ledger/parsexp.h
2008-07-22 03:48:35 -04:00

261 lines
6.7 KiB
C++

/*
* Copyright (c) 2003-2007, John Wiegley. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of New Artisans LLC nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _PARSEXP_H
#define _PARSEXP_H
#include "valexpr.h"
namespace ledger {
namespace expr {
DECLARE_EXCEPTION(error, parse_error);
class parser_t
{
#define EXPR_PARSE_NORMAL 0x00
#define EXPR_PARSE_PARTIAL 0x01
#define EXPR_PARSE_RELAXED 0x02
#define EXPR_PARSE_NO_MIGRATE 0x04
#define EXPR_PARSE_NO_REDUCE 0x08
#define EXPR_PARSE_ALLOW_DATE 0x10
public:
typedef uint_least8_t flags_t;
private:
struct token_t
{
enum kind_t {
VALUE, // any kind of literal value
IDENT, // [A-Za-z_][-A-Za-z0-9_:]*
DOLLAR, // $
AT_SYM, // @
DOT, // .
DOTDOT, // ..
SLASH, // /
LPAREN, // (
RPAREN, // )
LBRACKET, // [
RBRACKET, // ]
EQUAL, // =
NEQUAL, // !=
LESS, // <
LESSEQ, // <=
GREATER, // >
GREATEREQ, // >=
MINUS, // -
PLUS, // +
STAR, // *
KW_DIV,
EXCLAM, // !
KW_AND,
KW_OR,
KW_MOD,
#if 0
PIPE, // |
KW_UNION,
#endif
COMMA, // ,
TOK_EOF,
UNKNOWN
} kind;
char symbol[3];
value_t value;
std::size_t length;
explicit token_t() : kind(UNKNOWN), length(0) {
TRACE_CTOR(token_t, "");
}
token_t(const token_t& other) {
assert(false);
TRACE_CTOR(token_t, "copy");
*this = other;
}
~token_t() {
TRACE_DTOR(token_t);
}
token_t& operator=(const token_t& other) {
if (&other == this)
return *this;
assert(false);
return *this;
}
void clear() {
kind = UNKNOWN;
length = 0;
value = NULL_VALUE;
symbol[0] = '\0';
symbol[1] = '\0';
symbol[2] = '\0';
}
void parse_ident(std::istream& in);
void next(std::istream& in, flags_t flags);
void rewind(std::istream& in);
void unexpected();
static void unexpected(char c, char wanted = '\0');
};
mutable token_t lookahead;
mutable bool use_lookahead;
token_t& next_token(std::istream& in, flags_t tflags) const
{
if (use_lookahead)
use_lookahead = false;
else
lookahead.next(in, tflags);
return lookahead;
}
void push_token(const token_t& tok) const
{
assert(&tok == &lookahead);
use_lookahead = true;
}
void push_token() const
{
use_lookahead = true;
}
public:
value_expr expr;
private:
ptr_op_t parse_value_term(std::istream& in, scope_t& scope,
const flags_t flags) const;
#if 0
ptr_op_t parse_predicate_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
ptr_op_t parse_path_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
#endif
ptr_op_t parse_unary_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
#if 0
ptr_op_t parse_union_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
#endif
ptr_op_t parse_mul_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
ptr_op_t parse_add_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
ptr_op_t parse_logic_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
ptr_op_t parse_and_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
ptr_op_t parse_or_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
ptr_op_t parse_querycolon_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
ptr_op_t parse_value_expr(std::istream& in, scope_t& scope,
const flags_t flags) const;
value_expr& parse_expr(std::istream& in, string& str,
scope_t& scope, const flags_t flags) {
try {
ptr_op_t top_node = parse_value_expr(in, scope, flags);
expr = value_expr(top_node, str);
if (use_lookahead) {
use_lookahead = false;
lookahead.rewind(in);
}
lookahead.clear();
}
catch (error * err) {
err->context.push_back
(new line_context(str, (long)in.tellg() - 1,
"While parsing value expression:"));
throw err;
}
return expr;
}
public:
parser_t() : use_lookahead(false) {}
value_expr& parse(std::istream& in,
const flags_t flags = EXPR_PARSE_RELAXED)
{
return parse_expr(in, empty_string, *global_scope, flags);
}
value_expr& parse(std::istream& in,
const flags_t flags = EXPR_PARSE_RELAXED,
scope_t& scope)
{
return parse_expr(in, empty_string, scope, flags);
}
value_expr& parse(string& str, const flags_t flags = EXPR_PARSE_RELAXED)
{
std::istringstream stream(str);
return parse_expr(stream, str, *global_scope, flags);
}
value_expr& parse(string& str, const flags_t flags = EXPR_PARSE_RELAXED,
scope_t& scope)
{
std::istringstream stream(str);
return parse_expr(stream, str, scope, flags);
}
};
void dump(std::ostream& out, const ptr_op_t node, const int depth = 0);
bool print(std::ostream& out,
const ptr_op_t node,
const bool relaxed = true,
const ptr_op_t node_to_find = NULL,
unsigned long * start_pos = NULL,
unsigned long * end_pos = NULL);
} // namespace expr
} // namespace ledger
#endif // _PARESXP_H