feat: configure spaces on Tab per language

src/ruby_config.rb

@@ -145,6 +145,8 @@ module Vamp
       @highlight_trailing_whitespace = false
       @whitespace_characters = {}
       @whitespace_scope = "all"
+      @tab_spaces = nil
+      @language_tab_spaces = {}
       @diff_context_lines = 10
       @diff_expand_lines = 15
       @diff_view_mode = "split"
@@ -254,6 +256,25 @@ module Vamp
       @whitespace_scope = scope
     end
 
+    # @param spaces [Integer, nil] spaces per Tab, or nil for a literal tab
+    # @return [Integer, nil]
+    def tab_spaces=(spaces)
+      @tab_spaces = tab_spaces!(spaces)
+    end
+
+    # @param languages [Hash{String => Integer, nil}] syntax language names to Tab widths
+    # @return [Hash{String => Integer, nil}]
+    def language_tab_spaces=(languages)
+      raise TypeError, "language_tab_spaces must be a Hash" unless languages.is_a?(Hash)
+
+      @language_tab_spaces = languages.to_h do |language, spaces|
+        language = nonempty_string!(language, "Tab language")
+        raise ArgumentError, "Tab language must not contain control characters" if language.match?(/[[:cntrl:]]/)
+
+        [language, tab_spaces!(spaces)]
+      end
+    end
+
     # @param lines [Integer] nonnegative context lines around each diff change
     # @return [Integer]
     def diff_context_lines=(lines)
@@ -329,6 +350,7 @@ module Vamp
         "highlight_trailing_whitespace" => @highlight_trailing_whitespace,
         "whitespace_characters" => @whitespace_characters,
         "whitespace_scope" => @whitespace_scope,
+        "tab_spaces" => @tab_spaces, "language_tab_spaces" => @language_tab_spaces,
         "top_bar" => @bar.top, "bottom_bar" => @bar.bottom, "labels" => @labels,
         "popup" => { "command" => @popup.command, "search" => @popup.search },
         "diff_context_lines" => @diff_context_lines, "diff_expand_lines" => @diff_expand_lines,
@@ -337,6 +359,16 @@ module Vamp
     end
 
     private
+    # @param spaces [Integer, nil]
+    # @return [Integer, nil]
+    def tab_spaces!(spaces)
+      unless spaces.nil? || (spaces.is_a?(Integer) && spaces.between?(1, 255))
+        raise ArgumentError, "tab_spaces must be nil or an Integer between 1 and 255"
+      end
+
+      spaces
+    end
+
     # @param value [Integer]
     # @param label [String]
     # @param minimum [Integer]