doc: warn about reassigning _ in REPL

thefourtheye · thefourtheye · commit 48d79a4e93a9 · 2016-02-26T02:58:11.000+05:30
When users assign a value to `_` in REPL, it is prone to unexpected results or messing up with REPL's internals. For example, #3704. This patch issues a warning about the same.
diff --git a/doc/api/repl.markdown b/doc/api/repl.markdown
@@ -86,6 +86,10 @@ The special variable `_` (underscore) contains the result of the last expression
 4
 ```
 
+*NOTE*: Explicitly assigning a value to `_` in the REPL can produce unexpected
+results. Also, attempting to create `_` as a `const` variable in the REPL will
+fail.
+
 The REPL provides access to any variables in the global scope. You can expose
 a variable to the REPL explicitly by assigning it to the `context` object
 associated with each `REPLServer`.  For example:

Original file line number	Diff line number	Diff line change
@@ -86,6 +86,10 @@ The special variable `_` (underscore) contains the result of the last expression
`86`	`86`	`4`
`87`	`87`	```
`88`	`88`
	`89`	+NOTE: Explicitly assigning a value to `_` in the REPL can produce unexpected
	`90`	+results. Also, attempting to create `_` as a `const` variable in the REPL will
	`91`	`+fail.`
	`92`	`+`
`89`	`93`	`The REPL provides access to any variables in the global scope. You can expose`
`90`	`94`	a variable to the REPL explicitly by assigning it to the `context` object
`91`	`95`	associated with each `REPLServer`. For example: