zclsyntax: identifiers in the scanner

zcl/zclsyntax/generate.go

@@ -1,5 +1,6 @@
 package zclsyntax
 
 //go:generate go run expression_vars_gen.go
+//go:generate ruby unicode2ragel.rb --url=http://www.unicode.org/Public/9.0.0/ucd/DerivedCoreProperties.txt -m UnicodeDerived -p ID_Start,ID_Continue -o unicode_derived.rl
 //go:generate ragel -Z scan_tokens.rl
 //go:generate gofmt -w scan_tokens.go

zcl/zclsyntax/scan_tokens.rl

@@ -20,6 +20,7 @@ func scanTokens(data []byte, filename string, start zcl.Pos) []Token {
     }
 
     %%{
+        include UnicodeDerived "unicode_derived.rl";
 
         UTF8Cont = 0x80 .. 0xBF;
         AnyUTF8 = (
@@ -31,6 +32,7 @@ func scanTokens(data []byte, filename string, start zcl.Pos) []Token {
         BrokenUTF8 = any - AnyUTF8;
 
         NumberLit = digit (digit|'.'|('e'|'E') ('+'|'-')? digit)*;
+        Ident = ID_Start ID_Continue*;
 
         # Tabs are not valid, but we accept them in the scanner and mark them
         # as tokens so that we can produce diagnostics advising the user to
@@ -42,6 +44,7 @@ func scanTokens(data []byte, filename string, start zcl.Pos) []Token {
         main := |*
             Spaces           => {};
             NumberLit        => { token(TokenNumberLit) };
+            Ident            => { token(TokenIdent) };
             Tabs             => { token(TokenTabs) };
             AnyUTF8          => { token(TokenInvalid) };
             BrokenUTF8       => { token(TokenBadUTF8) };

zcl/zclsyntax/scan_tokens_test.go

@@ -148,6 +148,71 @@ func TestScanTokens(t *testing.T) {
 			},
 		},
 
+		// TokenIdent
+		{
+			`hello`,
+			[]Token{
+				{
+					Type:  TokenIdent,
+					Bytes: []byte(`hello`),
+					Range: zcl.Range{
+						Start: zcl.Pos{Byte: 0, Line: 1, Column: 1},
+						End:   zcl.Pos{Byte: 5, Line: 1, Column: 6},
+					},
+				},
+				{
+					Type:  TokenEOF,
+					Bytes: []byte{},
+					Range: zcl.Range{
+						Start: zcl.Pos{Byte: 5, Line: 1, Column: 6},
+						End:   zcl.Pos{Byte: 5, Line: 1, Column: 6},
+					},
+				},
+			},
+		},
+		{
+			`h3ll0`,
+			[]Token{
+				{
+					Type:  TokenIdent,
+					Bytes: []byte(`h3ll0`),
+					Range: zcl.Range{
+						Start: zcl.Pos{Byte: 0, Line: 1, Column: 1},
+						End:   zcl.Pos{Byte: 5, Line: 1, Column: 6},
+					},
+				},
+				{
+					Type:  TokenEOF,
+					Bytes: []byte{},
+					Range: zcl.Range{
+						Start: zcl.Pos{Byte: 5, Line: 1, Column: 6},
+						End:   zcl.Pos{Byte: 5, Line: 1, Column: 6},
+					},
+				},
+			},
+		},
+		{
+			`héllo`, // combining acute accent
+			[]Token{
+				{
+					Type:  TokenIdent,
+					Bytes: []byte(`héllo`),
+					Range: zcl.Range{
+						Start: zcl.Pos{Byte: 0, Line: 1, Column: 1},
+						End:   zcl.Pos{Byte: 7, Line: 1, Column: 6},
+					},
+				},
+				{
+					Type:  TokenEOF,
+					Bytes: []byte{},
+					Range: zcl.Range{
+						Start: zcl.Pos{Byte: 7, Line: 1, Column: 6},
+						End:   zcl.Pos{Byte: 7, Line: 1, Column: 6},
+					},
+				},
+			},
+		},
+
 		// Invalid things
 		{
 			`|`,

zcl/zclsyntax/unicode2ragel.rb

@@ -0,0 +1,335 @@
+#!/usr/bin/env ruby
+#
+# This scripted has been updated to accept more command-line arguments:
+#
+#    -u, --url                        URL to process
+#    -m, --machine                    Machine name
+#    -p, --properties                 Properties to add to the machine
+#    -o, --output                     Write output to file
+#
+# Updated by: Marty Schoch <marty.schoch@gmail.com>
+# 
+# This script uses the unicode spec to generate a Ragel state machine
+# that recognizes unicode alphanumeric characters.  It generates 5
+# character classes: uupper, ulower, ualpha, udigit, and ualnum.
+# Currently supported encodings are UTF-8 [default] and UCS-4.
+#
+# Usage: unicode2ragel.rb [options]
+#    -e, --encoding [ucs4 | utf8]     Data encoding
+#    -h, --help                       Show this message
+#
+# This script was originally written as part of the Ferret search
+# engine library.
+#
+# Author: Rakan El-Khalil <rakan@well.com>
+
+require 'optparse'
+require 'open-uri'
+
+ENCODINGS = [ :utf8, :ucs4 ]
+ALPHTYPES = { :utf8 => "byte", :ucs4 => "rune" }
+DEFAULT_CHART_URL = "http://www.unicode.org/Public/5.1.0/ucd/DerivedCoreProperties.txt"
+DEFAULT_MACHINE_NAME= "WChar"
+
+###
+# Display vars & default option
+
+TOTAL_WIDTH = 80
+RANGE_WIDTH = 23
+@encoding = :utf8
+@chart_url = DEFAULT_CHART_URL
+machine_name = DEFAULT_MACHINE_NAME
+properties = []
+@output = $stdout
+
+###
+# Option parsing
+
+cli_opts = OptionParser.new do |opts|
+  opts.on("-e", "--encoding [ucs4 | utf8]", "Data encoding") do |o|
+    @encoding = o.downcase.to_sym
+  end
+  opts.on("-h", "--help", "Show this message") do
+    puts opts
+    exit
+  end
+  opts.on("-u", "--url URL", "URL to process") do |o|
+    @chart_url = o 
+  end
+  opts.on("-m", "--machine MACHINE_NAME", "Machine name") do |o|
+    machine_name = o
+  end
+  opts.on("-p", "--properties x,y,z", Array, "Properties to add to machine") do |o|
+    properties = o
+  end
+  opts.on("-o", "--output FILE", "output file") do |o|
+    @output = File.new(o, "w+")
+  end
+end
+
+cli_opts.parse(ARGV)
+unless ENCODINGS.member? @encoding
+  puts "Invalid encoding: #{@encoding}"
+  puts cli_opts
+  exit
+end
+
+##
+# Downloads the document at url and yields every alpha line's hex
+# range and description.
+
+def each_alpha( url, property ) 
+  open( url ) do |file|
+    file.each_line do |line|
+      next if line =~ /^#/;
+      next if line !~ /; #{property} #/;
+
+      range, description = line.split(/;/)
+      range.strip!
+      description.gsub!(/.*#/, '').strip!
+
+      if range =~ /\.\./
+           start, stop = range.split '..'
+      else start = stop = range
+      end
+
+      yield start.hex .. stop.hex, description
+    end
+  end
+end
+
+###
+# Formats to hex at minimum width
+
+def to_hex( n )
+  r = "%0X" % n
+  r = "0#{r}" unless (r.length % 2).zero?
+  r
+end
+
+###
+# UCS4 is just a straight hex conversion of the unicode codepoint.
+
+def to_ucs4( range )
+  rangestr  =   "0x" + to_hex(range.begin)
+  rangestr << "..0x" + to_hex(range.end) if range.begin != range.end
+  [ rangestr ]
+end
+
+##
+# 0x00     - 0x7f     -> 0zzzzzzz[7]
+# 0x80     - 0x7ff    -> 110yyyyy[5] 10zzzzzz[6]
+# 0x800    - 0xffff   -> 1110xxxx[4] 10yyyyyy[6] 10zzzzzz[6]
+# 0x010000 - 0x10ffff -> 11110www[3] 10xxxxxx[6] 10yyyyyy[6] 10zzzzzz[6] 
+
+UTF8_BOUNDARIES = [0x7f, 0x7ff, 0xffff, 0x10ffff]
+
+def to_utf8_enc( n )
+  r = 0
+  if n <= 0x7f
+    r = n
+  elsif n <= 0x7ff
+    y = 0xc0 | (n >> 6)
+    z = 0x80 | (n & 0x3f)
+    r = y << 8 | z
+  elsif n <= 0xffff
+    x = 0xe0 | (n >> 12)
+    y = 0x80 | (n >>  6) & 0x3f
+    z = 0x80 |  n        & 0x3f
+    r = x << 16 | y << 8 | z
+  elsif n <= 0x10ffff
+    w = 0xf0 | (n >> 18)
+    x = 0x80 | (n >> 12) & 0x3f
+    y = 0x80 | (n >>  6) & 0x3f
+    z = 0x80 |  n        & 0x3f
+    r = w << 24 | x << 16 | y << 8 | z
+  end
+
+  to_hex(r)
+end
+
+def from_utf8_enc( n )
+  n = n.hex
+  r = 0
+  if n <= 0x7f
+    r = n
+  elsif n <= 0xdfff
+    y = (n >> 8) & 0x1f
+    z =  n       & 0x3f
+    r = y << 6 | z
+  elsif n <= 0xefffff
+    x = (n >> 16) & 0x0f
+    y = (n >>  8) & 0x3f
+    z =  n        & 0x3f
+    r = x << 10 | y << 6 | z
+  elsif n <= 0xf7ffffff
+    w = (n >> 24) & 0x07
+    x = (n >> 16) & 0x3f
+    y = (n >>  8) & 0x3f
+    z =  n        & 0x3f
+    r = w << 18 | x << 12 | y << 6 | z
+  end
+  r
+end
+
+###
+# Given a range, splits it up into ranges that can be continuously
+# encoded into utf8.  Eg: 0x00 .. 0xff => [0x00..0x7f, 0x80..0xff]
+# This is not strictly needed since the current [5.1] unicode standard
+# doesn't have ranges that straddle utf8 boundaries.  This is included
+# for completeness as there is no telling if that will ever change.
+
+def utf8_ranges( range )
+  ranges = []
+  UTF8_BOUNDARIES.each do |max|
+    if range.begin <= max
+      if range.end <= max
+        ranges << range
+        return ranges
+      end
+
+      ranges << (range.begin .. max)
+      range = (max + 1) .. range.end
+    end
+  end
+  ranges
+end
+
+def build_range( start, stop )
+  size = start.size/2
+  left = size - 1
+  return [""] if size < 1
+
+  a = start[0..1]
+  b = stop[0..1]
+
+  ###
+  # Shared prefix
+
+  if a == b
+    return build_range(start[2..-1], stop[2..-1]).map do |elt|
+      "0x#{a} " + elt
+    end
+  end
+
+  ###
+  # Unshared prefix, end of run
+
+  return ["0x#{a}..0x#{b} "] if left.zero?
+  
+  ###
+  # Unshared prefix, not end of run
+  # Range can be 0x123456..0x56789A
+  # Which is equivalent to:
+  #     0x123456 .. 0x12FFFF
+  #     0x130000 .. 0x55FFFF
+  #     0x560000 .. 0x56789A
+
+  ret = []
+  ret << build_range(start, a + "FF" * left)
+
+  ###
+  # Only generate middle range if need be.
+
+  if a.hex+1 != b.hex
+    max = to_hex(b.hex - 1)
+    max = "FF" if b == "FF"
+    ret << "0x#{to_hex(a.hex+1)}..0x#{max} " + "0x00..0xFF " * left
+  end
+
+  ###
+  # Don't generate last range if it is covered by first range
+  
+  ret << build_range(b + "00" * left, stop) unless b == "FF"
+  ret.flatten!
+end
+
+def to_utf8( range )
+  utf8_ranges( range ).map do |r|   
+    begin_enc = to_utf8_enc(r.begin)
+    end_enc = to_utf8_enc(r.end)
+    build_range begin_enc, end_enc
+  end.flatten!
+end
+
+##
+# Perform a 3-way comparison of the number of codepoints advertised by
+# the unicode spec for the given range, the originally parsed range,
+# and the resulting utf8 encoded range.
+
+def count_codepoints( code )
+  code.split(' ').inject(1) do |acc, elt|
+    if elt =~ /0x(.+)\.\.0x(.+)/
+      if @encoding == :utf8
+        acc * (from_utf8_enc($2) - from_utf8_enc($1) + 1)
+      else
+        acc * ($2.hex - $1.hex + 1)
+      end
+    else
+      acc
+    end
+  end
+end
+
+def is_valid?( range, desc, codes )
+  spec_count  = 1
+  spec_count  = $1.to_i if desc =~ /\[(\d+)\]/
+  range_count = range.end - range.begin + 1
+
+  sum = codes.inject(0) { |acc, elt| acc + count_codepoints(elt) }
+  sum == spec_count and sum == range_count
+end
+
+##
+# Generate the state maching to stdout
+
+def generate_machine( name, property )
+  pipe = " "
+  @output.puts "    #{name} = "
+  each_alpha( @chart_url, property ) do |range, desc|
+
+    codes = (@encoding == :ucs4) ? to_ucs4(range) : to_utf8(range)
+
+    #raise "Invalid encoding of range #{range}: #{codes.inspect}" unless 
+    #  is_valid? range, desc, codes
+
+    range_width = codes.map { |a| a.size }.max
+    range_width = RANGE_WIDTH if range_width < RANGE_WIDTH
+
+    desc_width  = TOTAL_WIDTH - RANGE_WIDTH - 11
+    desc_width -= (range_width - RANGE_WIDTH) if range_width > RANGE_WIDTH
+
+    if desc.size > desc_width
+      desc = desc[0..desc_width - 4] + "..."
+    end
+
+    codes.each_with_index do |r, idx|
+      desc = "" unless idx.zero?
+      code = "%-#{range_width}s" % r
+      @output.puts "      #{pipe} #{code} ##{desc}"
+      pipe = "|"
+    end
+  end
+  @output.puts "      ;"
+  @output.puts ""
+end
+
+@output.puts <<EOF
+# The following Ragel file was autogenerated with #{$0} 
+# from: #{@chart_url}
+#
+# It defines #{properties}.
+#
+# To use this, make sure that your alphtype is set to #{ALPHTYPES[@encoding]},
+# and that your input is in #{@encoding}.
+
+%%{
+    machine #{machine_name};
+    
+EOF
+
+properties.each { |x| generate_machine( x, x ) }
+
+@output.puts <<EOF
+}%%
+EOF