Exception: Strling::Core::STRlingParseError

Inherits:
StandardError
  • Object
show all
Defined in:
lib/strling/core/errors.rb

Overview

Rich parse error with position tracking and instructional hints.

This error class transforms parse failures into learning opportunities by providing:

  • The specific error message

  • The exact position where the error occurred

  • The full line of text containing the error

  • A beginner-friendly hint explaining how to fix the issue

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(message, pos, text: '', hint: nil) ⇒ STRlingParseError

Initialize a STRlingParseError.

Parameters:

  • message (String) —

    A concise description of what went wrong

  • pos (Integer) —

    The character position (0-indexed) where the error occurred

  • text (String) (defaults to: '') —

    The full input text being parsed (default: “”)

  • hint (String, nil) (defaults to: nil) —

    An instructional hint explaining how to fix the error (default: nil)



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# File 'lib/strling/core/errors.rb', line 39

def initialize(message, pos, text: '', hint: nil)
  @message = message
  @pos = pos
  @text = text
  @hint = hint

  # Call parent constructor with formatted message
  super(format_error)
end

Instance Attribute Details

#hint ⇒ String? (readonly)

Returns An instructional hint explaining how to fix the error.

Returns:

  • (String, nil) —

    An instructional hint explaining how to fix the error



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# File 'lib/strling/core/errors.rb', line 31

def hint
  @hint
end

#message ⇒ String (readonly)

Returns A concise description of what went wrong.

Returns:

  • (String) —

    A concise description of what went wrong



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# File 'lib/strling/core/errors.rb', line 22

def message
  @message
end

#pos ⇒ Integer (readonly)

Returns The character position (0-indexed) where the error occurred.

Returns:

  • (Integer) —

    The character position (0-indexed) where the error occurred



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# File 'lib/strling/core/errors.rb', line 25

def pos
  @pos
end

#text ⇒ String (readonly)

Returns The full input text being parsed.

Returns:

  • (String) —

    The full input text being parsed



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# File 'lib/strling/core/errors.rb', line 28

def text
  @text
end

Instance Method Details

#format_error ⇒ String

Format the error in the visionary state format.

Returns:

  • (String) —

    A formatted error message with context and hints



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# File 'lib/strling/core/errors.rb', line 52

def format_error
  if text.empty?
    # Fallback to simple format if no text provided
    return "#{message} at position #{pos}"
  end

  # Find the line containing the error
  lines = text.lines(chomp: true)
  current_pos = 0
  line_num = 1
  line_text = ''
  col = pos

  lines.each_with_index do |line, i|
    line_len = line.length + 1 # +1 for newline
    if current_pos + line_len > pos
      line_num = i + 1
      line_text = line
      col = pos - current_pos
      break
    end
    current_pos += line_len
  end

  # Error is beyond the last line
  if line_text.empty?
    if !lines.empty?
      line_num = lines.length
      line_text = lines[-1]
      col = line_text.length
    else
      line_text = text
      col = pos
    end
  end

  # Build the formatted error message
  parts = ["STRling Parse Error: #{message}", '']
  parts << "> #{line_num} | #{line_text}"
  parts << ">   | #{' ' * col}^"

  if hint
    parts << ''
    parts << "Hint: #{hint}"
  end

  parts.join("\n")
end

#to_formatted_string ⇒ String

Backwards/JS-friendly alias for getting the formatted error string.

Returns:

  • (String) —

    The formatted error message (same as ‘to_s`)



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# File 'lib/strling/core/errors.rb', line 111

def to_formatted_string
  format_error
end

#to_lsp_diagnostic ⇒ Hash

Convert the error to LSP Diagnostic format.

Returns a hash compatible with the Language Server Protocol Diagnostic specification, which can be serialized to JSON for communication with LSP clients.

Returns:

  • (Hash) —

    A hash containing:

    • range: The line/column range where the error occurred

    • severity: Error severity (1 = Error)

    • message: The error message with hint if available

    • source: “STRling”

    • code: A normalized error code derived from the message



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# File 'lib/strling/core/errors.rb', line 127

def to_lsp_diagnostic
  # Find the line and column containing the error
  lines = text.empty? ? [] : text.lines(chomp: true)
  current_pos = 0
  line_num = 0 # 0-indexed for LSP
  col = pos

  lines.each_with_index do |line, i|
    line_len = line.length + 1 # +1 for newline
    if current_pos + line_len > pos
      line_num = i
      col = pos - current_pos
      break
    end
    current_pos += line_len
  end

  # Error is beyond the last line
  if col == pos && !lines.empty?
    line_num = lines.length - 1
    col = lines[-1].length
  end

  # Build the diagnostic message
  diagnostic_message = message
  diagnostic_message += "\n\nHint: #{hint}" if hint

  # Create error code from message (normalize to snake_case)
  error_code = message.downcase
  [' ', "'", '"', '(', ')', '[', ']', '{', '}', '\\', '/'].each do |char|
    error_code = error_code.gsub(char, '_')
  end
  error_code = error_code.split('_').reject(&:empty?).join('_')

  {
    range: {
      start: { line: line_num, character: col },
      end: { line: line_num, character: col + 1 }
    },
    severity: 1, # 1 = Error, 2 = Warning, 3 = Information, 4 = Hint
    message: diagnostic_message,
    source: 'STRling',
    code: error_code
  }
end

#to_s ⇒ String

Return the formatted error message.

Returns:

  • (String) —

    The formatted error message



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# File 'lib/strling/core/errors.rb', line 104

def to_s
  format_error
end