Add the spacing utility

src/utility/spacing.lisp

@@ -0,0 +1,67 @@
+;; Bootstrap's spacing utility is a powerful toolset that allows developers to
+;; modify an element's margin and padding with a range of classes. These
+;; classes are built using a consistent scale of spacing variables for
+;; predictable spacing across the application, ensuring a unified look and feel
+;; throughout.
+
+;; The spacing classes follow a simple {property}{sides}-{size} pattern for
+;; defining the space on the widget. 'Property' is either 'm' for margins or
+;; 'p' for padding. 'Sides' refers to the side of the element where the space
+;; should be applied: top (t), bottom (b), left (start/s), right (end/e), x
+;; (horizontal sides), y (vertical sides), or blank (all sides). 'Size'
+;; represents the size of the space, ranging from 0 (no space) to 5 (most
+;; space), or 'auto' for automatic margins.
+
+;; Furthermore, Bootstrap's spacing utility also incorporates responsive
+;; variations, meaning developers can assign spacing values that are specific
+;; to a certain breakpoint, ensuring the design's responsiveness. These classes
+;; follow the {property}{sides}-{breakpoint}-{size} pattern and the breakpoint
+;; can be 'sm', 'md', 'lg', 'xl', 'xxl'.
+
+;; In summary, Bootstrap's spacing utility provides a flexible, responsive, and
+;; coherent system for managing spaces in a web layout, aiding in creating
+;; beautiful and well-structured user interfaces.
+
+(defpackage :cl-sbt-spacing
+  (:use :cl)
+  (:export :spacing)
+  (:documentation "A module for generating Bootstrap spacing classes."))
+
+(in-package :cl-sbt-spacing)
+
+(defun spacing (&key (property nil) (side nil) (size nil) (breakpoint nil))
+  "Generates a Bootstrap spacing class.
+
+PROPERTY: Specifies the property, should be :m (margin) or :p (padding).
+
+SIDE: Specifies the side, should be :t (top), :b (bottom), :s (start),
+:e (end), :x (horizontal), :y (vertical), or nil (all sides).
+
+SIZE: Specifies the size, should be a number from 0 to 5, or :auto.
+
+BREAKPOINT: Specifies the breakpoint, should be :xs, :sm, :md, :lg, :xl, or
+:xxl, or nil (all breakpoints).
+
+Example 1:
+  (spacing (:property :m :side :t :size 3 :breakpoint :md))
+  ; This will generate a string 'mt-md-3'
+
+Example 2:
+  (spacing (:property :p :side :b :size 2 :breakpoint :lg))
+  ; This will generate a string 'pb-lg-2', which represents a large breakpoint
+  ; with bottom padding of size 2.
+
+Example 3:
+  (spacing (:property :m :size :auto))
+  ; This will generate a string 'm-auto', which sets auto margin on all sides
+  ; for all breakpoints.
+
+Example 4:
+  (spacing (:property :p :side :x :size 5))
+  ; This will generate a string 'px-5', which sets horizontal padding of size 5
+  ; for all breakpoints."
+  (let ((property-str (if (null property) "" (string property)))
+        (side-str (if (null side) "" (string side)))
+        (size-str (if (null size) "" (if (eq size :auto) "auto" (format nil "~d" size))))
+        (breakpoint-str (if (null breakpoint) "" (format nil "~a-" (string breakpoint)))))
+    (string-downcase (concatenate 'string property-str side-str "-" breakpoint-str size-str))))