Generic sourcefile() function (#469)

* Having a generic version of this is useful for other syntax tree types
  such as `JuliaLowering.SyntaxTree`
* Function to get the `SourceFile` for a syntax object
* Generic `highlight()` implementation in terms of this
* Cleanup: Remove internal `interpolate_literal()` function which
  accidentally has still survived from early prototyping.

Author: c42f

src/expr.jl

@@ -519,19 +519,27 @@ function build_tree(::Type{Expr}, stream::ParseStream;
     only(_fixup_Expr_children!(SyntaxHead(K"None",EMPTY_FLAGS), loc, Any[entry.ex]))
 end
 
+"""
+Get the source file for a given syntax object
+"""
+function sourcefile(node::SyntaxNode)
+    node.source
+end
+
 function _to_expr(node::SyntaxNode)
+    file = sourcefile(node)
     if !haschildren(node)
-        offset, txtbuf = _unsafe_wrap_substring(sourcetext(node.source))
-        return _leaf_to_Expr(node.source, txtbuf, head(node), byte_range(node) .+ offset, node)
+        offset, txtbuf = _unsafe_wrap_substring(sourcetext(file))
+        return _leaf_to_Expr(file, txtbuf, head(node), byte_range(node) .+ offset, node)
     end
     cs = children(node)
     args = Any[_to_expr(c) for c in cs]
-    _internal_node_to_Expr(node.source, byte_range(node), head(node), byte_range.(cs), head.(cs), args)
+    _internal_node_to_Expr(file, byte_range(node), head(node), byte_range.(cs), head.(cs), args)
 end
 
 function Base.Expr(node::SyntaxNode)
     ex = _to_expr(node)
-    loc = source_location(LineNumberNode, node.source, first(byte_range(node)))
+    loc = source_location(LineNumberNode, sourcefile(node), first_byte(node))
     only(_fixup_Expr_children!(SyntaxHead(K"None",EMPTY_FLAGS), loc, Any[ex]))
 end
 

src/source_files.jl

@@ -193,9 +193,26 @@ function _print_marker_line(io, prefix_str, str, underline, singleline, color,
     end
 end
 
+function highlight(io::IO, x; kws...)
+    highlight(io, sourcefile(x), byte_range(x); kws...)
+end
+
 """
-Print the lines of source code surrounding the given byte `range`, which is
-highlighted with background `color` and markers in the text.
+    highlight(io::IO, source::SourceFile, range::UnitRange;
+              color, note, notecolor,
+              context_lines_before, context_lines_inner, context_lines_after,
+    highlight(io, x; kws...)
+
+Print the lines of source code `source` surrounding the given byte `range`
+which is highlighted with background `color` and underlined with markers in the
+text. A `note` in `notecolor` may be provided as annotation.
+
+In the second form, `x` is an object with `sourcefile(x)` and `byte_range(x)`
+implemented.
+
+The context arguments `context_lines_before`, etc, refer to the number of
+lines of code which will be printed as context before and after, with `inner`
+referring to context lines inside a multiline region.
 """
 function highlight(io::IO, source::SourceFile, range::UnitRange;
                    color=(120,70,70), context_lines_before=2,

src/syntax_tree.jl

@@ -137,21 +137,16 @@ byte_range(ex) = first_byte(ex):last_byte(ex)
 Get the full source text of a node.
 """
 function sourcetext(node::AbstractSyntaxNode)
-    view(node.source, byte_range(node))
+    view(sourcefile(node), byte_range(node))
 end
 
-source_line(node::AbstractSyntaxNode) = source_line(node.source, node.position)
-source_location(node::AbstractSyntaxNode) = source_location(node.source, node.position)
-
-function interpolate_literal(node::SyntaxNode, val)
-    @assert kind(node) == K"$"
-    SyntaxNode(node.source, node.raw, node.position, node.parent, true, val)
-end
+source_line(node::AbstractSyntaxNode) = source_line(sourcefile(node), node.position)
+source_location(node::AbstractSyntaxNode) = source_location(sourcefile(node), node.position)
 
 function _show_syntax_node(io, current_filename, node::AbstractSyntaxNode,
                            indent, show_byte_offsets)
-    fname = node.source.filename
-    line, col = source_location(node.source, node.position)
+    fname = sourcefile(node).filename
+    line, col = source_location(node)
     posstr = "$(lpad(line, 4)):$(rpad(col,3))│"
     if show_byte_offsets
         posstr *= "$(lpad(first_byte(node),6)):$(rpad(last_byte(node),6))│"
@@ -301,10 +296,6 @@ function child_position_span(node::SyntaxNode, path::Int...)
     n, n.position, span(n)
 end
 
-function highlight(io::IO, node::SyntaxNode; kws...)
-    highlight(io, node.source, byte_range(node); kws...)
-end
-
 function highlight(io::IO, source::SourceFile, node::GreenNode, path::Int...; kws...)
     _, p, span = child_position_span(node, path...)
     q = p + span - 1