#define EVAL_OPERATOR_DIVIDE '/'
#define EVAL_OPERATOR_SIGN_PLUS 'P'
#define EVAL_OPERATOR_SIGN_MINUS 'M'
+#define EVAL_OPERATOR_ABS 'A'
+#define EVAL_OPERATOR_IF_THEN_ELSE '?'
// ----------------------------------------------------------------------------
// forward function definitions
// ----------------------------------------------------------------------------
// evaluation of expressions
-static inline calculated_number eval_check_number(calculated_number n, int *error) {
- if(unlikely(isnan(n))) {
- *error = EVAL_ERROR_VALUE_IS_NAN;
- return 0;
+static inline calculated_number eval_variable(EVAL_EXPRESSION *exp, EVAL_VARIABLE *v, int *error) {
+ static uint32_t this_hash = 0, now_hash = 0, after_hash = 0, before_hash = 0, status_hash = 0, removed_hash = 0, uninitialized_hash = 0, undefined_hash = 0, clear_hash = 0, warning_hash = 0, critical_hash = 0;
+ calculated_number n;
+
+ if(unlikely(this_hash == 0)) {
+ this_hash = simple_hash("this");
+ now_hash = simple_hash("now");
+ after_hash = simple_hash("after");
+ before_hash = simple_hash("before");
+ status_hash = simple_hash("status");
+ removed_hash = simple_hash("REMOVED");
+ uninitialized_hash = simple_hash("UNINITIALIZED");
+ undefined_hash = simple_hash("UNDEFINED");
+ clear_hash = simple_hash("CLEAR");
+ warning_hash = simple_hash("WARNING");
+ critical_hash = simple_hash("CRITICAL");
}
- if(unlikely(isinf(n))) {
- *error = EVAL_ERROR_VALUE_IS_INFINITE;
- return 0;
+ if(unlikely(v->hash == this_hash && !strcmp(v->name, "this"))) {
+ n = (exp->this)?*exp->this:NAN;
+ buffer_strcat(exp->error_msg, "[ $this = ");
+ print_parsed_as_constant(exp->error_msg, n);
+ buffer_strcat(exp->error_msg, " ] ");
+ return n;
}
- return n;
-}
+ if(unlikely(v->hash == after_hash && !strcmp(v->name, "after"))) {
+ n = (exp->after && *exp->after)?*exp->after:NAN;
+ buffer_strcat(exp->error_msg, "[ $after = ");
+ print_parsed_as_constant(exp->error_msg, n);
+ buffer_strcat(exp->error_msg, " ] ");
+ return n;
+ }
-static inline calculated_number eval_variable(EVAL_EXPRESSION *exp, EVAL_VARIABLE *v, int *error) {
- static uint32_t this_hash = 0;
+ if(unlikely(v->hash == before_hash && !strcmp(v->name, "before"))) {
+ n = (exp->before && *exp->before)?*exp->before:NAN;
+ buffer_strcat(exp->error_msg, "[ $before = ");
+ print_parsed_as_constant(exp->error_msg, n);
+ buffer_strcat(exp->error_msg, " ] ");
+ return n;
+ }
- if(unlikely(this_hash == 0))
- this_hash = simple_hash("this");
+ if(unlikely(v->hash == now_hash && !strcmp(v->name, "now"))) {
+ n = now_realtime_sec();
+ buffer_strcat(exp->error_msg, "[ $now = ");
+ print_parsed_as_constant(exp->error_msg, n);
+ buffer_strcat(exp->error_msg, " ] ");
+ return n;
+ }
- if(exp->this && v->hash == this_hash && !strcmp(v->name, "this")) {
- buffer_strcat(exp->error_msg, "[ $this = ");
- print_parsed_as_constant(exp->error_msg, *exp->this);
+ if(unlikely(v->hash == status_hash && !strcmp(v->name, "status"))) {
+ n = (exp->status)?*exp->status:RRDCALC_STATUS_UNINITIALIZED;
+ buffer_strcat(exp->error_msg, "[ $status = ");
+ print_parsed_as_constant(exp->error_msg, n);
buffer_strcat(exp->error_msg, " ] ");
- return *exp->this;
+ return n;
+ }
+
+ if(unlikely(v->hash == removed_hash && !strcmp(v->name, "REMOVED"))) {
+ n = RRDCALC_STATUS_REMOVED;
+ buffer_strcat(exp->error_msg, "[ $REMOVED = ");
+ print_parsed_as_constant(exp->error_msg, n);
+ buffer_strcat(exp->error_msg, " ] ");
+ return n;
+ }
+
+ if(unlikely(v->hash == uninitialized_hash && !strcmp(v->name, "UNINITIALIZED"))) {
+ n = RRDCALC_STATUS_UNINITIALIZED;
+ buffer_strcat(exp->error_msg, "[ $UNINITIALIZED = ");
+ print_parsed_as_constant(exp->error_msg, n);
+ buffer_strcat(exp->error_msg, " ] ");
+ return n;
+ }
+
+ if(unlikely(v->hash == undefined_hash && !strcmp(v->name, "UNDEFINED"))) {
+ n = RRDCALC_STATUS_UNDEFINED;
+ buffer_strcat(exp->error_msg, "[ $UNDEFINED = ");
+ print_parsed_as_constant(exp->error_msg, n);
+ buffer_strcat(exp->error_msg, " ] ");
+ return n;
+ }
+
+ if(unlikely(v->hash == clear_hash && !strcmp(v->name, "CLEAR"))) {
+ n = RRDCALC_STATUS_CLEAR;
+ buffer_strcat(exp->error_msg, "[ $CLEAR = ");
+ print_parsed_as_constant(exp->error_msg, n);
+ buffer_strcat(exp->error_msg, " ] ");
+ return n;
+ }
+
+ if(unlikely(v->hash == warning_hash && !strcmp(v->name, "WARNING"))) {
+ n = RRDCALC_STATUS_WARNING;
+ buffer_strcat(exp->error_msg, "[ $WARNING = ");
+ print_parsed_as_constant(exp->error_msg, n);
+ buffer_strcat(exp->error_msg, " ] ");
+ return n;
+ }
+
+ if(unlikely(v->hash == critical_hash && !strcmp(v->name, "CRITICAL"))) {
+ n = RRDCALC_STATUS_CRITICAL;
+ buffer_strcat(exp->error_msg, "[ $CRITICAL = ");
+ print_parsed_as_constant(exp->error_msg, n);
+ buffer_strcat(exp->error_msg, " ] ");
+ return n;
}
- calculated_number n;
if(exp->rrdcalc && health_variable_lookup(v->name, v->hash, exp->rrdcalc, &n)) {
buffer_sprintf(exp->error_msg, "[ $%s = ", v->name);
print_parsed_as_constant(exp->error_msg, n);
}
*error = EVAL_ERROR_UNKNOWN_VARIABLE;
- buffer_sprintf(exp->error_msg, "unknown variable '%s'", v->name);
+ buffer_sprintf(exp->error_msg, "[ undefined variable '%s' ] ", v->name);
return 0;
}
break;
}
- return eval_check_number(n, error);
+ return n;
+}
+
+static inline int is_true(calculated_number n) {
+ if(isnan(n)) return 0;
+ if(isinf(n)) return 1;
+ if(n == 0) return 0;
+ return 1;
}
calculated_number eval_and(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) && eval_value(exp, &op->ops[1], error);
+ return is_true(eval_value(exp, &op->ops[0], error)) && is_true(eval_value(exp, &op->ops[1], error));
}
calculated_number eval_or(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) || eval_value(exp, &op->ops[1], error);
+ return is_true(eval_value(exp, &op->ops[0], error)) || is_true(eval_value(exp, &op->ops[1], error));
}
calculated_number eval_greater_than_or_equal(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) >= eval_value(exp, &op->ops[1], error);
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ calculated_number n2 = eval_value(exp, &op->ops[1], error);
+ return isgreaterequal(n1, n2);
}
calculated_number eval_less_than_or_equal(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) <= eval_value(exp, &op->ops[1], error);
-}
-calculated_number eval_not_equal(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) != eval_value(exp, &op->ops[1], error);
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ calculated_number n2 = eval_value(exp, &op->ops[1], error);
+ return islessequal(n1, n2);
}
calculated_number eval_equal(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) == eval_value(exp, &op->ops[1], error);
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ calculated_number n2 = eval_value(exp, &op->ops[1], error);
+ if(isnan(n1) && isnan(n2)) return 1;
+ if(isinf(n1) && isinf(n2)) return 1;
+ if(isnan(n1) || isnan(n2)) return 0;
+ if(isinf(n1) || isinf(n2)) return 0;
+ return n1 == n2;
+}
+calculated_number eval_not_equal(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
+ return !eval_equal(exp, op, error);
}
calculated_number eval_less(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) < eval_value(exp, &op->ops[1], error);
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ calculated_number n2 = eval_value(exp, &op->ops[1], error);
+ return isless(n1, n2);
}
calculated_number eval_greater(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) > eval_value(exp, &op->ops[1], error);
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ calculated_number n2 = eval_value(exp, &op->ops[1], error);
+ return isgreater(n1, n2);
}
calculated_number eval_plus(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) + eval_value(exp, &op->ops[1], error);
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ calculated_number n2 = eval_value(exp, &op->ops[1], error);
+ if(isnan(n1) || isnan(n2)) return NAN;
+ if(isinf(n1) || isinf(n2)) return INFINITY;
+ return n1 + n2;
}
calculated_number eval_minus(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) - eval_value(exp, &op->ops[1], error);
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ calculated_number n2 = eval_value(exp, &op->ops[1], error);
+ if(isnan(n1) || isnan(n2)) return NAN;
+ if(isinf(n1) || isinf(n2)) return INFINITY;
+ return n1 - n2;
}
calculated_number eval_multiply(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) * eval_value(exp, &op->ops[1], error);
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ calculated_number n2 = eval_value(exp, &op->ops[1], error);
+ if(isnan(n1) || isnan(n2)) return NAN;
+ if(isinf(n1) || isinf(n2)) return INFINITY;
+ return n1 * n2;
}
calculated_number eval_divide(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return eval_value(exp, &op->ops[0], error) / eval_value(exp, &op->ops[1], error);
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ calculated_number n2 = eval_value(exp, &op->ops[1], error);
+ if(isnan(n1) || isnan(n2)) return NAN;
+ if(isinf(n1) || isinf(n2)) return INFINITY;
+ return n1 / n2;
}
calculated_number eval_nop(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
return eval_value(exp, &op->ops[0], error);
}
calculated_number eval_not(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return !eval_value(exp, &op->ops[0], error);
+ return !is_true(eval_value(exp, &op->ops[0], error));
}
calculated_number eval_sign_plus(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
return eval_value(exp, &op->ops[0], error);
}
calculated_number eval_sign_minus(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
- return -eval_value(exp, &op->ops[0], error);
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ if(isnan(n1)) return NAN;
+ if(isinf(n1)) return INFINITY;
+ return -n1;
+}
+calculated_number eval_abs(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
+ calculated_number n1 = eval_value(exp, &op->ops[0], error);
+ if(isnan(n1)) return NAN;
+ if(isinf(n1)) return INFINITY;
+ return abs(n1);
+}
+calculated_number eval_if_then_else(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error) {
+ if(is_true(eval_value(exp, &op->ops[0], error)))
+ return eval_value(exp, &op->ops[1], error);
+ else
+ return eval_value(exp, &op->ops[2], error);
}
static struct operator {
const char *print_as;
char precedence;
char parameters;
+ char isfunction;
calculated_number (*eval)(EVAL_EXPRESSION *exp, EVAL_NODE *op, int *error);
} operators[256] = {
// this is a random access array
// we always access it with a known EVAL_OPERATOR_X
- [EVAL_OPERATOR_AND] = { "&&", 2, 2, eval_and },
- [EVAL_OPERATOR_OR] = { "||", 2, 2, eval_or },
- [EVAL_OPERATOR_GREATER_THAN_OR_EQUAL] = { ">=", 3, 2, eval_greater_than_or_equal },
- [EVAL_OPERATOR_LESS_THAN_OR_EQUAL] = { "<=", 3, 2, eval_less_than_or_equal },
- [EVAL_OPERATOR_NOT_EQUAL] = { "!=", 3, 2, eval_not_equal },
- [EVAL_OPERATOR_EQUAL] = { "==", 3, 2, eval_equal },
- [EVAL_OPERATOR_LESS] = { "<", 3, 2, eval_less },
- [EVAL_OPERATOR_GREATER] = { ">", 3, 2, eval_greater },
- [EVAL_OPERATOR_PLUS] = { "+", 4, 2, eval_plus },
- [EVAL_OPERATOR_MINUS] = { "-", 4, 2, eval_minus },
- [EVAL_OPERATOR_MULTIPLY] = { "*", 5, 2, eval_multiply },
- [EVAL_OPERATOR_DIVIDE] = { "/", 5, 2, eval_divide },
- [EVAL_OPERATOR_NOT] = { "!", 6, 1, eval_not },
- [EVAL_OPERATOR_SIGN_PLUS] = { "+", 6, 1, eval_sign_plus },
- [EVAL_OPERATOR_SIGN_MINUS] = { "-", 6, 1, eval_sign_minus },
- [EVAL_OPERATOR_NOP] = { NULL, 7, 1, eval_nop },
- [EVAL_OPERATOR_EXPRESSION_OPEN] = { NULL, 7, 1, eval_nop },
+ [EVAL_OPERATOR_AND] = { "&&", 2, 2, 0, eval_and },
+ [EVAL_OPERATOR_OR] = { "||", 2, 2, 0, eval_or },
+ [EVAL_OPERATOR_GREATER_THAN_OR_EQUAL] = { ">=", 3, 2, 0, eval_greater_than_or_equal },
+ [EVAL_OPERATOR_LESS_THAN_OR_EQUAL] = { "<=", 3, 2, 0, eval_less_than_or_equal },
+ [EVAL_OPERATOR_NOT_EQUAL] = { "!=", 3, 2, 0, eval_not_equal },
+ [EVAL_OPERATOR_EQUAL] = { "==", 3, 2, 0, eval_equal },
+ [EVAL_OPERATOR_LESS] = { "<", 3, 2, 0, eval_less },
+ [EVAL_OPERATOR_GREATER] = { ">", 3, 2, 0, eval_greater },
+ [EVAL_OPERATOR_PLUS] = { "+", 4, 2, 0, eval_plus },
+ [EVAL_OPERATOR_MINUS] = { "-", 4, 2, 0, eval_minus },
+ [EVAL_OPERATOR_MULTIPLY] = { "*", 5, 2, 0, eval_multiply },
+ [EVAL_OPERATOR_DIVIDE] = { "/", 5, 2, 0, eval_divide },
+ [EVAL_OPERATOR_NOT] = { "!", 6, 1, 0, eval_not },
+ [EVAL_OPERATOR_SIGN_PLUS] = { "+", 6, 1, 0, eval_sign_plus },
+ [EVAL_OPERATOR_SIGN_MINUS] = { "-", 6, 1, 0, eval_sign_minus },
+ [EVAL_OPERATOR_ABS] = { "abs(",6,1, 1, eval_abs },
+ [EVAL_OPERATOR_IF_THEN_ELSE] = { "?", 7, 3, 0, eval_if_then_else },
+ [EVAL_OPERATOR_NOP] = { NULL, 8, 1, 0, eval_nop },
+ [EVAL_OPERATOR_EXPRESSION_OPEN] = { NULL, 8, 1, 0, eval_nop },
// this should exist in our evaluation list
- [EVAL_OPERATOR_EXPRESSION_CLOSE] = { NULL, 7, 1, eval_nop }
+ [EVAL_OPERATOR_EXPRESSION_CLOSE] = { NULL, 99, 1, 0, eval_nop }
};
#define eval_precedence(operator) (operators[(unsigned char)(operator)].precedence)
calculated_number n = operators[op->operator].eval(exp, op, error);
- return eval_check_number(n, error);
+ return n;
}
// ----------------------------------------------------------------------------
static inline void print_parsed_as_constant(BUFFER *out, calculated_number n) {
if(unlikely(isnan(n))) {
- buffer_strcat(out, "NaN");
+ buffer_strcat(out, "nan");
return;
}
if(unlikely(isinf(n))) {
- buffer_strcat(out, "INFINITE");
+ buffer_strcat(out, "inf");
return;
}
print_parsed_as_value(out, &op->ops[1], error);
buffer_strcat(out, ")");
}
+ else if(op->operator == EVAL_OPERATOR_IF_THEN_ELSE && operators[op->operator].parameters == 3) {
+ buffer_strcat(out, "(");
+ print_parsed_as_value(out, &op->ops[0], error);
+
+ if(operators[op->operator].print_as)
+ buffer_sprintf(out, " %s ", operators[op->operator].print_as);
+
+ print_parsed_as_value(out, &op->ops[1], error);
+ buffer_strcat(out, " : ");
+ print_parsed_as_value(out, &op->ops[2], error);
+ buffer_strcat(out, ")");
+ }
+
+ if(operators[op->operator].isfunction)
+ buffer_strcat(out, ")");
}
// ----------------------------------------------------------------------------
return 0;
}
+#define parse_close_function(x) parse_close_subexpression(x)
+
static inline int parse_close_subexpression(const char **string) {
const char *s = *string;
- // (
+ // )
if(s[0] == ')') {
*string = &s[1];
return 1;
static inline int parse_constant(const char **string, calculated_number *number) {
char *end = NULL;
calculated_number n = strtold(*string, &end);
- if(unlikely(!end || *string == end || isnan(n) || isinf(n))) {
+ if(unlikely(!end || *string == end)) {
*number = 0;
return 0;
}
return 1;
}
+static inline int parse_abs(const char **string) {
+ const char *s = *string;
+
+ // ABS
+ if((s[0] == 'A' || s[0] == 'a') && (s[1] == 'B' || s[1] == 'b') && (s[2] == 'S' || s[2] == 's') && s[3] == '(') {
+ *string = &s[3];
+ return 1;
+ }
+
+ return 0;
+}
+
+static inline int parse_if_then_else(const char **string) {
+ const char *s = *string;
+
+ // ?
+ if(s[0] == '?') {
+ *string = &s[1];
+ return 1;
+ }
+
+ return 0;
+}
+
static struct operator_parser {
unsigned char id;
int (*parse)(const char **);
{ EVAL_OPERATOR_MINUS, parse_minus },
{ EVAL_OPERATOR_MULTIPLY, parse_multiply },
{ EVAL_OPERATOR_DIVIDE, parse_divide },
+ { EVAL_OPERATOR_IF_THEN_ELSE, parse_if_then_else },
/* we should not put in this list the following:
*
op1 = parse_next_operand_given_its_operator(string, EVAL_OPERATOR_SIGN_MINUS, error);
op1->precedence = eval_precedence(EVAL_OPERATOR_SIGN_MINUS);
}
+ else if(parse_abs(string)) {
+ op1 = parse_next_operand_given_its_operator(string, EVAL_OPERATOR_ABS, error);
+ op1->precedence = eval_precedence(EVAL_OPERATOR_ABS);
+ }
else if(parse_open_subexpression(string)) {
EVAL_NODE *sub = parse_full_expression(string, error);
if(sub) {
return NULL;
}
- EVAL_NODE *op = eval_node_alloc(2);
+ EVAL_NODE *op = eval_node_alloc(operators[operator].parameters);
op->operator = operator;
op->precedence = precedence;
+ if(operator == EVAL_OPERATOR_IF_THEN_ELSE && op->count == 3) {
+ skip_spaces(string);
+
+ if(**string != ':') {
+ eval_node_free(op);
+ eval_node_free(op1);
+ eval_node_free(op2);
+ *error = EVAL_ERROR_IF_THEN_ELSE_MISSING_ELSE;
+ return NULL;
+ }
+ (*string)++;
+
+ skip_spaces(string);
+
+ EVAL_NODE *op3 = parse_one_full_operand(string, error);
+ if(!op3) {
+ eval_node_free(op);
+ eval_node_free(op1);
+ eval_node_free(op2);
+ // error is already reported
+ return NULL;
+ }
+
+ eval_node_set_value_to_node(op, 2, op3);
+ }
+
eval_node_set_value_to_node(op, 1, op2);
// precedence processing
;
}
else if(**string) {
- if(op1) eval_node_free(op1);
+ eval_node_free(op1);
op1 = NULL;
*error = EVAL_ERROR_MISSING_OPERATOR;
}
// high level function to parse an expression or a sub-expression
static inline EVAL_NODE *parse_full_expression(const char **string, int *error) {
- EVAL_NODE *op1 = NULL;
-
- op1 = parse_one_full_operand(string, error);
+ EVAL_NODE *op1 = parse_one_full_operand(string, error);
if(!op1) {
*error = EVAL_ERROR_MISSING_OPERAND;
return NULL;
buffer_reset(exp->error_msg);
exp->result = eval_node(exp, (EVAL_NODE *)exp->nodes, &exp->error);
+ if(unlikely(isnan(exp->result))) {
+ if(exp->error == EVAL_ERROR_OK)
+ exp->error = EVAL_ERROR_VALUE_IS_NAN;
+ }
+ else if(unlikely(isinf(exp->result))) {
+ if(exp->error == EVAL_ERROR_OK)
+ exp->error = EVAL_ERROR_VALUE_IS_INFINITE;
+ }
+ else if(unlikely(exp->error == EVAL_ERROR_UNKNOWN_VARIABLE)) {
+ // although there is an unknown variable
+ // the expression was evaluated successfully
+ exp->error = EVAL_ERROR_OK;
+ }
+
if(exp->error != EVAL_ERROR_OK) {
+ exp->result = NAN;
+
if(buffer_strlen(exp->error_msg))
buffer_strcat(exp->error_msg, "; ");
EVAL_EXPRESSION *expression_parse(const char *string, const char **failed_at, int *error) {
const char *s = string;
int err = EVAL_ERROR_OK;
- unsigned long pos = 0;
EVAL_NODE *op = parse_full_expression(&s, &err);
if (error) *error = err;
if(!op) {
- pos = s - string + 1;
+ unsigned long pos = s - string + 1;
error("failed to parse expression '%s': %s at character %lu (i.e.: '%s').", string, expression_strerror(err), pos, s);
return NULL;
}
case EVAL_ERROR_UNKNOWN_VARIABLE:
return "undefined variable";
+ case EVAL_ERROR_IF_THEN_ELSE_MISSING_ELSE:
+ return "missing second sub-expression of inline conditional";
+
default:
return "unknown error";
}