Class: TinyBuff

Inherits:
Object
  • Object
show all
Defined in:
lib/fancy_buff.rb

Overview

a text buffer with marks, selections, and rudimentary editing

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(content = '') ⇒ TinyBuff

content: the starting content of the buffer as a String



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# File 'lib/fancy_buff.rb', line 6

def initialize(content='')
  @content = content.lines.map(&:chomp)
  @marks = {}
  @selections = {}

  @length = @content
    .map{|l| l.length }
    .sum
end

Instance Attribute Details

#length ⇒ Object (readonly)

Returns the value of attribute length.



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# File 'lib/fancy_buff.rb', line 3

def length
  @length
end

Instance Method Details

#[](line_range, max_len = nil) ⇒ Object

line_range: the Range of lines to return (NOT line indexes numbers) max_len (optional): the maximum length of each line to return; useful when you want to

return a rectangular region of text for display, for example



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# File 'lib/fancy_buff.rb', line 24

def [](line_range, max_len=nil)
  !!max_len ? @content[line_range] : @content[line_range].map{|l| l[..max_len] }
end

#delete_at(index) ⇒ Object

index: the indext of the line to delete (NOT the 1-based line number)



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# File 'lib/fancy_buff.rb', line 75

def delete_at(index)
  @length -= @content[index].length
  @content.delete_at(index)
end

#delete_range(char_range) ⇒ Object

char_range: the range of characters to remove from this TinyBuff



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# File 'lib/fancy_buff.rb', line 81

def delete_range(char_range)
  # TODO: this deletes the Range of characters, which may span multiple lines
end

#insert_line(line, index) ⇒ Object

line: the line to insert index: the index to insert it at (NOT the 1-based line number)



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# File 'lib/fancy_buff.rb', line 61

def insert_line(line, index)
  @content.insert(line, index)
  @length += line.length
end

#insert_text(str, char_num) ⇒ Object

str: the String to insert char_num: the char_num at which to start the insertion



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# File 'lib/fancy_buff.rb', line 68

def insert_text(str, char_num)
  # TODO: this is tricky because if the string contains multiple lines then
  # you're not just inserting in the middle of an existing line, you're
  # inserting some text which may include multiple lines
end

#lines ⇒ Object

returns the number of lines



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# File 'lib/fancy_buff.rb', line 17

def lines
  @content.length
end

#mark(sym, char_num) ⇒ Object

set a mark, as in the Vim sense

sym: the name of the mark char_num: the number of characters from the top of the buffer to set the

mark



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# File 'lib/fancy_buff.rb', line 42

def mark(sym, char_num)
  @marks[sym] = char_num

  nil
end

#pop ⇒ Object

deletes and returns the last line of this buffer



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# File 'lib/fancy_buff.rb', line 95

def pop
  @length -= (@content.pop).length

  nil
end

#push(line) ⇒ Object Also known as: <<

line: the line to add to the end of the buffer



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# File 'lib/fancy_buff.rb', line 86

def push(line)
  @content << line
  @length += line.length

  nil
end

#rect(col, row, wid, hgt) ⇒ Object

col: starting column (zero-based) row: starting line (zero-based) wid: the number of characters per line hgt: the number of rows



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# File 'lib/fancy_buff.rb', line 32

def rect(col, row, wid, hgt)
  @content[row..(row + hgt - 1)]
    .map{|row| row.chomp.chars[col..(col + wid - 1)].join }
end

#select(sym, char_range) ⇒ Object

selects a named range of characters

sym: the name of the range char_range: a Range representing the starting and ending byte of the

selection



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# File 'lib/fancy_buff.rb', line 53

def select(sym, char_range)
  @selections[sym] = char_range

  nil
end

#shift ⇒ Object

deletes and returns the first line of the buffer



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# File 'lib/fancy_buff.rb', line 111

def shift
  @length -= (@content.shift).length
end

#to_s ⇒ Object 



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# File 'lib/fancy_buff.rb', line 115

def to_s
  @content.join("\n")
end

#unshift(line) ⇒ Object Also known as: >>

line: the line to be added to the beginning of the buffer



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# File 'lib/fancy_buff.rb', line 102

def unshift(line)
  @content.unshift(line)
  @length += line.length

  nil
end