I am learning Scala and was using Programming in Scala book by Martin Odersky. When I was trying example in Chapter 10 it isn't producing the expected result. I tried to modify the code a bit here and there with no luck. Can anyone tell me where I am going wrong?
import Element.elem
object Spiral {
val space = elem(" ")
val corner = elem("+")
def spiral(nEdges: Int, direction: Int): Element = {
if(nEdges == 1)
corner
else {
val sp = spiral(nEdges - 1, (direction + 3) % 4)
//println("H: " + sp.height + " W: " + sp.width + " D " + direction)
def verticalBar = elem('|', 1, sp.height - 1) //updated based on google errata which was otherwise def verticalBar = elem('|', 1, sp.height)
def horizantalBar = elem('-', sp.width, 1)
if(direction == 0)
(corner beside horizantalBar) above (sp beside space)
else if (direction == 1)
(sp) beside (corner above verticalBar) //updated based on google errata which was otherwise (sp above space) beside (corner above verticalBar)
else if (direction == 2)
(space beside sp) above (horizantalBar beside corner)
else
(verticalBar above corner) beside (sp) //updated based on google errata which was otherwise (verticalBar above corner) beside (space above sp)
}
}
//Not working as expected, need to debug and fix
def main (args: Array[String]) {
val nSides = args(0).toInt
println(spiral(nSides, 0))
}
}
Here is the expected when run with 14 as argument
+-------------
|
| +---------+
| | |
| | +-----+ |
| | | | |
| | | +-+ | |
| | | + | | |
| | | | | |
| | +---+ | |
| | | |
| +-------+ |
| |
+-----------+
What I am getting
+-------------
| +---------+
I think the code should be ,
def spiral(nEdges: Int, direction: Int): Element = {
if (nEdges == 1)
elem("+")
else {
val sp = spiral(nEdges - 1, (direction + 3) % 4)
def verticalBar = elem('|', 1, sp.height)
def horizontalBar = elem('-', sp.width, 1)
if (direction == 0)
(corner beside horizontalBar) above (sp beside space)
else if (direction == 1)
(sp above space) beside (corner above verticalBar)
else if (direction == 2)
(space beside sp) above (horizontalBar beside corner)
else
(verticalBar above corner) beside (space above sp)
}
}
I haven't run this, could you please check if this works ?
您可能没有更新Element类,而是在方法上方和旁边添加了widen和heightn函数调用。
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