# Mythryl-Yacc Parser Generator (c) 1989 Andrew W. Appel, David R. Tarditi
# Compiled by:
# src/app/yacc/src/mythryl-yacc.lib### "First secure an independent income,
### then practice virtue."
###
### -- Greek saying
package grammar
: (weak) Grammar # Grammar is from src/app/yacc/src/grammar.api{
# define types term and nonterm using those in lr_table
# Term = TERM of Int
# Nonterm = NONTERM of Int
include package lr_table;
Symbol = TERMINAL Terminal
| NONTERMINAL Nonterminal;
Grammar = GRAMMAR
{ rules: List {
lhs: Nonterminal,
rhs: List( Symbol ),
precedence: Null_Or( Int ),
rulenum: Int },
noshift: List( Terminal ),
eop: List( Terminal ),
terms: Int,
nonterms: Int,
start: Nonterminal,
precedence: Terminal -> Null_Or( Int ),
term_to_string: Terminal -> String,
nonterm_to_string: Nonterminal -> String };
};
package internal_grammar
: (weak) Internal_Grammar # Internal_Grammar is from src/app/yacc/src/internal-grammar.api{
package grammar = grammar;
include package grammar;
Rule = RULE
{ lhs: Nonterminal,
rhs: List( Symbol ),
num: Int,# internal # Assigned by coreutils
rulenum: Int,
precedence: Null_Or( Int ) };
my eq_term: (Terminal, Terminal) -> Bool = (==);
my gt_term: (Terminal, Terminal) -> Bool = \\ (TERM i, TERM j) => i>j; end ;
my eq_nonterm: (Nonterminal, Nonterminal) -> Bool
= (==);
my gt_nonterm: (Nonterminal, Nonterminal) -> Bool
= \\ (NONTERM i, NONTERM j) = i>j;
my eq_symbol: (Symbol, Symbol) -> Bool
= (==);
fun gt_symbol ( TERMINAL (TERM i), TERMINAL (TERM j)) => i > j;
gt_symbol (NONTERMINAL (NONTERM i), NONTERMINAL (NONTERM j)) => i > j;
gt_symbol ( TERMINAL _, NONTERMINAL _ ) => FALSE;
gt_symbol (NONTERMINAL _, TERMINAL _ ) => TRUE;
end;
package symbol_assoc
=
table_g (
package {
Key = Symbol;
gt = gt_symbol;
}
);
package nonterm_assoc
=
table_g (
package {
Key = Nonterminal;
gt = gt_nonterm;
}
);
debug = FALSE;
fun pr_rule (a as symbol_to_string, nonterm_to_string, print)
=
{ print_symbol = print o symbol_to_string;
fun print_rhs (h ! t)
=>
{ print_symbol h;
print " ";
print_rhs t;
};
print_rhs NIL
=>
();
end;
\\ (RULE { lhs, rhs, num, rulenum, precedence, ... } )
=>
{ (print o nonterm_to_string) lhs;
print " : ";
print_rhs rhs;
if debug
print " num = ";
print (int::to_string num);
print " rulenum = ";
print (int::to_string rulenum);
print " precedence = ";
case precedence
NULL => print " none";
THE i => print (int::to_string i);
esac;
();
fi;
}; end ;
};
fun pr_grammar (a as (symbol_to_string, nonterm_to_string, print))
(GRAMMAR { rules, terms, nonterms, start, ... } )
=
{ stipulate
pr_rule = pr_rule a;
herein
fun print_rule { lhs, rhs, precedence, rulenum }
=
{ pr_rule (RULE { lhs, rhs, num=>0,
rulenum, precedence } );
print "\n";
};
end;
print "grammar = \n";
list::apply print_rule rules;
print "\n";
print (" terms = " + (int::to_string terms) +
" nonterms = " + (int::to_string nonterms) +
" start = ");
(print o nonterm_to_string) start;
();
};
};