Lumesh Syntax Overview

 1# Integers
 2let num = 42
 3let negative = -100
 4
 5# Floating-point numbers
 6let pi = 3.14159
 7let percent = 85%
 8
 9# Strings
10let str1 = "Double-quoted string,\nwith escape support"
11let str2 = 'Single-quoted raw string,\nno escape'
12let template = `Template string $var ${var + 1}`
13
14# Booleans
15let flag = True
16let disabled = False
17
18# Null values
19let empty = None
20
21# File sizes
22let a = 3000K

 1# Lists (List)
 2let arr = [1, 2, 3, "mixed", True]
 3let nested = [[1, 2], [3, 4]]
 4
 5# Hash Map (HMap) - Unordered, fast lookup
 6# let hmap = H{name: "Alice", age: 25}
 7
 8# Ordered Map (Map) - Ordered, supports range queries
 9let map = {a: 1, b: 2, c: 3}
10
11# Ranges (Range)
12let range1 = 1..10      # 1 to 9 (excluding 10)
13let range2 = 1..=10     # 1 to 10 (including 10)
14let range3 = 1..10:2    # 1, 3, 5, 7, 9 (step of 2)
15
16let array = 1...10      # Create an array directly from the range

1# Variable declaration and assignment
2let x = 10
3let name = "Lumesh"
4
5# Multiple variable assignment
6let a, b, c = 1, 2, 3
7let x, y = getValue()

 1# Use := for delayed assignment; the expression will not execute immediately
 2let cmd := ls -l /tmp
 3let calculation := 2 + 3 * 4
 4
 5# Execute only when needed
 6eval(cmd)           # Executes ls -l /tmp
 7eval(calculation)   # Calculates to 14
 8
 9# If it's a command, it can also be executed directly
10cmd

 1# Array destructuring
 2let [first, second, *rest] = [1, 2, 3, 4, 5]
 3# first = 1, second = 2, rest = [3, 4, 5]
 4
 5# Map destructuring
 6let {name, age} = {name: "Bob", age: 30, city: "NYC"}
 7# name = "Bob", age = 30
 8
 9# Renaming destructuring
10let {name: username, age: userAge} = user_data

1let a = 10 + 5      # Addition: 15
2let b = 10 - 3      # Subtraction: 7
3let c = 4 * 6       # Multiplication: 24
4let d = 15 / 3      # Division: 5
5let e = 17 % 5      # Modulus: 2
6let f = 2 ^ 3       # Exponentiation: 8

 1# Basic comparisons
 2a == b      # Equal
 3a != b      # Not equal
 4a > b       # Greater than
 5a < b       # Less than
 6a >= b      # Greater than or equal
 7a <= b      # Less than or equal
 8
 9# Pattern matching
10text ~= "pattern"       # Regex match
11text ~: "substring"     # Contains match
12text !~= "pattern"      # Regex not match
13text !~: "substring"    # Does not contain match

1condition1 && condition2    # Logical AND
2condition1 || condition2    # Logical OR
3!condition                  # Logical NOT

 1# Standard pipeline - Pass standard output or structured data
 2cmd1 | cmd2
 3
 4# Positional pipeline - Replace specified parameter positions
 5data |_ process_func arg1 _ arg3
 6
 7# Loop pipeline - Dispatch one element at a time, loop execution, can specify parameter positions
 8list |> transform(param1, param2, _)
 9
10# PTY pipeline - For interactive programs
11cmd1 |^ interactive_program

 1# Ignore errors and continue execution
 2risky_command ?.
 3
 4# Print error to standard output
 5command ?+
 6
 7# Print error to standard error output
 8command ??
 9
10# Print error and override result
11command ?>
12
13# Terminate the program on error
14command ?!
15
16# Custom error handling, can be used to provide default values
17command ?: error_handler

1# if-else expression
2let result = if condition {
3    "true branch"
4} else {
5    "false branch"
6}
7
8# Ternary operator, supports nesting
9let value = condition ? true_value : false_value

 1# while loop
 2while condition {
 3    # Loop body
 4    update_condition()
 5}
 6
 7# for loop, can be used for strings, string splitting follows IFS settings; can use * wildcard
 8for item in collection {
 9    process(item)
10}
11
12# Range loop
13for i in 0..10 {
14    println(i)
15}
16
17# Infinite loop
18loop {
19    if break_condition {
20        break
21    }
22}
23
24# Simple repetition
25repeat 10 {a += 1}

1match value {
2    1 => "one",
3    2, 3 => "two or three",
4    xx => "is symbol/string xx",
5    '\w' => "is word",
6    '\d+' => "is digit",
7    _ => "default case"
8}

 1# Basic function
 2fn greet(name) {
 3    "Hello, " + name
 4}
 5
 6# Function with default parameters
 7fn add(a, b = 0) {
 8    a + b
 9}
10
11# Variable parameter function
12fn sum(a, *numbers) {
13    numbers | List.fold(0, (acc, x) -> acc + x)
14}

 1# Single-parameter lambda
 2let square = x -> x * x
 3
 4# Multi-parameter lambda
 5let add = (a, b) -> a + b
 6
 7# Complex lambda body
 8let process = data -> {
 9    let filtered = data | List.filter(x -> x > 0)
10    filtered | List.map(x -> x * 2)
11}

1@timing
2@cache(300)
3fn expensive_calculation(input) {
4    # Complex calculation
5    heavy_computation(input)
6}

 1# String chained operations
 2"hello world"
 3    .split(' ')
 4    .map(s -> s.to_upper())
 5    .join('-')
 6
 7# Data processing chain
 8data
 9    .filter(x -> x.active)
10    .sort(x -> x.priority)
11    .take(10)

 1# Array indexing
 2let arr = [1, 2, 3, 4, 5]
 3let first = arr[0]          # 1
 4
 5# Array slicing
 6let slice1 = arr[1:4]       # [2, 3, 4]
 7let slice2 = arr[1:]        # [2, 3, 4, 5]
 8let slice3 = arr[:3]        # [1, 2, 3]
 9let slice4 = arr[-3:]       # [3, 4, 5]
10let slice5 = arr[::2]       # [1, 3, 5] (step of 2)
11
12# Map indexing
13let obj = {name: "Alice", age: 25}
14let name = obj[name]      # "Alice"
15let ages = obj.age        # 25 (dot access)
16let age = obj@age         # 25 (@ access)

1# Basic range
21..10           # 1 to 10
31..<10          # 1 to 9 (explicitly excluding)
4
5# Ranges with step
61..10:2         # 1, 3, 5, 7, 9
70..100:10       # 0, 10, 20, ..., 90

 1# String interpolation
 2let name = "World"
 3let age = 18
 4let greeting = `Hello, ${age > 18 ? "Mr." : "Dear"} $name!`
 5
 6# Multi-line string
 7let multiline = "
 8This is a
 9multi-line string
10"
11
12# Raw string (no escape)
13let raw = 'C:\path\to\file'

 1# List operations
 2let numbers = [1, 2, 3, 4, 5]
 3numbers.append(6)             # Add element
 4numbers + 6                   # Add element
 5# numbers.pop()               # Remove last element
 6numbers - 4                   # Remove specified element
 7numbers.len()                 # Get length
 8
 9# Map operations
10let person = {name: "Bob", age: 30}
11# person.city = "NYC"         # Add property
12person + {city: "NYC"}         # Add property
13# del person.age              # Delete property
14person.keys()               # Get all keys

1# Import modules
2use my_mod
3use my_mod as a
4
5# Use module functions
6Fs.ls("/tmp")
7String.split("hello world", " ")
8Math.sin(Math.PI / 2)

1# Single-line comment
2let x = 10  # End-of-line comment

1# Define custom operators
2let _+ = (a, b) -> a.concat(b)  # Custom addition
3let __! = x -> Math.sum(x)     # Custom prefix operator
4
5# Use custom operators
6[1, 2] _+ [3, 4]    # [1, 2, 3, 4]
7[5, 6, 7]  __!              # 18