Merge pull request #299 from egiurleo/elsif

kddnewton · web-flow · commit 61eefa8ebb62 · 2023-03-08T14:04:44.000-05:00
Combine `Elsif` node with `IfNode`
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -17,6 +17,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) a
 
 - Fixed the AST output by adding blocks to `Command` and `CommandCall` nodes in the `FieldVisitor`.
 - Fixed the location of lambda local variables (e.g., `->(; a) {}`).
+- The `Elsif` node has been folded into `IfNode`. A `keyword` field has been added to `IfNode` specifying if the node represents an `if` or `elsif`.
 
 ## [6.0.1] - 2023-02-26
 
diff --git a/lib/syntax_tree/dsl.rb b/lib/syntax_tree/dsl.rb
@@ -347,16 +347,6 @@ def Else(keyword, statements)
       )
     end
 
-    # Create a new Elsif node.
-    def Elsif(predicate, statements, consequent)
-      Elsif.new(
-        predicate: predicate,
-        statements: statements,
-        consequent: consequent,
-        location: Location.default
-      )
-    end
-
     # Create a new EmbDoc node.
     def EmbDoc(value)
       EmbDoc.new(value: value, location: Location.default)
@@ -478,8 +468,9 @@ def Ident(value)
     end
 
     # Create a new IfNode node.
-    def IfNode(predicate, statements, consequent)
+    def IfNode(keyword, predicate, statements, consequent)
       IfNode.new(
+        keyword: keyword,
         predicate: predicate,
         statements: statements,
         consequent: consequent,
diff --git a/lib/syntax_tree/field_visitor.rb b/lib/syntax_tree/field_visitor.rb
@@ -353,15 +353,6 @@ def visit_else(node)
         end
       end
 
-      def visit_elsif(node)
-        node(node, "elsif") do
-          field("predicate", node.predicate)
-          field("statements", node.statements)
-          field("consequent", node.consequent) if node.consequent
-          comments(node)
-        end
-      end
-
       def visit_embdoc(node)
         node(node, "embdoc") { field("value", node.value) }
       end
diff --git a/lib/syntax_tree/mutation_visitor.rb b/lib/syntax_tree/mutation_visitor.rb
@@ -322,14 +322,6 @@ def visit_else(node)
         )
       end
 
-      # Visit a Elsif node.
-      def visit_elsif(node)
-        node.copy(
-          statements: visit(node.statements),
-          consequent: visit(node.consequent)
-        )
-      end
-
       # Visit a EmbDoc node.
       def visit_embdoc(node)
         node.copy
diff --git a/lib/syntax_tree/node.rb b/lib/syntax_tree/node.rb
@@ -4853,95 +4853,6 @@ def ===(other)
     end
   end
 
-  # Elsif represents another clause in an +if+ or +unless+ chain.
-  #
-  #     if variable
-  #     elsif other_variable
-  #     end
-  #
-  class Elsif < Node
-    # [Node] the expression to be checked
-    attr_reader :predicate
-
-    # [Statements] the expressions to be executed
-    attr_reader :statements
-
-    # [nil | Elsif | Else] the next clause in the chain
-    attr_reader :consequent
-
-    # [Array[ Comment | EmbDoc ]] the comments attached to this node
-    attr_reader :comments
-
-    def initialize(predicate:, statements:, consequent:, location:)
-      @predicate = predicate
-      @statements = statements
-      @consequent = consequent
-      @location = location
-      @comments = []
-    end
-
-    def accept(visitor)
-      visitor.visit_elsif(self)
-    end
-
-    def child_nodes
-      [predicate, statements, consequent]
-    end
-
-    def copy(predicate: nil, statements: nil, consequent: nil, location: nil)
-      node =
-        Elsif.new(
-          predicate: predicate || self.predicate,
-          statements: statements || self.statements,
-          consequent: consequent || self.consequent,
-          location: location || self.location
-        )
-
-      node.comments.concat(comments.map(&:copy))
-      node
-    end
-
-    alias deconstruct child_nodes
-
-    def deconstruct_keys(_keys)
-      {
-        predicate: predicate,
-        statements: statements,
-        consequent: consequent,
-        location: location,
-        comments: comments
-      }
-    end
-
-    def format(q)
-      q.group do
-        q.group do
-          q.text("elsif ")
-          q.nest("elsif".length - 1) { q.format(predicate) }
-        end
-
-        unless statements.empty?
-          q.indent do
-            q.breakable_force
-            q.format(statements)
-          end
-        end
-
-        if consequent
-          q.group do
-            q.breakable_force
-            q.format(consequent)
-          end
-        end
-      end
-    end
-
-    def ===(other)
-      other.is_a?(Elsif) && predicate === other.predicate &&
-        statements === other.statements && consequent === other.consequent
-    end
-  end
-
   # EmbDoc represents a multi-line comment.
   #
   #     =begin
@@ -6460,25 +6371,29 @@ def contains_conditional?
     end
   end
 
-  # If represents the first clause in an +if+ chain.
+  # If an +if+ or +elsif+ clause in an +if+ chain.
   #
   #     if predicate
   #     end
   #
   class IfNode < Node
+    # [Kw] the opening keyword of the conditional statement
+    attr_reader :keyword
+
     # [Node] the expression to be checked
     attr_reader :predicate
 
     # [Statements] the expressions to be executed
     attr_reader :statements
 
-    # [nil | Elsif | Else] the next clause in the chain
+    # [nil | IfNode | Else] the next clause in the chain
     attr_reader :consequent
 
     # [Array[ Comment | EmbDoc ]] the comments attached to this node
     attr_reader :comments
 
-    def initialize(predicate:, statements:, consequent:, location:)
+    def initialize(keyword:, predicate:, statements:, consequent:, location:)
+      @keyword = keyword
       @predicate = predicate
       @statements = statements
       @consequent = consequent
@@ -6494,9 +6409,16 @@ def child_nodes
       [predicate, statements, consequent]
     end
 
-    def copy(predicate: nil, statements: nil, consequent: nil, location: nil)
+    def copy(
+      keyword: nil,
+      predicate: nil,
+      statements: nil,
+      consequent: nil,
+      location: nil
+    )
       node =
         IfNode.new(
+          keyword: keyword || self.keyword,
           predicate: predicate || self.predicate,
           statements: statements || self.statements,
           consequent: consequent || self.consequent,
@@ -6515,17 +6437,42 @@ def deconstruct_keys(_keys)
         statements: statements,
         consequent: consequent,
         location: location,
+        keyword: keyword,
         comments: comments
       }
     end
 
     def format(q)
-      ConditionalFormatter.new("if", self).format(q)
+      if keyword.value == "elsif"
+        q.group do
+          q.group do
+            q.text("elsif ")
+            q.nest("elsif".length - 1) { q.format(predicate) }
+          end
+
+          unless statements.empty?
+            q.indent do
+              q.breakable_force
+              q.format(statements)
+            end
+          end
+
+          if consequent
+            q.group do
+              q.breakable_force
+              q.format(consequent)
+            end
+          end
+        end
+      else
+        ConditionalFormatter.new(keyword.value, self).format(q)
+      end
     end
 
     def ===(other)
       other.is_a?(IfNode) && predicate === other.predicate &&
-        statements === other.statements && consequent === other.consequent
+        statements === other.statements && consequent === other.consequent &&
+        keyword === other.keyword
     end
 
     # Checks if the node was originally found in the modifier form.
@@ -11328,7 +11275,7 @@ class UnlessNode < Node
     # [Statements] the expressions to be executed
     attr_reader :statements
 
-    # [nil | Elsif | Else] the next clause in the chain
+    # [nil | IfNode | Else] the next clause in the chain
     attr_reader :consequent
 
     # [Array[ Comment | EmbDoc ]] the comments attached to this node
diff --git a/lib/syntax_tree/parser.rb b/lib/syntax_tree/parser.rb
@@ -1575,7 +1575,8 @@ def on_elsif(predicate, statements, consequent)
         ending.location.start_column
       )
 
-      Elsif.new(
+      IfNode.new(
+        keyword: beginning,
         predicate: predicate,
         statements: statements,
         consequent: consequent,
@@ -2062,6 +2063,7 @@ def on_if(predicate, statements, consequent)
       )
 
       IfNode.new(
+        keyword: beginning,
         predicate: predicate,
         statements: statements,
         consequent: consequent,
@@ -2083,9 +2085,10 @@ def on_ifop(predicate, truthy, falsy)
     # :call-seq:
     #   on_if_mod: (untyped predicate, untyped statement) -> IfNode
     def on_if_mod(predicate, statement)
-      consume_keyword(:if)
+      beginning = consume_keyword(:if)
 
       IfNode.new(
+        keyword: beginning,
         predicate: predicate,
         statements:
           Statements.new(body: [statement], location: statement.location),
diff --git a/lib/syntax_tree/translation/parser.rb b/lib/syntax_tree/translation/parser.rb
@@ -1037,50 +1037,6 @@ def visit_else(node)
           end
         end
 
-        # Visit an Elsif node.
-        def visit_elsif(node)
-          begin_start = node.predicate.end_char
-          begin_end =
-            if node.statements.empty?
-              node.statements.end_char
-            else
-              node.statements.body.first.start_char
-            end
-
-          begin_token =
-            if buffer.source[begin_start...begin_end].include?("then")
-              srange_find(begin_start, begin_end, "then")
-            elsif buffer.source[begin_start...begin_end].include?(";")
-              srange_find(begin_start, begin_end, ";")
-            end
-
-          else_token =
-            case node.consequent
-            when Elsif
-              srange_length(node.consequent.start_char, 5)
-            when Else
-              srange_length(node.consequent.start_char, 4)
-            end
-
-          expression = srange(node.start_char, node.statements.end_char - 1)
-
-          s(
-            :if,
-            [
-              visit(node.predicate),
-              visit(node.statements),
-              visit(node.consequent)
-            ],
-            smap_condition(
-              srange_length(node.start_char, 5),
-              begin_token,
-              else_token,
-              nil,
-              expression
-            )
-          )
-        end
-
         # Visit an ENDBlock node.
         def visit_END(node)
           s(
@@ -1361,7 +1317,7 @@ def visit_if(node)
 
               else_token =
                 case node.consequent
-                when Elsif
+                when IfNode
                   srange_length(node.consequent.start_char, 5)
                 when Else
                   srange_length(node.consequent.start_char, 4)
diff --git a/lib/syntax_tree/visitor.rb b/lib/syntax_tree/visitor.rb
@@ -131,9 +131,6 @@ class Visitor < BasicVisitor
     # Visit an Else node.
     alias visit_else visit_child_nodes
 
-    # Visit an Elsif node.
-    alias visit_elsif visit_child_nodes
-
     # Visit an EmbDoc node.
     alias visit_embdoc visit_child_nodes
 
diff --git a/lib/syntax_tree/yarv/compiler.rb b/lib/syntax_tree/yarv/compiler.rb
@@ -916,17 +916,6 @@ def visit_else(node)
         iseq.pop unless last_statement?
       end
 
-      def visit_elsif(node)
-        visit_if(
-          IfNode.new(
-            predicate: node.predicate,
-            statements: node.statements,
-            consequent: node.consequent,
-            location: node.location
-          )
-        )
-      end
-
       def visit_ensure(node)
       end
 
@@ -1054,6 +1043,7 @@ def visit_if(node)
       def visit_if_op(node)
         visit_if(
           IfNode.new(
+            keyword: Kw.new(value: "if", location: Location.default),
             predicate: node.predicate,
             statements:
               Statements.new(body: [node.truthy], location: Location.default),
diff --git a/lib/syntax_tree/yarv/decompiler.rb b/lib/syntax_tree/yarv/decompiler.rb
diff --git a/test/node_test.rb b/test/node_test.rb
