Finally building an AST with Pest.

.gitignore

@@ -1,2 +1,3 @@
 /target
-.idea
+.idea
+*.swp

src/ast/mod.rs

@@ -0,0 +1,134 @@
+use pest::{iterators::{Pair, Pairs}, Parser};
+use crate::parser::{DeimosParser, Rule};
+
+#[derive(Debug)]
+pub struct CompilationUnit {
+    namespace: Option<Fqn>,
+    declarations: Vec<Declaration>,
+}
+
+#[derive(Debug)]
+pub struct Fqn {
+    identifiers: Vec<Identifier>
+}
+
+#[derive(Debug)]
+pub enum Declaration {
+    Interface {
+        identifier: Identifier,
+        type_declaration: TypeDeclaration,
+    },
+    Implementation {
+        identifier: Identifier,
+        type_declaration: TypeDeclaration
+    },
+    Module {
+        identifier: Identifier,
+        declarations: Vec<Declaration>,
+    },
+    Function {
+        identifier: Identifier,
+        statement: Statement 
+    }
+}
+
+#[derive(Debug)]
+pub struct TypeDeclaration {
+    generics: Vec<GenericParameter>,
+    extends: Vec<Identifier>,
+    declarations: Vec<Declaration>,
+}
+
+#[derive(Debug)]
+pub struct Identifier {
+    name: String
+}
+
+#[derive(Debug)]
+pub struct GenericParameter {
+    identifier: Identifier,
+    bound: Option<GenericBound>
+}
+
+#[derive(Debug)]
+pub enum GenericBound {
+    Extends {
+        identifier: Identifier
+    },
+    Super {
+        identifier: Identifier
+    }
+}
+
+#[derive(Debug)]
+pub enum Statement {
+    BlockStatement {
+        statements: Vec<Statement>
+    },
+    CallStatement,
+    AssignmentStatement
+}
+
+fn build_identifier(pair: Pair<Rule>) -> Identifier {
+    match pair.as_rule() {
+        Rule::identifier => {
+            Identifier {
+                name: String::from(pair.as_str())
+            }
+        }
+        _ => panic!("Expected an identifier.") 
+    } 
+}
+
+fn build_fqn(fqn_pair: Pair<Rule>) -> Fqn {
+    let mut identifiers: Vec<Identifier> = vec![];
+    for pair in fqn_pair.into_inner() {
+        match pair.as_rule() {
+            Rule::identifier => {
+                identifiers.push(build_identifier(pair));
+            }
+            _ => panic!("Expected only identifiers.")
+        }
+    }
+    Fqn {
+        identifiers
+    }
+}
+
+fn build_compilation_unit(pair: Pair<Rule>)-> CompilationUnit {
+    let mut namespace: Option<Fqn> = None;
+    let mut declarations: Vec<Declaration> = vec![];
+
+    for pair in pair.into_inner() {
+        match pair.as_rule() {
+            Rule::namespace => {
+                let fqn_pair = pair.into_inner().next().unwrap(); 
+                namespace = Some(build_fqn(fqn_pair));
+            }
+            Rule::declaration => {
+                todo!();
+            }
+            Rule::EOI => {} // ignore
+            _ => panic!("Expected only namespace, declaration, or EOI rules, found: {}", pair)
+        }    
+    }
+
+    CompilationUnit {
+        namespace,
+        declarations
+    }
+}
+
+pub fn build_ast(src: &str) -> CompilationUnit {
+    let pair = DeimosParser::parse(Rule::compilation_unit, src)
+        .expect("Unsuccessful parse.")
+        .next()
+        .expect("Expcted compilation_unit.");
+    match pair.as_rule() {
+        Rule::compilation_unit => {
+            build_compilation_unit(pair)
+        },
+        _ => panic!("Expected compilation_unit rule.")
+    }
+}
+

src/bin/dvm/main.rs

@@ -1,3 +1,4 @@
+use deimos::ast::build_ast;
 use deimos::vm::dm_type::DmType;
 use deimos::vm::lib::{DmConstant, DmLib};
 use deimos::vm::object_type::{DmField, DmFn, DmImplementation, DmInterface, DmMethod};
@@ -13,6 +14,9 @@ fn main() {
     // - write a single lib with a main()
     // - call the main fn
     // fn main() { println "Hello, World!" }
+    
+    let compilation_unit = build_ast("ns hello::test::bye");
+    println!("{:?}", compilation_unit);
 
     // std/core/array lib
     let mut array_lib = DmLib::new("std/core/array");

src/lib.rs

@@ -1,4 +1,6 @@
+#![allow(warnings)]
 mod compiler;
 pub mod parser;
 mod util;
 pub mod vm;
+pub mod ast;

src/parser/deimos.pest

@@ -58,4 +58,4 @@ string_char = {
     | "\\" ~ ( "u" ~ ASCII_HEX_DIGIT{4} )
 }
 
-WHITESPACE = _{ " " | "\t" | "\n" | "\r" }
+WHITESPACE = _{ " " | "\t" | "\n" | "\r" }