5. Hashes

module "/pliant/language/unsafe.pli"
var (Dictionary Str Int) age
# insertion
implicit age
  insert "Nat" 24
  insert "Jules" 25
  insert "Josh" 17
# when you know keys already exist:
age "Nat" := 24
age "Jules" := 25
age "Josh" := 17
#-----------------------------
var (Dictionary Str Str) food_color
implicit food_color
  insert "Apple" "red"
  insert "Banana" "yellow"
  insert "Lemon" "yellow"
  insert "Carrot" "orange"
#-----------------------------

#-----------------------------
 dict insert key value
#-----------------------------
# food_color defined per the introduction
food_color insert "Raspberry" "pink"
console "Known foods:" eol
each x food_color
  console (food_color key x) eol

 Known foods:
 Banana
 Apple
 Raspberry
 Carrot
#-----------------------------

#-----------------------------
# does dict have a value for key ?
if (dict exists key)
  # it exists
else
  # it doesn't
 
#-----------------------------
# food_color per the introduction

var List:Str fruits; fruits += "Banana"; fruits += "Martini"
each name fruits
  if (food_color exists name)
    console name " is a food." eol
  else
    console name " is a drink." eol

 Banana is a food.
 Martini is a drink.
#-----------------------------
age := new (Dictionary Str Int)
implicit age
  insert "Toddler" 3
  insert "Unborn" 0
  insert "Phantasm" undefined

var List:Str things
things+="Toddler", things+="Phantasm"; things+="Relic"

each thing things
  console thing ": "
  if (age exists thing)
    console "Exists "
    console (shunt age:thing<>undefined "Defined " "")
    console (shunt age:thing>0 "True " "")
  console eol

# Toddler: Exists Defined True 
# Unborn: Exists Defined 
# Phantasm: Exists 
# Relic: 
#-----------------------------

#-----------------------------
# remove the first element in dict with key value
dict -= dict value

#-----------------------------
# food_color as per Introduction
function print_foods
  each food food_color
    console "key : " (food_color key food)  ", value: " (shunt food="" "(undef)" food) eol
  console eol

console "Initially:" eol
print_foods

console "With Banana undef" eol
food_color "Banana" := "" # no true way to undef a Str...
print_foods

console "With Banana deleted" eol
food_color -= food_color "Banana"
print_foods

# Initially:
# key : Lemon, value: yellow
# key : Banana, value: yellow
# key : Apple, value: red
# key : Carrot, value: orange
# 
# With Banana undef
# key : Lemon, value: yellow
# key : Banana, value: (undef)
# key : Apple, value: red
# key : Carrot, value: orange
# 
# With Banana deleted
# key : Lemon, value: yellow
# key : Apple, value: red
# key : Carrot, value: orange
#---------------------------

#-----------------------------
each value dict
  # the key is (dict key value)

#-----------------------------
# food_color per the introduction
each color food_color
  console (food_color key color) " is " color eol

# Banana is yellow.
# Apple is red.
# Carrot is orange.
# Lemon is yellow.

#-----------------------------
var Pointer:Str color :> food_color first
while exists:color
  console (food_color key color) " is " color
  color :> food_color next color
#---------------------------