-/**
- * Evaluate an expression of the form: [+ | -]? [var[op]val | [op]var | val | var] ...
- * +: all must match. this is the default
- * -: one must NOT match
- *
- * var>x
- * var<x
- * var>=x
- * var<=x
- * var==x
- * var!=x
- * var===x
- * var!==x
- */
-bool expr_evaluate(string s)
-{
- bool ret = false;
- if (str2chr(s, 0) == '+') {
- s = substring(s, 1, -1);
- } else if (str2chr(s, 0) == '-') {
- ret = true;
- s = substring(s, 1, -1);
- }
- bool expr_fail = false;
- for (int i = 0, n = tokenize_console(s); i < n; ++i) {
- int o;
- string k, v;
- s = argv(i);
- #define X(expr) \
- if (expr) \
- continue; \
- expr_fail = true; \
- break;
-
- #define BINOP(op, len, expr) \
- if ((o = strstrofs(s, op, 0)) >= 0) { \
- k = substring(s, 0, o); \
- v = substring(s, o + len, -1); \
- X(expr); \
- }
- BINOP(">=", 2, cvar(k) >= stof(v));
- BINOP("<=", 2, cvar(k) <= stof(v));
- BINOP(">", 1, cvar(k) > stof(v));
- BINOP("<", 1, cvar(k) < stof(v));
- BINOP("==", 2, cvar(k) == stof(v));
- BINOP("!=", 2, cvar(k) != stof(v));
- BINOP("===", 3, cvar_string(k) == v);
- BINOP("!==", 3, cvar_string(k) != v);
- {
- k = s;
- bool b = true;
- if (str2chr(k, 0) == '!') {
- k = substring(s, 1, -1);
- b = false;
- }
- float f = stof(k);
- bool isnum = ftos(f) == k;
- X(boolean(isnum ? f : cvar(k)) == b);
- }
- #undef BINOP
- #undef X
- }
- if (!expr_fail) {
- ret = !ret;
- }
- // now ret is true if we want to keep the item, and false if we want to get rid of it
- return ret;
-}
-