Successful work to compile, parse, and unparse basic Deimos.

sketching/may_2025/hello_world.dm

@@ -0,0 +1,5 @@
+fn main() {
+    println('Hello, World!');
+    let x = 'I greet you!';
+    println(x);
+}

src/ast/build.rs

@@ -259,6 +259,7 @@ fn build_compilation_unit(compilation_unit_pair: Pair<Rule>) -> CompilationUnit
             Rule::ModuleLevelDeclaration => {
                 declarations.push(build_module_level_declaration(inner_pair));
             }
+            Rule::EOI => {}
             _ => unreachable!(),
         }
     }
@@ -842,7 +843,7 @@ macro_rules! build_binary_expression {
                 right: Box::new(right),
             })
         } else {
-            $left_fn(inner.next().unwrap())
+            expect_and_use(inner.next().unwrap(), $left_rule, $left_fn)
         }
     }};
 }
@@ -1113,7 +1114,7 @@ fn build_boolean_literal(pair: Pair<Rule>) -> Literal {
 
 fn build_single_quote_string(pair: Pair<Rule>) -> Literal {
     let inner_pair = pair.into_inner().next().unwrap();
-    Literal::String(inner_pair.to_string())
+    Literal::String(inner_pair.as_span().as_str().to_string())
 }
 
 fn build_double_quote_string(pair: Pair<Rule>) -> Literal {

src/ast/unparse.rs

@@ -505,8 +505,10 @@ impl Unparse for FunctionDefinition {
             write!(buf, " ")?;
         }
         write!(buf, "fn ")?;
-        self.generics.unparse(buf)?;
-        write!(buf, " ")?;
+        if !self.generics.is_empty() {
+            self.generics.unparse(buf)?;
+            write!(buf, " ")?;
+        }
         self.identifier.unparse(buf)?;
         self.parameters.unparse(buf)?;
         write!(buf, " ")?;
@@ -694,12 +696,13 @@ impl Unparse for FieldDeclaration {
 
 impl Unparse for BlockStatement {
     fn unparse(&self, buf: &mut dyn std::fmt::Write) -> std::fmt::Result {
-        write!(buf, "{{")?;
+        write!(buf, "{{\n")?;
         for statement in &self.statements {
             statement.unparse(buf)?;
         }
         if let Some(expression) = &self.expression {
             expression.unparse(buf)?;
+            write!(buf, "\n")?;
         }
         write!(buf, "}}")?;
         unparse_ok!()

src/bin/dmc/ast_dump.rs

@@ -1,9 +1,22 @@
 use std::path::PathBuf;
-
+use pest::Parser;
 use deimos::ast::build::build_ast;
+use deimos::ast::unparse::Unparse;
+use deimos::parser::{DeimosParser, Rule};
 
-pub fn dump_ast(path: &PathBuf) {
+pub fn unparse(path: &PathBuf) {
     let src = std::fs::read_to_string(path).expect(&format!("Could not read {:?}", path));
-    let ast = build_ast(&src);
-    println!("{:?}", ast);
+    let parse_result = DeimosParser::parse(Rule::CompilationUnit, &src);
+    match parse_result {
+        Ok(mut pairs) => {
+            let compilation_unit_pair = pairs.next().unwrap();
+            let compilation_unit = build_ast(compilation_unit_pair);
+            let mut out = String::new();
+            compilation_unit.unparse(&mut out).expect("Failed to write to string.");
+            println!("{}", out);
+        },
+        Err(e) => {
+            eprintln!("{}", e);
+        }
+    }
 }

src/bin/dmc/main.rs

@@ -2,7 +2,7 @@ mod ast_dump;
 
 use std::path::PathBuf;
 
-use ast_dump::dump_ast;
+use ast_dump::unparse;
 use clap::{Parser, Subcommand};
 
 #[derive(Debug, Parser)]
@@ -16,15 +16,15 @@ struct Cli {
 #[derive(Debug, Subcommand)]
 enum Commands {
     #[command(arg_required_else_help = true)]
-    AstDump { paths: Vec<PathBuf> },
+    Unparse { paths: Vec<PathBuf> },
 }
 
 fn main() {
     let args = Cli::parse();
     match args.command {
-        Commands::AstDump { paths } => {
+        Commands::Unparse { paths } => {
             for path in paths {
-                dump_ast(&path);
+                unparse(&path);
             }
         }
     }

src/parser/deimos.pest

@@ -584,7 +584,7 @@ AndExpression = {
 }
 
 ComparisonExpression = {
-      AdditiveExpression
+      ShiftExpression
     ~ (
           ( Greater | Less | GreaterEqual | LessEqual | EqualTo | NotEqualTo )
         ~ Expression
@@ -762,7 +762,7 @@ StringLiteral = {
     | BacktickString
 }
 
-SingleQuoteString = ${ "'" ~ StringInner ~ "'" }
+SingleQuoteString = { "'" ~ StringInner? ~ "'" }
 
 DoubleQuoteString = {
       "\""
@@ -771,10 +771,10 @@ DoubleQuoteString = {
     ~ "\""
 }
 
-StringInner = @{ StringChar* }
+StringInner = @{ StringChar+ }
 
 StringChar = {
-      !( "\"" | "\\" ) ~ ANY
+      !( "\'" | "\\" ) ~ ANY
     | "\\" ~ ( "'" | "\\" | "/" | "b" | "f" | "n" | "r" | "t" )
     | "\\" ~ ( "u" ~ ASCII_HEX_DIGIT{4} )
 }
@@ -794,15 +794,15 @@ DStringExpression = {
 
 BacktickString = {
       "`"
-    ~ ( DStringInner? ~ DStringExpression )*
-    ~ DStringInner?
+    ~ ( BacktickInner? ~ DStringExpression )*
+    ~ BacktickInner?
     ~ "`"
 }
 
 BacktickInner = @{ BacktickStringChar+ }
 
 BacktickStringChar = {
-      !( "\"" | "\\" ) ~ ANY
+      !( "\\`" | "\\" ) ~ ANY
     | "\\" ~ ( "`" | "\\" | "/" | "b" | "f" | "n" | "r" | "t" | "$" )
     | "\\" ~ ( "u" ~ ASCII_HEX_DIGIT{4} )
 }