Start making generated parser

ldtext/LDText.fs

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+module LDText
+
+module Ast =
+    type Rung = Step list
+
+    and Instr = { Op: string; Args: Operand list }
+
+    and Step =
+        | StepInstr of Instr
+        | StepBranch of Step list
+
+    and Operand =
+        | OperandHole
+        | OperandTag of string

ldtext/Library.fs

@@ -0,0 +1,5 @@
+namespace ldtext
+
+module Say =
+    let hello name =
+        printfn "Hello %s" name

ldtext/Parser.fsy

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+%{
+open LDText.Ast
+// helper functions
+%}
+
+// start token
+%start start
+
+// tokens, used by lexer
+%token <string> IDENTIFIER
+%token LEFT_PAREN
+%token RIGHT_PAREN
+%token LEFT_BRACKET
+%token RIGHT_BRACKET
+%token COMMA
+%token SEMICOLON
+%token QUESTION_MARK
+%token EOF
+
+// return type of parser, marked by start token
+%type <Rung option> rung
+
+%%
+
+start:
+  | instr EOF { $1 }
+
+instr:
+  | IDENTIFIER LEFT_PAREN operands RIGHT_PAREN { StepInstr { Op = $1; Args = [ $3 ] } }
+
+operands:
+  | { }
+  | operand operands { $1; $2 }
+
+operand:
+  | IDENTIFIER { OperandTag $1 }
+  | QUESTION_MARK { OperandHole }
+%%

ldtext/ldtext.fsproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+  </PropertyGroup>
+
+  <ItemGroup><Compile Include="LDText.fs" />
+    <Compile Include="LDText.fs" />
+    <FsYacc Include="Parser.fsy">
+      <OtherFlags>--module Parser</OtherFlags>
+    </FsYacc>
+    <Compile Include="Library.fs" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="FsLexYacc" Version="11.3.0" />
+  </ItemGroup>
+
+</Project>