Add `make_node` utility function

This patch adds the `make_node(node, children)` method which creates a
new node with the same head as `node` but with replaced children.

src/Runic.jl

@@ -106,7 +106,6 @@ function format_node_with_children!(ctx::Context, node::JuliaSyntax.GreenNode)
 
     # The new node parts. `children′` aliases `children` and only copied below if any of the
     # nodes change ("copy-on-write").
-    head′ = JuliaSyntax.head(node)
     children = verified_children(node)
     children′ = children
     any_child_changed = false
@@ -161,8 +160,7 @@ function format_node_with_children!(ctx::Context, node::JuliaSyntax.GreenNode)
     ctx.next_sibling = next_sibling
     # Return a new node if any of the children changed
     if any_child_changed
-        span′ = mapreduce(JuliaSyntax.span, +, children′; init = 0)
-        return JuliaSyntax.GreenNode(head′, span′, children′)
+        return make_node(node, children′)
     else
         return nothing
     end

src/chisels.jl

@@ -37,6 +37,12 @@ end
 # JuliaSyntax extensions #
 ##########################
 
+# Create a new node with the same head but new children
+function make_node(node::JuliaSyntax.GreenNode, children′::AbstractVector{<:JuliaSyntax.GreenNode})
+    span′ = mapreduce(JuliaSyntax.span, +, children′; init = 0)
+    return JuliaSyntax.GreenNode(JuliaSyntax.head(node), span′, children′)
+end
+
 function is_leaf(node::JuliaSyntax.GreenNode)
     return !JuliaSyntax.haschildren(node)
 end
@@ -69,8 +75,7 @@ function replace_first_leaf(node::JuliaSyntax.GreenNode, child′::JuliaSyntax.G
         children′ = copy(verified_children(node))
         children′[1] = replace_first_leaf(children′[1], child′)
         @assert length(children′) > 0
-        span′ = mapreduce(JuliaSyntax.span, +, children′; init = 0)
-        return JuliaSyntax.GreenNode(JuliaSyntax.head(node), span′, children′)
+        return make_node(node, children′)
     end
 end
 

src/runestone.jl

@@ -260,9 +260,7 @@ function spaces_around_x(ctx::Context, node::JuliaSyntax.GreenNode, is_x::F) whe
     seek(ctx.fmt_io, pos)
     if any_changes
         # Create new node and return it
-        span′ = mapreduce(JuliaSyntax.span, +, children′; init = 0)
-        node′ = JuliaSyntax.GreenNode(JuliaSyntax.head(node), span′, children′)
-        return node′
+        return make_node(node, children′)
     else
         return nothing
     end
@@ -339,9 +337,8 @@ function no_spaces_around_x(ctx::Context, node::JuliaSyntax.GreenNode, is_x::F)
     seek(ctx.fmt_io, pos)
     if any_changes
         # Create new node and return it
-        span′ = mapreduce(JuliaSyntax.span, +, children′; init = 0)
-        @assert span′ < JuliaSyntax.span(node)
-        node′ = JuliaSyntax.GreenNode(JuliaSyntax.head(node), span′, children′)
+        node′ = make_node(node, children′)
+        @assert JuliaSyntax.span(node′) < JuliaSyntax.span(node)
         return node′
     else
         return nothing
@@ -397,8 +394,7 @@ function replace_with_in(ctx::Context, node::JuliaSyntax.GreenNode)
     for i in (in_index + 1):length(children′)
         accept_node!(ctx, children′[i])
     end
-    node′ = JuliaSyntax.GreenNode(JuliaSyntax.head(node), mapreduce(JuliaSyntax.span, +, children′; init = 0), children′)
-    return node′
+    return make_node(node, children′)
 end
 
 function replace_with_in_cartesian(ctx::Context, node::JuliaSyntax.GreenNode)
@@ -422,13 +418,10 @@ function replace_with_in_cartesian(ctx::Context, node::JuliaSyntax.GreenNode)
             accept_node!(ctx, child)
         end
     end
-    span′ = mapreduce(JuliaSyntax.span, +, children′; init = 0)
     if children === children′
-        # No changes
         return nothing
     end
-    node′ = JuliaSyntax.GreenNode(JuliaSyntax.head(node), span′, children′)
-    return node′
+    return make_node(node, children′)
 end
 
 # replace `=` and `∈` with `in` in for-loops
@@ -472,9 +465,8 @@ function for_loop_use_in(ctx::Context, node::JuliaSyntax.GreenNode)
         accept_node!(ctx, children′[i])
     end
     # Construct the full node and return
-    span′ = mapreduce(JuliaSyntax.span, +, children′; init = 0)
-    node′ = JuliaSyntax.GreenNode(JuliaSyntax.head(node), span′, children′)
-    @assert position(ctx.fmt_io) == pos + span′
+    node′ = make_node(node, children′)
+    @assert position(ctx.fmt_io) == pos + JuliaSyntax.span(node′)
     seek(ctx.fmt_io, pos) # reset
     return node′
 end