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/*
* cook - file construction tool
* Copyright (C) 1997 Peter Miller;
* All rights reserved.
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
*
* MANIFEST: functions to manipulate expression constant nodes
*/
#include <expr.h>
#include <expr/constant.h>
#include <expr/position.h>
#include <match.h>
#include <opcode/list.h>
#include <opcode/string.h>
#include <str_list.h>
typedef struct expr_constant_ty expr_constant_ty;
struct expr_constant_ty
{
expr_ty inherited;
string_ty *value;
expr_position_ty pos;
};
/*
* NAME
* destructor - release expression node resources
*
* SYNOPSIS
* void destructor _((expr_ty *));
*
* DESCRIPTION
* The destructor function is used to release any resources
* (dynamic memory, file descriptors, etc) which may be used the
* this expression node.
*
* CAVEAT
* It does NOT free the expression_node itself (this is the
* destructor, not delete).
*/
static void destructor _((expr_ty *));
static void
destructor(ep)
expr_ty *ep;
{
expr_constant_ty *this;
/* assert(ep->method == &method); */
this = (expr_constant_ty *)ep;
str_free(this->value);
this->value = 0;
expr_position_destructor(&this->pos);
}
/*
* NAME
* equal - test expression node equality
*
* SYNOPSIS
* int equal(expr_ty *e1, expr_ty *e2);
*
* DESCRIPTION
* The equal function is called to determine if two expression
* nodes are the same.
*
* RETURNS
* int; 1 if equal, 00 if not
*
* CAVEAT
* The expression nodes are already known to the the same class
* before this method is invoked.
*/
static int equal _((const expr_ty *, const expr_ty *));
static int
equal(a1, a2)
const expr_ty *a1;
const expr_ty *a2;
{
const expr_constant_ty *e1;
const expr_constant_ty *e2;
/* assert(e1->method == &method); */
/* assert(e2->method == &method); */
e1 = (const expr_constant_ty *)a1;
e2 = (const expr_constant_ty *)a2;
return str_equal(e1->value, e2->value);
}
/*
* NAME
* code_generate
*
* SYNOPSIS
* void code_generate(const expr_ty *, opcode_list_ty *);
*
* DESCRIPTION
* The code_generate function is used to generate code for the
* expression tree represented by this node.
*/
static void code_generate _((const expr_ty *, opcode_list_ty *));
static void
code_generate(ep, olp)
const expr_ty *ep;
opcode_list_ty *olp;
{
const expr_constant_ty *this;
/* assert(ep->method == &method); */
this = (const expr_constant_ty *)ep;
opcode_list_append(olp, opcode_string_new(this->value, &this->pos));
}
/*
* NAME
* method - class method table
*
* DESCRIPTION
* This is the class method table. It contains a description of
* the class, its name, size and pointers to its virtual methods.
*
* CAVEAT
* This symbol is NOT to be exported from this file scope.
*/
static expr_method_ty method =
{
"constant",
sizeof(expr_constant_ty),
destructor,
equal,
code_generate,
};
/*
* NAME
* expr_constant_new - create a new constant expression node
*
* SYNOPSIS
* expr_ty *expr_constant_new(string_ty *);
*
* DESCRIPTION
* The expr_constant_new function is used to create a new instance
* of a constant expression node.
*
* RETURNS
* expr_ty *; pointer to polymorphic expression instance.
*
* CAVEAT
* This function allocates data in dynamic memory. It is the
* caller's responsibility to free this data, using expr_delete,
* when it is no longer required.
*/
expr_ty *
expr_constant_new(s, pp)
string_ty *s;
const expr_position_ty *pp;
{
expr_ty *ep;
expr_constant_ty *this;
ep = expr_private_new(&method);
this = (expr_constant_ty *)ep;
this->value = str_copy(s);
expr_position_copy_constructor(&this->pos, pp);
return ep;
}
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