Class Pry::Indent
In: lib/pry/indent.rb
Parent: Object

Pry::Indent is a class that can be used to indent a number of lines containing Ruby code similar as to how IRB does it (but better). The class works by tokenizing a string using CodeRay and then looping over those tokens. Based on the tokens in a line of code that line (or the next one) will be indented or un-indented by correctly.

Methods

Included Modules

Helpers::BaseHelpers

Constants

SPACES = ' '   The amount of spaces to insert for each indent level.
OPEN_TOKENS = { 'def' => 'end', 'class' => 'end', 'module' => 'end', 'do' => 'end', 'if' => 'end', 'unless' => 'end', 'while' => 'end', 'until' => 'end', 'for' => 'end', 'case' => 'end', 'begin' => 'end', '[' => ']', '{' => '}', '(' => ')'   Hash containing all the tokens that should increase the indentation level. The keys of this hash are open tokens, the values the matching tokens that should prevent a line from being indented if they appear on the same line.
SINGLELINE_TOKENS = %w(if while until unless rescue)   Which tokens can either be open tokens, or appear as modifiers on a single-line.
IGNORE_TOKENS = [:space, :content, :string, :method, :ident, :constant, :pre_constant, :predefined_constant]   Collection of token types that should be ignored. Without this list keywords such as "class" inside strings would cause the code to be indented incorrectly.

:pre_constant and :preserved_constant are the CodeRay 0.9.8 and 1.0.0 classifications of "true", "false", and "nil".

STATEMENT_END_TOKENS = IGNORE_TOKENS + [:regexp, :integer, :float, :keyword, :delimiter, :reserved]   Tokens that indicate the end of a statement (i.e. that, if they appear directly before an "if" indicates that that if applies to the same line, not the next line)

:reserved and :keywords are the CodeRay 0.9.8 and 1.0.0 respectively classifications of "super", "next", "return", etc.

MIDWAY_TOKENS = %w(when else elsif ensure rescue)   Collection of tokens that should appear dedented even though they don‘t affect the surrounding code.

Attributes

indent_level  [R]  @return [String] String containing the spaces to be inserted before the next line.
stack  [R]  @return [Array<String>] The stack of open tokens.

Public Class methods

Public Instance methods

Return a string which, when printed, will rewrite the previous line with the correct indentation. Mostly useful for fixing ‘end’.

@param [String] prompt The user‘s prompt @param [String] code The code the user just typed in. @param [Fixnum] overhang (0) The number of chars to erase afterwards (i.e.,

  the difference in length between the old line and the new one).

@return [String]

Get the indentation for the start of the next line.

This is what‘s used between the prompt and the cursor in pry.

@return String The correct number of spaces

If the code just before an "if" or "while" token on a line looks like the end of a statement, then we want to treat that "if" as a singleline, not multiline statement.

Are we currently in the middle of a string literal.

This is used to determine whether to re-indent a given line, we mustn‘t re-indent within string literals because to do so would actually change the value of the String!

@return Boolean

Indents a string and returns it. This string can either be a single line or multiple ones.

@example

 str = <<TXT
 class User
 attr_accessor :name
 end
 TXT

 # This would result in the following being displayed:
 #
 # class User
 #   attr_accessor :name
 # end
 #
 puts Pry::Indent.new.indent(str)

@param [String] input The input string to indent. @return [String] The indented version of input.

Get the change in indentation indicated by the line.

By convention, you remove indent from the line containing end tokens, but add indent to the line after that which contains the start tokens.

This method returns a pair, where the first number is the number of closings on this line (i.e. the number of indents to remove before the line) and the second is the number of openings (i.e. the number of indents to add after this line)

@param [Array] tokens A list of tokens to scan. @return [Array[Integer]]

All the open delimiters, in the order that they first appeared.

@return [String]

Return a string which restores the CodeRay string status to the correct value by opening HEREDOCs and strings.

@return String

reset internal state

Return a pair of [rows, columns] which gives the size of the window.

If the window size cannot be determined, return nil.

Given a string of Ruby code, use CodeRay to export the tokens.

@param [String] string The Ruby to lex @return [Array] An Array of pairs of [token_value, token_type]

Update the internal state about what kind of strings are open.

Most of the complication here comes from the fact that HEREDOCs can be nested. For normal strings (which can‘t be nested) we assume that CodeRay correctly pairs open-and-close delimiters so we don‘t bother checking what they are.

@param [String] token The token (of type :delimiter)

[Validate]