php to processing - variable variables

grumo

Hi, I need to port this piece of php code but it uses variable variables, any idea on how to achieve this?

GoToLoop

Dunno PHP, sorry. And Java, just like C/C++, is very strongly typed.
That is, in Java we gotta declare the type of each variable and each container.

Your $lists seems like an array of String[] type.
So it's something like: String[] lists = {}

Unfortunately, we can't dynamically create variables in Java.
That is, all variables gotta be explicitly written in the source.
We can't just pick or concatenate a String and state that is a new variable now.

However, we can use a Map type container w/ {key : value} pairs.
I've chosen StringDict for this attempt: https://processing.org/reference/StringDict.html
But some HashMap<String, String> would be even faster...

// forum.processing.org/two/discussion/10726/
// php-to-processing-variable-variables

final String[] lists = {
  "interjections", 
  "determiners", 
  "adjectives", 
  "nouns", 
  "adverbs", 
  "verbs", 
  "prepositions", 
  "conjunctions", 
  "comparatives"
};

final StringDict paths = new StringDict(lists.length);

for (String part : lists)  paths.set(part, dataPath(part + ".txt"));

println(paths);
println();

println("verbs:", paths.get("verbs"));
exit();

grumo

thanks, really helpful

grumo

In this sense, how can I create a multidimensional array from this code? --original php script:

    for ($i=0; $i<2; $i++) {
            foreach ($lists as $part) ${$part}[$i]  = trim(${$part}[rand(0,count(${$part}) - 1)]);
        }

In this case $verb is different to $verb[1]``

GoToLoop

In Java, the [] array access operator always means the index of some array:
https://processing.org/reference/arrayaccess.html

Seems like in PHP, [] has multiple meanings.
While in ${$part}[$i] = the [] over there means array access,
in ${$part}[rand( ... )] apparently it means a char position within the String now.

And translating the latter to Java's String, it corresponds to its method charAt():
https://processing.org/reference/String_charAt_.html

Plus the count() function would correspond to String's length() method:
https://processing.org/reference/String_length_.html

And obviously, rand() is Processing's random(): 3:-O
https://processing.org/reference/random_.html

In short, it's randomly picking up 1 char outta the String as value and associating it w/ the same String as the key.
So the {key : value} pair relationship is <String, Character> in Java.

For that, this time we're gonna use a HashMap<String, Character> in place of previous StringDict.
More specifically, an array of Map<String, Character>[]: :D
https://processing.org/reference/HashMap.html

You see, If I got that right, the ${$part}[$i] is actually creating an array of Map[] in order to store 1 random() char.

Well, here it goes the probable solution for your mysterious PHP sample: #:-S

// forum.processing.org/two/discussion/10726/
// php-to-processing-variable-variables

final String[] lists = {
  "interjections", 
  "determiners", 
  "adjectives", 
  "nouns", 
  "adverbs", 
  "verbs", 
  "prepositions", 
  "conjunctions", 
  "comparatives"
};

import java.util.Map;

final int capacity = ceil(lists.length/.75);
final Map<String, Character>[] chars = new Map[] {
  new HashMap<String, Character>(capacity), new HashMap<String, Character>(capacity)
};

for (String part : lists)  for (int i = 0; i != chars.length; ++i)
  chars[i].put( part, part.charAt((int) random(part.length())) );

printArray(chars);
println();

println("verbs:", chars[0].get("verbs"), chars[1].get("verbs"));
exit();

grumo

how can i do an array of maps or dicts?

There should be a HasMap/StringDic tutorial, really powerful and useful..

GoToLoop

Before anything, an alternative to previous example: :D

// forum.processing.org/two/discussion/10726/
// php-to-processing-variable-variables

final String[] lists = {
  "interjections", 
  "determiners", 
  "adjectives", 
  "nouns", 
  "adverbs", 
  "verbs", 
  "prepositions", 
  "conjunctions", 
  "comparatives"
};

import java.util.Map;
import java.util.Map.Entry;

final int capacity = ceil(lists.length/.75), len = 2;
final Map<String, char[]> chars = new HashMap<String, char[]>(capacity);

for (String part : lists) {
  char[] ch = new char[len];
  for ( int i = 0; i != len; ch[i++] = part.charAt((int) random(part.length())) );
  chars.put(part, ch);
}

for (Entry<String, char[]> pair : chars.entrySet()) {
  print(pair.getKey(), ":  ");
  for (char ch : pair.getValue())  print(ch, ' ');
  println();
}

println("\nverbs:", chars.get("verbs")[0], chars.get("verbs")[1]);
exit();

GoToLoop

• In order to get those external words, we've gotta load them 1st.
• But I wonder which type are they: CSV, TSV or 1 word in each line.

• I'll just assume it's the latter. A simple loadStrings() will do the whole work then:
  https://processing.org/reference/loadStrings_.html

• In order to store the output from loadStrings(), we're gonna need Map<String, String[]>.

• That is, each grammar word is associated w/ an array of String[].

// forum.processing.org/two/discussion/10726/
// php-to-processing-variable-variables

// 2015-May-11

final String[] LIST = {
  "interjections", 
  "determiners", 
  "adjectives", 
  "nouns", 
  "adverbs", 
  "verbs", 
  "prepositions", 
  "conjunctions", 
  "comparatives"
};

import java.util.Map;
import java.util.Map.Entry;

final int CAPACITY = ceil(LIST.length/.75);
final Map<String, String[]> grammar = new HashMap<String, String[]>(CAPACITY);

for (String entry : LIST)  grammar.put(entry, loadStrings(entry + ".txt"));

for (Entry<String, String[]> pair : grammar.entrySet()) {
  println(pair.getKey(), ':');
  printArray(pair.getValue());
  println();
}

print("Random word value from \"verbs\" key: ");
String[] words = grammar.get("verbs");
println("\"" + words[(int) random(words.length)] + "\"");
exit();

grumo

In this case it would be better to just assign to different String vars each .txt file isn't?

GoToLoop

• Well, you've asked about what would be the equivalent PHP code in Processing/Java.
• PHP was creating variables dynamically at runtime.
• Java can't do that! All variables are statically declared in the source code before hand.
• Although we can rely on some Map-like container in order to emulate that.
• However, if you are satisfied in explicitly declaring each of those 9 "grammar" variables now,
  that's the Java's way after all. :P

GoToLoop

I was hoping I could do something like grammar.get("verbs")[random(n)]...

Haven't you spotted these last lines in my example? $-)

String[] words = grammar.get("verbs");
println( "\"" + words[ (int) random(words.length) ] + "\"" );

It's doing exactly what you asked for! They can be synthesized this way too:

grammar.get("verbs")[ (int) random(grammar.get("verbs").length) ]

But it's faster & shorter to temporarily store grammar.get("verbs") in some variable than repeating it more than once! :-B

GoToLoop

The Map approach would allow us to even choose a random() "grammar" category: ;;)

String category = LIST[ (int) random(LIST.length) ];
String[] words  = grammar.get(category);
String pickWord = words[ (int) random(words.length) ];

println( "Grammar Category:", category );
println( "Random  Word: \"" + pickWord + "\"" );

grumo

This is the version I just did with string arrays.. It's not that elegant but works.. (the only part I haven't ported is the one between "/* */" --cause I don't get the foreach clause. Any ideas?

GoToLoop

This is the version I just did with String arrays... It's not that elegant but works...

Well, I've posted many examples using Map containers already.
It's not easy to wrap around how to use them. And I didn't learn about them in 1 day either! b-(
Indeed separate variables are much easier & comfortable to get around... B-)

... 'cause I don't get the foreach clause.

There are 2 types of for () loops in Java: regular for ( ; ; ) & enhanced for ( : ):
https://processing.org/reference/for.html

PHP's foreach equivalent in Java is for ( : ). In my code posts you'll find lotsa them:

• for (String entry : LIST) {}
• for (Entry<String, String[]> pair : grammar.entrySet()) {}

P.S.: In PHP, the container to be traversed is the 1st argument before as.
While in Java's for ( : ) it's the opposite! It is placed after the :! :-t

grumo

Really helpful, man. Thanks a lot.