- change type signature to match implementation
relativeMouse : (Int, Int) -> (Int, Int) -> (Int, Int)
relativeMouse (ox, oy) (x,y) = (x - ox, y - oy)

-- use // for integer division
center: (Int, Int) -> (Int, Int)
center (w, h) = (w // 2, h // 2)

-- 1) map center over Window.dimensions to get a signal of origin positions
-- 2) map2 relativeMouse over the signal of origin positions and
--    Mouse.position to get signal of relative mouse positions
-- 3) map show over the signal of relative mouse positions to display them
main = Signal.map show (Signal.map2 relativeMouse (Signal.map center Window.dimensions) Mouse.position)

回答最后一个问题：
Signal.map2
是将1个函数映射到2个信号上的函数。对应的地图存在于
map5
之前

信号输入线也可以更改为

import Signal exposing ((<~), (~))

import Signal exposing（（注释是您所做的更改：

import Graphics.Element exposing (show)
import Mouse
import Signal
import Window

-- change type signature to match implementation
relativeMouse : (Int, Int) -> (Int, Int) -> (Int, Int)
relativeMouse (ox, oy) (x,y) = (x - ox, y - oy)

-- use // for integer division
center: (Int, Int) -> (Int, Int)
center (w, h) = (w // 2, h // 2)

-- 1) map center over Window.dimensions to get a signal of origin positions
-- 2) map2 relativeMouse over the signal of origin positions and
--    Mouse.position to get signal of relative mouse positions
-- 3) map show over the signal of relative mouse positions to display them
main = Signal.map show (Signal.map2 relativeMouse (Signal.map center Window.dimensions) Mouse.position)

回答最后一个问题：
Signal.map2
是将1个函数映射到2个信号上的函数。对应的映射存在于
map5

信号输入线也可以更改为

import Signal exposing ((<~), (~))

import Signal exposing（（注释是您所做的更改：

import Graphics.Element exposing (show)
import Mouse
import Signal
import Window

-- change type signature to match implementation
relativeMouse : (Int, Int) -> (Int, Int) -> (Int, Int)
relativeMouse (ox, oy) (x,y) = (x - ox, y - oy)

-- use // for integer division
center: (Int, Int) -> (Int, Int)
center (w, h) = (w // 2, h // 2)

-- 1) map center over Window.dimensions to get a signal of origin positions
-- 2) map2 relativeMouse over the signal of origin positions and
--    Mouse.position to get signal of relative mouse positions
-- 3) map show over the signal of relative mouse positions to display them
main = Signal.map show (Signal.map2 relativeMouse (Signal.map center Window.dimensions) Mouse.position)

回答最后一个问题：
Signal.map2
是将1个函数映射到2个信号上的函数。对应的映射存在于
map5

信号输入线也可以更改为

import Signal exposing ((<~), (~))

import Signal exposing（（注释是您所做的更改：

import Graphics.Element exposing (show)
import Mouse
import Signal
import Window

-- change type signature to match implementation
relativeMouse : (Int, Int) -> (Int, Int) -> (Int, Int)
relativeMouse (ox, oy) (x,y) = (x - ox, y - oy)

-- use // for integer division
center: (Int, Int) -> (Int, Int)
center (w, h) = (w // 2, h // 2)

-- 1) map center over Window.dimensions to get a signal of origin positions
-- 2) map2 relativeMouse over the signal of origin positions and
--    Mouse.position to get signal of relative mouse positions
-- 3) map show over the signal of relative mouse positions to display them
main = Signal.map show (Signal.map2 relativeMouse (Signal.map center Window.dimensions) Mouse.position)

回答最后一个问题：
Signal.map2
是将1个函数映射到2个信号上的函数。对应的映射存在于
map5

信号输入线也可以更改为

import Signal exposing ((<~), (~))

导入信号((