Fix SynType.CreateApp throwing "unexpected type: App"

[Copilot]

SynType.CreateApp was passing None for lessRange and greaterRange in the SynType.App constructor, causing an System.Exception: unexpected type: App at runtime when isPostfix is false and angle-bracket ranges are expected.

Change

• AstExtensions.fs: replace None with Some range0 for both lessRange and greaterRange in SynType.CreateApp, consistent with every other SynType.App call in the same file (Option, ResizeArray, Set, Map, List, etc.)

// Before
SynType.App(typ, None, args, dotsOrCommas args, None, (defaultArg isPostfix false), range0)

// After
SynType.App(typ, Some range0, args, dotsOrCommas args, Some range0, (defaultArg isPostfix false), range0)

Original prompt

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This section details on the original issue you should resolve

<issue_title>error when using SynType.CreateApp</issue_title>
<issue_description>SynType.CreateApp throws the error System.Exception: unexpected type: App. This seems to be caused by missing lessRange and greaterRange arguments, which I assume are required when isPostfix is false.

https://github.com/MoiraeSoftware/myriad/blob/3c9818faabf9d508c10c28d5ecd26e66fafb48a1/src/Myriad.Core/AstExtensions.fs#L195-L196</issue_description>

Comments on the Issue (you are @copilot in this section)

@7sharp9 Im guessing its just a case of adding a few range0 where they are expected to be present. @7sharp9 Yeah when the AST is updated there's typically something added in so it's just a matter of adding in fake locations for the code start/end elements.

• Fixes error when using SynType.CreateApp #179

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[7sharp9]

clean change.

[Copilot]

Pull request overview

Fixes runtime failures when constructing SynType.App nodes via SynType.CreateApp by providing the required angle-bracket ranges, aligning with the rest of AstExtensions’ SynType.App helpers.

Changes:

• Update SynType.CreateApp to pass Some range0 for both lessRange and greaterRange when building SynType.App.

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[Copilot]

This SynType.App invocation is still using positional arguments, while every other SynType.App call in this file uses named arguments (typeName=, lessRange=, greaterRange=, etc.). Consider switching this helper to named arguments as well to make the parameter intent explicit and reduce the chance of future FCS signature changes silently breaking the call again.

Suggested change

	SynType.App(typ, Some range0, args, dotsOrCommas args, Some range0, (defaultArg isPostfix false), range0)
	SynType.App(
	typeName = typ,
	lessRange = Some range0,
	typeArgs = args,
	commaRanges = dotsOrCommas args,
	greaterRange = Some range0,
	isPostfix = defaultArg isPostfix false,
	range = range0
	)