Sode.tmp.rb

 code between #DJDSTOP & #DJDSTART commented out by djdpre.rb (for ease in converting from unicon)
 this code was developed to test priority code

DJDSTOP

 def read_eq_db
   eq_db =  File.new("db","r")
   line = eq_db.gets
   while line do
     line = line.chomp
     if line =~ $lhs_re then
       lhs = $&
       rest = $'
     else
       puts "error in dependancies 1"
       $stderr.puts "error in dependencies 1"
       exit 1
     end
     if rest =~ $skip_re then
       rest = $'
     else
       puts "error in dependancies 2"
       $stderr.puts "error in dependencies 2"
       exit 1
     end
     if rest =~ $degree_re then
       degree = $&.to_i
       rest = $'
     else
       puts "error in dependancies 1"
       $stderr.puts "error in dependencies 1"
       exit 1
     end
     $eq_dep_data[lhs] = Eq_dep_rec.new(degree)

     while rest =~ $skip_re do
       $no_eqs += 1
       rest = $'
       if rest =~ $rhs_re then
         rhs = $&
         rest = $'
       else
         puts "error in dependancies 1"
         $stderr.puts "error in dependencies 1"
         exit 1
       end
       if rest =~ $skip_re then
         rest = $'
       else
         puts "error in dependancies 2"
         $stderr.puts "error in dependencies 2"
         exit 1
       end
       if rest =~ $degree_re then
         degree = $&.to_i
         rest = $'
       else
         puts "error in dependancies 1"
         $stderr.puts "error in dependencies 1"
         exit 1
       end
       if degree > $eq_dep_data[lhs].rhs_dat_val(rhs) then
         $eq_dep_data[lhs].rhs_dat_put(rhs,degree)
       end
     end

     line = eq_db.gets
   end
 end

 #DJDSTART

for details about emitted code see dennisdarland.com/cs/Chang/index.html

DJDSTOP

 def emit_pre_Si,operand)
 i
 no_a1
 no_a2
 no_a3
 no_a1 = no + "_a1"
 no_a2 = no + "_a2"
 no_a3 = no + "_a3"
 $sym_tbl[no_a1] = Sym_tbl_entry.new(IDENTIFIER,no_a1)
 $sym_tbl[no_a2] = Sym_tbl_entry.new(IDENTIFIER,no_a2)
 $sym_tbl[no_a3] = Sym_tbl_entry.new(IDENTIFIER,no_a3)

 i = 1
 while i <= $min_hdrs do
 if (j == 1) then
     $outhdr[1].puts no,"[1] = ",EVALF,"(Si(", operand,"[1]))"
     $outhdr[1].puts no_a1,"[1] = ",EVALF,"(ap_sin(",operand, "[1]))"
     $outhdr[1].puts no_a2,"[1] = ",EVALF,"(ap_cos(",operand, "[1]))"
     $outhdr[1].puts no_a3,"[1] = ",no_a1,"[1]  /", operand,"[1]"
 end
 else
     $outhdr[i].puts no_a1,"[",i,"] = (ATT(",i-1,",",no_a2,",",operand,",1))"
     $outhdr[i].puts no_a2,"[",i,"] = - ATT(",i-1,",",no_a1,",",operand,",1)"
     $outhdr[i].puts no_a3,"[",i,"] = ",EVALF,"((", no_a1,"[",i,"] - ATS(",i,",",operand,",",no_a3,",2))/",operand,"[1])"
     $outhdr[i].puts no,"[",i,"] = ATT(",i-1,",",no_a3,",",operand,",1)"

 end
 i += 1
 end
 return
 end
 def emit_Si(no,operand)
 no_a1
 no_a2
 no_a3
 no_a1 = no + "_a1"
 no_a2 = no + "_a2"
 no_a3 = no + "_a3"
     $outfile4.puts no_a1,"[k] = (ATT(k-1,",no_a2,",",operand,",1))"
     $outfile4.puts no_a2,"[k] = - ATT(k-1,",no_a1,",",operand,",1)"
     $outfile4.puts no_a3,"[k] = ",EVALF,"((", no_a1,"[k] - ATS(k,",operand,",",no_a3,",2))/",operand,"[1])"
     $outfile4.puts no,"[k] = ATT(k-1,",no_a3,",",operand,",1)"

 return
 end
 #----------------------------------------------------------
 #DJDSTART

get next token

lexical analysis and parsing derived in part from _Compilers - Principles, Techniques, and Tools_ by Alfred V. Aho, Ravi Sethi, Jeffery D. Ullman especially pages 74-78, and _Principles of Compiler Design_ by Alfred V. Aho, Jeffery D. Ullman

1. 181

lexical box determine tokens

parse

scan to determine priorities

DJDSTOP

 #main to test priority code
 #start main
 $eq_dep_data = Hash.new(0)
 $lhs_re = Regexp.new("^[a-zA-z]+[a-zA-Z0-9]*")
 $rhs_re = Regexp.new("^[a-zA-z]+[a-zA-Z0-9]*")
 $degree_re = Regexp.new("^[0-9]*")
 $skip_re = Regexp.new("^,")
 $no_eqs = 0
 read_eq_db
 echo_eq_db
 determine_priority
 echo_eq_db

 #DJDSTART