parser errors in editor for advanced function types

[sbijoshj]

This issue is for valid Haxe code that compiles but gets red lines in the editor. The advanced function types are ones that start with optional parameters, and functions that pass functions. Code examples:

var a:?Int->Void;  // '(', ID, or '{' expected, got '?'

var f:Int->(Int->Void)->Void;  // <type or anonymous> or '?' expected, got '('

Plugin version: Version: 0.10.1.1 for IDEA 2016.1 through 2016.3.2
IDEA version: IntelliJ IDEA 2016.3.3 - Build #IU-163.11103.6, built on January 16, 2017
(IDEA JRE: 1.8.0_112-release-408-b6 x86)
(IDEA JVM: OpenJDK Server VM by JetBrains s.r.o)
OS and OS version: Windows 7 Ultimate SP1
JDK version: 1.8.0_45-b15

[EricBishton]

So, fixing the first one was easy. Just had to allow a question mark in the first position.

The second requires a lot of code changes because the underlying rule is really incorrect. Once putting the correct rule in place, the associated code changes require reworking of the resolver, which has the potential to break a lot of things. So, I'll document the correct rule here and maybe revisit this if it turns out we can't use the new compiler's parser. (github.com/vshaxe/hxparser)

replace:

private functionTypeWrapper ::= functionTypeOrWrapper functionType*
private functionTypeOrWrapper ::= '?'? typeOrAnonymous | '(' functionTypeWrapper ')'
left functionType ::= '->' '?'? typeOrAnonymous

with this:

private typeWrapper ::= functionType | typeOrAnonymous

functionArgument ::=  (typeOrAnonymous | ('(' functionType ')'))
private functionOptionalArgument ::= '?'? functionArgument
functionType ::= functionOptionalArgument '->' (functionOptionalArgument '->')* functionArgument {pin=2 recoverWhile="functionTypeRecovery"}
functionTypeRecovery ::= !('}' | ';' | '>' | '=')

[as3boyan]

BTW, nested function types #294
I can't remember how this works, but maybe that could help

[EricBishton]

@as3boyan Thanks for the reminder. I had forgotten about that.

I found the exact same issue again (incorrectly built nested function types), and spent a few days trying to fix them. I need to move on at the moment, but I'll definitely be coming back to the issue.

[EricBishton]

Part 1 fixed with #578. bdda8f0

[sbijoshj]

🎉 Nice work!