Syntax Cheat Sheet A quick overview for experienced programmers

// This is a one-line comment

/*
    This is a block comment
*/


//========================================================
//                       STRINGS
//========================================================

// Strings are created with a single-quote (')
'Hello World!';

// Strings are joined with the 'stringy' operator (~)
'Hello, ' ~ ' World!';  //= 'Hello, World!'

// Backticks (`) are converted to single quotes
'That`s terrific!';  //= 'That's terrific!'

// Multi-line strings are surrounded by quote fences
'''
    This is
    a multiline
    string!
''';


//========================================================
//                   FLAGS / EQUALITY
//========================================================

// Booleans
true;
false;

// Negation
!true;  //= false
!false; //= true

// Equality check with '=='.  It acts like '===' in PHP
// and JavaScript. (no type coercion)
1 == 1;    //= true
1 == '1';  //= false

// Inequality
1 != 1; //= false
1 != 2; //= true

// Comparison
1 < 2;  //= true
1 > 2;  //= false
2 >= 2; //= true
2 <= 2; //= true


//========================================================
//                     VARIABLES
//========================================================

// Variables are declared with 'let'.
// They must always be initialized with a value.
let letters = 'abcde';
let year = 2020;

// built-in types have methods
'abdce'.length();   //= 5
'abcde'.reverse();  //= 'edcba'

// short-hand math assignment
year += 1;  // same as 'year = year + 1'

let greeting = 'Hi';
greeting ~= '!';  // 'Hi!' (stringy assignment)


//========================================================
//                       LISTS
//========================================================

// Lists are an ordered sequence of values, of any type.

let colors = ['red', 'blue', 'yellow'];

// Built-in methods
colors.length();    //= 3
colors.join(', ');  //= 'red, blue, yellow'

// Indexes are zero-based
colors[0];  //= 'red'
colors[1];  //= 'blue'

// Directly assign a value
colors[2] = 'orange';

// Add & remove items
colors.push('green');  // Add to the end
colors.pop();          //= 'green'

// List Add operator
colors #= 'purple';    // Same as 'push'
colors.pop();          //= 'purple'


//========================================================
//                        MAPS
//========================================================

// Maps are key/value pairs.
// They are like associative arrays in PHP.
// They use JavaScript object literal notation.

let user = {
    name: 'Taylor',
    age: 25,  // trailing commas are ok in multiline maps
};

user['age'];  //= 25

// Assign new fields.
user['address'] = '22 Treetop Road';

// Or use dot notation
user.address = '22 Treetop Road';

// Dot (.) notation is strict.
user.job;  // ERROR. 'job' key doesn't exist.

// Index notation ([]) is not strict.
user['job'];  // OK. Returns '', a safe falsey value.



//========================================================
//                       IF / ELSE
//========================================================

if (condition1) {
    // ...
} else if (condition2) {
    // ...
} else {
    // ...
}


//========================================================
//                       LOOPS
//========================================================

// 'for in' loops iterate through a list.
for (color in colors) {
    print(color);
}

// To loop through numbers, use the 'range' function.
for (n in range(1, 4)) {
    print('Color #' ~ n);
}

// A bare 'for' repeats forever until you exit with 'break'.
// Use this instead of 'while'.
for {
    let color = Palette.getNextColor();
    if (!color) { break; }
    if (color.isBoring) { continue; }
    print(color.name);
}


//========================================================
//                      FUNCTIONS
//========================================================

// Declaring a function
function hello(name) {
    return 'Hello, ' ~ name ~ '!'
}
hello('Tim');  //= 'Hello, Tom!'


// An optional argument with default value
function hello(name, greeting = 'Hello') {
    return greeting ~ ', ' ~ name ~ '!'
}
hello('Tim', 'Hi');  //= 'Hi, Tom!'


//========================================================
//                    SPECIAL STRINGS
//========================================================

// TypeStrings are secure literal strings that are
// prefixed with a type token.  They take parameterized
// values via fill().
let query = sql'select * from user where id = {}';
query.fill(userId);
let user = Db.select(query);

// Regular Expression strings are prefixed with 'r'.
let regex = r'\w+=(\d+)';
'foo=1234'.match(regex)[1]; //= '1234'


//========================================================
//                       MODULES
//========================================================

// You can organize functions into separate module files,
// each in its own namespace. Modules names are
// always UpperCamelCase.

// --- modules/ForumUser.tht ---

function hello(name) {
    print('Hello, ' ~ name ~ '!');
}

// --- pages/home.tht ---

// Modules are automatically imported from the 'modules'
// folder when called.
ForumUser.hello('Tina');  //= 'Hello, Tina!'

// Or import a module directly
import('other/OtherModule.tht');

OtherModule.otherFunction();