Add line wrapping to grammar output for documentation

diff --git a/scripts/auxiliar/yyout2grammar.py b/scripts/auxiliar/yyout2grammar.py
index 25b6f25a06520bf4710e610712481cada45c84a3..557db4f967de6fb22534121f6064f03e64a6beca 100755 (executable)
--- a/scripts/auxiliar/yyout2grammar.py
+++ b/scripts/auxiliar/yyout2grammar.py
@@ -1,14 +1,21 @@
 #! /usr/bin/env python
-
+#
+#  yyout2grammar.py
+#
+#  Auxiliary script of the GNU LilyPond music engraver
+#
 #  Convert from bison output file parser.output to
 #  Grammar and index.
 #  Drops all of the state information.
 #  Converts \\ to \
-#  Eliminates the @ variables created when {} is placed in the middle of a rule##  all of the c-code stuff
-#
+#  Eliminates the @ variables created when {} is placed
+#        in the middle of a rule
+#  Eliminates all of the c-code stuff
+#  Wraps lines that are longer than 78 characters for improved
+#        formatting
 #
 #  Copyright 2005 by Carl D. Sorensen
-#
+#  Licensed under the GPL, version 2 or any later version
 
 # to create input file, run
 #   bison -v parser.yy
@@ -22,12 +29,46 @@ import re
 
 atre = re.compile('(@\d+):')
 
+intro_re = re.compile (r'(.*[:|])\s')
+keyword_re = re.compile (r'(\S+)\s')
+
+# strip extra backslashes that are inserted by the python
+# string handling routines
+def strip_backslash(input_string):
+    i=input_string.find(r'"\\')
+    while i > -1 :
+        input_string = input_string[:i+1]+input_string[i+2:]
+        i = input_string.find(r'"\\')
+    return  input_string
+
+#  write an output line, adjusting to make sure that max_line_length
+#  is not exceeded
+def write_line (output_line, output_file):
+    max_line_length = 78
+    indent_value = 3
+    if len(output_line) > max_line_length:
+        intro = intro_re.match(output_line)
+        if intro:
+            output_file.write(intro.group(1)+" ")
+            indent_column = len(intro.group(1))
+            output_line = output_line[indent_column:]
+            keyword = keyword_re.search(output_line)
+            while keyword:
+                output_file.write(strip_backslash(keyword.group(1))+" \n")
+                output_line = output_line[keyword.end(1):]
+                keyword = keyword_re.search(output_line)
+                if keyword:
+                    output_file.write("".rjust(indent_column + indent_value))
+    else:
+        output_file.write(strip_backslash(output_line))
+    return
+
 write_me = True
 
 if len(sys.argv)!=3:
     print "Usage: yyout2grammar.py parser_output_file grammar_file."
 else:
-    in_name = sys.argv[1] 
+    in_name = sys.argv[1]
     out_name = sys.argv[2]
 
     print "input file name",in_name
@@ -37,10 +78,14 @@ else:
 
     at_items=[]
     inline = in_file.readline()
+
+    ## skip header material from file
     while inline != '' and not(inline.startswith("Grammar")):
         inline = in_file.readline()
+
+    ## process the Grammar lines
     if inline != '':
-        out_file.write(inline)
+        write_line(inline, out_file)
         inline = in_file.readline()
         while inline != '' and not(inline.startswith("Terminals")):
             i = inline.find("$accept:")
@@ -50,27 +95,26 @@ else:
             atfound = re.findall(atre,inline)
             if len(atfound) > 0:
                 at_items.extend(atfound)
-                print at_items
+                #  print at_items
                 write_me = False
                 inline=in_file.readline()
             else:
                 for at_item in at_items:
                     i=inline.find(at_item)
+                    ## remove @ item
                     if i >= 0:
                         inline=inline[:i] + inline[i+len(at_item):]
-                    i=inline.find('"\\\\')
-                    while i > -1 :
-                        inline = inline[:i+1]+inline[i+2:]
-                        i = inline.find('"\\\\')
+
             if write_me:
-                out_file.write(inline)
+                write_line(inline, out_file)
             inline = in_file.readline()
             write_me = True
     index_items = []
+
     #  Write the Terminals header line and the following blank line
-    out_file.write(inline)
+    write_line(inline, out_file)
     inline = in_file.readline()
-    out_file.write(inline)
+    write_line(inline, out_file)
     inline = in_file.readline()
     while inline != '' and not(inline.startswith("Nonterminals")):
         i=inline.find('"\\\\')
@@ -81,12 +125,13 @@ else:
         inline = in_file.readline()
     index_items.sort(lambda x,y:cmp(x.lower(),y.lower()))
     for index_item in index_items:
-        out_file.write(index_item)
-    out_file.write('\n')
+        write_line (index_item, out_file)
+    write_line ('\n', out_file)
+
     # Write the Nonterminals header and the blank line
-    out_file.write(inline)
+    write_line(inline, out_file)
     inline = in_file.readline()
-    out_file.write(inline)
+    write_line(inline, out_file)
     index_items = []
     index_item=in_file.readline()
     inline=in_file.readline()
@@ -101,4 +146,4 @@ else:
         inline=in_file.readline()
     index_items.sort(lambda x,y:cmp(x.lower(),y.lower()))
     for index_item in index_items:
-        out_file.write(index_item)
+        write_line (index_item, out_file)