detect.c

/**
 * YAML parser and emitter PHP extension
 *
 * Copyright (c) 2007 Ryusuke SEKIYAMA. All rights reserved.
 * Copyright (c) 2009 Keynetics Inc. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * @package     php_yaml
 * @author      Ryusuke SEKIYAMA <rsky0711@gmail.com>
 * @author      Bryan Davis <bpd@keynetics.com>
 * @copyright   2007 Ryusuke SEKIYAMA
 * @copyright   2009 Keynetics Inc
 * @license     http://www.opensource.org/licenses/mit-license.php  MIT License
 * @version     SVN: $Id$
 */


#include "php_yaml.h"
#include "php_yaml_int.h"


/* {{{ local macros
 */
#define ts_skip_space() \
	while (ptr < end && (*ptr == ' ' || *ptr == '\t')) { \
		ptr++; \
	}

#define ts_skip_number() \
	while (ptr < end && *ptr >= '0' && *ptr <= '9') { \
		ptr++; \
	}

/* }}} */


/* {{{ local prototypes
 */
static long eval_sexagesimal_l(long lval, char *sg, char *eos);

static double eval_sexagesimal_d(double dval, char *sg, char *eos);

/* }}} */


/* {{{ detect_scalar_type(const char *, size_t, yaml_event_t)
 * Guess what datatype the scalar encodes
 */
char *detect_scalar_type(const char *value, size_t length,
		const yaml_event_t *event)
{
	int flags = 0;
	long lval = 0;
	double dval = 0.0;

	/* is value a null? */
	if (0 == length || scalar_is_null(value, length, event)) {
		return YAML_NULL_TAG;
	}

	/* is value numeric? */
	flags = scalar_is_numeric(value, length, &lval, &dval, NULL);
	if (flags != Y_SCALAR_IS_NOT_NUMERIC) {
		return (flags & Y_SCALAR_IS_FLOAT) ? YAML_FLOAT_TAG : YAML_INT_TAG;
	}

	/* is value boolean? */
	flags = scalar_is_bool(value, length, event);
	if (-1 != flags) {
		return YAML_BOOL_TAG;
	}

	/* is value a timestamp? */
	if (scalar_is_timestamp(value, length)) {
		return YAML_TIMESTAMP_TAG;
	}

	/* no guess */
	return NULL;
}
/* }}} */


/* {{{ scalar_is_null(const char *,size_t,yaml_event_t)
 * Does this scalar encode a NULL value?
 *
 * specification is found at http://yaml.org/type/null.html.
 */
int
scalar_is_null(const char *value, size_t length,
		const yaml_event_t *event)
{
	if (NULL != event && event->data.scalar.quoted_implicit) {
		return 0;
	}

	if (NULL == event || event->data.scalar.plain_implicit) {
		if ((length == 1 && *value == '~') || length == 0 ||
				STR_EQ("NULL", value) || STR_EQ("Null", value) ||
				STR_EQ("null", value)) {
			return 1;
		}

	} else if (NULL != event && SCALAR_TAG_IS((*event), YAML_NULL_TAG)) {
		return 1;
	}

	return 0;
}
/* }}} */


/* {{{ scalar_is_bool(const char *,size_t,yaml_event_t)
 * Does this scalar encode a BOOL value?
 *
 * specification is found at http://yaml.org/type/bool.html.
 */
int
scalar_is_bool(const char *value, size_t length,
		const yaml_event_t *event)
{
	/* TODO: add ini setting to turn 'y'/'n' checks on/off */
	if (NULL == event || IS_NOT_QUOTED_OR_TAG_IS((*event), YAML_BOOL_TAG)) {
		if ((length == 1 && (*value == 'Y' || *value == 'y')) ||
				STR_EQ("YES", value) || STR_EQ("Yes", value) ||
				STR_EQ("yes", value) || STR_EQ("TRUE", value) ||
				STR_EQ("True", value) || STR_EQ("true", value) ||
				STR_EQ("ON", value) || STR_EQ("On", value) ||
				STR_EQ("on", value)) {
			return 1;
		}

		if ((length == 1 && (*value == 'N' || *value == 'n')) ||
				STR_EQ("NO", value) || STR_EQ("No", value) || 
				STR_EQ("no", value) || STR_EQ("FALSE", value) || 
				STR_EQ("False", value) || STR_EQ("false", value) ||
				STR_EQ("OFF", value) || STR_EQ("Off", value) ||
				STR_EQ("off", value)) {
			return 0;
		}

	} else if (NULL != event &&
			IS_NOT_IMPLICIT_AND_TAG_IS((*event), YAML_BOOL_TAG)) {
		if (0 == length || (1 == length && '0' == *value)) {
			return 0;
		} else {
			return 1;
		}
	}

	return -1;
}
/* }}} */


/* {{{ scalar_is_numeric()
 * Does this scalar encode a NUMERIC value?
 *
 * specification is found at http://yaml.org/type/float.html.
 * specification is found at http://yaml.org/type/int.html.
 */
int
scalar_is_numeric(const char *value, size_t length, long *lval,
		double *dval, char **str)
{
	const char *end = value + length;
	char *buf = { 0 }, *ptr = { 0 };
	int negative = 0;
	int type = 0;

	if (0 == length) {
		goto not_numeric;
	}

	/* trim */
	while (value < end && (*(end - 1) == ' ' || *(end - 1) == '\t')) {
		end--;
	}

	while (value < end && (*value == ' ' || *value == '\t')) {
		value++;
	}

	if (value == end) {
		goto not_numeric;
	}

	/* not a number */
	if (STR_EQ(".NAN", value) || STR_EQ(".NaN", value) ||
			STR_EQ(".nan", value)) {
		type = Y_SCALAR_IS_FLOAT | Y_SCALAR_IS_NAN;
		goto finish;
	}

	/* sign */
	if (*value == '+') {
		value++;

	} else if (*value == '-') {
		negative = 1;
		value++;
	}

	if (value == end) {
		goto not_numeric;
	}

	/* infinity */
	if (STR_EQ(".INF", value) || STR_EQ(".Inf", value) ||
			STR_EQ(".inf", value)) {
		type = Y_SCALAR_IS_FLOAT;
		type |= (negative ? Y_SCALAR_IS_INFINITY_N : Y_SCALAR_IS_INFINITY_P);
		goto finish;
	}

	/* alloc */
	buf = (char *) emalloc(length + 3);
	ptr = buf;
	if (negative) {
		*ptr++ = '-';
	}

	/* parse */
	if (*value == '0') {
		*ptr++ = *value++;
		if (value == end) {
			goto return_zero;
		}

		if (*value == 'b') {
			/* binary integer */
			*ptr++ = *value++;
			if (value == end) {
				goto not_numeric;
			}

			while (value < end && (*value == '_' || *value == '0')) {
				value++;
			}

			if (value == end) {
				goto return_zero;
			}

			/* check the sequence */
			while (value < end) {
				if (*value == '_') {
					value++;

				} else if (*value == '0' || *value == '1') {
					*ptr++ = *value++;

				} else {
					goto not_numeric;
				}
			}

			type = Y_SCALAR_IS_INT | Y_SCALAR_IS_BINARY;

		} else if (*value == 'x') {
			/* hexadecimal integer */
			*ptr++ = *value++;

			if (value == end) {
				goto not_numeric;
			}

			while (value < end && (*value == '_' || *value == '0')) {
				value++;
			}

			if (value == end) {
				goto return_zero;
			}

			/* check the sequence */
			while (value < end) {
				if (*value == '_') {
					value++;

				} else if ((*value >= '0' && *value <= '9') ||
						(*value >= 'A' && *value <= 'F') ||
						(*value >= 'a' && *value <= 'f')) {
					*ptr++ = *value++;

				} else {
					goto not_numeric;
				}
			}

			type = Y_SCALAR_IS_INT | Y_SCALAR_IS_HEXADECIMAL;

		} else if (*value == '_' || (*value >= '0' && *value <= '7')) {
			/* octal integer */
			while (value < end) {
				if (*value == '_') {
					value++;

				} else if (*value >= '0' && *value <= '7') {
					*ptr++ = *value++;

				} else {
					goto not_numeric;
				}
			}

			type = Y_SCALAR_IS_INT | Y_SCALAR_IS_OCTAL;

		} else if (*value == '.') {
			goto check_float;

		} else {
			goto not_numeric;
		}

	} else if (*value >= '1' && *value <= '9') {
		/* integer */
		*ptr++ = *value++;
		while (value < end) {
			if (*value == '_' || *value == ',') {
				value++;

			} else if (*value >= '0' && *value <= '9') {
				*ptr++ = *value++;

			} else if (*value == ':') {
				goto check_sexa;

			} else if (*value == '.') {
				goto check_float;

			} else {
				goto not_numeric;

			}
		}

		type = Y_SCALAR_IS_INT | Y_SCALAR_IS_DECIMAL;

	} else if (*value == ':') {
		/* sexagecimal */

check_sexa:
		while (value < end - 2) {
			if (*value == '.') {
				type = Y_SCALAR_IS_FLOAT | Y_SCALAR_IS_SEXAGECIMAL;
				goto check_float;
			}

			if (*value != ':') {
				goto not_numeric;
			}

			*ptr++ = *value++;
			if (*(value + 1) == ':') {
				if (*value >= '0' && *value <= '9') {
					*ptr++ = *value++;

				} else {
					goto not_numeric;
				}

			} else {
				if ((*value >= '0' && *value <= '5') &&
						(*(value + 1) >= '0' && *(value + 1) <= '9')) {
					*ptr++ = *value++;
					*ptr++ = *value++;

				} else {
					goto not_numeric;
				}
			}
		}

		if (*value == '.') {
			type = Y_SCALAR_IS_FLOAT | Y_SCALAR_IS_SEXAGECIMAL;
			goto check_float;

		} else if (value == end) {
			type = Y_SCALAR_IS_INT | Y_SCALAR_IS_SEXAGECIMAL;

		} else {
			goto not_numeric;
		}

	} else if (*value == '.') {
		/* float */
		*ptr++ = '0';

check_float:
		*ptr++ = *value++;
		if (value == end) {
			/* don't treat strings ending with a period as numbers */
			/* mostly here to catch the degenerate case of `.` as input */
			goto not_numeric;
		}

		if (type == (Y_SCALAR_IS_FLOAT | Y_SCALAR_IS_SEXAGECIMAL)) {
			/* sexagecimal float */
			while (value < end && (*(end - 1) == '_' || *(end - 1) == '0')) {
				end--;
			}

			if (value == end) {
				*ptr++ = '0';
			}

			while (value < end) {
				if (*value == '_') {
					value++;

				} else if (*value >= '0' && *value <= '9') {
					*ptr++ = *value++;

				} else {
					goto not_numeric;
				}
			}

		} else {
			/* decimal float */
			int is_exp = 0;
			while (value < end) {
				if (*value == '_') {
					value++;

				} else if (*value >= '0' && *value <= '9') {
					*ptr++ = *value++;

				} else if (*value == 'E' || *value == 'e') {
					/* exponential */
					is_exp = 1;

					*ptr++ = *value++;
					if (value == end || (*value != '+' && *value != '-')) {
						goto not_numeric;
					}

					*ptr++ = *value++;
					if (value == end || *value < '0' || *value > '9' ||
							(*value == '0' && value + 1 == end)) {
						goto not_numeric;
					}

					*ptr++ = *value++;
					while (value < end) {
						if (*value >= '0' && *value <= '9') {
							*ptr++ = *value++;

						} else {
							goto not_numeric;
						}
					}

				} else {
					goto not_numeric;
				}
			}

			/* trim */
			if (!is_exp) {
				while (*(ptr - 1) == '0') {
					ptr--;
				}

				if (*(ptr - 1) == '.') {
					*ptr++ = '0';
				}
			}

			type = Y_SCALAR_IS_FLOAT | Y_SCALAR_IS_DECIMAL;
		}

	} else {
		goto not_numeric;
	}

	/* terminate */
	*ptr = '\0';

finish:
	/* convert & assign */
	if ((type & Y_SCALAR_IS_INT) && lval != NULL) {
		switch (type & Y_SCALAR_FORMAT_MASK) {
		case Y_SCALAR_IS_BINARY:
			ptr = buf + 2;
			if (*ptr == 'b') {
				ptr++;
			}

			*lval = strtol(ptr, (char **) NULL, 2);
			if (*buf == '-') {
				*lval *= -1L;
			}
			break;

		case Y_SCALAR_IS_OCTAL:
			*lval = strtol(buf, (char **) NULL, 8);
			break;

		case Y_SCALAR_IS_HEXADECIMAL:
			*lval = strtol(buf, (char **) NULL, 16);
			break;

		case Y_SCALAR_IS_SEXAGECIMAL:
			*lval = eval_sexagesimal_l(0, buf, ptr);
			if (*buf == '-') {
				*lval *= -1L;
			}
			break;

		default:
			*lval = atol(buf);
			break;
		}

	} else if ((type & Y_SCALAR_IS_FLOAT) && dval != NULL) {
		switch (type & Y_SCALAR_FORMAT_MASK) {
		case Y_SCALAR_IS_SEXAGECIMAL:
			*dval = eval_sexagesimal_d(0.0, buf, ptr);
			if (*buf == '-') {
				*dval *= -1.0;
			}
			break;

		case Y_SCALAR_IS_INFINITY_P:
			*dval = php_get_inf();
			break;

		case Y_SCALAR_IS_INFINITY_N:
			*dval = -php_get_inf();
			break;

		case Y_SCALAR_IS_NAN:
			*dval = php_get_nan();
			break;

		default:
			*dval = atof(buf);
			break;
		}
	}

	if (buf != NULL) {
		if (str != NULL) {
			*str = buf;

		} else {
			efree(buf);
		}
	}

	/* return */
	return type;


return_zero:
	if (lval != NULL) {
		*lval = 0;
	}

	if (dval != NULL) {
		*dval = 0.0;
	}

	if (buf != NULL) {
		efree(buf);
	}

	return (Y_SCALAR_IS_INT | Y_SCALAR_IS_ZERO);


not_numeric:
	if (buf != NULL) {
		efree(buf);
	}

	return Y_SCALAR_IS_NOT_NUMERIC;
}
/* }}} */


/* {{{ scalar_is_timestamp(const char *,size_t)
 * Does this scalar encode a TIMESTAMP value?
 *
 * specification is found at http://yaml.org/type/timestamp.html.
 */
int scalar_is_timestamp(const char *value, size_t length)
{
	const char *ptr = value;
	const char *end = value + length;
	const char *pos1, *pos2;

	/* skip leading space */
	ts_skip_space();

	/* check 4 digit year and separator */
	pos1 = pos2 = ptr;
	ts_skip_number();
	if (ptr == pos1 || ptr == end || ptr - pos2 != 4 || *ptr != '-') {
		return 0;
	}

	/* check 1 or 2 month and separator */
	pos2 = ++ptr;
	ts_skip_number();
	if (ptr == pos2 || ptr == end || ptr - pos2 > 2 || *ptr != '-') {
		return 0;
	}

	/* check 1 or 2 digit day */
	pos2 = ++ptr;
	ts_skip_number();
	if (ptr == pos2 || ptr - pos2 > 2) {
		return 0;
	}

	/* check separator */
	pos2 = ptr;
	if (ptr == end) {
		/* date only format requires YYYY-MM-DD */
		return (pos2 - pos1 == 10) ? 1 : 0;
	}

	/* time separator is T or whitespace */
	if (*ptr == 'T' || *ptr == 't') {
		ptr++;

	} else {
		ts_skip_space();
	}

	/* check 1 or 2 digit hour and separator */
	pos1 = ptr;
	ts_skip_number();
	if (ptr == pos1 || ptr == end || ptr - pos1 > 2 || *ptr != ':') {
		return 0;
	}

	/* check 2 digit minute and separator */
	pos1 = ++ptr;
	ts_skip_number();
	if (ptr == end || ptr - pos1 != 2 || *ptr != ':') {
		return 0;
	}

	/* check 2 digit second */
	pos1 = ++ptr;
	ts_skip_number();
	if (ptr == end) {
		return (ptr - pos1 == 2) ? 1 : 0;
	}

	/* check optional fraction */
	if (*ptr == '.') {
		ptr++;
		ts_skip_number();
	}

	/* skip optional separator space */
	ts_skip_space();
	if (ptr == end) {
		return 1;
	}

	/* check time zone */
	if (*ptr == 'Z') {
		ptr++;
		ts_skip_space();
		return (ptr == end) ? 1 : 0;
	}

	/* check time zone offset sign */
	if (*ptr != '+' && *ptr != '-') {
		return 0;
	}

	/* check 1 or 2 digit time zone hour */
	pos1 = ++ptr;
	ts_skip_number();
	if (ptr == pos1 || ptr - pos1 == 3 || ptr - pos1 > 4) {
		return 0;
	}

	if (ptr == end) {
		return 1;
	}

	/* optional time zone minute */
	if (*ptr != ':') {
		return 0;
	}

	pos1 = ++ptr;
	ts_skip_number();

	if (ptr - pos1 != 2) {
		return 0;
	}

	/* skip following space */
	ts_skip_space();
	return (ptr == end) ? 1 : 0;
}
/* }}} */


/* {{{ eval_sexagesimal_l()
 * Convert a base 60 number to a long
 */
static long eval_sexagesimal_l(long lval, char *sg, char *eos)
{
	char *ep;

	while (sg < eos && (*sg < '0' || *sg > '9')) {
		sg++;
	}

	ep = sg;
	while (ep < eos && *ep >= '0' && *ep <= '9') {
		ep++;
	}

	if (sg == eos) {
		return lval;
	}

	return eval_sexagesimal_l(
			lval * 60 + strtol(sg, (char **) NULL, 10), ep, eos);
}
/* }}} */


/* {{{ eval_sexagesimal_d()
 * Convert a base 60 number to a double
 */
static double eval_sexagesimal_d(double dval, char *sg, char *eos)
{
	char *ep;

	while (sg < eos && *sg != '.' && (*sg < '0' || *sg > '9')) {
		sg++;
	}

	ep = sg;
	while (ep < eos && *ep >= '0' && *ep <= '9') {
		ep++;
	}

	if (sg == eos || *sg == '.') {
		return dval;
	}

	return eval_sexagesimal_d(
			dval * 60.0 + strtod(sg, (char **) NULL), ep, eos);
}
/* }}} */



/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: noet sw=4 ts=4 fdm=marker
 * vim<600: noet sw=4 ts=4 
 */