Class: Oppen::PrintStack
- Inherits:
-
Object
- Object
- Oppen::PrintStack
- Defined in:
- lib/oppen/print_stack.rb
Overview
Class that represents a stack that builds an output string using the values of the tokens that were pushed into it.
Defined Under Namespace
Classes: PrintStackEntry
Instance Attribute Summary collapse
-
#buffer ⇒ Object
readonly
IO element that builds the output.
-
#config ⇒ Object
readonly
Config containing customization flags.
-
#genspace ⇒ Object
readonly
Callable that generate spaces.
-
#items ⇒ Object
readonly
Array representing the stack of PrintStackEntries.
-
#margin ⇒ Object
readonly
Page margin (Called length in the original paper).
-
#new_line ⇒ Object
readonly
Delimiter between lines in output.
-
#space ⇒ Integer
readonly
Current available space (Called index in the original paper).
Instance Method Summary collapse
-
#handle_begin(token, token_length) ⇒ Nil
Handle Begin Token.
-
#handle_break(token, token_length) ⇒ Nil
Handle Break Token.
-
#handle_end ⇒ Nil
Handle End Token.
-
#handle_string(token, token_length) ⇒ Nil
Handle String Token.
-
#indent(amount) ⇒ Nil
Add indentation by ‘amount`.
-
#initialize(margin, new_line, config, space, out) ⇒ PrintStack
constructor
A new instance of PrintStack.
-
#output ⇒ String
Returns the output of the print stack.
-
#pop ⇒ PrintStackEntry
Pop a PrintStackEntry from the stack.
-
#print(token, token_length) ⇒ Nil
Core method responsible for building the print stack and the output string.
-
#print_new_line(amount) ⇒ Nil
Add a new line to the output.
-
#push(print_stack_entry) ⇒ Nil
Push a PrintStackEntry into the stack.
-
#top ⇒ PrintStackEntry
Get the element at the top of the stack.
-
#write(obj) ⇒ Nil
Write a string to the output.
Constructor Details
#initialize(margin, new_line, config, space, out) ⇒ PrintStack
Returns a new instance of PrintStack.
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# File 'lib/oppen/print_stack.rb', line 44 def initialize(margin, new_line, config, space, out) @buffer = out @config = config @genspace = if space.respond_to?(:call) raise ArgumentError, 'space argument must be a Proc of arity 1' \ if space.to_proc.arity != 1 space else ->(n) { space * n } end @items = [] @new_line = new_line @margin = margin @space = margin end |
Instance Attribute Details
#buffer ⇒ Object (readonly)
IO element that builds the output.
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# File 'lib/oppen/print_stack.rb', line 22 def buffer @buffer end |
#config ⇒ Object (readonly)
Config containing customization flags
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# File 'lib/oppen/print_stack.rb', line 25 def config @config end |
#genspace ⇒ Object (readonly)
Callable that generate spaces
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# File 'lib/oppen/print_stack.rb', line 28 def genspace @genspace end |
#items ⇒ Object (readonly)
Array representing the stack of PrintStackEntries.
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# File 'lib/oppen/print_stack.rb', line 31 def items @items end |
#margin ⇒ Object (readonly)
Page margin (Called length in the original paper).
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# File 'lib/oppen/print_stack.rb', line 37 def margin @margin end |
#new_line ⇒ Object (readonly)
Delimiter between lines in output
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# File 'lib/oppen/print_stack.rb', line 34 def new_line @new_line end |
#space ⇒ Integer (readonly)
Current available space (Called index in the original paper).
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# File 'lib/oppen/print_stack.rb', line 42 def space @space end |
Instance Method Details
#handle_begin(token, token_length) ⇒ Nil
Handle Begin Token.
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# File 'lib/oppen/print_stack.rb', line 98 def handle_begin(token, token_length) if token_length > space type = if token.break_type == Token::BreakType::CONSISTENT Token::BreakType::CONSISTENT else Token::BreakType::INCONSISTENT end if config&.indent_anchor == Config::IndentAnchor::ON_BEGIN indent = token.offset if !items.empty? indent += top.offset end else indent = space - token.offset end push PrintStackEntry.new indent, type else push PrintStackEntry.new 0, Token::BreakType::FITS end end |
#handle_break(token, token_length) ⇒ Nil
Handle Break Token.
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# File 'lib/oppen/print_stack.rb', line 137 def handle_break(token, token_length) block = top case block.break_type in Token::BreakType::FITS @space -= token.length write token in Token::BreakType::CONSISTENT @space = block.offset - token.offset indent = if config&.indent_anchor == Config::IndentAnchor::ON_BEGIN token.offset else margin - space end print_new_line indent in Token::BreakType::INCONSISTENT if token_length > space @space = block.offset - token.offset indent = if config&.indent_anchor == Config::IndentAnchor::ON_BEGIN token.offset else margin - space end print_new_line indent else @space -= token.length write token end end end |
#handle_end ⇒ Nil
Handle End Token.
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# File 'lib/oppen/print_stack.rb', line 125 def handle_end pop end |
#handle_string(token, token_length) ⇒ Nil
Handle String Token.
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# File 'lib/oppen/print_stack.rb', line 177 def handle_string(token, token_length) @space = [0, space - token_length].max write token end |
#indent(amount) ⇒ Nil
Called Indent as well in the original paper.
Add indentation by ‘amount`.
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# File 'lib/oppen/print_stack.rb', line 246 def indent(amount) write genspace.call(amount) end |
#output ⇒ String
Returns the output of the print stack
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# File 'lib/oppen/print_stack.rb', line 65 def output buffer.string end |
#pop ⇒ PrintStackEntry
Pop a PrintStackEntry from the stack.
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# File 'lib/oppen/print_stack.rb', line 194 def pop if items.empty? raise 'Popping empty stack' end items.pop end |
#print(token, token_length) ⇒ Nil
Called Print in the original paper.
Core method responsible for building the print stack and the output string.
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# File 'lib/oppen/print_stack.rb', line 77 def print(token, token_length) case token in Token::Begin handle_begin token, token_length in Token::End handle_end in Token::Break handle_break token, token_length in Token::String handle_string token, token_length end end |
#print_new_line(amount) ⇒ Nil
Called PrintNewLine as well in the original paper.
Add a new line to the output.
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# File 'lib/oppen/print_stack.rb', line 220 def print_new_line(amount) write new_line if config&.indent_anchor == Config::IndentAnchor::ON_BEGIN @space = margin - top.offset - amount indent margin - space else indent amount end end |
#push(print_stack_entry) ⇒ Nil
Push a PrintStackEntry into the stack.
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# File 'lib/oppen/print_stack.rb', line 187 def push(print_stack_entry) items.append(print_stack_entry) end |
#top ⇒ PrintStackEntry
Get the element at the top of the stack.
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# File 'lib/oppen/print_stack.rb', line 205 def top if items.empty? raise 'Accessing empty stack' end items.last end |
#write(obj) ⇒ Nil
Write a string to the output.
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# File 'lib/oppen/print_stack.rb', line 235 def write(obj) buffer.write(obj.to_s) end |