File Coverage

bin/bc

Criterion	Covered	Total	%
statement	713	987	72.2
branch	356	542	65.6
condition	131	183	71.5
subroutine	21	37	56.7
pod			n/a
total	1221	1749	69.8

#!/usr/bin/perl

=begin metadata

Name: bc
Description: an arbitrary precision calculator language
Author: Philip A. Nelson, [e-mail]
License: gpl

=end metadata

=cut

=head1 NAME

bc - an arbitrary precision calculator language

=head1 SYNOPSIS

Run a bc program from FILE

	bc [-bdiqswy] FILE...

Start an interactive bc session

	bc [-bdiqswy]

=head1 DESCRIPTION

This is the PerlPowerTools implementation of the GNU version of bc, a
standard calculator language. This is documented at:

https://www.gnu.org/software/bc/manual/html_mono/bc.html

=head2 Options

=over

=item * -b - use Math::BigFloat

=item * -d - turn on debugging output

=item * -l - use mathlib

=item * -y - turn on parser debugging output

=back

=head2 Environment

There are no environment variables that affect this program.

=head1 The bc language

NOTE: Some of this documentation is lifted straight from the GNU
documentation for its version of B.

C is a language that supports arbitrary precision numbers with
interactive execution of statements.  There are some similarities in
the syntax to the C programming language.

=begin comment      ### XXX hidden because function support generate syntax errors

A standard math library is
available by command line option.  If requested, the math library is
defined before processing any files.

=end comment

C starts by processing code from all the files listed on the
command line in the order listed. If no files are listed, then stdin
is read.  If a file contains a command to halt the processor,
C will never read from the standard input.

Dash ('-') is a pseudo-filename which represents stdin.  This makes
it possible to do something like C and have bc
run commands from fileA before prompting for input, and then run
commands from fileB after interactive input is finished.

=begin comment      ### XXX for accuracy, the following is superceded by the above

C starts by processing code from all the files listed on the
command line in the order listed. After all files have been
processed, C reads from the standard input. All code is executed
as it is read. (If a file contains a command to halt the processor,
C will never read from the standard input.)

=end comment

C will terminate interactive input via stdin if you enter C
or press C.

=head1 BASIC ELEMENTS

=head2 Numbers

The most basic element in C is the number. Numbers are arbitrary
precision numbers. This precision is both in the integer part and the
fractional part. All numbers are represented internally in decimal and
all computation is done in decimal.

=begin comment      ### hidden because it doesn't seem to be true in this implementation

(This version truncates results
from divide and multiply operations.)

=end comment


There are two attributes of
numbers, the length and the scale. The length is the total number of
significant decimal digits in a number and the scale is the total number
of decimal digits after the decimal point. For example, .000001 has a
length of 6 and scale of 6, while 1935.000 has a length of 7 and a scale
of 3.

=head2 Variables

Numbers are stored in two types of variables, simple variables and
arrays. Both simple variables and array variables are named. Names
begin with a letter followed by any number of letters, digits and
underscores. All letters must be lower case.

=begin comment      ### hidden because it's not applicable and confusing

(Full alphanumeric names
are an extension. In POSIX C all names are a single lower case
letter.)

=end comment

The type of variable is clear by the context because all
array variable names will be followed by brackets ( [ ] ).

=head2 Special Variables

=over 8

=item C

Defines how some operations use digits after the decimal point.
The default value is 0.

=item C

Defines the conversion base for input numbers. Defaults to 10.

=item C

Defines the conversion base for output numbers. Defaults to 10.

=back

=head2 Comments

Comments in C start with the characters '/*' and end with the
characters '*/'. Comments may start anywhere and appear as a single
space in the input. Note that this causes comments to delimit other
input items, therefore a comment cannot be included the middle of a
variable name. Comments include any newlines (end of line) between
the start and the end of the comment.

To support the use of scripts for C, a single line comment has
been added as an extension. A single line comment starts at a '#'
character and continues to the next end of the line. The end of line
character is not part of the comment and is processed normally.

=head1 EXPRESSIONS

Numbers are manipulated by expressions and statements. Since
the language was designed to be interactive, statements and expressions
are executed as soon as possible. There is no main program. Instead,
code is executed as it is encountered.

A simple expression is just a constant. C converts constants into
internal decimal numbers using the current input base, specified by the
variable C.

Full expressions are similar to many other high level languages.
Since there is only one kind of number, there are no rules for mixing
types. Instead, there are rules on the scale of expressions. Every
expression has a scale. This is derived from the scale of original
numbers, the operation performed and in many cases, the value of the
variable C.

=begin comment          ### replace by the above for accurary w.r.t this implementation

The numbers are manipulated by expressions and statements. Since the language was designed to be interactive, statements and expressions are executed as soon as possible. There is no main program. Instead, code is executed as it is encountered. (Functions, discussed in detail later, are defined when encountered.)

A simple expression is just a constant. bc converts constants into internal decimal numbers using the current input base, specified by the variable ibase. (There is an exception in functions.) The legal values of ibase are 2 through 16. Assigning a value outside this range to ibase will result in a value of 2 or 16. Input numbers may contain the characters 0-9 and A-F. (Note: They must be capitals. Lower case letters are variable names.) Single digit numbers always have the value of the digit regardless of the value of ibase. (i.e. A = 10.) For multi-digit numbers, bc changes all input digits greater or equal to ibase to the value of ibase-1. This makes the number FFF always be the largest 3 digit number of the input base.

Full expressions are similar to many other high level languages. Since there is only one kind of number, there are no rules for mixing types. Instead, there are rules on the scale of expressions. Every expression has a scale. This is derived from the scale of original numbers, the operation performed and in many cases, the value of the variable scale. Legal values of the variable scale are 0 to the maximum number representable by a C integer.

=end comment

=head2 Basic Expressions

In the following descriptions of legal expressions, "expr" refers to
a complete expression and "VAR" refers to a simple or an array variable.
A simple variable is just a NAME and an array variable is specified as
NAME[EXPR].

Unless specifically mentioned the scale of the result is the maximum
scale of the expressions involved.

=over 4

=item C<- expr>

The result is the negation of the expression.

=item C<++ VAR>

The variable is incremented by one and the new value is the result
of the expression.

=item C<-- VAR>

The variable is decremented by one and the new value is the result
of the expression.

=item C

The result of the expression is the value of the variable and then
the variable is incremented by one.

=item C

The result of the expression is the value of the variable and then
the variable is decremented by one.

=item C

The result of the expression is the sum of the two expressions.

=item C

The result of the expression is the difference of the two
expressions.

=item C

The result of the expression is the product of the two expressions.

=item C

The result of the expression is the quotient of the two
expressions. The scale of the result is the value of the variable
C

=item C

The result of the expression is the "remainder" and it is computed
in the following way. To compute a%b, first a/b is computed to
SCALE digits. That result is used to compute a-(a/b)*b to the
scale of the maximum of SCALE+scale(b) and scale(a). If SCALE is
set to zero and both expressions are integers this expression is
the integer remainder function.

=item C

The result of the expression is the value of the first raised to
the second.

=begin comment      ### hidden because it doesn't seem to be true in the implementation

The second expression must be an integer. (If the
second expression is not an integer, a warning is generated and the
expression is truncated to get an integer value.)

=end comment

The scale of the result is SCALE if the exponent is negative. If the
exponent is positive the scale of the result is the minimum of the
scale of the first expression times the value of the exponent and the
maximum of SCALE and the scale of the first expression. (e.g.
scale(a^b) = min(scale(a)*b, max(SCALE, scale(a))).) It should be
noted that expr^0 will always return the value of 1.


=item C<( expr )>

This alters the standard precedence to force the evaluation of the
expression.

=item C

The variable is assigned the value of the expression.

=item C

This is equivalent to "VAR = VAR op expr" with the exception
that the "VAR" part is evaluated only once. This can make a
difference if "VAR" is an array.

=back

=head2 Relational Expressions

Relational expressions are a special kind of expression that always
evaluate to 0 or 1, 0 if the relation is false and 1 if the relation is
true. These may appear in any legal expression. (POSIX C requires
that relational expressions are used only in C, C, and C
statements and that only one relational test may be done in them.) The
relational operators are

=over 4

=item expr1 < expr2

The result is 1 if expr1 is strictly less than expr2.

=item expr1 <= expr2

The result is 1 if expr1 is less than or equal to expr2.

=item expr1 > expr2

The result is 1 if expr1 is strictly greater than expr2.

=item expr1 >= expr2

The result is 1 if expr1 is greater than or equal to expr2.

=item expr1 == expr2

The result is 1 if expr1 is equal to expr2.

=item expr1 != expr2

The result is 1 if expr1 is not equal to expr2.

=back

=head2 Boolean Expressions

Boolean operations are also legal. (POSIX C does NOT have
boolean operations). The result of all boolean operations are 0 and 1
(for false and true) as in relational expressions. The boolean
operators are:

=over 4

=item C

The result is 1 if expr is 0.

=item C

The result is 1 if both expressions are non-zero.

=item C

The result is 1 if either expression is non-zero.

=back

=head2 Precedence

The expression precedence is as follows: (lowest to highest)

	= += etc     operators (assignment)  right associative
	||           OR operator             left associative
	&&           AND operator            left associative
	!            NOT operator            nonassociative
	< > etc      relational operators    left associative
	+ and -      operators               left associative
	*, / and %   operators               left associative
	^            operator (power)        right associative
	unary -      operator                nonassociative
	++ and --    operators               nonassociative

This differs from POSIX-compliant C, which puts assignment between
relational operators and addition/subtraction. As a result, expressions
behave more like they do in most languages (including perl and C).

=head2 Special Expressions

There are a few more special expressions that are provided in C.
These have to do with user-defined functions and standard functions.
These are:

=over 4

=item C

The value of the C function is the number of significant
digits in the expression.

=begin comment          ### hidden because it's not supported

=item C

The C function (an extension) will read a number from the
standard input, regardless of where the function occurs. Beware,
this can cause problems with the mixing of data and program in the
standard input. The best use for this function is in a previously
written program that needs input from the user, but never allows
program code to be input from the user. The value of the `read'
function is the number read from the standard input using the
current value of the variable C for the conversion base.

=end comment

=item C

The value of the C function is the number of digits after the
decimal point in the expression.

=item C

The value of the C function is the square root of the
expression. If the expression is negative, a run time error is
generated.

=back

=head2 Statements

Statements (as in most algebraic languages) provide the sequencing of
expression evaluation. In C statements are executed "as soon as
possible." Execution happens when a newline is encountered and there
is one or more complete statements. Due to this immediate execution,
newlines are very important in C. In fact, both a semicolon and a
newline are used as statement separators. An improperly placed
newline will cause a syntax error.

Because newlines are statement separators, it is possible to hide a
newline by using the backslash character. The sequence "\" (where
 represents a newline your typed) appears to C as whitespace
instead of an actual newline.

A statement list is a series of statements separated by semicolons
and newlines.

The following is a list of C statements and what they do. Things
enclosed in brackets ( [ ] ) are optional parts of the statement.

=over 4

=item EXPRESSION

This statement does one of two things. If the expression starts
with "  ...", it is considered to be an
assignment statement. If the expression is not an assignment
statement, the expression is evaluated and printed to the output.
After the number is printed, a newline is printed.

For example, "a=1" is an assignment statement and "(a=1)" is an
expression that has an embedded assignment.

=begin comment          ### hidden because obase and last don't seem to work

All numbers that are printed are printed in the base specified by the
variable OBASE. The legal values for OBASE are 2 through BC_BASE_MAX
(*note Environment Variables::). For bases 2 through 16, the usual
method of writing numbers is used. For bases greater than 16, C
uses a multi-character digit method of printing the numbers where each
higher base digit is printed as a base 10 number. The multi-character
digits are separated by spaces. Each digit contains the number of
characters required to represent the base ten value of "OBASE -1".
Since numbers are of arbitrary precision, some numbers may not be
printable on a single output line. These long numbers will be split
across lines using the "\" as the last character on a line. The
maximum number of characters printed per line is 70. Due to the
interactive nature of C, printing a number causes the side effect
of assigning the printed value to the special variable LAST. This
allows the user to recover the last value printed without having to
retype the expression that printed the number. Assigning to LAST is
legal and will overwrite the last printed value with the assigned
value. The newly assigned value will remain until the next number is
printed or another value is assigned to LAST. (Some installations may
allow the use of a single period (.) which is not part of a number as
a short hand notation for for LAST.)

=end comment

=item STRING

The string is printed to the output. Strings start with a double
quote character and contain all characters until the next double
quote character. All characters are taken literally, including
any newline. No newline character is printed after the string.

=item C LIST

The C statement (an extension) provides another method of
output. The LIST is a list of strings and expressions separated by
commas. Each string or expression is printed in the order of the
list. No terminating newline is printed. Expressions are
evaluated and their value is printed and assigned to the variable
C. Strings in the print statement are printed to the output
and may contain special characters. Special characters start with
the backslash character. The special characters include:

	\a  alert or bell
	\b  backspace
	\f  form feed
	\n  newline
	\r  carriage return
	\q  double quote
	\t  tab
	\e  backslash.

Any other character following a backslash will be ignored.

=item { STATEMENT_LIST }

This is the compound statement. It allows multiple statements to
be grouped together for execution.

=item C ( EXPRESSION ) STATEMENT

The C statement evaluates the expression and executes STATEMENT
depending on the value of the expression. If the expression is
non-zero, STATEMENT is executed. Otherwise it isn't. (The statement
can be a block enclosed in { }.)

=begin comment          ### if-else is not supported in this implementation

If the expression is non-zero, statement1 is executed. If statement2
is present and the value of the expression is 0, then statement2 is
executed. (The C clause is an extension.)

=end comment

=item C ( EXPRESSION ) STATEMENT

The while statement will execute the statement while the expression
is non-zero. It evaluates the expression before each execution of
the statement. Termination of the loop is caused by a zero
expression value or the execution of a C statement.

=item C ( [EXPRESSION1] ; [EXPRESSION2] ; [EXPRESSION3] ) STATEMENT

The C statement controls repeated execution of the statement.
EXPRESSION1 is evaluated before the loop. EXPRESSION2 is
evaluated before each execution of the statement. If it is
non-zero, the statement is evaluated. If it is zero, the loop is
terminated.

After each execution of the statement, EXPRESSION3 is
evaluated before the reevaluation of expression2. If EXPRESSION1
or EXPRESSION3 are missing, nothing is evaluated at the point they
would be evaluated. If EXPRESSION2 is missing, it is the same as
substituting the value 1 for EXPRESSION2.

(The optional expressions are an extension. POSIX C requires all
three expressions.)

The following is equivalent code for the C
statement:

	expression1;
	while (expression2) {
		statement;
		expression3;
	}

=item C

This statement causes a forced exit of the most recent enclosing
C statement or C statement.

=item C

When the C statement is read, the C processor is
terminated, regardless of where the C statement is found. For
example, C will cause C to terminate.

=back

=head1 EXAMPLE

The following illustrates how C expressions can be written in
script form and fed to C via stdin.

=begin comment

Note that the /* and */ are necessary to around the C code example
in order to prevent -l from processing these statements when reading

	/*

=end comment

	print "\nCompute balances after withdrawals\n"

	bal = 100.00
	withdrawal = 20.00;

	while (1) {
		print "Balance: ", "\t", bal, "\n"
		print "Withdrawal: ", "\t", withdrawal, "\n"
		if ( (bal - withdrawal) < 0 ) break;
		bal -= withdrawal
	}

	print "Balance:", bal

	quit

=begin comment

	*/

=end comment

=head1 BUGS AND LIMITATIONS

This implementation of C is mostly POSIX compliant and has similar
extensions to GNU C. However, some features and extensions are
either not supported or are not working.

Perhaps the biggest non-working feature would be Function definitions
via the C syntax, which if used generates syntax errors. As a
consequence, the -l option (to load math library definitions) doesn't
work either.

Setting the following variables don't seem to have the intended effects:

	scale
	ibase
	obase

Hexadecimal values, for use when ibase is > 10, are not supported.

Old style assignment operators (=+, =-, =*, =/, =%, =^) are not
required to be supported by the POSIX standard, and they are not
supported by this implementation. However, they will not generate
any errors. Instead you will get a result you don't expect.
For example:

	v=3; v += 2  # v is 5 as you would expect
	v=3; v =+ 2  # v is 2 because the 2nd expression is seen as v = +2

=head1 COMPARISON TO GNU C AND OTHERS

The following C features are not supported in this implementation.
(Some are syntactically accepted, but simply return zero).

	* -w, --warn option
	* -s, --standard option
	* -q, --quiet option
	* -v, --version option
	* long options (e.g. --help)
	* LC_ language and NLSPATH environment variables
	* "last" special variable
	* "if" statement: "else" clause
	* "read" function
	* "continue" statement
	* "halt" statement
	* "limits" pseudo statement
	* "warranty" pseudo statement
	* function definitions

In addition, the GNU implementation set the precedence of assignment
below + and - and above relational operators (< > etc). This
implementation seems to make it the lowest precedence (i.e. below ||),
as most perl (and C) users would expect.

=head1 REFERENCES

POSIX C L

GNU C L

=head2 GNU's mathlib

Load the GNU math extensions with the C<-l> switch:

	% bc -l FILE

The library provides these functions:

=over 4

=item * a(x) - the arctangent of X, where X is expressed in radians

=item * c(x) - the cosine of X, where X is expressed in radians

=item * e(X) - the natural base, e, raised to the X power

=item * j(n,x) - the Bessel function of order n, where n is an integer

=item * l(X) - the natural logarithm of X

=item * s(x) - the sine of X, where X is expressed in radians

=back

=head1 AUTHOR

Philip A. Nelson originally translated GNU bc to Perl for the PerlPowerTools
project.

https://github.com/briandfoy/PerlPowerTools

=head1 LICENSE

You can use and modify this program under the terms of the GNU Public
License version 2. A copy of this license is in the PerlPowerTools
repository:

	https://github.com/briandfoy/PerlPowerTools/

=cut

use strict;

use Math::Trig;
use POSIX;

# The symbol table : the keys are the identifiers, the value is in the
# "var" field if it is a variable, in the "func" field if it is a
# function.
my %sym_table;
my @stmt_list = ();
my @ope_stack;
my @backup_sym_table;
my $input;
my $cur_file = '-';
my $bignum = 0;
my $do_stdin = 0;
my $line;
my $var;
my $yychar;
my $yydebug;
my $yyerrflag;
my $yylval;
my $yyn;
my $yym;
my $yyssp;
my $yystate;
my $yyval;
my $yyvsp;

my $debug = 0;
sub debug(&) {
  my $fn = shift;
  print STDERR "\t".&$fn()
    if $debug;
}

my $INT=257;
my $FLOAT=258;
my $STRING=259;
my $IDENT=260;
my $C_COMMENT=261;
my $BREAK=262;
my $DEFINE=263;
my $AUTO=264;
my $RETURN=265;
my $PRINT=266;
my $AUTO_LIST=267;
my $IF=268;
my $ELSE=269;
my $QUIT=270;
my $WHILE=271;
my $FOR=272;
my $EQ=273;
my $NE=274;
my $GT=275;
my $GE=276;
my $LT=277;
my $LE=278;
my $PP=279;
my $MM=280;
my $P_EQ=281;
my $M_EQ=282;
my $F_EQ=283;
my $D_EQ=284;
my $EXP_EQ=285;
my $MOD_EQ=286;
my $L_SHIFT=287;
my $R_SHIFT=288;
my $E_E=289;
my $O_O=290;
my $EXP=291;
my $UNARY=292;
my $PPP=293;
my $MMM=294;
my $YYERRCODE=256;
my @yylhs = (                                            -1,
    0,    0,    1,    1,    1,    3,    4,    9,    3,    3,
    3,   12,    3,   13,    3,   14,    3,   15,   17,    3,
   18,   19,   20,    3,    3,   10,   10,   16,   16,    8,
    8,    6,    6,    2,    2,    5,    5,   22,   22,   23,
   23,   24,   24,    7,    7,   25,   25,   11,   11,   21,
   21,   21,   21,   21,   21,   21,   21,   21,   21,   21,
   21,   21,   21,   21,   21,   21,   21,   21,   21,   21,
   21,   21,   21,   21,   21,   21,   21,   21,   21,   21,
   21,   21,   21,   21,   21,   21,   21,   26,   26,
);
my @yylen = (                                             2,
    0,    2,    1,    2,    2,    1,    0,    0,   13,    1,
    1,    0,    3,    0,    4,    0,    7,    0,    0,    8,
    0,    0,    0,   13,    1,    1,    4,    0,    1,    1,
    3,    0,    1,    1,    1,    0,    1,    1,    3,    0,
    1,    1,    3,    0,    3,    1,    3,    1,    3,    4,
    3,    3,    3,    3,    3,    3,    3,    3,    3,    3,
    3,    3,    3,    3,    3,    3,    3,    3,    3,    3,
    3,    3,    3,    2,    2,    2,    2,    2,    2,    2,
    2,    3,    6,    1,    1,    1,    1,    1,    4,
);
my @yydefred = (                                          1,
    0,    0,   85,   86,   87,    0,    0,   11,    7,    0,
   12,    0,    6,   18,    0,    0,    0,    0,    0,    0,
   14,    0,   34,   35,    2,    3,    0,   10,    0,    0,
    5,    0,    0,    0,   81,    0,    0,    0,    0,    0,
    0,    0,   76,   77,   80,   74,    0,    0,   75,    4,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,   78,   79,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,   29,    0,    0,   51,    0,
   30,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,   50,    0,    0,    0,   27,    0,   16,
    0,   21,    0,   15,    0,    0,    0,   38,    0,    0,
    0,    0,    0,    0,   89,   31,    0,    0,    0,   33,
    0,   19,    0,    0,   39,   17,    0,   22,    0,   20,
    0,    0,    0,    0,    8,   23,   46,    0,    0,    0,
    0,   45,    0,    0,   47,    9,   24,
);
my @yydgoto = (                                           1,
   25,  140,   86,   36,  129,  141,  155,   90,  159,   28,
   82,   38,   48,  132,   40,   91,  147,  134,  151,  160,
   29,  130,   77,   78,  158,   30,
);
my @yysindex = (                                          0,
  475,   -8,    0,    0,    0,   84, -239,    0,    0,  -11,
    0,    3,    0,    0,   19, -218, -218,  899,  899,  899,
    0,  899,    0,    0,    0,    0,   -8,    0,  893,  -54,
    0,  899,  899,  899,    0, -199,  899,  899,  958,   24,
  958,  -26,    0,    0,    0,    0,  -32,  958,    0,    0,
  899,  899,  899,  899,  899,  899,  899,  899,  899,  899,
  899,  899,  899,  899,  899,  899,  899,  899,  899,  899,
  899,  899,    0,    0,  893,  893,   25,   48,  830,   65,
  852,   64,  893,   27,  958,    0,   53,  899,    0,   26,
    0,  923,  923,  142,  142,  142,  142,  416,  416,  -21,
  -21,  -30,  -30,  -29,  -29, -180, -180,  142,  142,  142,
  142,  142,  142,    0,  899,   67, -146,    0,  899,    0,
   85,    0,  874,    0,  958,  893,  899,    0,   86,   87,
  893,   -8,   -8,  958,    0,    0,  893,   -8, -127,    0,
  958,    0,   88,   41,    0,    0,  958,    0,   -8,    0,
  958, -116,  108, -103,    0,    0,    0,   18,  958,   -8,
 -100,    0,   31,  958,    0,    0,    0,
);
my @yyrindex = (                                          0,
    0,    0,    0,    0,    0,  -10,    0,    0,    0,   28,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,   30,   37,
    0,    0,  127,    0,    0,    0,    0,    0,    0,    0,
  119,   57,    0,    0,    0,    0,    0,   36,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    4,  -40,    0,  139,    0,    0,
    0,   34,   66,    0,  145,    0,    0,    0,    0,    0,
    0,  820,  822,  507,  518,  537,  551,  405,  442,  298,
  380,  122,  192,  129,  167,   76,   99,  572,  579,  680,
  758,  777,  799,    0,    0,   13,  149,    0,    0,    0,
    0,    0,    0,    0,   36,  -38,    0,    0,    0,  153,
   93, 1023, 1023,  119,    0,    0,   29,   60,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
  145,  499,    0,    0,    0,    0,    0,    0,   36, 1023,
    0,    0,    0,    0,    0,    0,    0,
);
my @yygindex = (                                          0,
    0,  358,   52,    0,    0, -108,    0,   38,    0,    0,
    0,    0,    0,    0,    0,  337,    0,    0,    0,    0,
 1278,    0,    0,    0,    0,    2,
);
my @yytable = (                                          88,
   42,   24,   43,   42,   65,   43,   65,   65,   89,   63,
   61,   63,   62,   82,   64,   65,   64,   43,   44,   35,
   63,   61,   89,   62,  142,   64,   88,   24,   37,  144,
   88,   88,   88,   88,   88,   24,   88,   26,   83,   25,
   24,   42,   39,   13,   82,   28,   84,   82,   88,   89,
   23,  164,   27,   89,   89,   89,   89,   89,   41,   89,
   80,  161,   82,   85,   88,  114,   88,  120,   26,   83,
   25,   89,   83,   84,   13,   48,   23,   84,   84,   84,
   84,   84,   88,   84,   23,   67,   26,   83,   25,   23,
   84,  115,   13,   88,   28,   84,   82,   88,   88,   88,
   88,   88,   49,   88,  117,   89,   48,  119,   66,   48,
   66,  122,   67,  128,   88,   88,   67,   67,   67,   67,
   67,   83,   67,   33,   48,  133,  138,  127,   82,   84,
  139,   62,  145,   49,   67,   66,   49,   89,   64,   66,
   66,   66,   66,   66,   32,   66,  148,  154,  156,   88,
  124,   49,   26,   83,   25,  166,  157,   66,   13,  165,
   28,   84,   62,  149,   62,   62,   62,   40,   67,   64,
   64,   64,   64,   64,   34,   64,   65,   28,   65,   41,
   62,   88,   32,   63,   61,   28,   62,   64,   64,   36,
   48,   66,  146,   37,    0,    0,  163,    0,  150,    0,
   67,   63,    0,    0,    0,    0,    0,   65,   65,   65,
   65,   65,    0,   65,   62,  167,    0,   49,    0,    0,
    0,   64,    0,   66,    0,   65,   67,   68,   69,   70,
   71,   72,   63,    0,   63,   63,   63,    0,   73,   74,
   51,   52,   53,   54,   55,   56,   62,    0,    0,    0,
   63,    0,    0,   64,   57,   58,   59,   60,   66,   65,
   66,   66,   88,   88,   88,   88,   88,   88,    0,   66,
   88,   88,   88,   88,   88,   88,   88,   88,   88,   88,
   88,    0,   88,   88,   63,   89,   89,   89,   89,   89,
   89,   65,    0,   89,   89,   89,   89,   89,   89,   89,
   89,   89,   89,   89,    0,   89,   89,   53,    0,   84,
   84,   84,   84,   84,   84,    0,   63,    0,    0,    0,
    0,    0,    0,   84,   84,   84,   84,   84,    0,   88,
   88,   88,   88,   88,   88,    0,    0,    0,   53,    0,
    0,   53,    0,   88,   88,   88,   88,   88,   67,   67,
   67,   67,   67,   67,    0,    0,   53,    0,   26,   31,
    0,    0,   67,   67,   67,   67,    0,    0,    0,    0,
    0,   66,   66,   66,   66,   66,   66,   87,    0,    0,
    0,    0,    0,    0,   50,   66,   66,   66,   66,   52,
   53,    0,    0,    0,   62,   62,   62,   62,   62,   62,
    0,   64,   64,   64,   64,   64,   64,    0,   62,   62,
   62,   62,    0,    0,   60,   64,   64,   64,   64,    0,
   52,  121,   53,   52,    0,    0,    0,    0,   57,   58,
   59,   60,   66,    0,    0,    0,    0,    0,   52,   65,
   65,   65,   65,   65,   65,   60,    0,  125,   60,    0,
    0,   61,   65,   65,   65,   65,   65,   63,   61,    0,
   62,  136,   64,   60,   63,   63,   63,   63,   63,   63,
  143,    0,   52,    0,    0,    0,    0,    0,   63,   63,
   63,   63,   61,    0,   24,   61,    0,  153,    0,    0,
    0,    0,    0,    0,    0,    0,    0,   60,    0,    0,
   61,    0,    0,    0,   52,    0,  152,   22,   44,    0,
    0,    0,    7,    0,   20,  162,   56,   18,    0,   19,
  125,    0,    0,    0,    0,    0,    0,   57,    0,   60,
    0,   44,    0,   23,   61,    0,   44,    0,   44,    0,
    0,   44,    0,   44,    0,    0,   58,   56,    0,    0,
   56,    0,    0,    0,    0,    0,    0,   44,   57,    0,
   59,   57,    0,    0,    0,   56,   61,    0,    0,    0,
   53,   53,   53,   53,   53,   53,   57,   58,    0,    0,
   58,   68,    0,    0,   53,   53,   53,   53,   69,    0,
    0,   59,    0,    0,   59,   58,    0,   21,    0,   56,
    0,    0,    0,    0,    0,    0,    0,    0,    0,   59,
   57,    0,   68,    0,    0,   68,    0,    0,    0,   69,
    0,   44,   69,   44,    0,    0,    0,    0,    0,   58,
   68,   56,    0,    0,    0,    0,    0,   69,    0,    0,
    0,    0,   57,   59,    0,    0,    0,    0,    0,    0,
    0,    0,   52,   52,   52,   52,   52,   52,    0,    0,
    0,   58,    0,    0,   68,    0,   52,   52,   52,   52,
    0,   69,    0,    0,    0,   59,    0,   60,   60,   60,
   60,   60,   60,    0,    0,    0,    0,    0,    0,   70,
    0,   60,   60,    0,    0,    0,   68,    0,    0,    0,
    0,    0,    0,   69,   59,   60,   66,    0,    0,    0,
    0,    0,    0,    0,   61,   61,   61,   61,   61,   61,
   70,    0,    0,   70,    0,    0,    0,    0,   61,   61,
    2,    3,    4,    5,    6,    0,    8,    9,   70,   10,
   11,    0,   12,    0,   13,   14,   15,    0,    0,    0,
    0,    0,    0,   16,   17,   44,   44,   44,   44,    0,
   44,   44,    0,   44,   44,    0,   44,   71,   44,   44,
   44,    0,   70,    0,    0,    0,    0,   44,   44,   56,
   56,   56,   56,   56,   56,    0,   72,    0,    0,    0,
   57,   57,   57,   57,   57,   57,    0,    0,   71,    0,
    0,   71,    0,    0,   70,    0,    0,    0,   73,   58,
   58,   58,   58,   58,   58,    0,   71,   72,    0,    0,
   72,    0,    0,   59,   59,   59,   59,   59,   59,   54,
    0,   55,    0,    0,    0,   72,    0,    0,    0,   73,
    0,    0,   73,    0,   68,   68,   68,   68,   68,   68,
   71,   69,   69,   69,   69,   69,   69,   73,    0,    0,
   54,    0,   55,   54,    0,   55,   65,    0,    0,   72,
    0,   63,   61,    0,   62,    0,   64,    0,   54,    0,
   55,    0,   71,    0,    0,    0,    0,    0,   65,    0,
    0,   73,  118,   63,   61,    0,   62,    0,   64,    0,
    0,   72,    0,    0,    0,    0,    0,    0,    0,    0,
   65,    0,   54,    0,   55,   63,   61,    0,   62,    0,
   64,    0,  116,   73,    0,    0,    0,    0,    0,   65,
    0,   22,    0,    0,   63,   61,    7,   62,   20,   64,
    0,   18,    0,   19,   54,    0,   55,    0,    0,    0,
    0,    0,   70,   70,   70,   70,   70,   70,    0,   65,
    0,    0,    0,    0,   63,   61,  135,   62,    0,   64,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
   22,    0,    0,    0,    0,    7,    0,   20,    0,    0,
   18,    0,   19,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
   71,   71,   71,   71,   71,   71,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,   72,
   72,   72,   72,   72,   72,   32,    0,    0,    0,    0,
   32,    0,   32,    0,    0,   32,    0,   32,    0,    0,
    0,   73,   73,   73,   73,   73,   73,    0,    0,    0,
   21,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,   54,   54,   55,   55,    0,    0,    0,    0,
    0,    0,   51,   52,   53,   54,   55,   56,    0,    0,
    0,    0,    0,    0,    0,    0,   57,   58,   59,   60,
   66,    0,    0,    0,   51,   52,   53,   54,   55,   56,
    0,    0,    0,    0,    0,    0,    0,    0,   57,   58,
   59,   60,   66,    0,    0,   32,   51,   52,   53,   54,
   55,   56,    0,    0,    0,    3,    4,    5,    6,    0,
   57,   58,   59,   60,   66,   51,   52,   53,   54,   55,
   56,    0,    0,    0,    0,    0,    0,   16,   17,   57,
   58,   59,   60,   66,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,   53,   54,   55,
   56,    0,    0,    0,    0,    0,    0,    0,    0,   57,
   58,   59,   60,   66,    3,    4,    5,    6,    0,    8,
    9,    0,   10,   11,    0,   12,    0,   13,   14,   15,
    0,    0,    0,    0,    0,    0,   16,   17,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,   32,
   32,   32,   32,    0,   32,   32,    0,   32,   32,    0,
   32,    0,   32,   32,   32,   45,   46,   47,    0,   49,
    0,   32,   32,    0,    0,    0,    0,    0,    0,   75,
   76,   79,    0,    0,   81,   83,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,   92,   93,
   94,   95,   96,   97,   98,   99,  100,  101,  102,  103,
  104,  105,  106,  107,  108,  109,  110,  111,  112,  113,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,  123,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,  126,    0,    0,    0,  131,    0,    0,    0,
    0,    0,    0,    0,  137,
);
my @yycheck = (                                          10,
   41,   10,   41,   44,   37,   44,   37,   37,   41,   42,
   43,   42,   45,   10,   47,   37,   47,   16,   17,  259,
   42,   43,   10,   45,  133,   47,   37,   10,   40,  138,
   41,   42,   43,   44,   45,   10,   47,   10,   10,   10,
   10,  260,   40,   10,   41,   10,   10,   44,   59,   37,
   59,  160,    1,   41,   42,   43,   44,   45,   40,   47,
  260,   44,   59,   40,   91,   41,   10,   41,   41,   41,
   41,   59,   44,   37,   41,   10,   59,   41,   42,   43,
   44,   45,   93,   47,   59,   10,   59,   59,   59,   59,
   39,   44,   59,   37,   59,   59,   93,   41,   42,   43,
   44,   45,   10,   47,   40,   93,   41,   44,   10,   44,
  291,   59,   37,  260,  125,   59,   41,   42,   43,   44,
   45,   93,   47,   40,   59,   41,   41,   61,  125,   93,
   44,   10,  260,   41,   59,   37,   44,  125,   10,   41,
   42,   43,   44,   45,   61,   47,   59,  264,   41,   93,
  125,   59,  125,  125,  125,  125,  260,   59,  125,  260,
  125,  125,   41,  123,   43,   44,   45,   41,   93,   41,
   42,   43,   44,   45,   91,   47,   10,   59,   37,   41,
   59,  125,  123,   42,   43,   41,   45,   59,   47,   41,
  125,   93,  141,   41,   -1,   -1,  159,   -1,  147,   -1,
  125,   10,   -1,   -1,   -1,   -1,   -1,   41,   42,   43,
   44,   45,   -1,   47,   93,  164,   -1,  125,   -1,   -1,
   -1,   93,   -1,  125,   -1,   59,  281,  282,  283,  284,
  285,  286,   41,   -1,   43,   44,   45,   -1,  293,  294,
  273,  274,  275,  276,  277,  278,  125,   -1,   -1,   -1,
   59,   -1,   -1,  125,  287,  288,  289,  290,  291,   93,
  291,  291,  273,  274,  275,  276,  277,  278,   -1,  291,
  281,  282,  283,  284,  285,  286,  287,  288,  289,  290,
  291,   -1,  293,  294,   93,  273,  274,  275,  276,  277,
  278,  125,   -1,  281,  282,  283,  284,  285,  286,  287,
  288,  289,  290,  291,   -1,  293,  294,   10,   -1,  273,
  274,  275,  276,  277,  278,   -1,  125,   -1,   -1,   -1,
   -1,   -1,   -1,  287,  288,  289,  290,  291,   -1,  273,
  274,  275,  276,  277,  278,   -1,   -1,   -1,   41,   -1,
   -1,   44,   -1,  287,  288,  289,  290,  291,  273,  274,
  275,  276,  277,  278,   -1,   -1,   59,   -1,    1,    2,
   -1,   -1,  287,  288,  289,  290,   -1,   -1,   -1,   -1,
   -1,  273,  274,  275,  276,  277,  278,   41,   -1,   -1,
   -1,   -1,   -1,   -1,   27,  287,  288,  289,  290,   10,
   93,   -1,   -1,   -1,  273,  274,  275,  276,  277,  278,
   -1,  273,  274,  275,  276,  277,  278,   -1,  287,  288,
  289,  290,   -1,   -1,   10,  287,  288,  289,  290,   -1,
   41,   85,  125,   44,   -1,   -1,   -1,   -1,  287,  288,
  289,  290,  291,   -1,   -1,   -1,   -1,   -1,   59,  273,
  274,  275,  276,  277,  278,   41,   -1,   90,   44,   -1,
   -1,   10,   37,  287,  288,  289,  290,   42,   43,   -1,
   45,  125,   47,   59,  273,  274,  275,  276,  277,  278,
  134,   -1,   93,   -1,   -1,   -1,   -1,   -1,  287,  288,
  289,  290,   41,   -1,   10,   44,   -1,  151,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   93,   -1,   -1,
   59,   -1,   -1,   -1,  125,   -1,  149,   33,   10,   -1,
   -1,   -1,   38,   -1,   40,  158,   10,   43,   -1,   45,
  163,   -1,   -1,   -1,   -1,   -1,   -1,   10,   -1,  125,
   -1,   33,   -1,   59,   93,   -1,   38,   -1,   40,   -1,
   -1,   43,   -1,   45,   -1,   -1,   10,   41,   -1,   -1,
   44,   -1,   -1,   -1,   -1,   -1,   -1,   59,   41,   -1,
   10,   44,   -1,   -1,   -1,   59,  125,   -1,   -1,   -1,
  273,  274,  275,  276,  277,  278,   59,   41,   -1,   -1,
   44,   10,   -1,   -1,  287,  288,  289,  290,   10,   -1,
   -1,   41,   -1,   -1,   44,   59,   -1,  123,   -1,   93,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   59,
   93,   -1,   41,   -1,   -1,   44,   -1,   -1,   -1,   41,
   -1,  123,   44,  125,   -1,   -1,   -1,   -1,   -1,   93,
   59,  125,   -1,   -1,   -1,   -1,   -1,   59,   -1,   -1,
   -1,   -1,  125,   93,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,  273,  274,  275,  276,  277,  278,   -1,   -1,
   -1,  125,   -1,   -1,   93,   -1,  287,  288,  289,  290,
   -1,   93,   -1,   -1,   -1,  125,   -1,  273,  274,  275,
  276,  277,  278,   -1,   -1,   -1,   -1,   -1,   -1,   10,
   -1,  287,  288,   -1,   -1,   -1,  125,   -1,   -1,   -1,
   -1,   -1,   -1,  125,  289,  290,  291,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,  273,  274,  275,  276,  277,  278,
   41,   -1,   -1,   44,   -1,   -1,   -1,   -1,  287,  288,
  256,  257,  258,  259,  260,   -1,  262,  263,   59,  265,
  266,   -1,  268,   -1,  270,  271,  272,   -1,   -1,   -1,
   -1,   -1,   -1,  279,  280,  257,  258,  259,  260,   -1,
  262,  263,   -1,  265,  266,   -1,  268,   10,  270,  271,
  272,   -1,   93,   -1,   -1,   -1,   -1,  279,  280,  273,
  274,  275,  276,  277,  278,   -1,   10,   -1,   -1,   -1,
  273,  274,  275,  276,  277,  278,   -1,   -1,   41,   -1,
   -1,   44,   -1,   -1,  125,   -1,   -1,   -1,   10,  273,
  274,  275,  276,  277,  278,   -1,   59,   41,   -1,   -1,
   44,   -1,   -1,  273,  274,  275,  276,  277,  278,   10,
   -1,   10,   -1,   -1,   -1,   59,   -1,   -1,   -1,   41,
   -1,   -1,   44,   -1,  273,  274,  275,  276,  277,  278,
   93,  273,  274,  275,  276,  277,  278,   59,   -1,   -1,
   41,   -1,   41,   44,   -1,   44,   37,   -1,   -1,   93,
   -1,   42,   43,   -1,   45,   -1,   47,   -1,   59,   -1,
   59,   -1,  125,   -1,   -1,   -1,   -1,   -1,   37,   -1,
   -1,   93,   41,   42,   43,   -1,   45,   -1,   47,   -1,
   -1,  125,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   37,   -1,   93,   -1,   93,   42,   43,   -1,   45,   -1,
   47,   -1,   93,  125,   -1,   -1,   -1,   -1,   -1,   37,
   -1,   33,   -1,   -1,   42,   43,   38,   45,   40,   47,
   -1,   43,   -1,   45,  125,   -1,  125,   -1,   -1,   -1,
   -1,   -1,  273,  274,  275,  276,  277,  278,   -1,   37,
   -1,   -1,   -1,   -1,   42,   43,   93,   45,   -1,   47,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   33,   -1,   -1,   -1,   -1,   38,   -1,   40,   -1,   -1,
   43,   -1,   45,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
  273,  274,  275,  276,  277,  278,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,  273,
  274,  275,  276,  277,  278,   33,   -1,   -1,   -1,   -1,
   38,   -1,   40,   -1,   -1,   43,   -1,   45,   -1,   -1,
   -1,  273,  274,  275,  276,  277,  278,   -1,   -1,   -1,
  123,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,  273,  274,  273,  274,   -1,   -1,   -1,   -1,
   -1,   -1,  273,  274,  275,  276,  277,  278,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,  287,  288,  289,  290,
  291,   -1,   -1,   -1,  273,  274,  275,  276,  277,  278,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,  287,  288,
  289,  290,  291,   -1,   -1,  123,  273,  274,  275,  276,
  277,  278,   -1,   -1,   -1,  257,  258,  259,  260,   -1,
  287,  288,  289,  290,  291,  273,  274,  275,  276,  277,
  278,   -1,   -1,   -1,   -1,   -1,   -1,  279,  280,  287,
  288,  289,  290,  291,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,  275,  276,  277,
  278,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,  287,
  288,  289,  290,  291,  257,  258,  259,  260,   -1,  262,
  263,   -1,  265,  266,   -1,  268,   -1,  270,  271,  272,
   -1,   -1,   -1,   -1,   -1,   -1,  279,  280,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,  257,
  258,  259,  260,   -1,  262,  263,   -1,  265,  266,   -1,
  268,   -1,  270,  271,  272,   18,   19,   20,   -1,   22,
   -1,  279,  280,   -1,   -1,   -1,   -1,   -1,   -1,   32,
   33,   34,   -1,   -1,   37,   38,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   51,   52,
   53,   54,   55,   56,   57,   58,   59,   60,   61,   62,
   63,   64,   65,   66,   67,   68,   69,   70,   71,   72,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   88,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,  115,   -1,   -1,   -1,  119,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,  127,
);
my $YYFINAL=1;
my $YYMAXTOKEN=294;
my @yyname = (
"end-of-file",'','','','','','','','','',"'\\n'",'','','','','','','','','','','','','','','','','','','','',
'','',"'!'",'','','',"'%'","'&'",'',"'('","')'","'*'","'+'","','","'-'","'.'","'/'",'',
'','','','','','','','','','',"';'",'',"'='",'','','','','','','','','','','','','','','','','','','','','','','',
'','','','','','',"'['",'',"']'",'','','','','','','','','','','','','','','','','','','','','','','','','','','',
'','',"'{'","'|'","'}'",'','','','','','','','','','','','','','','','','','','','','','','','','','','','','',
'','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','',
'','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','','',
'','','','','','','','','','','','','','','','','','','','','','',"INT","FLOAT","STRING","IDENT",
"C_COMMENT","BREAK","DEFINE","AUTO","RETURN","PRINT","AUTO_LIST","IF","ELSE",
"QUIT","WHILE","FOR","EQ","NE","GT","GE","LT","LE","PP","MM","P_EQ","M_EQ",
"F_EQ","D_EQ","EXP_EQ","MOD_EQ","L_SHIFT","R_SHIFT","E_E","O_O","EXP","UNARY",
"PPP","MMM",
);
my @yyrule = (
"\$accept : stmt_list_exec",
"stmt_list_exec :",
"stmt_list_exec : stmt_list_exec stmt_exec",
"stmt_exec : terminator",
"stmt_exec : stmt_compile terminator",
"stmt_exec : error terminator",
"stmt_compile : QUIT",
"\$\$1 :",
"\$\$2 :",
"stmt_compile : DEFINE \$\$1 IDENT '(' arg_list ')' terminator_or_void '{' terminator auto_list \$\$2 stmt_list_block '}'",
"stmt_compile : return",
"stmt_compile : BREAK",
"\$\$3 :",
"stmt_compile : PRINT \$\$3 expr_list_commas",
"\$\$4 :",
"stmt_compile : '{' \$\$4 stmt_list_block '}'",
"\$\$5 :",
"stmt_compile : IF '(' stmt_compile ')' \$\$5 terminator_or_void stmt_compile",
"\$\$6 :",
"\$\$7 :",
"stmt_compile : WHILE \$\$6 '(' stmt_compile_or_void ')' terminator_or_void \$\$7 stmt_compile",
"\$\$8 :",
"\$\$9 :",
"\$\$10 :",
"stmt_compile : FOR '(' stmt_compile_or_void ';' \$\$8 stmt_compile_or_void ';' \$\$9 stmt_compile_or_void ')' \$\$10 terminator_or_void stmt_compile",
"stmt_compile : expr",
"return : RETURN",
"return : RETURN '(' expr ')'",
"stmt_compile_or_void :",
"stmt_compile_or_void : stmt_compile",
"stmt_list_block : stmt_compile_or_void",
"stmt_list_block : stmt_list_block terminator stmt_compile_or_void",
"terminator_or_void :",
"terminator_or_void : terminator",
"terminator : ';'",
"terminator : '\\n'",
"arg_list :",
"arg_list : arg_list_nonempty",
"arg_list_nonempty : IDENT",
"arg_list_nonempty : arg_list_nonempty ',' IDENT",
"param_list :",
"param_list : param_list_nonempty",
"param_list_nonempty : expr",
"param_list_nonempty : param_list_nonempty ',' expr",
"auto_list :",
"auto_list : AUTO auto_list_nonempty terminator",
"auto_list_nonempty : IDENT",
"auto_list_nonempty : auto_list_nonempty ',' IDENT",
"expr_list_commas : expr",
"expr_list_commas : expr_list_commas ',' expr",
"expr : IDENT '(' param_list ')'",
"expr : '(' expr ')'",
"expr : expr O_O expr",
"expr : expr E_E expr",
"expr : expr EQ expr",
"expr : expr NE expr",
"expr : expr GT expr",
"expr : expr GE expr",
"expr : expr LT expr",
"expr : expr LE expr",
"expr : expr L_SHIFT expr",
"expr : expr R_SHIFT expr",
"expr : expr '+' expr",
"expr : expr '-' expr",
"expr : expr '*' expr",
"expr : expr '/' expr",
"expr : expr EXP expr",
"expr : expr '%' expr",
"expr : ident P_EQ expr",
"expr : ident M_EQ expr",
"expr : ident F_EQ expr",
"expr : ident D_EQ expr",
"expr : ident EXP_EQ expr",
"expr : ident MOD_EQ expr",
"expr : '-' expr",
"expr : '!' expr",
"expr : PP ident",
"expr : MM ident",
"expr : ident PPP",
"expr : ident MMM",
"expr : '+' expr",
undef, # "expr : '&' STRING", # removed feature but we didn't want to disturb sequence
"expr : IDENT '=' expr",
"expr : IDENT '[' expr ']' '=' expr",
"expr : ident",
"expr : INT",
"expr : FLOAT",
"expr : STRING",
"ident : IDENT",
"ident : IDENT '[' expr ']'",
);
sub yyclearin { $yychar = -1; }
sub yyerrok { $yyerrflag = 0; }
my $YYSTACKSIZE = 500;
my @yyss;
my @yyvs;
$yyss[$YYSTACKSIZE] = 0;
$yyvs[$YYSTACKSIZE] = 0;

sub yy_err_recover
{
  if ($yyerrflag < 3)
  {
    $yyerrflag = 3;
    while (1)
    {
      if (($yyn = $yysindex[$yyss[$yyssp]]) &&
          ($yyn += $YYERRCODE) >= 0 &&
          $yycheck[$yyn] == $YYERRCODE)
      {
       print "yydebug: state $yyss[$yyssp], error recovery shifting",
             " to state $yytable[$yyn]\n" if $yydebug;
        $yyss[++$yyssp] = $yystate = $yytable[$yyn];
        $yyvs[++$yyvsp] = $yylval;
        return 1;
      }
      else
      {
        print "yydebug: error recovery discarding state ",
              $yyss[$yyssp], "\n"  if $yydebug;
        return(1) if $yyssp <= 0;
        --$yyssp;
        --$yyvsp;
      }
    }
  }
  else
  {
    return (1) if $yychar == 0;
    if ($yydebug)
    {
      my $yys = '';
      if ($yychar <= $YYMAXTOKEN) { $yys = $yyname[$yychar]; }
      if (!$yys) { $yys = 'illegal-symbol'; }
      print "yydebug: state $yystate, error recovery discards ",
            "token $yychar ($yys)\n";
    }
    return 1;
  }
0;
} # yy_err_recover

sub clear_flags
{
  yyclearin();
  $yyerrflag = $yyssp = $yyvsp = $yyss[0] = $yystate = 0;
}

sub yyparse
{
yyloop: while(1)
  {
    yyreduce: {
      last yyreduce if ($yyn = $yydefred[$yystate]);
      if ($yychar < 0)
      {
        if (($yychar = &yylex) < 0) { $yychar = 0; }
        if ($yydebug)
        {
          my $yys = '';
          if ($yychar <= $#yyname) { $yys = $yyname[$yychar]; }
          if (!$yys) { $yys = 'illegal-symbol'; };
          print "yydebug: state $yystate, reading $yychar ($yys)\n";
        }
      }
      if (($yyn = $yysindex[$yystate]) && ($yyn += $yychar) >= 0 &&
              $yycheck[$yyn] == $yychar)
      {
        print "yydebug: state $yystate, shifting to state ",
              $yytable[$yyn], "\n"  if $yydebug;
        $yyss[++$yyssp] = $yystate = $yytable[$yyn];
        $yyvs[++$yyvsp] = $yylval;
        yyclearin();
        --$yyerrflag if $yyerrflag > 0;
        next yyloop;
      }
      if (($yyn = $yyrindex[$yystate]) && ($yyn += $yychar) >= 0 &&
            $yycheck[$yyn] == $yychar)
      {
        $yyn = $yytable[$yyn];
        last yyreduce;
      }
      if (! $yyerrflag) {
        &yyerror('syntax error');
      }
      return(1) if &yy_err_recover;
    } # yyreduce
    print "yydebug: state $yystate, reducing by rule ",
          "$yyn ($yyrule[$yyn])\n"  if $yydebug;
    $yym = $yylen[$yyn];
    $yyval = $yyvs[$yyvsp+1-$yym];
    switch:
    {
if ($yyn == 4) {
{

		  my ($res, $val) = exec_stmt(shift @stmt_list);
		  if($res == 0 and defined($val) and
		     $cur_file ne 'main::DATA') {
		    print "$val\n";
		  }
		  start_stmt();

last switch;
} }
if ($yyn == 5) {
{
		  @ope_stack = ();
		  @stmt_list = ();
		  start_stmt();
		  &yyerrok;

last switch;
} }
if ($yyn == 7) {
{
		  start_stmt();

last switch;
} }
if ($yyn == 8) {
{
		  start_stmt();
		  start_stmt();

last switch;
} }
if ($yyn == 9) {
{
		  finish_stmt();    # The last one is empty
		  push_instr('RETURN', 0);
		  my $body = finish_stmt();
		  push_instr('{}', $body);
		  my $code = finish_stmt();
		  push_instr('FUNCTION-DEF', $yyvs[$yyvsp-10], $code);

last switch;
} }
if ($yyn == 11) {
{ push_instr('BREAK');
last switch;
} }
if ($yyn == 12) {
{
		  push_instr(',');
		  start_stmt();
		  start_stmt();

last switch;
} }
if ($yyn == 13) {
{
		  finish_stmt();  # The last one is empty
		  my $stmt = finish_stmt();
		  push_instr('PRINT', $stmt);

last switch;
} }
if ($yyn == 14) {
{
		  start_stmt();
		  start_stmt();

last switch;
} }
if ($yyn == 15) {
{
		  finish_stmt();  # The last one is empty
		  my $stmt = finish_stmt();
		  push_instr('{}', $stmt);

last switch;
} }
if ($yyn == 16) {
{ start_stmt();
last switch;
} }
if ($yyn == 17) {
{
		  my $stmt = finish_stmt();
		  push_instr('IF', $stmt);

last switch;
} }
if ($yyn == 18) {
{ start_stmt();
last switch;
} }
if ($yyn == 19) {
{
		  my $stmt = finish_stmt();
		  push_instr('FOR-COND', $stmt);
                  start_stmt();

last switch;
} }
if ($yyn == 20) {
{
		  my $stmt = finish_stmt();
		  push_instr('FOR-INCR', []);
		  push_instr('FOR-BODY', $stmt);

last switch;
} }
if ($yyn == 21) {
{ start_stmt();
last switch;
} }
if ($yyn == 22) {
{
		  my $stmt = finish_stmt();
		  push_instr('FOR-COND', $stmt);
		  start_stmt();

last switch;
} }
if ($yyn == 23) {
{
		  my $stmt = finish_stmt();
		  push_instr('FOR-INCR', $stmt);
		  start_stmt();

last switch;
} }
if ($yyn == 24) {
{
		  my $stmt = finish_stmt();
		  push_instr('FOR-BODY', $stmt);

last switch;
} }
if ($yyn == 26) {
{ push_instr('RETURN', 0);
last switch;
} }
if ($yyn == 27) {
{ push_instr('RETURN', 1);
last switch;
} }
if ($yyn == 30) {
{
		   my $stmt = finish_stmt();
		   if(scalar(@$stmt) > 0) {
		     push_instr('STMT', $stmt);
		   }
		   start_stmt();

last switch;
} }
if ($yyn == 31) {
{
		   my $stmt = finish_stmt();
		   if(scalar(@$stmt) > 0) {
		     push_instr('STMT', $stmt);
		   }
		   start_stmt();

last switch;
} }
if ($yyn == 38) {
{ push_instr('a', $yyvs[$yyvsp-0]);
last switch;
} }
if ($yyn == 39) {
{ push_instr('a', $yyvs[$yyvsp-0]);
last switch;
} }
if ($yyn == 46) {
{ push_instr('A', $yyvs[$yyvsp-0]);
last switch;
} }
if ($yyn == 47) {
{ push_instr('A', $yyvs[$yyvsp-0]);
last switch;
} }
if ($yyn == 48) {
{
		  my $stmt = finish_stmt();
		  push_instr('PRINT-STMT', $stmt);
		  start_stmt();

last switch;
} }
if ($yyn == 49) {
{
		  my $stmt = finish_stmt();
		  push_instr('PRINT-STMT', $stmt);
		  start_stmt();

last switch;
} }
if ($yyn == 50) {
{
		  push_instr('FUNCTION-CALL', $yyvs[$yyvsp-3]);

last switch;
} }
if ($yyn == 51) {
{
last switch;
} }
if ($yyn == 52) {
{ push_instr('||_');
last switch;
} }
if ($yyn == 53) {
{ push_instr('&&_');
last switch;
} }
if ($yyn == 54) {
{ push_instr('==_');
last switch;
} }
if ($yyn == 55) {
{ push_instr('!=_');
last switch;
} }
if ($yyn == 56) {
{ push_instr('>_');
last switch;
} }
if ($yyn == 57) {
{ push_instr('>=_');
last switch;
} }
if ($yyn == 58) {
{ push_instr('<_');
last switch;
} }
if ($yyn == 59) {
{ push_instr('<=_');
last switch;
} }
if ($yyn == 60) {
{ push_instr('<<_');
last switch;
} }
if ($yyn == 61) {
{ push_instr('>>_');
last switch;
} }
if ($yyn == 62) {
{ push_instr('+_');
last switch;
} }
if ($yyn == 63) {
{ push_instr('-_');
last switch;
} }
if ($yyn == 64) {
{ push_instr('*_');
last switch;
} }
if ($yyn == 65) {
{ push_instr('/_');
last switch;
} }
if ($yyn == 66) {
{ push_instr('^_');
last switch;
} }
if ($yyn == 67) {
{ push_instr('%_');
last switch;
} }
if ($yyn == 68) {
{
		  push_instr('+_');
		  push_instr('V', $yyvs[$yyvsp-2]);
		  push_instr('=V');

last switch;
} }
if ($yyn == 69) {
{
		  push_instr('-_');
		  push_instr('V', $yyvs[$yyvsp-2]);
		  push_instr('=V');

last switch;
} }
if ($yyn == 70) {
{
		  push_instr('*_');
		  push_instr('V', $yyvs[$yyvsp-2]);
		  push_instr('=V');

last switch;
} }
if ($yyn == 71) {
{
		  push_instr('/_');
		  push_instr('V', $yyvs[$yyvsp-2]);
		  push_instr('=V');

last switch;
} }
if ($yyn == 72) {
{
		  push_instr('^_');
		  push_instr('V', $yyvs[$yyvsp-2]);
		  push_instr('=V');

last switch;
} }
if ($yyn == 73) {
{
		  push_instr('%_');
		  push_instr('V', $yyvs[$yyvsp-2]);
		  push_instr('=V');

last switch;
} }
if ($yyn == 74) {
{
		  push_instr('m_');

last switch;
} }
if ($yyn == 75) {
{
		  push_instr('!_');

last switch;
} }
if ($yyn == 76) {
{
		  # 'v'.$2 has already been pushed in the 'ident' rule
		  push_instr('N', 1);
		  push_instr('+_');
		  push_instr('V', $yyvs[$yyvsp-0]);
		  push_instr('=V');

last switch;
} }
if ($yyn == 77) {
{
		  push_instr('N', 1);
		  push_instr('-_');
		  push_instr('V', $yyvs[$yyvsp-0]);
		  push_instr('=V');

last switch;
} }
if ($yyn == 78) {
{
		  # $1 is already on the stack (see the "ident:" rule)
		  push_instr('v', $yyvs[$yyvsp-1])     ;
		  push_instr('V', '*tmp') ;
		  push_instr('=V')        ;  # *tmp = $1
		  push_instr(',')         ;

		  push_instr('N', 1)      ;
		  push_instr('+_')        ;
		  push_instr('V', $yyvs[$yyvsp-1])     ;
		  push_instr('=V')        ;  # $1 = $1 + 1
		  push_instr(',')         ;

		  push_instr('v', '*tmp') ;  # Return *tmp


last switch;
} }
if ($yyn == 79) {
{
		  # See PPP for comments
		  push_instr('v', $yyvs[$yyvsp-1]);
		  push_instr('V', '*tmp');
		  push_instr('=V');
		  push_instr(',');
		  push_instr('N', 1);
		  push_instr('-_');
		  push_instr('V', $yyvs[$yyvsp-1]);
		  push_instr('=V');
		  push_instr(',');
		  push_instr('v', '*tmp');

last switch;
} }
if ($yyn == 80) {
{ $yyval = $yyvs[$yyvsp-0];
last switch;
} }
if ($yyn == 82) {
{
		  push_instr('V', $yyvs[$yyvsp-2]);
		  push_instr('=V');
		  $yyval = $yyvs[$yyvsp-0];

last switch;
} }
if ($yyn == 83) {
{
		  # Add [] to the name in order to allow the same name
		  # for an array and a scalar
		  push_instr('P', $yyvs[$yyvsp-5]);
		  push_instr('=P');
		  $yyval = $yyvs[$yyvsp-0];

last switch;
} }
if ($yyn == 84) {
{ $yyval = $yyvs[$yyvsp-0];
last switch;
} }
if ($yyn == 85) {
{ push_instr('N', $yyvs[$yyvsp-0]);
last switch;
} }
if ($yyn == 86) {
{ push_instr('N', $yyvs[$yyvsp-0]);
last switch;
} }
if ($yyn == 87) {
{ push_instr('S', $yyvs[$yyvsp-0]);
last switch;
} }
if ($yyn == 88) {
{ push_instr('v', $yyvs[$yyvsp-0]);
last switch;
} }
if ($yyn == 89) {
{
		  push_instr('p', $yyvs[$yyvsp-3]);
		  $yyval = $yyvs[$yyvsp-3].'[]'.$yyvs[$yyvsp-1];

last switch;
} }
    } # switch
    $yyssp -= $yym;
    $yystate = $yyss[$yyssp];
    $yyvsp -= $yym;
    $yym = $yylhs[$yyn];
    if ($yystate == 0 && $yym == 0)
    {
      print "yydebug: after reduction, shifting from state 0 ",
            "to state $YYFINAL\n" if $yydebug;
      $yystate = $YYFINAL;
      $yyss[++$yyssp] = $YYFINAL;
      $yyvs[++$yyvsp] = $yyval;
      if ($yychar < 0)
      {
        if (($yychar = &yylex) < 0) { $yychar = 0; }
        if ($yydebug)
        {
          my $yys = '';
          if ($yychar <= $#yyname) { $yys = $yyname[$yychar]; }
          if (!$yys) { $yys = 'illegal-symbol'; }
          print "yydebug: state $YYFINAL, reading $yychar ($yys)\n";
        }
      }
      return(0) if $yychar == 0;
      next yyloop;
    }
    if (($yyn = $yygindex[$yym]) && ($yyn += $yystate) >= 0 &&
        $yyn <= $#yycheck && $yycheck[$yyn] == $yystate)
    {
        $yystate = $yytable[$yyn];
    } else {
        $yystate = $yydgoto[$yym];
    }
    print "yydebug: after reduction, shifting from state ",
        "$yyss[$yyssp] to state $yystate\n" if $yydebug;
    $yyss[++$yyssp] = $yystate;
    $yyvs[++$yyvsp] = $yyval;
  } # yyloop
} # yyparse

my @file_list;
my $mathlib = 0;
sub command_line
{
  while (@ARGV && $ARGV[0] =~ m/\A\-/) {
    my $f = shift @ARGV;
    if ($f eq '-b') {
      eval { require Math::BigFloat } or die "This program requires the Math::BigFloat module\n";
      $bignum = 1;
    } elsif ($f eq '-d') {
      eval { require Data::Dumper; Data::Dumper->import; 1; } or die "This program requires the Data::Dumper module\n";
      $debug = 1;
    } elsif ($f eq '-y') {
      $yydebug = 1;
    } elsif ($f eq '-l') {
      $mathlib = 1;
    } elsif ($f eq '--') {
      last;
    } else {
      usage();
    }
  }
  if (@ARGV) {
    @file_list = @ARGV;
  } else {
    $do_stdin = 1;
  }
}

sub usage {
  warn "usage: bc [-b] [-d] [-y] [-l] [file ...]\n";
  exit 1;
}

# After finishing a file, open the next one.  Return whether there
# really is a next one that was opened.
sub next_file
{
  if (defined $input) {
    close $input;
    $input = undef;
  }
  if ($do_stdin) {
    $input = *STDIN;
    $do_stdin = 0;
    $cur_file = '-';
    return 1;
  }
  if (@file_list) {
    my $file = shift @file_list;

    debug { "reading from $file\n" };

    die "path '$file' is a directory\n" if (-d $file);
    open($input, '<', $file) or die("cannot open '$file': $!\n");
    $cur_file = $file;
    return 1;

  }

  debug { "no next file\n" };

  return 0;
}

# print an error message
sub yyerror
{
    print STDERR "\"$cur_file\", " if $cur_file ne '-';
#    debug { "yyerror-stmt_list : ".Dumper(\@stmt_list) };

    print STDERR "line $.: ", @_, "\n";

    @ope_stack = ();
    start_stmt();
}

# Hand-coded lex
sub yylex
{
 lexloop: {
   # get a line of input, if we need it.
   if ($line eq '')
	{
	  while(! ($line = <$input>)) {
	      &next_file || do {
		return(0); };
	  }
	}

	# Skip over white space, and grab the first character.
	# If there is no such character, then grab the next line.
	$line =~ s/^\s*(.|\n)//	|| next lexloop;
	my $char = $1;

	if ($char eq '/' and $line =~ /^\*/) {
          # C-style comment
 	  while($line !~ m%\*/%) {
	    $line = <$input>;
	  }
	  $line =~ s%.*?\*/% %;
	  yylex();
	}

        elsif ($char eq '#') {
	  # comment, so discard the line
	  $line = "\n";
	  &yylex;

	} elsif ($char eq '\\' and $line eq "\n") {

	  # Discard the newline
	  $line = '';
	  yylex();

	} elsif ($char =~ /^(['"])/) {

          $yylval = "";

          my $c = $1;
 	  while($line !~ /$c/) {
            $yylval .= $line;
	    $line = <$input>;
	  }

	  $line =~ s%(.*?)$c% %;
          $yylval .= $1;

	    $STRING;

	} elsif ($char =~ /^[\dA-F]/ or
		 ($char eq '.' and $line =~ /\d/)) {

	  if($char =~ /[A-F]/) {
	    &yyerror('Sorry, hexadecimal values are not supported');
	  }

	  $line = "0.$line" if($char eq '.');

          # number, is it integer or float?
	  if ($line =~ s/^(\d+)//) {
	      my $str = $char . $1;
	      $yylval = $bignum ? Math::BigFloat->new($str) : int($str);
          } else {
	      $yylval = $bignum ? Math::BigFloat->new($char) : int($char);
	  }
	  my $type = $INT;

	  if ($line =~ s/^(\.\d*)//) {
	      my $tmp = "0$1"; # ".1" -> "0.1"
	      $yylval += $tmp;
	      $type = $FLOAT;
	  }
	  if ($line =~ s/^[eE]([-+]*\d+)//) {
	      my $mult = $bignum ? Math::BigFloat->new('10') : 10;
	      $mult = $mult ** $1;
	      $yylval *= $mult;
	      $type = $FLOAT;
	  }

	  $type;

     } elsif ($char =~ /^[a-z]/) {
          # Uppercase is reserved for hexadecimal numbers
	  $line =~ s/^([\w\d]*)//;
	  $yylval = $char.$1;

	  if($yylval eq 'auto') {
	    $AUTO;
	  } elsif($yylval eq 'break') {
	    $BREAK;
	  } elsif($yylval eq 'define') {
	    $DEFINE;
	  } elsif($yylval eq 'for') {
	    $FOR;
	  } elsif($yylval eq 'if') {
	    $IF;
	  } elsif($yylval eq 'else') {
	    $ELSE;
	  } elsif($yylval eq 'print') {
	    $PRINT;
	  } elsif($yylval eq 'quit') {
	    # $QUIT;
	    # GNU bc exits immediately when it encounters quit, even if
	    # seen in unreachable code like "if (0 == 1) quit"
	    # OpenBSD bc acts like this too but calls it a bug
	    exit;
	  } elsif($yylval eq 'return') {
	    $RETURN;
	  } elsif($yylval eq 'while') {
	    $WHILE;
	  } else {
	    $IDENT;
	  }

	} elsif ($char eq '^' && $line =~ s/=//) {
	    $EXP_EQ;
	} elsif ($char eq '^') {
	    $EXP;
	} elsif ($char eq '|' && $line =~ s/^\|//) {
	    $O_O;
	} elsif ($char eq '&' && $line =~ s/^&//) {
	    $E_E;

	} elsif ($char eq '%' && $line =~ s/^=//) {
	    $MOD_EQ;
	} elsif ($char eq '!' && $line =~ s/^=//) {
	    $NE;
	} elsif ($char eq '=' && $line =~ s/^=//) {
	    $EQ;

	} elsif ($char =~ /^[<>]/ && $line =~ s/^=//) {
	    $char eq '<' ? $LE : $GE;
	} elsif ($char =~ /^[<>]/ && $line =~ s/^$char//) {
	    $char eq '<' ? $L_SHIFT : $R_SHIFT;
	} elsif ($char =~ /^[<>]/) {
	    $char eq '<' ? $LT : $GT;

 	} elsif ($char eq '+' && $line =~ s/^\+(\s*\w)/$1/) {
	    $PP;
	} elsif ($char eq '+' && $line =~ s/^=//) {
	    $P_EQ;
	} elsif ($char eq '+' && $line =~ s/^\+//) {
	    $PPP;
	} elsif ($char eq '-' && $line =~ s/^\-(\s*\w)/$1/) {
	    $MM;
	} elsif ($char eq '-' && $line =~ s/^\-//) {
	    $MMM;
	} elsif ($char eq '-' && $line =~ s/^=//) {
	    $M_EQ;
	} elsif ($char eq '*' && $line =~ s/^=//) {
	    $F_EQ;
	} elsif ($char eq '/' && $line =~ s/^=//) {
	    $D_EQ;
	} else {
	    $yylval = $char;
	    ord($char);
	}
    }
}

sub bi_length
{
  my $stack = shift;

  $_ = pop @$stack;
  die "length(n): missing argument\n" unless defined;

  my ($a, $b);
  die "NaN" unless ($a, $b) = /[-+]?(\d*)\.?(\d+)?/;

  $a =~ s/^0+//;
  $b =~ s/0+$//;

  my $len = length($a) + length($b);

  return $len == 0 ? 1 : $len;
}

sub bi_scale
{
  my $stack = shift;

  $_ = pop @$stack;
  die "scale(n): missing argument\n" unless defined;

  my ($a, $b);
  die "NaN" unless ($a, $b) = /[-+]?(\d*)\.?(\d+)?/;

  return length($b);
}

sub bi_sqrt
{
  my $stack = shift;

  $_ = pop @$stack;
  die "sqrt(n): missing argument\n" unless defined;

  return sqrt($_);
}

# mathlib sine function
sub bi_s
{
  my $stack = shift;

  my $val = pop @$stack;
  die "s(n): missing argument\n" unless defined $val;
  my $bignum = ref $val;
  $val = $val->numify() if $bignum;
  return sin($val);
}

# mathlib cosine function
sub bi_c
{
  my $stack = shift;

  my $val = pop @$stack;
  die "c(n): missing argument\n" unless defined $val;
  my $bignum = ref $val;
  $val = $val->numify() if $bignum;
  return cos($val);
}

# mathlib arctan function
sub bi_a
{
  my $stack = shift;

  my $val = pop @$stack;
  die "a(n): missing argument\n" unless defined $val;
  my $bignum = ref $val;
  $val = $val->numify() if $bignum;
  return Math::Trig::atan($val);
}

# mathlib ln function
sub bi_l
{
  my $stack = shift;

  my $val = pop @$stack;
  die "l(n): missing argument\n" unless defined $val;
  my $bignum = ref $val;
  $val = $val->numify() if $bignum;
  return log($val);
}

# mathlib exp function
sub bi_e
{
  my $stack = shift;

  my $val = pop @$stack;
  die "e(n): missing argument\n" unless defined $val;
  my $bignum = ref $val;
  $val = $val->numify() if $bignum;
  return exp($val);
}

# mathlib jn function
sub bi_j
{
  my $stack = shift;

  my $val = pop @$stack;
  my $n = pop @$stack;
  die "j(n,x): missing argument\n" if (!defined($n) || !defined($val));
  my $bignum = ref $val;
  $val = $val->numify() if $bignum;
  return POSIX::jn($n, $val);
}

# Initialize the symbol table
sub init_table
{
  $sym_table{'scale'} = { type => 'var', value => 0};
  $sym_table{'ibase'} = { type => 'var', value => 0};
  $sym_table{'obase'} = { type => 'var', value => 0};
  $sym_table{'last'} = { type => 'var', value => 0};

  register_builtin('length', \&bi_length);
  register_builtin('scale', \&bi_scale);
  register_builtin('sqrt', \&bi_sqrt);
  if ($mathlib) {
    register_builtin('a', \&bi_a);
    register_builtin('c', \&bi_c);
    register_builtin('e', \&bi_e);
    register_builtin('j', \&bi_j);
    register_builtin('l', \&bi_l);
    register_builtin('s', \&bi_s);
  }
}

sub register_builtin {
  my $name = shift;
  my $func = shift;

  $name .= '()';
  if (exists $sym_table{$name}) {
    die "conflicting builtin: $name\n";
  }
  $sym_table{$name} = { 'type' => 'builtin', 'value' => $func };
  return;
}

#
# Pseudo-code
#

# Compilation time: a stack of statements is maintained. Each statement
# is itself a stack of instructions.
# Each instruction is appended to the statement which is on the top.
# When a sub-block (IF, DEFINE...) is encountered, a
# new, empty statement is pushed onto the stack, and it receives the
# instructions in the sub-block.

my $cur_stmt;


# Pushes one instruction onto the current statement
# First element is the type, others are 0 or more arguments, depending on
# the type.
sub push_instr
{
  die "Internal error: no cur stmt" unless($cur_stmt);
  my @args = @_;
  push(@$cur_stmt, [ @args ]);
}

# Pushes a new statement onto the stack of statements, and makes it the
# current
sub start_stmt
{
  $cur_stmt = [];
  push(@stmt_list, $cur_stmt);
}

# Closes a statement, and returns a reference on it.
sub finish_stmt
{
  my $stmt = pop @stmt_list;
  $cur_stmt = $stmt_list[$#stmt_list];
  return $stmt;
}

my ($res, $val);

#
# exec_stmt
# Really executes a statement. Calls itself recursively when it
# encounters sub-statements (in block, loops, functions...)
#
sub exec_stmt
{
  my $stmt = shift;

  my $return = 0; # 1 if a "return" statement is encountered

  my @stmt_s = @$stmt;
#  print STDERR "ko\n";"executing statement: ".Dumper(\@stmt_s);


# Each instruction in the stack is an array which first element gives
# the type. Others elements may contain references to sub-statements

  my $instr;

 INSTR: while (defined($instr = shift @stmt_s)) {

   $_ = $instr->[0];

   print STDERR ("instruction: ".join(', ', @$instr)."\n" ) if $debug;

# remove the stack top value, and forget about it
   if($_ eq ',') {
     $res = pop @ope_stack;
     next INSTR;

   } elsif($_ eq 'N') {

# N for number
     push(@ope_stack, 0 + $instr->[1]);
     next INSTR;

   } elsif($_ eq '+_'  or $_ eq '-_'  or $_ eq '*_'  or $_ eq '/_'  or
	   $_ eq '^_'  or $_ eq '%_'  or $_ eq '==_' or $_ eq '!=_' or
	   $_ eq '>_'  or $_ eq '>=_' or $_ eq '<_'  or $_ eq '<=_' or
	   $_ eq '<<_' or $_ eq '>>_' or $_ eq '||_' or $_ eq '&&_') {

# Binary operators
	  my $b = pop(@ope_stack); my $a = pop(@ope_stack);

	  if   ($_ eq '+_') { $res = $a + $b    ; 1 }
	  elsif($_ eq '-_') { $res = $a - $b    ; 1 }
	  elsif($_ eq '*_') { $res = $a * $b    ; 1 }
	  elsif($_ eq '/_') { die 'divide by 0' if ($bignum ? $b->is_zero : $b == 0); $res = $a / $b }
	  elsif($_ eq '^_') { $res = $a ** $b   ; 1 }
	  elsif($_ eq '%_') { die 'modulo by 0' if ($bignum ? $b->is_zero : $b == 0); $res = $a % $b }

	  elsif($_ eq '==_') { $res = 0 + ($a == $b) ; 1 }
	  elsif($_ eq '!=_') { $res = 0 + ($a != $b) ; 1 }
	  elsif($_ eq '>_')  { $res = 0 + ($a > $b)  ; 1 }
	  elsif($_ eq '>=_') { $res = 0 + ($a >= $b) ; 1 }
	  elsif($_ eq '<_')  { $res = 0 + ($a < $b)  ; 1 }
	  elsif($_ eq '<=_') { $res = 0 + ($a <= $b) ; 1 }

	  elsif($_ eq '<<_') { $res = ($a << $b) ; 1 }
	  elsif($_ eq '>>_') { $res = ($a >> $b) ; 1 }

	  elsif($_ eq '||_') { $res = ($a || $b) ? 1 : 0 ; 1 }
	  elsif($_ eq '&&_') { $res = ($a && $b) ? 1 : 0 ; 1 }

	  ;

	  push(@ope_stack, $res);
	  next INSTR;


# Unary operators

   } elsif($_ eq 'm_') {

     $res = pop(@ope_stack);
     push(@ope_stack, -$res);
     next INSTR;

   } elsif($_ eq '!_') {

     $res = pop(@ope_stack);
     push(@ope_stack, 0+!$res);
     next INSTR;

   } elsif($_ eq 'V') {

# Variable or array identifier
     push(@ope_stack, $instr->[1]);
     next INSTR;

   } elsif($_ eq 'P') {
     my $index = splice @ope_stack, -2, 1; # rval remains top of stack
     $index = floor_idx($index);
     if ($index == -1) {
       print STDERR "Non-integer index $index for array\n";
       $return = 3;
       @ope_stack = ();
       @stmt_list=();
       last INSTR;
     }
     push @ope_stack, $instr->[1] . '[]' . $index;
     next INSTR;

   } elsif($_ eq 'v') {

# Variable value : initialized to 0
# '*' is reserved for internal variables

     my $name = $instr->[1];
     unless (defined($sym_table{$name})
	     and $sym_table{$name}{'type'} eq 'var') {
       $sym_table{$name}{'value'} = 0;
       $sym_table{$name}{'type'} = 'var';
     }
     push(@ope_stack, $sym_table{$name}{'value'});
     next INSTR;

   } elsif($_ eq 'p') {

# Array value : initialized to 0
     my ($name, $idx) = ($instr->[1], pop(@ope_stack));
     $idx = floor_idx($idx);
     if ($idx == -1) {
       print STDERR "Non-integer index $idx for array\n";
       $return = 3;
       @ope_stack = ();
       @stmt_list=();
       last INSTR;
     }

#     debug {"p: $name, $idx.\n"};
     $name .= '[]';
     unless (defined($sym_table{$name})
	     and $sym_table{$name}{'type'} eq 'array') {

       $sym_table{$name} = { type => 'array'};
     }
     unless ($sym_table{$name}{'value'}[$idx]) {
       $sym_table{$name}{'value'}[$idx] = { type => 'var',
					    value => 0 };
     }
     push(@ope_stack, $sym_table{$name}{'value'}[$idx]{'value'});
     next INSTR;

   } elsif($_ eq '=V') {

# Attribution of a value to a variable
# ope_stack ends with a NUMBER and an IDENTIFIER
     my $varName = pop(@ope_stack);
     my $value = pop(@ope_stack);
     $sym_table{$varName} = { type => 'var',
			      value => $value };
     push(@ope_stack, $value);
     $return = 3; # do not print result
     next INSTR;

   } elsif($_ eq '=P') {

     my $varName = pop(@ope_stack);
     my $value = pop(@ope_stack);
     my ($name, $idx) = split /\[\]/, $varName, 2;
     $name .= '[]';
     unless (defined($sym_table{$name})
	     and $sym_table{$name}{'type'} eq 'array')
     {
       $sym_table{$name} = { type => 'array',
			     value => [] };
     }
     $sym_table{$name}{'value'}[$idx] = { type => 'var',
					  value => $value };
     push(@ope_stack, $value);
     $return = 3; # do not print result
     next INSTR;

   } elsif($_ eq 'IF') {
# IF statement

     my $cond = pop @ope_stack;
     if($cond) {
       ($return, $val) = exec_stmt($instr->[1]);
       push(@ope_stack, $val), last INSTR if $return;
     } else {
       $val = undef;
     }

#     debug {"IF: $val.\n"};
     push(@ope_stack, $val);
#     debug {"IF: ope_stack=".Dumper(\@ope_stack)};
     next INSTR;

   } elsif($_ eq 'FOR-COND') {
# WHILE and FOR statement

#     debug {"while-cond: stmt_s=".Dumper(\@stmt_s)};

     my $i_cond = $instr;
     my $i_incr = shift @stmt_s;
     my $i_body = shift @stmt_s;

     $val = 1;

#     debug { "cond: ".Dumper($i_cond) };

   LOOP: while(1) {

     @ope_stack=();
     if($#{ $i_cond->[1] } >= 0) {
       ($return, $val) = exec_stmt($i_cond->[1]);
#       debug {"results of cond: $return, $val"};
       push(@ope_stack, $val), last INSTR
	 if($return == 1 or $return == 2);
       last LOOP if $val == 0;
     }

#     debug {"while: executing a body\n"};

     if($#{ $i_body->[1] } >= 0) {
       ($return, $val) = exec_stmt($i_body->[1]);
       push(@ope_stack, $val);

       if($return == 1) {
	 last INSTR;
       } elsif($return == 2) {
	 $return = 0 ;
	 last INSTR;
       }
     }

     if($#{ $i_incr->[1] } >= 0) {
#       debug {"for: executing the increment: ".Dumper($i_incr)};
       @ope_stack = ();
       ($return, $val) = exec_stmt($i_incr->[1]);
	 push(@ope_stack, $val);
	 last INSTR if($return == 1 or $return == 2);
     }

   }
     $return = 3;
     push(@ope_stack, 1);  # whatever
     next INSTR;

   } elsif($_ eq 'FUNCTION-CALL') {

# Function call
     push @backup_sym_table, undef;   # Hmmm...

     my $name = $instr->[1];
     $name .= '()';

     unless($sym_table{$name}) {
       print STDERR "No function $name has been defined\n";
       @ope_stack = (0);
       $return = 3;
       last INSTR;
     }

     if($sym_table{$name}{type} eq 'builtin') {
       ($return, $val) =
	 (1, &{ $sym_table{$name}{value} }(\@ope_stack));
     } else {
       ($return, $val) = exec_stmt($sym_table{$name}{'value'});

# Restore the symbols temporarily pushed in 'a' and 'A' instructions
       debug {"restoring backup: ".Dumper(\@backup_sym_table)};

#       pop @backup_sym_table;    # The first is undef
       while($var = pop @backup_sym_table) {
	 debug {"restoring var: ".Dumper($var)};
	 if($var->{'type'} eq 'undef') {
	   delete $sym_table{$var->{'name'}};;
	 } else {
	   $sym_table{$var->{'name'}} = $var->{'entry'};
	 }
       }

#       push @backup_sym_table, undef;
     }

#     debug {"result from function $name: $return, $val.\n"};
     push(@ope_stack, $val);

     if($return == 1) {
       $return = 0; # so the result will be printed
     } elsif($return == 2) {
       print STDERR "No enclosing while or for";
       yy_err_recover();
     } elsif($return == 3) {
       $return = 0;
     }
     next INSTR;

   } elsif($_ eq 'a' or $_ eq  'A') {

# Function arguments and auto list declaration
# The difference is that function arguments are initialized from the
# operation stack, while auto variables are initialized to zero
     my ($where, $name) = ($_, $instr->[1]);

     if(defined $sym_table{$name}) {
       debug { "backup $name, $sym_table{$name}\n" };
       push @backup_sym_table,  { name => $name,
				    entry => $sym_table{$name} };
     } else {
       debug { "backup $name, undef \n" };
       push @backup_sym_table,  { name => $name,
				    type => 'undef' };
     }
     $sym_table{$name} = { type => 'var',
			   value => ($where eq 'a' ?
				     shift(@ope_stack) : 0) };

#     debug { "new entry $name in sym table: $sym_table{$name}{'value'}" };
     next INSTR;

   } elsif($_ eq '{}') {

# Grouped statements
     if(scalar @{ $instr->[1] } > 0) {
       ($return, $val) = exec_stmt($instr->[1]);
     } else {
       ($return, $val) = (0, 0);
     }

     push(@ope_stack, $val), last INSTR
       if($return eq 1 or $return eq 2);

     $return = 3;
     push(@ope_stack, $val);
     next INSTR;

   } elsif($_ eq 'STMT') {

     @ope_stack=();
     if(scalar $instr->[1] > 0) {
       ($return, $val) = exec_stmt($instr->[1]);
     } else {
       ($return, $val) = (3, undef);
     }

     @ope_stack = ($val), last INSTR
	if($return eq 1 or $return eq 2);

     $return = 3;
     @ope_stack = ($val);

     next INSTR;

   } elsif($_ eq 'RETURN') {
# Return statement

#     debug {"returning $instr->[1].\n"};
     my $value = ($instr->[1] == 0) ? 0
       : pop(@ope_stack);

     $return = 1;
     @ope_stack = ($value);

     last INSTR;

   } elsif($_ eq 'BREAK') {
# Break statement

#     debug {"breaking.\n"};

     $return = 1;
     push(@ope_stack, 0);

     last INSTR;

   } elsif($_ eq 'PRINT') {
# PRINT statement

     if(scalar @{ $instr->[1] } > 0) {
       ($return, $val) = exec_stmt($instr->[1]);
     } else {
       ($return, $val) = (0, 0);
     }

     push(@ope_stack, $val), last INSTR
       if($return eq 1 or $return eq 2);

     $return = 3;
     next INSTR;

   } elsif($_ eq 'PRINT-STMT') {

     @ope_stack=();
     if(scalar $instr->[1] > 0) {
       ($return, $val) = exec_stmt($instr->[1]);
     } else {
       ($return, $val) = (3, undef);
     }

     last INSTR if($return eq 1 or $return eq 2);

     $return = 3;

     print $val;
     next INSTR;

   } elsif($_ eq 'FUNCTION-DEF') {

# Function definition
     my ($name, $code) = ($instr->[1], $instr->[2]);
     push(@$code, ["RETURN", 0]);
     $sym_table{$name.'()'} = { type => 'func',
				value => $code };
     $return = 3;
     push(@ope_stack, 1); # whatever
     next INSTR;

   } elsif($_ eq 'S') {

# S for string
     $_ = $instr->[1];
     s/ \\a  /\a/gx;
     s/ \\b  /\b/gx;
     s/ \\f  /\f/gx;
     s/ \\n  /\n/gx;
     s/ \\r  /\r/gx;
     s/ \\t  /\t/gx;
     s/ \\q  /"/gx;   # "
     s/ \\\\ /\\/gx;
     push(@ope_stack, $_);
     next INSTR;

   } else {

     die "internal error: illegal statement $_";

   }

 }

  if ($return == 3) {
    @ope_stack = ();
  } else {
    if(scalar @ope_stack != 1) {
      die("internal error: ope_stack = ".join(", ", @ope_stack).".\n");
    }

    $val = pop(@ope_stack);
#    debug {"Returning ($return, $val)\n"};
#    debug {"ope_stack at e-o-func: ".Dumper(\@ope_stack)};
  }

  return ($return, $val);

}

sub floor_idx {
  my $idx = shift;
  if ($idx =~ m/\A([0-9]+)\.?/) {
    return $1;
  }
  return -1;
}

sub main
{
  my $status;
  while(1)
    {
      $line = '';
      eval {
        clear_flags();
        $status = yyparse();
        1;
      } or do {
        yyerror($@);
      };

      exit $status if ! $@;
    }
}

select(STDERR);
$| = 1;
select(STDOUT);

command_line();
init_table();
next_file();
start_stmt();
main();

__END__