refactor Ast

Author: Mr-Leshiy

rust/cbork-cddl-parser/src/lib.rs

@@ -24,6 +24,6 @@ pub enum Extension {
 /// - If there is an issue with parsing the CDDL input.
 pub fn validate_cddl(input: &mut String, extension: &Extension) -> anyhow::Result<()> {
     let ast = parser::parse_cddl(input, extension)?;
-    preprocessor::process_ast(ast)?;
+    let _ast = preprocessor::process_ast(ast)?;
     Ok(())
 }

rust/cbork-cddl-parser/src/parser.rs

@@ -1,7 +1,7 @@
 //! A parser for CDDL using the [pest](https://github.com/pest-parser/pest).
 //! Utilized for parsing in accordance with RFC-8610, RFC-9165.
 
-use pest::{iterators::Pairs, Parser};
+use pest::{iterators::Pair, Parser};
 
 use crate::Extension;
 
@@ -54,14 +54,13 @@ const POSTLUDE: &str = include_str!("grammar/postlude.cddl");
 
 /// PEST Abstract Syntax Tree (AST) representing parsed CDDL syntax.
 #[derive(Debug)]
-#[allow(dead_code)]
-pub(crate) enum PestAst<'a> {
+pub(crate) enum Ast<'a> {
     /// Represents the AST for RFC-8610 CDDL rules.
-    Rfc8610(Pairs<'a, rfc_8610::Rule>),
+    Rfc8610(Vec<Pair<'a, rfc_8610::Rule>>),
     /// Represents the AST for RFC-9165 CDDL rules.
-    Rfc9165(Pairs<'a, rfc_9165::Rule>),
+    Rfc9165(Vec<Pair<'a, rfc_9165::Rule>>),
     /// Represents the AST for CDDL Modules rules.
-    Cddl(Pairs<'a, cddl::Rule>),
+    Cddl(Vec<Pair<'a, cddl::Rule>>),
 }
 
 /// Parses and checks semantically a CDDL input string.
@@ -82,18 +81,22 @@ pub(crate) enum PestAst<'a> {
 /// - If there is an issue with parsing the CDDL input.
 pub(crate) fn parse_cddl<'a>(
     input: &'a mut String, extension: &Extension,
-) -> anyhow::Result<PestAst<'a>> {
+) -> anyhow::Result<Ast<'a>> {
     input.push_str("\n\n");
     input.push_str(POSTLUDE);
 
     let ast = match extension {
         Extension::RFC8610 => {
-            rfc_8610::Parser::parse(rfc_8610::Rule::cddl, input).map(PestAst::Rfc8610)?
+            rfc_8610::Parser::parse(rfc_8610::Rule::cddl, input)
+                .map(|p| Ast::Rfc8610(p.collect()))?
         },
         Extension::RFC9165 => {
-            rfc_9165::Parser::parse(rfc_9165::Rule::cddl, input).map(PestAst::Rfc9165)?
+            rfc_9165::Parser::parse(rfc_9165::Rule::cddl, input)
+                .map(|p| Ast::Rfc9165(p.collect()))?
+        },
+        Extension::CDDL => {
+            cddl::Parser::parse(cddl::Rule::cddl, input).map(|p| Ast::Cddl(p.collect()))?
         },
-        Extension::CDDL => cddl::Parser::parse(cddl::Rule::cddl, input).map(PestAst::Cddl)?,
     };
     Ok(ast)
 }

rust/cbork-cddl-parser/src/preprocessor/mod.rs

@@ -1,48 +1,37 @@
 //! A CDDL AST preprocessor.
-//! First processing step, which takes a CDDL `AST` and returning a list of CDDL
-//! `Expression`.
 //!
-//! Preprocessor steps:
-//! - Resolve #include and #import directives, by just adding the imported rules into the
-//!   final expression list
-//! - Resolves all generics by taking the generic arguments and substituting it.
+//! - Validates the root rule of the AST to be a `cddl` rule.
+//! - Filters out all rules that are not `expr` rules.
+//! - (TODO) Resolve #include and #import directives, by just adding the imported rules
+//!   into the final expression list
 
 use anyhow::{anyhow, ensure};
-use pest::{
-    iterators::{Pair, Pairs},
-    RuleType,
-};
+use pest::{iterators::Pair, RuleType};
 
-use crate::parser::{cddl, rfc_8610, rfc_9165, PestAst};
+use crate::parser::{cddl, rfc_8610, rfc_9165, Ast};
 
 /// Processes the AST.
-pub(crate) fn process_ast(ast: PestAst) -> anyhow::Result<()> {
+pub(crate) fn process_ast(ast: Ast) -> anyhow::Result<Ast> {
     match ast {
-        PestAst::Rfc8610(ast) => {
-            let _exprs = process_root(ast, rfc_8610::Rule::cddl, rfc_8610::Rule::expr)?;
+        Ast::Rfc8610(ast) => {
+            process_root(ast, rfc_8610::Rule::cddl, rfc_8610::Rule::expr).map(Ast::Rfc8610)
         },
-        PestAst::Rfc9165(ast) => {
-            let _exprs = process_root(ast, rfc_9165::Rule::cddl, rfc_9165::Rule::expr)?;
-        },
-        PestAst::Cddl(ast) => {
-            let exprs = process_root(ast, cddl::Rule::cddl, cddl::Rule::expr)?;
-
-            for expr in exprs {
-                println!("{:?}", expr.as_rule());
-            }
+        Ast::Rfc9165(ast) => {
+            process_root(ast, rfc_9165::Rule::cddl, rfc_9165::Rule::expr).map(Ast::Rfc9165)
         },
+        Ast::Cddl(ast) => process_root(ast, cddl::Rule::cddl, cddl::Rule::expr).map(Ast::Cddl),
     }
-    Ok(())
 }
 
 /// Process the root rule of the AST.
 /// Returns a vector of expressions of the underlying AST.
 fn process_root<R: RuleType>(
-    mut ast: Pairs<'_, R>, root_rule: R, expr_rule: R,
+    ast: Vec<Pair<'_, R>>, root_rule: R, expr_rule: R,
 ) -> anyhow::Result<Vec<Pair<'_, R>>> {
-    let ast_root = ast.next().ok_or(anyhow!("Empty AST."))?;
+    let mut ast_iter = ast.into_iter();
+    let ast_root = ast_iter.next().ok_or(anyhow!("Empty AST."))?;
     ensure!(
-        ast_root.as_rule() == root_rule && ast.next().is_none(),
+        ast_root.as_rule() == root_rule && ast_iter.next().is_none(),
         "AST must have only one root rule, which must be a `{root_rule:?}` rule."
     );
     Ok(ast_root