# Mythryl-Yacc Parser Generator (c) 1989 Andrew W. Appel, David R. Tarditi
# Compiled by:
# src/app/yacc/src/mythryl-yacc.lib### "Laughter without a tinge of philosophy
### is but a sneeze of humor.
###
### "Genuine humor is replete with wisdom."
###
### -- Mark Twain,
### quoted in Mark Twain and I,
### Opie Read
generic package print_package_g (
package lr_table: Lr_Table; # Lr_Table is from src/app/yacc/lib/base.api package shrink_lr_table: Shrink_Lr_Table; # Shrink_Lr_Table is from src/app/yacc/src/shrink-lr-table.api sharing lr_table == shrink_lr_table::lr_table;
)
: (weak) Print_Package # Print_Package is from src/app/yacc/src/print-package.api{
include package rw_vector;
include package list;
infix my 9 sub;
package lr_table = lr_table;
include package shrink_lr_table;
include package lr_table;
# line_length = approximately the largest number of characters to allow
# on a line when printing out an encode string
line_length = 72;
# max_length = length of a table entry. All table entries are encoded
# using two 16-bit integers, one for the terminal number and the other
# for the entry. Each integer is printed as two characters (low byte,
# high byte), using the ML ascii escape sequence. We need 4
# characters for each escape sequence and 16 characters for each entry
max_length = 16;
# number of entries we can fit on a row
entry_count = line_length / max_length;
# convert integer between 0 and 255 to the three character ascii
# decimal escape sequence for it
stipulate
lookup = rw_vector::make_rw_vector (256, "\x00");
# fun int_to_string i
# =
# if (i >= 100) "\\" + (int::to_string i);
# elif (i >= 10) "\\0" + (int::to_string i);
# else "\\00" + (int::to_string i);
# fi;
fun int_to_string i
=
sprintf "\\x%02x" i;
fun loop n
=
if (n !=256)
rw_vector::set (lookup, n, int_to_string n);
loop (n+1);
fi;
my _ = loop 0;
herein
fun chr i
=
lookup[ i ];
end;
fun make_package { table, name, print, verbose }
=
entries
where
states = state_count table;
rules = rule_count table;
fun print_pair_list (print_start: (X, Y) -> Void) l
=
f (l, 0)
where
fun f (EMPTY, _) => ();
f (PAIR (a, b, r), count)
=>
if (count >= entry_count)
#
print "\\\n\\"; print_start (a, b); f (r, 1);
else
print_start (a, b); f (r, (count+1));
fi;
end;
end;
fun print_list print_start l
=
f (l, 0)
where
fun f (NIL, _)
=>
();
f (a ! r, count)
=>
if (count >= entry_count)
#
print "\\\n\\";
print_start a;
f (r, 1);
else
print_start a;
f (r, count+1);
fi;
end;
end;
fun print_finish _
=
print "\\x00\\x00\\\n\\";
fun print_pair_row print_start
=
\\ entrylist
=
{ print_entries entrylist;
print_finish();
}
where
print_entries
=
print_pair_list print_start;
end;
fun print_pair_row_with_default (print_start, pr_default)
=
{ f = print_pair_row print_start;
\\ (l, default)
=
{ pr_default default;
f l;
};
};
fun print_table (print_row, count)
=
{ print "\"\\\n\\";
f 0
where
fun f i
=
if (i != count)
print_row i;
f (i+1);
fi;
end;
print "\";\n";
};
print_char
=
print o chr;
# Print an integer between 0 and 2^16-1 as a
# 2-byte character, with the low byte first:
#
fun print_int i
=
{ print_char (i % 256);
print_char (i / 256);
};
# encode actions as integers:
#
# ACCEPT => 0
# ERROR => 1
# SHIFT i => 2 + i
# REDUCE rulenum => numstates+2+rulenum
fun print_action (REDUCE rulenum) => print_int (rulenum+states+2);
print_action (SHIFT (STATE i)) => print_int (i+2);
print_action ACCEPT => print_int 0;
print_action ERROR => print_int 1;
end;
fun print_terminal_action (TERM t, action)
=
{ print_int (t+1);
print_action action;
};
fun print_goto (NONTERM n, STATE s)
=
{ print_int (n+1);
print_int s;
};
my ((row_count, row_numbers, action_rows), entries)
=
shrink_action_list (table, verbose);
stipulate
a = rw_vector::from_list action_rows;
herein
fun get_action_row i
=
a[ i ];
end;
fun print_goto_row i
=
f (g (STATE i))
where
f = print_pair_row print_goto;
g = describe_goto table;
end;
fun print_action_row i
=
f (get_action_row i)
where
f = print_pair_row_with_default
( print_terminal_action,
print_action
);
end;
print "my ";
print name;
print "=";
print "{ action_rows =\n";
print_table (print_action_row, row_count);
print " action_row_numbers =\n\"";
print_list (\\ i => print_int i; end ) row_numbers;
print "\";\n";
print " goto_table =\n";
print_table (print_goto_row, states);
print " numstates = ";
print (int::to_string states);
print ";\n numrules = ";
print (int::to_string rules);
print ";\n\
\ s = REF \"\"; index = REF 0;\n\
\ string_to_int = \\\\ () = \n\
\ { i = *index;\n\
\ index := i+2;\n\
\ string::get_byte(*s, i) + string::get_byte(*s, i+1) * 256;\n\
\ };\n\
\\n\
\ string_to_list = \\\\ s' =\n\
\ { len = string::length_in_bytes s';\n\
\ fun f () =\n\
\ if (*index < len)\n\
\ string_to_int() ! f();\n\
\ else NIL; fi;\n\
\ index := 0;\n\
\ s := s';\n\
\ f ();\n\
\ };\n\
\\n\
\ string_to_pairlist = \\\\ (conv_key, conv_entry) = f\n\
\ where \n\
\ fun f ()\n\
\ =\n\
\ case (string_to_int ())\n\
\ 0 => EMPTY;\n\
\ n => PAIR (conv_key (n - 1), conv_entry (string_to_int()), f());\n\
\ esac;\n\
\ end;\n\
\\n\
\ string_to_pairlist_default = \\\\ (conv_key, conv_entry) =\n\
\ { conv_row = string_to_pairlist (conv_key, conv_entry);\n\
\ \\\\ () =\n\
\ { default = conv_entry (string_to_int());\n\
\ row = conv_row();\n\
\ (row, default);\n\
\ };\n\
\ };\n\
\\n\
\ string_to_table = \\\\ (convert_row, s') =\n\
\ { len = string::length_in_bytes s';\n\
\ fun f ()\n\
\ =\n\
\ if (*index < len)\n\
\ convert_row() ! f();\n\
\ else NIL; fi;\n\
\ s := s';\n\
\ index := 0;\n\
\ f ();\n\
\ };\n\
\\n\
\stipulate\n\
\ memo = rw_vector::make_rw_vector (numstates+numrules, ERROR);\n\
\ my _ ={ fun g i\n\
\ =\n\
\ { rw_vector::set (memo, i, REDUCE (i-numstates));\n\
\ g (i+1);\n\
\ };\n\
\\n\
\ fun f i\n\
\ =\n\
\ if (i == numstates)\n\
\ g i;\n\
\ else rw_vector::set (memo, i, SHIFT (STATE i));\n\
\ f (i+1);\n\
\ fi;\n\
\\n\
\ f 0\n\
\ except\n\
\ INDEX_OUT_OF_BOUNDS = ();\n\
\ };\n\
\herein\n\
\ entry_to_action\n\
\ =\n\
\ \\\\ 0 => ACCEPT;\n\
\ 1 => ERROR;\n\
\ j => rw_vector::get (memo, (j - 2));\n\
\ end;\n\
\end;\n\
\\n\
\ goto_table = rw_vector::from_list (string_to_table (string_to_pairlist (NONTERM, STATE), goto_table));\n\
\ action_rows = string_to_table (string_to_pairlist_default (TERM, entry_to_action), action_rows);\n\
\ action_row_numbers = string_to_list action_row_numbers;\n\
\ action_table\n\
\ =\n\
\ { action_row_lookup\n\
\ =\n\
\ { a=rw_vector::from_list (action_rows);\n\
\\n\
\ \\\\ i = rw_vector::get (a, i);\n\
\ };\n\
\\n\
\ rw_vector::from_list (map action_row_lookup action_row_numbers);\n\
\ };\n\
\\n\
\ lr_table::make_lr_table {\n\
\ actions => action_table,\n\
\ gotos => goto_table,\n\
\ rule_count => numrules,\n\
\ state_count => numstates,\n\
\ initial_state => STATE ";
print (int::to_string ((\\ (STATE i) = i) (initial_state table)));
print " };\n\
\};\n";
end; # fun make_package
};