Lumesh Rand Module

Lumesh `rand` Module Documentation

Module Name: rand
You can view help using help rand.

Function Description: Provides random number generation, random sampling, and randomization operations.

Function Directory

Function Category	Function Name	Calling Format	Core Functionality
Boolean Generation	`ratio`	`Rand.ratio [numerator] [denominator]`	Generate a boolean value based on probability
String Generation	`alpha`	`Rand.alpha [length]`	Generate a random alphabetic string
String Generation	`alphanum`	`Rand.alphanum [length]`	Generate a random alphanumeric string
Numeric Generation	`int`	`Rand.int [min] [max]`	Generate a random integer
Sampling Operation	`choose`	`Rand.choose [list]`	Randomly select an element from a list
List Operation	`shuffle`	`Rand.shuffle [list]`	Randomly shuffle the order of a list

Function Details

1. `Rand.ratio` - Probability Boolean Generation

Parameter Description:

Parameter Mode	Parameter Type	Description
No Parameters	-	Defaults to returning `true` with 50% probability
Single Parameter	`Float`	Specifies the probability of `true` (0.0 to 1.0)
Two Parameters	`Integer, Integer`	Specifies probability in fraction form (e.g., `3 5` means 3/5 probability)

Return Value: Boolean
Example:

# Basic call
Rand.ratio          # => true (50% probability)
Rand.ratio 0.3      # => false (70% probability)

# Fraction form
Rand.ratio 1 4      # => true (25% probability)

2. `Rand.alpha` - Random Alphabetic String

Parameter Description:

Parameter Mode	Parameter Type	Description
No Parameters	-	Returns a single random letter
Single Parameter	`Integer`	Specifies the length of the generated string

Return Value: String
Example:

Rand.alpha       # => "k"
Rand.alpha 5     # => "qjZRy"

3. `Rand.alphanum` - Random Alphanumeric String

Parameter Description:

Parameter Mode	Parameter Type	Description
No Parameters	-	Returns a single random letter or digit
Single Parameter	`Integer`	Specifies the length of the generated string

Return Value: String
Example:

Rand.alphanum        # => "7"
Rand.alphanum 8      # => "F3g9K2wQ"

4. `Rand.int` - Random Integer Generation

Parameter Description:

Parameter Mode	Parameter Type	Description
No Parameters	-	Returns a random integer in the entire `i64` range
Single Parameter	`Integer`	Returns an integer in the range [0, max] (supports negative numbers)
Two Parameters	`Integer, Integer`	Returns an integer in the range [min, max]

Return Value: Integer
Example:

Rand.int             # => -327683491 (example)
Rand.int 100         # => 57
Rand.int -50 50      # => -12

5. `Rand.choose` - List Random Sampling

Parameter Description:

Parameter	Type	Description
1	`List`	The data list to sample from

Return Value: Any element from the list (returns None for an empty list)
Example:

Rand.choose [1 2 3]          # => 2
Rand.choose ["A" "B" "C"]    # => "B"

6. `Rand.shuffle` - List Randomization

Parameter Description:

Parameter	Type	Description
1	`List`	The data list to randomize

Return Value: A new list with elements in random order
Example:

ori = List.from(0..12)
Rand.shuffle ori    # => [3, 8, 7, 11 ...]

Output Example:

┌───┬───┬───┬────┬───┬───┬───┬───┬───┬────┬───┬───┐
│ 3 │ 8 │ 7 │ 11 │ 9 │ 2 │ 5 │ 0 │ 6 │ 10 │ 4 │ 1 │
└───┴───┴───┴────┴───┴───┴───┴───┴───┴────┴───┴───┘

Usage Scenario Examples

Batch Generate Test Data:

# Generate 10 random usernames
fn gen_user() {
  name = (List.join "-" [Rand.alpha(3), Rand.int(1000, 9999)])
  age = (Rand.int 18 60)
  return [name, age]
}

repeat 10 { gen_user | print }

Output Example:

+-------------------------+
| USERNAME      AGE       |
+=========================+
| xQz-4823      34        |
| kFt-7391      22        |
| ...           ...       |
+-------------------------+

updated at 2025-07-15

# libs # random

Lumesh Rand Module