Merge pull request #334 from ruby-syntax-tree/ctags

Ctags

Author: kddnewton

lib/syntax_tree/cli.rb

@@ -154,6 +154,92 @@ def failure
       end
     end
 
+    # An action of the CLI that generates ctags for the given source.
+    class CTags < Action
+      attr_reader :entries
+
+      def initialize(options)
+        super(options)
+        @entries = []
+      end
+
+      def run(item)
+        lines = item.source.lines(chomp: true)
+
+        SyntaxTree
+          .index(item.source)
+          .each do |entry|
+            line = lines[entry.location.line - 1]
+            pattern = "/^#{line.gsub("\\", "\\\\\\\\").gsub("/", "\\/")}$/;\""
+
+            entries << case entry
+            when SyntaxTree::Index::ModuleDefinition
+              parts = [entry.name, item.filepath, pattern, "m"]
+
+              if entry.nesting != [[entry.name]]
+                parts << "class:#{entry.nesting.flatten.tap(&:pop).join(".")}"
+              end
+
+              parts.join("\t")
+            when SyntaxTree::Index::ClassDefinition
+              parts = [entry.name, item.filepath, pattern, "c"]
+
+              if entry.nesting != [[entry.name]]
+                parts << "class:#{entry.nesting.flatten.tap(&:pop).join(".")}"
+              end
+
+              unless entry.superclass.empty?
+                inherits = entry.superclass.join(".").delete_prefix(".")
+                parts << "inherits:#{inherits}"
+              end
+
+              parts.join("\t")
+            when SyntaxTree::Index::MethodDefinition
+              parts = [entry.name, item.filepath, pattern, "f"]
+
+              unless entry.nesting.empty?
+                parts << "class:#{entry.nesting.flatten.join(".")}"
+              end
+
+              parts.join("\t")
+            when SyntaxTree::Index::SingletonMethodDefinition
+              parts = [entry.name, item.filepath, pattern, "F"]
+
+              unless entry.nesting.empty?
+                parts << "class:#{entry.nesting.flatten.join(".")}"
+              end
+
+              parts.join("\t")
+            when SyntaxTree::Index::AliasMethodDefinition
+              parts = [entry.name, item.filepath, pattern, "a"]
+
+              unless entry.nesting.empty?
+                parts << "class:#{entry.nesting.flatten.join(".")}"
+              end
+
+              parts.join("\t")
+            when SyntaxTree::Index::ConstantDefinition
+              parts = [entry.name, item.filepath, pattern, "C"]
+
+              unless entry.nesting.empty?
+                parts << "class:#{entry.nesting.flatten.join(".")}"
+              end
+
+              parts.join("\t")
+            end
+          end
+      end
+
+      def success
+        puts(<<~HEADER)
+          !_TAG_FILE_FORMAT	2	/extended format; --format=1 will not append ;" to lines/
+          !_TAG_FILE_SORTED	1	/0=unsorted, 1=sorted, 2=foldcase/
+        HEADER
+
+        entries.sort.each { |entry| puts(entry) }
+      end
+    end
+
     # An action of the CLI that formats the source twice to check if the first
     # format is not idempotent.
     class Debug < Action
@@ -488,6 +574,8 @@ def run(argv)
             AST.new(options)
           when "c", "check"
             Check.new(options)
+          when "ctags"
+            CTags.new(options)
           when "debug"
             Debug.new(options)
           when "doc"