RESL

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📊 Literals ​

Literals are the fundamental building blocks of RESL expressions, representing basic data types that store individual values.

🔢 Numbers ​

RESL supports both integers and floating-point numbers with intuitive syntax.

Integers ​

Whole numbers without decimal points:

resl
42
-17
0

Floating-Point Numbers ​

Numbers with decimal points:

resl
3.14159
-2.5
0.0
42.0

Usage Examples ​

resl
{
    port = 8080;
    timeout = 30.5;
    offset = -10;

    ["server_port": port, "timeout_seconds": timeout, "time_offset": offset]
}

📝 Strings ​

Strings represent text values and must be enclosed in double quotes.

Basic Strings ​

resl
"Hello, World!"
"Configuration value"
"app-name"
""

Escape Sequences ​

RESL supports standard escape sequences for special characters:

resl
"Line 1\nLine 2"
"Say \"Hello\""
"Path: C:\\temp"
"Tab\tseparated"

Common Escape Sequences ​

  • \" - Double quote
  • \\ - Backslash
  • \n - Newline

Usage Examples ​

resl
{
    app_name = "My Application";
    description = "A powerful\nconfiguration tool";
    file_path = "C:\\configs\\app.resl";
    message = "Status: \"ready\"";

    ["app": app_name, "desc": description, "path": file_path, "msg": message]
}

✅ Booleans ​

Boolean values represent true/false states:

resl
true
false

Usage Examples ​

resl
{
    debug_mode = true;
    production = false;
    ssl_enabled = true;

    server_config = [
        "debug": debug_mode,
        "production": production,
        "ssl": ssl_enabled
    ];

    server_config
}

In Conditionals ​

Booleans are commonly used with conditional expressions:

resl
{
    is_production = true;
    log_level = ? is_production : "error" | "debug";

    ["environment": "production", "logging": log_level]
}

⚫ Null ​

The null literal represents the absence of a value:

resl
null

Usage Examples ​

resl
{
    optional_field = null;
    default_value = null;

    config = [
        "required_field": "value",
        "optional_field": optional_field,
        "computed_field": ? (default_value == null) : "fallback" | default_value
    ];

    config
}

Null Checking ​

resl
{
    user_id = null;
    guest_mode = ? (user_id == null) : true | false;

    ["guest": guest_mode]
}

🎯 Type Behavior ​

Automatic Type Recognition ​

RESL automatically recognizes literal types:

resl
{
    number_int = 42;
    number_float = 42.0;
    text = "42";
    flag = true;
    empty = null;

    ["types": [number_int, number_float, text, flag, empty]]
}

Type Checking ​

Use the type_of() built-in function to check types:

resl
{
    value = 42;
    value_type = type_of(value);

    text = "hello";
    text_type = type_of(text);

    ["value_type": value_type, "text_type": text_type]
}

🔍 Common Patterns ​

Environment Configuration ​

resl
{
    environment = "development";
    debug = ? (environment == "development") : true | false;
    port = ? (environment == "production") : 80 | 3000;

    ["env": environment, "debug": debug, "port": port]
}

Feature Flags ​

resl
{
    feature_flags = [
        "new_ui": true,
        "beta_features": false,
        "analytics": true
    ];

    feature_flags
}

Default Values ​

resl
{
    user_config = null;
    timeout = ? (user_config == null) : 30 | user_config;

    ["timeout": timeout]
}

➡️ Next Steps ​

Now that you understand literals, learn about Collections to see how to organize multiple values using lists and maps.