Imager::Expr::Assem(3)User Contributed Perl DocumentatioImager::Expr::Assem(3)NAMEImager::Expr::Assem - an assembler for producing code for the Imager
register machine
SYNOPSIS
use Imager::Expr::Assem;
my $expr = Imager::Expr->new(assem=>'...', ...)
DESCRIPTION
This module is a simple Imager::Expr compiler that compiles a low-level
language that has a nearly 1-to-1 relationship to the internal
representation used for compiled register machine code.
Syntax
Each line can contain multiple statements separated by semi-colons.
Anything after '#' in a line is ignored.
Types of statements:
variable definition
"var" name:type
defines variable name to have type, which can be any of "n" or
"num" for a numeric type or "pixel", "p" or "c" for a pixel or
color type.
Variable names cannot include white-space.
operators
Operators can be split into 3 basic types, those that have a result
value, those that don't and the null operator, eg. jump has no
value.
The format for operators that return a value is typically:
result = operator operand ...
and for those that don't return a value:
operator operand
where operator is any valid register machine operator, result is
any variable defined with "var", and operands are variables,
constants or literals, or for jump operators, labels.
The set operator can be simplified to:
result = operator
All operators maybe preceded by a label, which is any non-white-
space text immediately followed by a colon (':').
BUGS
Note that the current optimizer may produce incorrect optimization for
your code, fortunately the optimizer will disable itself if you include
any jump operator in your code. A single jump to anywhere after your
final "ret" operator can be used to disable the optimizer without
slowing down your code.
There's currently no high-level code generation that can generate code
with loops or real conditions.
SEE ALSOImager(3), transform.perl, regmach.c
AUTHOR
Tony Cook <tony@develop-help.com>
perl v5.14.3 2012-09-28 Imager::Expr::Assem(3)
