Module: Kumi::Frontends::SourceFrame

Defined in:
lib/kumi/frontends/source_frame.rb

Overview

Renders a parse/semantic error against its source as a ‘file:line:col` header plus a caret-annotated code frame. The location is taken from the error’s structured ‘Location` when present; we no longer scrape it out of the message text, which is what produced the flaky `?:?` headers.

Class Method Summary collapse

Class Method Details

.clean_message(message) ⇒ Object

Strip the canonical ‘file:line:col:` / `file:line:` location prefix the message may already carry (LocatedError#to_s and ErrorEntry#to_s both prepend it), so render adds the header exactly once. Now that every location renders one way, this is a single prefix to remove.



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# File 'lib/kumi/frontends/source_frame.rb', line 45

def clean_message(message)
  message.to_s.sub(/\A\S+:\d+(?::\d+)?:\s+/, "").strip
end

.code_frame(src, line, col, context: 2) ⇒ Object 



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# File 'lib/kumi/frontends/source_frame.rb', line 49

def code_frame(src, line, col, context: 2)
  return "" if line.nil?

  lines = src.lines
  return "" if lines.empty?

  from = [line - 1 - context, 0].max
  to   = [line - 1 + context, lines.length - 1].min
  (from..to).flat_map { |i| frame_row(lines[i], i + 1, line, col) }.join("\n")
end

.frame_row(text, number, target_line, col) ⇒ Object

The source line plus, when it is the target line and we know the column, a caret pointer beneath it. Column 0/nil means “column unknown” — skip it.



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# File 'lib/kumi/frontends/source_frame.rb', line 62

def frame_row(text, number, target_line, col)
  marker = number == target_line ? "➤" : " "
  row = format("%s %4d | %s", marker, number, text.to_s.rstrip)
  return [row] unless number == target_line && col && col >= 1

  [row, format("       | %s^", " " * (col - 1))]
end

.location_of(error) ⇒ Object

The structured location, if the error exposes a line and column. Both Kumi’s LocatedError and the parser’s SyntaxError satisfy this; anything else falls through to nil rather than a guessed coordinate.



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# File 'lib/kumi/frontends/source_frame.rb', line 31

def location_of(error)
  return nil unless error.respond_to?(:location)

  loc = error.location
  return nil unless loc.respond_to?(:line)
  return nil if loc.line.nil?

  loc
end

.render(error, src:, file_label:) ⇒ Object

Build the full user-facing error string for ‘error` raised while loading `src` labelled `file_label`. When the error carries a usable location we emit `file:line:col: message` and a code frame; when it does not, we emit a clean `file: message` with no invented coordinates.



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# File 'lib/kumi/frontends/source_frame.rb', line 16

def render(error, src:, file_label:)
  loc = location_of(error)
  message = clean_message(error.message)
  return "#{file_label}: #{message}" unless loc

  # Render the header through Location#to_s (the one location dialect),
  # substituting the caller's file label for the path.
  header = "#{Kumi::Syntax::Location.new(file: file_label, line: loc.line, column: loc.column)}: #{message}"
  frame = code_frame(src, loc.line, loc.column)
  frame.empty? ? header : "#{header}\n#{frame}"
end