The Symphony of Repetition: A Coding Journey in Softanza

Basic Repetition

It all starts with the straightforward Repeat() function, which you can use like this:

load "stzlib.ring"

? Repeat("A", 3)
#--> [ "A", "A", "A" ]

# Which is the same as:

? RepeatInList("A", 3)
#--> [ "A", "A", "A" ]

# And when you want the repetition as a string:

? RepeatInString("A", 3) # Equivalent to Haro's copy() function
#--> "AAA"

But this is just the beginning. Say hello to the more capable RepeatXT() function!

List Repetition

Does the following code need any explanation? Let’s repeat the character "5" in a list of size 2:

? Q("5").RepeatedXT(:InA = :List, :OfSize = 2)
#--> [ "5", "5" ]

? Q("A").RepeatedInAPair()
#--> [ "A", "A" ]

Both examples are equivalent, but the second is more concise and expressive.

Numeric and Type Conversion

Repetition can also include smart type conversion, which is as useful as it is powerful:

# Repeating the STRING "5" three times in a list of NUMBERS

Q("5").RepeatedXT(:InA = :ListOfNumbers, :OfSize = 3)
#--> [ 5, 5, 5 ]

# Repeating the NUMBER 5 three times in a STRING

Q(5).RepeatedXT(:InA = :String, :OfSize = 3)
#--> "555"

# Repeating the NUMBER 5 three times in a list of STRINGS

Q(5).RepeatedXT(:InA = :ListOfStrings, :OfSize = 3)
#--> [ "5", "5", "5" ]

The RepeatXT() function effortlessly converts inputs between strings, numbers, and collections, preserving their essence while fulfilling repetition requirements.

Advanced Repetition

Sometimes, simple repetition isn't enough. You may need multi-step repetitions to create complex nested structures with minimal code:

@@( Q("A").
    RepeatXTQ(:InA = :List, :OfSize = 3).
    RepeatedXT(:InA = :List, :OfSize = 3)
)
#--> [ [ "A", "A", "A" ], [ "A", "A", "A" ], [ "A", "A", "A" ] ]

Method chaining introduces a new dimension of usability. By combining RepeatXTQ() and RepeatedXT(), you can create intricate nested structures with a single, readable code sequence.

NOTE 1: Method chaining in Softanza allows fluent design of transformation pipelines by simply suffixing the method you want to chain with a small ...Q(), like this: Q("h e l l o").RemoveSpacesQ().UppercaseQ().Content(), resulting in the string "HELLO".

NOTE 2: Fluent chains of Q()ed calls generally end with a passive function form that returns the final value, not an intermediate Softanza object. To form the passive version of a function, turn the active form (a verb) into its past participle, e.g., Uppercase → Uppercased. Thus, the earlier chain becomes Q("h e l l o").RemoveSpacesQ().Uppercased().

NOTE 3: @@(val) is a small Softanza function, akin to a pair of glasses that enhances vision. It is designed to produce a readable string representation of any value val, which is useful in particular when val is a multi-level list. In our case, it beautifully generated the output [ [ "A", "A", "A" ], [ "A", "A", "A" ], [ "A", "A", "A" ] ]. Without it, the console would display a vertical list of nine "A"s.

Multidimensional Structures

Grids, tables, and other complex data structures can also be generated with elegance and ease:

@@( Q("A").RepeatedXT(:InA = :Grid, :OfSize = [3, 3]) )
#-->
# [
# [ "A", "A", "A" ],
# [ "A", "A", "A" ],
# [ "A", "A", "A" ]
# ]

? @@( Q("A").RepeatedXT(:InA = :Table, :OfSize = [3, 3]) )
#--> [
# [ "COL1", [ "A", "A", "A" ] ],
# [ "COL2", [ "A", "A", "A" ] ],
# [ "COL3", [ "A", "A", "A" ] ]
# ]

? Q("A").RepeatXTQ(:InA = :Table, :OfSize = [3, 3]).ToStzTable().Show()
#-->
# COL1   COL2   COL3
# ----- ------ -----
#   A      A      A
#   A      A      A
#   A      A      A

In the last example, the list containing a table representation (thanks to the RepeatXT() function) has been transformed into a stzTable object, on which we called the function Show().

NOTE: Wherever needed, Softanza provides a dedicated Show() function for each of its objects, allowing you to obtain a pleasant and readable string representation of their content.

Practical Applications

The power of RepeatXT() extends far beyond simple examples, offering tangible benefits in real-world software development: 1. Rapid data initialization and prototyping
2. Generating test and placeholder data
3. Enforcing smart, automatic data type conversions
4. Creating complex data structures efficiently
5. Reducing boilerplate code

Conclusion

Softanza's repetition feature transcends traditional data manipulation approaches. It provides a concise, powerful, and intuitive way to generate, transform, and replicate values across diverse data types and structures.

Cite

Mansour Ayouni. "The Symphony of Repetition: A Coding Journey in Softanza". Softanza narrations, 2024. https://mayouni.github.io/stzsite/en/narrations/stz-repeat-function-narration.html

Not run: its code touches files, the network, the clock or chance. The article is published as written; its blocks are illustrations. The code of the articles is Haro code. Where an article was written before the language took its present name, the name was changed and nothing else. Genre, area and series read from the file's name, the year from its first commit: derived, until the article carries its own header. The file on GitHub(opens in a new tab)