newLisp Challenge 2!

Before we continue with Tutorial 5 on newLISP, let’s do now some exercises in newLISP programming. You’ve to solve some problems. To do so successfully, recall the contents of the first four tutorials on newLISP of mine. In addition, you can use this link for info on newLISP functions: http://www.newlisp.org/downloads/manual_frame.html

Notice that for some problems one could find better solutions when invoking other functions than discussed in the first four tutorials.

Below the solutions first for the beginner level tasks and then for the intermediate level.

A. Beginner level

1. Function Between
→ Returns the substring between e.g. { and }, if found, or returns nil.

Example:
Return 12 if the substring {12} exists in the input

Solution:
(if (find “{(.*)}” “There were {12} objects!” 1) $1)

Return value:
12

Source:
https://github.com/danielstjules/Stringy#betweenstring-start-string-end–int-offset

2. Function: Camelize
→ Returns a camelCase version of the string.

Requirements:
→ Trims surrounding spaces,
→ capitalizes letters following dashes and underscores and
→ removes dashes and underscores.

Examples:
Camel-Case -> camelCase
Camel_Case -> camelCase
Camel-case -> camelCase
CAMEL-cASE -> camelCase

Solution:
(append (first (parse (lower-case {CAMEL-cASE}) {_|-} 0 )) (title-case (apply string (rest (parse (lower-case {CAMEL-cASE}) {_|-} 0)))))

Notice that this function is less complex as it seems: at the end of this text, I’ll break it in the consisting parts. In addition, I’ll give a regex solution.

Return value:
camelCase

Source:
https://github.com/danielstjules/Stringy#camelize

3. Function Collapsewhitespace
→ Trims the string and replaces consecutive whitespace characters with a single space.

Solution:
(replace {[ ]+} (trim { A B C }) { } 0)

Return value:
A B C

Source:
https://github.com/danielstjules/Stringy#collapsewhitespace

4. Function Return-CSV
→ Returns a CSV-string consisting of the characters in the input, separated by e.g. delimiter ;

Solution:
(join (explode {ABC}) {;})

Return value:
A;B;C

Source (modified):
https://github.com/danielstjules/Stringy#chars

5. Function Countsubstring
→ Returns the number of occurrences of a substring in the given input.

Requirement:
→ Casesensitive.

Solution, casesensitive:
(if (find-all {a} {A little man shook his bald head.}) $count)

Return value:
3

Solution, caseinsensitive:
(if (find-all {A|a} {A little man shook his bald head.}) $count)

Return value:
4

Source:
https://github.com/danielstjules/Stringy#countsubstrstring-substring–boolean-casesensitive–true-

6. Function Dasherize
→ Returns a lowercase and trimmed string separated by dashes.

Requirements:
→ Dashes are inserted before uppercase characters (with the exception of the first character of the string).
→ Spaces as well as underscores are replaced by dashes.

Example:
fooBar -> foo-bar

Solution:
(trim (replace {([A-Z _]{1})} {FooBar} (append {-} (trim (trim (lower-case $1) “_”))) 0) “-“)

Return value:
foo-bar

Source:
https://github.com/danielstjules/Stringy#dasherize

7. Function EnsureLeft
→ Ensures that input begins with a specific prefix. If it doesn’t, it’s prepended.

Example (with prefix “https://”):
foobar.com -> https://foobar.com
https://foobar.com -> https://foobar.com

Solution:
(if (starts-with {foobar.com} {https://} 1) {foobar.com} (append {https://} {foobar.com} ))

Return value:
https://foobar.com

Source:
https://github.com/danielstjules/Stringy#ensureleftstring-substring

8. Function EnsureRight
→ Ensures that input ends with a specific suffix. If it doesn’t, it’s appended.

Example (here with suffix “.com”):
– foobar -> foobar.com
– foobar.com -> foobar.com

(if (ends-with {foobar} {.com} 1) {foobar} (append {foobar} {.com}))

Return value:
foobar.com

Source:
https://github.com/danielstjules/Stringy#ensurerightstring-substring

9. Function PadLeft
→ Returns a string of a given length (here 9) such that the beginning of the string is padded.

Solution:
(append (dup {$} (- 9 (length {abc}))) {abc})

Return value:
$$$$$$abc