Refactor Parsing/Runtime

Signed-off-by: Will Hawkins <hawkinsw@obs.cr>

Sources/P4Parser/Program.swift

@@ -0,0 +1,75 @@
+// p4rse, Copyright 2026, Will Hawkins
+//
+// This file is part of p4rse.
+//
+// This file is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+import Common
+import P4Lang
+import P4Runtime
+import SwiftTreeSitter
+import TreeSitterExtensions
+import TreeSitterP4
+
+public struct Program {
+  public static func Parse(_ source: String) -> Result<P4Lang.Program> {
+    let p = SwiftTreeSitter.Parser.init()
+
+    do {
+      try p.setLanguage(p4lang)
+    } catch {
+      return Result.Error(Error(withMessage: "Could not configure the P4 parser"))
+    }
+
+    let result = p.parse(source)
+    guard let tree = result,
+      !tree.isError(lang: p4lang),
+      !tree.containsMissing(lang: p4lang)
+    else {
+      return Result.Error(Error(withMessage: "Could not compile the P4 program"))
+    }
+
+    guard
+      let parser_declaration_query = try? SwiftTreeSitter.Query(
+        language: p4lang,
+        data: String(
+          "(parserDeclaration (parserType parser_name: (identifier) @parser-name) (parserStates) @parser-states)"
+        ).data(using: String.Encoding.utf8)!)
+    else {
+      return Result.Error(
+        Error(withMessage: "Could not compile the parser declaration tree sitter query"))
+    }
+
+    var program = P4Lang.Program()
+
+    // Set up a lexical scope for parsing.
+    var program_scope = LexicalScopes().enter()
+
+    let parser_qc = parser_declaration_query.execute(in: tree)
+
+    for parser_declaration in parser_qc {
+      switch Parser.Parse(
+        withName: Identifier(name: parser_declaration.nodes[0].text!),
+        node: parser_declaration.nodes[1], inTree: tree, withLexicalScopes: program_scope)
+      {
+      case Result.Ok((let parser, let new_program_scope)):
+        program.types.append(parser)
+        program_scope = new_program_scope
+      case Result.Error(let error): return Result.Error(error)
+      }
+    }
+
+    return Result.Ok(program)
+  }
+}