字符串提取

求问各位熟知正则表达式大神告知
如何实现字符串中的字母+数字提取，如：

" WB-5D--灰色深棕" 则提取 “WB-5D”
“AC-8DR 自然棕灰” 则提取 “AC-8DR”
“WD-3-----黑色”  则提取“WD-3”

word<-c("WB-5D-棕色","WB-5ER----黑","WB-ADC 哈哈哈","哦哦哦 WB-5CCC",
                "300自然黑","3.45哈哈哈")

pattern<-'[a-zA-Z0-9]+-[a-zA-Z0-9]+|[0-9]+|[0-9]+.[0-9]+'


gregout<-gregexpr(pattern,word)
getcontent <- function(s,g){
  substring(s,g,g+attr(g,'match.length')-1)
}

catch=0
for(i in 1:length(word)){
    catch[i]<-getcontent(word[i],gregout[[i]])
}


机智如我自行解决，参考了 http://www.tuicool.com/articles/vEziEj