使用erlang实现动态替换字符串中的变量
通过erlang，我们可以使用
{ok, Ts, _} = erl_scan:string(String).
来获取Tokens，然后调用：
{ok, Expr} = erl_parse:parse_exprs(Ts).
转换成可以执行的表达式，之后通过
erl_eval:exprs(Expr, Binding).
来执行表达式。
实验步骤如下：
1> F =fun(Str,Binding) ->1> {ok,Ts,_} = erl_scan:string(Str),1> io:format("~p~n", [Ts]),1> Ts1 = case lists:reverse(Ts) of1> [{dot,_}|_] -> Ts;1> TsR -> lists:reverse([{dot,1} | TsR])1> end,1> io:format("~p~n", [Ts1]),1> {ok,Expr} = erl_parse:parse_exprs(Ts1),1> io:format("~p~n", [Expr]),1> erl_eval:exprs(Expr, Binding) end.#Fun<erl_eval.12.113037538>2> F("lists:concat(['haha',B,'ok!']).",[{'B',23}]).[{atom,1,lists}, {':',1}, {atom,1,concat}, {'(',1}, {'[',1}, {atom,1,haha}, {',',1}, {var,1,'B'}, {',',1}, {atom,1,'ok!'}, {']',1}, {')',1}, {dot,1}][{atom,1,lists}, {':',1}, {atom,1,concat}, {'(',1}, {'[',1}, {atom,1,haha}, {',',1}, {var,1,'B'}, {',',1}, {atom,1,'ok!'}, {']',1}, {')',1}, {dot,1}][{call,1, {remote,1,{atom,1,lists},{atom,1,concat}}, [{cons,1, {atom,1,haha}, {cons,1,{var,1,'B'},{cons,1,{atom,1,'ok!'},{nil,1}}}}]}]{value,"haha23ok!",[{'B',23}]}3>