Geohash: Difference between revisions

}</lang>

=={{header|Wren}}==

{{trans|Swift}}

{{libheader|Wren-fmt}}

<lang ecmascript>import "/fmt" for Fmt

var gBase32 = "0123456789bcdefghjkmnpqrstuvwxyz"

var encodeGeohash = Fn.new { |location, prec|

var latRange = -90..90

var lngRange = -180..180

var hash = ""

var hashVal = 0

var bits = 0

var even = true

while (hash.count < prec) {

var val = even ? location[1] : location[0]

var rng = even ? lngRange : latRange

var mid = (rng.from + rng.to) / 2

if (val > mid) {

hashVal = hashVal*2 + 1

rng = mid..rng.to

if (even) lngRange = mid..lngRange.to else latRange = mid..latRange.to

} else {

hashVal = hashVal * 2

if (even) lngRange = lngRange.from..mid else latRange = latRange.from..mid

}

even = !even

if (bits < 4) {

bits = bits + 1

} else {

bits = 0

hash = hash + gBase32[hashVal]

hashVal = 0

}

}

return hash

var data = [

[[51.433718, -0.214126], 2],

[[51.433718, -0.214126], 9],

[[57.64911, 10.40744 ], 11]

]

for (d in data) {

var geohash = encodeGeohash.call(d[0], d[1])

var loc = "[%(Fmt.f(9, d[0][0], 6)), %(Fmt.f(9, d[0][1], 6))]"

System.print("geohash for %(loc), precision %(Fmt.d(-2, d[1])) = %(geohash)")

}</lang>

{{out}}

<pre>

geohash for [51.433718, -0.214126], precision 2 = gc

geohash for [51.433718, -0.214126], precision 9 = gcpue5hp4

geohash for [57.649110, 10.407440], precision 11 = u4pruydqqvj

</pre>