Function ParseLine

engine/Poseidon/UI/Map/UIMapExtDisplay.cpp:1093–1175

typedef RString (*OnValueFunction)(RString name, const EditorParams& params, void* context);
typedef RString (*OnExpressionFunction)(RString name, const EditorParams& params, void* context);

static RString ParseLine(RString format, const EditorParams& params, OnRequiredFunction onRequired,
                         OnValueFunction onValue, OnExpressionFunction onExpression, void* context)
{
    static const int len = 1024;
    char dst[len];
    int i = 0;
    for (const char* ptr = format; *ptr; ptr++)
    {
        if (*ptr == '%')
        {
            ptr++;
            if (!*ptr)
            {
                Fail("Syntax error");
                break;
            }
            else if (*ptr == '%')
            {
                dst[i++] = *ptr;
                if (i >= len - 1)
                {
                    Fail("Buffer overflow");
                    break;
                }
            }
            else if (*ptr == '!')
            {
                onRequired(context);
            }
            else if (*ptr == '(')
            {
                ptr++;
                const char* begin = ptr;
                while (*ptr && *ptr != ')')
                    ptr++;
                RString name(begin, ptr - begin);
                if (!*ptr)
                    ptr--;

                // expression
                RString value = onExpression(name, params, context);
                int n = value.GetLength();
                if (i + n >= len - 1)
                {
                    Fail("Buffer overflow");
                    break;
                }
                strcpy(dst + i, value);
                i += n;
            }
            else
            {
                const char* begin = ptr;
                while (*ptr && __iscsym(*ptr))
                    ptr++;
                RString name(begin, ptr - begin);
                ptr--;