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Smaug123claude
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claude
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Support discriminated unions of alternative argument sets
An [<ArgParser>] type may now be a discriminated union, each of whose cases holds one record of that case's arguments; and a record field may be union-typed in the same way. Exactly one case's arguments must be supplied: the case whose arguments appear is selected, arguments from two cases are a conflict naming both witnesses, a selected-but- incomplete case reports its own missing arguments, and when nothing selects a case the unique case which needs no arguments (if there is one) is chosen. Argument names must be globally unique across cases (already enforced by the existing collision check), so selection never depends on value conversion and parsing stays linear. The erased runtime already understood Sum schemas (property-tested against the exhaustive expand-every-alternative semantics); this wires the generator up: union lowering in the parse tree, tree-shaped erased schemas, selection-aware assembly (slots of unselected cases are never read), and ParseOutcome.Success now carries the selection. Generation-time checks, exercised in ArgParserConflictTests: - at most one case of a union may be satisfiable with no arguments; - positional args may not appear inside union cases, nor alongside a union arg; - the argument name "help" is reserved (it always meant help at runtime; now generation refuses it too). Help text for union schemas is currently the flat list of every case's arguments; grouping it by case is a follow-up. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
1 parent 5fd4cf0 commit 881c04c

13 files changed

Lines changed: 2519 additions & 844 deletions

‎ConsumePlugin/ArgParserConflictTests.fs‎

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@@ -128,3 +128,58 @@ type NoConflict =
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NormalField : string
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}
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// ============================================================================
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// Discriminated-union and reserved-name conflicts
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// ============================================================================
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(*
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// The argument name "help" is reserved (in any casing): --help always displays help.
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[<ArgParser>]
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type ReservedHelpName =
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{
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[<ArgumentLongForm "help">]
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Foo : int
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}
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type AllOptionalA =
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{
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A : int option
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}
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type AllOptionalB =
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{
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B : int option
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}
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// Two cases which are both satisfiable with no arguments: an empty command line could not
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// choose between them, so generation must refuse.
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[<ArgParser>]
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type AmbiguousEmptyCases =
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| CaseA of AllOptionalA
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| CaseB of AllOptionalB
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type SomePositionals =
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{
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[<PositionalArgs>]
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Rest : string list
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}
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type NotPositional =
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{
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C : int
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}
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type PositionalOrNot =
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| Pos of SomePositionals
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| NotPos of NotPositional
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// Positional args cannot appear inside union cases: the parser could not tell which
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// alternative a positional arg belongs to.
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[<ArgParser>]
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type PositionalInsideUnion =
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{
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Choice : PositionalOrNot
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}
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*)

‎ConsumePlugin/ConsumePlugin.fsproj‎

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@@ -100,6 +100,10 @@
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<Compile Include="GeneratedArgParserNegationTests.fs">
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<MyriadFile>ArgParserNegationTests.fs</MyriadFile>
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</Compile>
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<Compile Include="DuArgs.fs" />
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<Compile Include="GeneratedDuArgs.fs">
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<MyriadFile>DuArgs.fs</MyriadFile>
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</Compile>
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<Compile Include="Nested/Args.fs" />
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<Compile Include="Nested/GeneratedArgs.fs">
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<MyriadFile>Nested/Args.fs</MyriadFile>

‎ConsumePlugin/DuArgs.fs‎

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@@ -0,0 +1,45 @@
1+
namespace ConsumePlugin
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open WoofWare.Myriad.Plugins
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type FooArgs =
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{
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[<ArgumentHelpText "The foo argument">]
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Foo : int
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}
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type BarArgs =
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{
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Bar : int
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Baz : int
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}
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/// The motivating example of discriminated-union argument parsing: the user supplies either
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/// `--foo=3`, or both `--bar=8` and `--baz=9`, and the parse tells us which.
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[<ArgParser>]
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type DuArgs =
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| FooCase of FooArgs
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| BarCase of BarArgs
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type AutoMode =
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{
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Quiet : bool option
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}
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type ManualMode =
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{
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Level : int
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}
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type Mode =
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| Auto of AutoMode
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| Manual of ManualMode
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/// A union nested inside a record, with a case (Auto) which is satisfiable with no arguments:
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/// an empty command line picks it.
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[<ArgParser>]
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type WithModeArgs =
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{
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Verbose : bool
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Mode : Mode
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}

‎ConsumePlugin/GeneratedArgParserNegationTests.fs‎

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Original file line numberDiff line numberDiff line change
@@ -770,8 +770,9 @@ module private ArgParserRuntime_BoolNegation =
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[<RequireQualifiedAccess>]
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type ParseOutcome =
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/// Every argument was routed, converted and defaulted without error: the typed layer's
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/// slots are fully populated and it may assemble the result.
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| Success
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/// slots are fully populated and it may assemble the result. The selection records which
774+
/// case was chosen for every discriminated union in the schema.
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| Success of selection : Selection
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/// A `--help`-shaped token was seen; the typed layer should render help and stop.
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| HelpRequested
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/// The parse was aborted mid-scan (historically these conditions threw immediately). The
@@ -950,7 +951,7 @@ module private ArgParserRuntime_BoolNegation =
950951
| None -> ()
951952

952953
if errors.Count = 0 then
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ParseOutcome.Success
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ParseOutcome.Success selection
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else
955956
ParseOutcome.Errors (List.ofSeq errors)
956957
namespace ConsumePlugin
@@ -989,8 +990,9 @@ module BoolNegationArgParse =
989990
}
990991
]
991992
Tree =
992-
(ArgParserRuntime_BoolNegation.ErasedTree.Product[ArgParserRuntime_BoolNegation.ErasedTree.Leaf
993-
0])
993+
(ArgParserRuntime_BoolNegation.ErasedTree.Product (
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[ ArgParserRuntime_BoolNegation.ErasedTree.Leaf 0 ]
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))
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Positional = None
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}
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@@ -1043,16 +1045,14 @@ module BoolNegationArgParse =
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parser_callbacks
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args
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with
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| ArgParserRuntime_BoolNegation.ParseOutcome.Success ->
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let arg_0 =
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match arg_0 with
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| Some x -> x
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| None ->
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failwith
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"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse"
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1048+
| ArgParserRuntime_BoolNegation.ParseOutcome.Success parser_selection ->
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{
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EnableFeature = arg_0
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EnableFeature =
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(match arg_0 with
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| Some x -> x
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| None ->
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failwith
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"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse")
10561056
}
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| ArgParserRuntime_BoolNegation.ParseOutcome.HelpRequested ->
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helpText () |> failwithf "Help text requested.\n%s"
@@ -1098,8 +1098,9 @@ module FlagNegationArgParse =
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}
10991099
]
11001100
Tree =
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(ArgParserRuntime_BoolNegation.ErasedTree.Product[ArgParserRuntime_BoolNegation.ErasedTree.Leaf
1102-
0])
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(ArgParserRuntime_BoolNegation.ErasedTree.Product (
1102+
[ ArgParserRuntime_BoolNegation.ErasedTree.Leaf 0 ]
1103+
))
11031104
Positional = None
11041105
}
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@@ -1173,16 +1174,14 @@ module FlagNegationArgParse =
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parser_callbacks
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args
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with
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| ArgParserRuntime_BoolNegation.ParseOutcome.Success ->
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let arg_0 =
1178-
match arg_0 with
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| Some x -> x
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| None ->
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failwith
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"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse"
1183-
1177+
| ArgParserRuntime_BoolNegation.ParseOutcome.Success parser_selection ->
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{
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DryRun = arg_0
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DryRun =
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(match arg_0 with
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| Some x -> x
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| None ->
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failwith
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"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse")
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}
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| ArgParserRuntime_BoolNegation.ParseOutcome.HelpRequested ->
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helpText () |> failwithf "Help text requested.\n%s"
@@ -1236,8 +1235,9 @@ module MultipleFormsNegationArgParse =
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}
12371236
]
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Tree =
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(ArgParserRuntime_BoolNegation.ErasedTree.Product[ArgParserRuntime_BoolNegation.ErasedTree.Leaf
1240-
0])
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(ArgParserRuntime_BoolNegation.ErasedTree.Product (
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[ ArgParserRuntime_BoolNegation.ErasedTree.Leaf 0 ]
1240+
))
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Positional = None
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}
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@@ -1290,16 +1290,14 @@ module MultipleFormsNegationArgParse =
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parser_callbacks
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args
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with
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| ArgParserRuntime_BoolNegation.ParseOutcome.Success ->
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let arg_0 =
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match arg_0 with
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| Some x -> x
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| None ->
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failwith
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"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse"
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1293+
| ArgParserRuntime_BoolNegation.ParseOutcome.Success parser_selection ->
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{
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VerboseMode = arg_0
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VerboseMode =
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(match arg_0 with
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| Some x -> x
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| None ->
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failwith
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"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse")
13031301
}
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| ArgParserRuntime_BoolNegation.ParseOutcome.HelpRequested ->
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helpText () |> failwithf "Help text requested.\n%s"
@@ -1385,14 +1383,13 @@ module CombinedFeaturesArgParse =
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}
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]
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Tree =
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(ArgParserRuntime_BoolNegation.ErasedTree.Product[ArgParserRuntime_BoolNegation.ErasedTree.Leaf
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0
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ArgParserRuntime_BoolNegation.ErasedTree.Leaf
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1
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ArgParserRuntime_BoolNegation.ErasedTree.Leaf
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2])
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(ArgParserRuntime_BoolNegation.ErasedTree.Product (
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[
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ArgParserRuntime_BoolNegation.ErasedTree.Leaf 0
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ArgParserRuntime_BoolNegation.ErasedTree.Leaf 1
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ArgParserRuntime_BoolNegation.ErasedTree.Leaf 2
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]
1392+
))
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Positional = None
13971394
}
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@@ -1489,32 +1486,26 @@ module CombinedFeaturesArgParse =
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parser_callbacks
14901487
args
14911488
with
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| ArgParserRuntime_BoolNegation.ParseOutcome.Success ->
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let arg_0 =
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match arg_0 with
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| Some x -> x
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| None ->
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failwith
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"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse"
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let arg_1 =
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match arg_1 with
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| Some x -> x
1503-
| None ->
1504-
failwith
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"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse"
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1507-
let arg_2 =
1508-
match arg_2 with
1509-
| Some x -> x
1510-
| None ->
1511-
failwith
1512-
"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse"
1513-
1489+
| ArgParserRuntime_BoolNegation.ParseOutcome.Success parser_selection ->
15141490
{
1515-
Debug = arg_1
1516-
NormalBool = arg_2
1517-
Verbose = arg_0
1491+
Debug =
1492+
(match arg_1 with
1493+
| Some x -> x
1494+
| None ->
1495+
failwith
1496+
"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse")
1497+
NormalBool =
1498+
(match arg_2 with
1499+
| Some x -> x
1500+
| None ->
1501+
failwith
1502+
"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse")
1503+
Verbose =
1504+
(match arg_0 with
1505+
| Some x -> x
1506+
| None ->
1507+
failwith
1508+
"WoofWare.Myriad internal error in generated parser: required argument missing after successful parse")
15181509
}
15191510
| ArgParserRuntime_BoolNegation.ParseOutcome.HelpRequested ->
15201511
helpText () |> failwithf "Help text requested.\n%s"

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