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Diffstat (limited to 'gmp-6.3.0/demos/calc/calc.y')
| -rw-r--r-- | gmp-6.3.0/demos/calc/calc.y | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/gmp-6.3.0/demos/calc/calc.y b/gmp-6.3.0/demos/calc/calc.y new file mode 100644 index 0000000..0fa1206 --- /dev/null +++ b/gmp-6.3.0/demos/calc/calc.y @@ -0,0 +1,318 @@ +%{ +/* A simple integer desk calculator using yacc and gmp. + +Copyright 2000-2002 Free Software Foundation, Inc. + +This file is part of the GNU MP Library. + +This program is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free Software +Foundation; either version 3 of the License, or (at your option) any later +version. + +This program is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A +PARTICULAR PURPOSE. See the GNU General Public License for more details. + +You should have received a copy of the GNU General Public License along with +this program. If not, see https://www.gnu.org/licenses/. */ + + +/* This is a simple program, meant only to show one way to use GMP for this + sort of thing. There's few features, and error checking is minimal. + Standard input is read, calc_help() below shows the inputs accepted. + + Expressions are evaluated as they're read. If user defined functions + were wanted it'd be necessary to build a parse tree like pexpr.c does, or + a list of operations for a stack based evaluator. That would also make + it possible to detect and optimize evaluations "mod m" like pexpr.c does. + + A stack is used for intermediate values in the expression evaluation, + separate from the yacc parser stack. This is simple, makes error + recovery easy, minimizes the junk around mpz calls in the rules, and + saves initializing or clearing "mpz_t"s during a calculation. A + disadvantage though is that variables must be copied to the stack to be + worked on. A more sophisticated calculator or language system might be + able to avoid that when executing a compiled or semi-compiled form. + + Avoiding repeated initializing and clearing of "mpz_t"s is important. In + this program the time spent parsing is obviously much greater than any + possible saving from this, but a proper calculator or language should + take some trouble over it. Don't be surprised if an init/clear takes 3 + or more times as long as a 10 limb addition, depending on the system (see + the mpz_init_realloc_clear example in tune/README). */ + + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "gmp.h" +#define NO_CALC_H /* because it conflicts with normal calc.c stuff */ +#include "calc-common.h" + + +#define numberof(x) (sizeof (x) / sizeof ((x)[0])) + + +void +calc_help (void) +{ + printf ("Examples:\n"); + printf (" 2+3*4 expressions are evaluated\n"); + printf (" x=5^6 variables a to z can be set and used\n"); + printf ("Operators:\n"); + printf (" + - * arithmetic\n"); + printf (" / %% division and remainder (rounding towards negative infinity)\n"); + printf (" ^ exponentiation\n"); + printf (" ! factorial\n"); + printf (" << >> left and right shifts\n"); + printf (" <= >= > \\ comparisons, giving 1 if true, 0 if false\n"); + printf (" == != < /\n"); + printf (" && || logical and/or, giving 1 if true, 0 if false\n"); + printf ("Functions:\n"); + printf (" abs(n) absolute value\n"); + printf (" bin(n,m) binomial coefficient\n"); + printf (" fib(n) fibonacci number\n"); + printf (" gcd(a,b,..) greatest common divisor\n"); + printf (" kron(a,b) kronecker symbol\n"); + printf (" lcm(a,b,..) least common multiple\n"); + printf (" lucnum(n) lucas number\n"); + printf (" nextprime(n) next prime after n\n"); + printf (" powm(b,e,m) modulo powering, b^e%%m\n"); + printf (" root(n,r) r-th root\n"); + printf (" sqrt(n) square root\n"); + printf ("Other:\n"); + printf (" hex \\ set hex or decimal for input and output\n"); + printf (" decimal / (\"0x\" can be used for hex too)\n"); + printf (" quit exit program (EOF works too)\n"); + printf (" ; statements are separated with a ; or newline\n"); + printf (" \\ continue expressions with \\ before newline\n"); + printf (" # xxx comments are # though to newline\n"); + printf ("Hex numbers must be entered in upper case, to distinguish them from the\n"); + printf ("variables a to f (like in bc).\n"); +} + + +int ibase = 0; +int obase = 10; + + +/* The stack is a fixed size, which means there's a limit on the nesting + allowed in expressions. A more sophisticated program could let it grow + dynamically. */ + +mpz_t stack[100]; +mpz_ptr sp = stack[0]; + +#define CHECK_OVERFLOW() \ + if (sp >= stack[numberof(stack)]) /* FIXME */ \ + { \ + fprintf (stderr, \ + "Value stack overflow, too much nesting in expression\n"); \ + YYERROR; \ + } + +#define CHECK_EMPTY() \ + if (sp != stack[0]) \ + { \ + fprintf (stderr, "Oops, expected the value stack to be empty\n"); \ + sp = stack[0]; \ + } + + +mpz_t variable[26]; + +#define CHECK_VARIABLE(var) \ + if ((var) < 0 || (var) >= numberof (variable)) \ + { \ + fprintf (stderr, "Oops, bad variable somehow: %d\n", var); \ + YYERROR; \ + } + + +#define CHECK_UI(name,z) \ + if (! mpz_fits_ulong_p (z)) \ + { \ + fprintf (stderr, "%s too big\n", name); \ + YYERROR; \ + } + +%} + +%union { + char *str; + int var; +} + +%token EOS BAD +%token HELP HEX DECIMAL QUIT +%token ABS BIN FIB GCD KRON LCM LUCNUM NEXTPRIME POWM ROOT SQRT +%token <str> NUMBER +%token <var> VARIABLE + +/* operators, increasing precedence */ +%left LOR +%left LAND +%nonassoc '<' '>' EQ NE LE GE +%left LSHIFT RSHIFT +%left '+' '-' +%left '*' '/' '%' +%nonassoc UMINUS +%right '^' +%nonassoc '!' + +%% + +top: + statement + | statements statement; + +statements: + statement EOS + | statements statement EOS + | error EOS { sp = stack[0]; yyerrok; }; + +statement: + /* empty */ + | e { + mpz_out_str (stdout, obase, sp); putchar ('\n'); + sp--; + CHECK_EMPTY (); + } + | VARIABLE '=' e { + CHECK_VARIABLE ($1); + mpz_swap (variable[$1], sp); + sp--; + CHECK_EMPTY (); + } + | HELP { calc_help (); } + | HEX { ibase = 16; obase = -16; } + | DECIMAL { ibase = 0; obase = 10; } + | QUIT { exit (0); }; + +/* "e" leaves it's value on the top of the mpz stack. A rule like "e '+' e" + will have done a reduction for the first "e" first and the second "e" + second, so the code receives the values in that order on the stack. */ +e: + '(' e ')' /* value on stack */ + | e '+' e { sp--; mpz_add (sp, sp, sp+1); } + | e '-' e { sp--; mpz_sub (sp, sp, sp+1); } + | e '*' e { sp--; mpz_mul (sp, sp, sp+1); } + | e '/' e { sp--; mpz_fdiv_q (sp, sp, sp+1); } + | e '%' e { sp--; mpz_fdiv_r (sp, sp, sp+1); } + | e '^' e { CHECK_UI ("Exponent", sp); + sp--; mpz_pow_ui (sp, sp, mpz_get_ui (sp+1)); } + | e LSHIFT e { CHECK_UI ("Shift count", sp); + sp--; mpz_mul_2exp (sp, sp, mpz_get_ui (sp+1)); } + | e RSHIFT e { CHECK_UI ("Shift count", sp); + sp--; mpz_fdiv_q_2exp (sp, sp, mpz_get_ui (sp+1)); } + | e '!' { CHECK_UI ("Factorial", sp); + mpz_fac_ui (sp, mpz_get_ui (sp)); } + | '-' e %prec UMINUS { mpz_neg (sp, sp); } + + | e '<' e { sp--; mpz_set_ui (sp, mpz_cmp (sp, sp+1) < 0); } + | e LE e { sp--; mpz_set_ui (sp, mpz_cmp (sp, sp+1) <= 0); } + | e EQ e { sp--; mpz_set_ui (sp, mpz_cmp (sp, sp+1) == 0); } + | e NE e { sp--; mpz_set_ui (sp, mpz_cmp (sp, sp+1) != 0); } + | e GE e { sp--; mpz_set_ui (sp, mpz_cmp (sp, sp+1) >= 0); } + | e '>' e { sp--; mpz_set_ui (sp, mpz_cmp (sp, sp+1) > 0); } + + | e LAND e { sp--; mpz_set_ui (sp, mpz_sgn (sp) && mpz_sgn (sp+1)); } + | e LOR e { sp--; mpz_set_ui (sp, mpz_sgn (sp) || mpz_sgn (sp+1)); } + + | ABS '(' e ')' { mpz_abs (sp, sp); } + | BIN '(' e ',' e ')' { sp--; CHECK_UI ("Binomial base", sp+1); + mpz_bin_ui (sp, sp, mpz_get_ui (sp+1)); } + | FIB '(' e ')' { CHECK_UI ("Fibonacci", sp); + mpz_fib_ui (sp, mpz_get_ui (sp)); } + | GCD '(' gcdlist ')' /* value on stack */ + | KRON '(' e ',' e ')' { sp--; mpz_set_si (sp, + mpz_kronecker (sp, sp+1)); } + | LCM '(' lcmlist ')' /* value on stack */ + | LUCNUM '(' e ')' { CHECK_UI ("Lucas number", sp); + mpz_lucnum_ui (sp, mpz_get_ui (sp)); } + | NEXTPRIME '(' e ')' { mpz_nextprime (sp, sp); } + | POWM '(' e ',' e ',' e ')' { sp -= 2; mpz_powm (sp, sp, sp+1, sp+2); } + | ROOT '(' e ',' e ')' { sp--; CHECK_UI ("Nth-root", sp+1); + mpz_root (sp, sp, mpz_get_ui (sp+1)); } + | SQRT '(' e ')' { mpz_sqrt (sp, sp); } + + | VARIABLE { + sp++; + CHECK_OVERFLOW (); + CHECK_VARIABLE ($1); + mpz_set (sp, variable[$1]); + } + | NUMBER { + sp++; + CHECK_OVERFLOW (); + if (mpz_set_str (sp, $1, ibase) != 0) + { + fprintf (stderr, "Invalid number: %s\n", $1); + YYERROR; + } + }; + +gcdlist: + e /* value on stack */ + | gcdlist ',' e { sp--; mpz_gcd (sp, sp, sp+1); }; + +lcmlist: + e /* value on stack */ + | lcmlist ',' e { sp--; mpz_lcm (sp, sp, sp+1); }; + +%% + +yyerror (char *s) +{ + fprintf (stderr, "%s\n", s); +} + +int calc_option_readline = -1; + +int +main (int argc, char *argv[]) +{ + int i; + + for (i = 1; i < argc; i++) + { + if (strcmp (argv[i], "--readline") == 0) + calc_option_readline = 1; + else if (strcmp (argv[i], "--noreadline") == 0) + calc_option_readline = 0; + else if (strcmp (argv[i], "--help") == 0) + { + printf ("Usage: calc [--option]...\n"); + printf (" --readline use readline\n"); + printf (" --noreadline don't use readline\n"); + printf (" --help this message\n"); + printf ("Readline is only available when compiled in,\n"); + printf ("and in that case it's the default on a tty.\n"); + exit (0); + } + else + { + fprintf (stderr, "Unrecognised option: %s\n", argv[i]); + exit (1); + } + } + +#if WITH_READLINE + calc_init_readline (); +#else + if (calc_option_readline == 1) + { + fprintf (stderr, "Readline support not available\n"); + exit (1); + } +#endif + + for (i = 0; i < numberof (variable); i++) + mpz_init (variable[i]); + + for (i = 0; i < numberof (stack); i++) + mpz_init (stack[i]); + + return yyparse (); +} |