timyates

Two line Tree in Groovy

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Update!

Wow... Kiyotaka Oku's fork of this shows how to do it in one line :-)

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The other day, I saw Harold Cooper's One-line tree in Python via autovivication, and wondered if the same thing was possible in Groovy.

timyates

import groovy.stream.Stream

// Repeat an object indefinitely
Stream s = Stream.from { 1 }
assert s.take( 5 ).collect() == [ 1, 1, 1, 1, 1 ]

// Use an Iterable
Stream s = Stream.from 1..3
assert s.collect() == [ 1, 2, 3 ]

timyates

{
    "folders":
    [
        { "path":"grails-app/conf",             "name":"Configuration"        },
        { "path":"grails-app/controllers",      "name":"Controllers"          },
        { "path":"grails-app/domain",           "name":"Domain Objects"       },
        { "path":"grails-app/i18n",             "name":"Internationalization" },
        { "path":"grails-app/services",         "name":"Services"             },
        { "path":"grails-app/taglib",           "name":"Tag Libraries"        },
        { "path":"grails-app/utils",            "name":"Utils"                },

timyates

@GrabResolver( name='bloidonia', root='https://raw.github.com/timyates/bloidonia-repo/master')
@Grab('com.bloidonia:groovy-stream:0.2')
import groovy.stream.Stream 

def s = Stream.from 1..4
assert [1,2,3,4] == s.collect()

timyates

findPerpendicularDistance = ( point, line ) ->
  [pointX,pointY] = point[0..1]
  lineStart = x: line[0][0], y: line[0][1]
  lineEnd   = x: line[1][0], y: line[1][1]
  slope = ( lineEnd.y - lineStart.y ) / ( lineEnd.x - lineStart.x )
  intercept = lineStart.y - ( slope * lineStart.x )
  Math.abs( slope * pointX - pointY + intercept ) / Math.sqrt( Math.pow( slope, 2) + 1)

douglasPeucker = ( points, epsilon ) ->
  maxIndex = maxDistance = 0

timyates

import groovy.swing.*
import java.awt.*
import javax.swing.*
import javax.swing.event.*
import org.codehaus.groovy.control.customizers.ImportCustomizer
import org.codehaus.groovy.control.CompilerConfiguration

String script = '''color = Color.RED
                  |fillRect 10, 10, 100, 100'''.stripMargin()

timyates

def tr = { inputs, outputs ->
  (inputs,outputs) = [inputs,outputs].collect { it instanceof List ? it : [ it ] }
  assert inputs.size() == outputs.size(), 'tr: Inputs and outputs must be the same size'
  delegate.collect { item ->
    inputs.indexOf( item ).with { idx ->
      idx == -1 ? item : outputs[ idx ]
    }
  }
}

timyates

// No commas
def a = 'tim'
def nocom = match( a ) {
  when 'dave' 'Hi Dave'
  when 'tim'  'Hi Tim'
  otherwise 'none of the above'
}
assert nocom == 'Hi Tim'

// Commas

timyates

def str = 'Groovy is cool'

assert str.takeWhile { it != ' ' } == 'Groovy'
assert str.dropWhile { it != ' ' } == ' is cool'

timyates

def nums = [ 10, 20, 30 ]

// First element of nums (10) is used as default value
def product = nums.inject { acc, num -> acc * num }
assert product == 6000