Errlang: no match of right hand side value
erlang
Solution
Probably, 'Pid' has some value assigned already and you're trying to re-assign it.
Here is how it behaves on my machine:
Eshell V5.9.1 (abort with ^G)
1> c(echo).
{ok,echo}
2> f.
f
3> Pid = echo:start().
<0.39.0>
4> Pid = echo:start().
** exception error: no match of right hand side value <0.41.0>
5>
As you can see, the first 'Pid = ' construction woks fine, but the second one throws error message you described.
I think, you used Pid in the shell before already and it has some value assigned.
Try to 'reset' Pid variable and use it like following:
8> f(Pid).
ok
9> Pid.
* 1: variable 'Pid' is unbound
10> Pid = echo:start().
<0.49.0>
Or you can forget all variables by using such a construction:
13> f().
ok
14> Pid = echo:start().
<0.54.0>
Pay attention on used f(). - not just f.
Problem
I'm getting started with Erlang, but I'm already in troubles. I copied this example from a book: ``` -module(echo). -export([start/0, loop/0]). start() -> spawn(echo, loop, []). loop() -> receive {From, Message} -> From ! Message, loop() end. ``` But when I try it I get an error I don't understand: ``` 31> c(echo). {ok,echo} 32> f. f 33> Pid = echo:start(). ** exception error: no match of right hand side value <0.119.0> ``` Why does this happen?