Current File : //opt/alt/ruby33/share/ruby/erb/compiler.rb
# frozen_string_literal: true
#--
# ERB::Compiler
#
# Compiles ERB templates into Ruby code; the compiled code produces the
# template result when evaluated. ERB::Compiler provides hooks to define how
# generated output is handled.
#
# Internally ERB does something like this to generate the code returned by
# ERB#src:
#
# compiler = ERB::Compiler.new('<>')
# compiler.pre_cmd = ["_erbout=+''"]
# compiler.put_cmd = "_erbout.<<"
# compiler.insert_cmd = "_erbout.<<"
# compiler.post_cmd = ["_erbout"]
#
# code, enc = compiler.compile("Got <%= obj %>!\n")
# puts code
#
# <i>Generates</i>:
#
# #coding:UTF-8
# _erbout=+''; _erbout.<< "Got ".freeze; _erbout.<<(( obj ).to_s); _erbout.<< "!\n".freeze; _erbout
#
# By default the output is sent to the print method. For example:
#
# compiler = ERB::Compiler.new('<>')
# code, enc = compiler.compile("Got <%= obj %>!\n")
# puts code
#
# <i>Generates</i>:
#
# #coding:UTF-8
# print "Got ".freeze; print(( obj ).to_s); print "!\n".freeze
#
# == Evaluation
#
# The compiled code can be used in any context where the names in the code
# correctly resolve. Using the last example, each of these print 'Got It!'
#
# Evaluate using a variable:
#
# obj = 'It'
# eval code
#
# Evaluate using an input:
#
# mod = Module.new
# mod.module_eval %{
# def get(obj)
# #{code}
# end
# }
# extend mod
# get('It')
#
# Evaluate using an accessor:
#
# klass = Class.new Object
# klass.class_eval %{
# attr_accessor :obj
# def initialize(obj)
# @obj = obj
# end
# def get_it
# #{code}
# end
# }
# klass.new('It').get_it
#
# Good! See also ERB#def_method, ERB#def_module, and ERB#def_class.
class ERB::Compiler # :nodoc:
class PercentLine # :nodoc:
def initialize(str)
@value = str
end
attr_reader :value
alias :to_s :value
end
class Scanner # :nodoc:
@scanner_map = {}
class << self
def register_scanner(klass, trim_mode, percent)
@scanner_map[[trim_mode, percent]] = klass
end
alias :regist_scanner :register_scanner
end
def self.default_scanner=(klass)
@default_scanner = klass
end
def self.make_scanner(src, trim_mode, percent)
klass = @scanner_map.fetch([trim_mode, percent], @default_scanner)
klass.new(src, trim_mode, percent)
end
DEFAULT_STAGS = %w(<%% <%= <%# <%).freeze
DEFAULT_ETAGS = %w(%%> %>).freeze
def initialize(src, trim_mode, percent)
@src = src
@stag = nil
@stags = DEFAULT_STAGS
@etags = DEFAULT_ETAGS
end
attr_accessor :stag
attr_reader :stags, :etags
def scan; end
end
class TrimScanner < Scanner # :nodoc:
def initialize(src, trim_mode, percent)
super
@trim_mode = trim_mode
@percent = percent
if @trim_mode == '>'
@scan_reg = /(.*?)(%>\r?\n|#{(stags + etags).join('|')}|\n|\z)/m
@scan_line = self.method(:trim_line1)
elsif @trim_mode == '<>'
@scan_reg = /(.*?)(%>\r?\n|#{(stags + etags).join('|')}|\n|\z)/m
@scan_line = self.method(:trim_line2)
elsif @trim_mode == '-'
@scan_reg = /(.*?)(^[ \t]*<%\-|<%\-|-%>\r?\n|-%>|#{(stags + etags).join('|')}|\z)/m
@scan_line = self.method(:explicit_trim_line)
else
@scan_reg = /(.*?)(#{(stags + etags).join('|')}|\n|\z)/m
@scan_line = self.method(:scan_line)
end
end
def scan(&block)
@stag = nil
if @percent
@src.each_line do |line|
percent_line(line, &block)
end
else
@scan_line.call(@src, &block)
end
nil
end
def percent_line(line, &block)
if @stag || line[0] != ?%
return @scan_line.call(line, &block)
end
line[0] = ''
if line[0] == ?%
@scan_line.call(line, &block)
else
yield(PercentLine.new(line.chomp))
end
end
def scan_line(line)
line.scan(@scan_reg) do |tokens|
tokens.each do |token|
next if token.empty?
yield(token)
end
end
end
def trim_line1(line)
line.scan(@scan_reg) do |tokens|
tokens.each do |token|
next if token.empty?
if token == "%>\n" || token == "%>\r\n"
yield('%>')
yield(:cr)
else
yield(token)
end
end
end
end
def trim_line2(line)
head = nil
line.scan(@scan_reg) do |tokens|
tokens.each do |token|
next if token.empty?
head = token unless head
if token == "%>\n" || token == "%>\r\n"
yield('%>')
if is_erb_stag?(head)
yield(:cr)
else
yield("\n")
end
head = nil
else
yield(token)
head = nil if token == "\n"
end
end
end
end
def explicit_trim_line(line)
line.scan(@scan_reg) do |tokens|
tokens.each do |token|
next if token.empty?
if @stag.nil? && /[ \t]*<%-/ =~ token
yield('<%')
elsif @stag && (token == "-%>\n" || token == "-%>\r\n")
yield('%>')
yield(:cr)
elsif @stag && token == '-%>'
yield('%>')
else
yield(token)
end
end
end
end
ERB_STAG = %w(<%= <%# <%)
def is_erb_stag?(s)
ERB_STAG.member?(s)
end
end
Scanner.default_scanner = TrimScanner
begin
require 'strscan'
rescue LoadError
else
class SimpleScanner < Scanner # :nodoc:
def scan
stag_reg = (stags == DEFAULT_STAGS) ? /(.*?)(<%[%=#]?|\z)/m : /(.*?)(#{stags.join('|')}|\z)/m
etag_reg = (etags == DEFAULT_ETAGS) ? /(.*?)(%%?>|\z)/m : /(.*?)(#{etags.join('|')}|\z)/m
scanner = StringScanner.new(@src)
while ! scanner.eos?
scanner.scan(@stag ? etag_reg : stag_reg)
yield(scanner[1])
yield(scanner[2])
end
end
end
Scanner.register_scanner(SimpleScanner, nil, false)
class ExplicitScanner < Scanner # :nodoc:
def scan
stag_reg = /(.*?)(^[ \t]*<%-|<%-|#{stags.join('|')}|\z)/m
etag_reg = /(.*?)(-%>|#{etags.join('|')}|\z)/m
scanner = StringScanner.new(@src)
while ! scanner.eos?
scanner.scan(@stag ? etag_reg : stag_reg)
yield(scanner[1])
elem = scanner[2]
if /[ \t]*<%-/ =~ elem
yield('<%')
elsif elem == '-%>'
yield('%>')
yield(:cr) if scanner.scan(/(\r?\n|\z)/)
else
yield(elem)
end
end
end
end
Scanner.register_scanner(ExplicitScanner, '-', false)
end
class Buffer # :nodoc:
def initialize(compiler, enc=nil, frozen=nil)
@compiler = compiler
@line = []
@script = +''
@script << "#coding:#{enc}\n" if enc
@script << "#frozen-string-literal:#{frozen}\n" unless frozen.nil?
@compiler.pre_cmd.each do |x|
push(x)
end
end
attr_reader :script
def push(cmd)
@line << cmd
end
def cr
@script << (@line.join('; '))
@line = []
@script << "\n"
end
def close
return unless @line
@compiler.post_cmd.each do |x|
push(x)
end
@script << (@line.join('; '))
@line = nil
end
end
def add_put_cmd(out, content)
out.push("#{@put_cmd} #{content.dump}.freeze#{"\n" * content.count("\n")}")
end
def add_insert_cmd(out, content)
out.push("#{@insert_cmd}((#{content}).to_s)")
end
# Compiles an ERB template into Ruby code. Returns an array of the code
# and encoding like ["code", Encoding].
def compile(s)
enc = s.encoding
raise ArgumentError, "#{enc} is not ASCII compatible" if enc.dummy?
s = s.b # see String#b
magic_comment = detect_magic_comment(s, enc)
out = Buffer.new(self, *magic_comment)
self.content = +''
scanner = make_scanner(s)
scanner.scan do |token|
next if token.nil?
next if token == ''
if scanner.stag.nil?
compile_stag(token, out, scanner)
else
compile_etag(token, out, scanner)
end
end
add_put_cmd(out, content) if content.size > 0
out.close
return out.script, *magic_comment
end
def compile_stag(stag, out, scanner)
case stag
when PercentLine
add_put_cmd(out, content) if content.size > 0
self.content = +''
out.push(stag.to_s)
out.cr
when :cr
out.cr
when '<%', '<%=', '<%#'
scanner.stag = stag
add_put_cmd(out, content) if content.size > 0
self.content = +''
when "\n"
content << "\n"
add_put_cmd(out, content)
self.content = +''
when '<%%'
content << '<%'
else
content << stag
end
end
def compile_etag(etag, out, scanner)
case etag
when '%>'
compile_content(scanner.stag, out)
scanner.stag = nil
self.content = +''
when '%%>'
content << '%>'
else
content << etag
end
end
def compile_content(stag, out)
case stag
when '<%'
if content[-1] == ?\n
content.chop!
out.push(content)
out.cr
else
out.push(content)
end
when '<%='
add_insert_cmd(out, content)
when '<%#'
out.push("\n" * content.count("\n")) # only adjust lineno
end
end
def prepare_trim_mode(mode) # :nodoc:
case mode
when 1
return [false, '>']
when 2
return [false, '<>']
when 0, nil
return [false, nil]
when String
unless mode.match?(/\A(%|-|>|<>){1,2}\z/)
warn_invalid_trim_mode(mode, uplevel: 5)
end
perc = mode.include?('%')
if mode.include?('-')
return [perc, '-']
elsif mode.include?('<>')
return [perc, '<>']
elsif mode.include?('>')
return [perc, '>']
else
[perc, nil]
end
else
warn_invalid_trim_mode(mode, uplevel: 5)
return [false, nil]
end
end
def make_scanner(src) # :nodoc:
Scanner.make_scanner(src, @trim_mode, @percent)
end
# Construct a new compiler using the trim_mode. See ERB::new for available
# trim modes.
def initialize(trim_mode)
@percent, @trim_mode = prepare_trim_mode(trim_mode)
@put_cmd = 'print'
@insert_cmd = @put_cmd
@pre_cmd = []
@post_cmd = []
end
attr_reader :percent, :trim_mode
# The command to handle text that ends with a newline
attr_accessor :put_cmd
# The command to handle text that is inserted prior to a newline
attr_accessor :insert_cmd
# An array of commands prepended to compiled code
attr_accessor :pre_cmd
# An array of commands appended to compiled code
attr_accessor :post_cmd
private
# A buffered text in #compile
attr_accessor :content
def detect_magic_comment(s, enc = nil)
re = @percent ? /\G(?:<%#(.*)%>|%#(.*)\n)/ : /\G<%#(.*)%>/
frozen = nil
s.scan(re) do
comment = $+
comment = $1 if comment[/-\*-\s*([^\s].*?)\s*-\*-$/]
case comment
when %r"coding\s*[=:]\s*([[:alnum:]\-_]+)"
enc = Encoding.find($1.sub(/-(?:mac|dos|unix)/i, ''))
when %r"frozen[-_]string[-_]literal\s*:\s*([[:alnum:]]+)"
frozen = $1
end
end
return enc, frozen
end
def warn_invalid_trim_mode(mode, uplevel:)
warn "Invalid ERB trim mode: #{mode.inspect} (trim_mode: nil, 0, 1, 2, or String composed of '%' and/or '-', '>', '<>')", uplevel: uplevel + 1
end
end
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