Remove dbg in assert_builds.

Cargo.lock

@@ -148,6 +148,8 @@ version = "0.1.0"
 dependencies = [
  "clap",
  "codespan-reporting",
+ "indoc",
+ "log",
  "pest",
  "pest_derive",
 ]
@@ -178,6 +180,12 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
+[[package]]
+name = "indoc"
+version = "2.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4c7245a08504955605670dbf141fceab975f15ca21570696aebe9d2e71576bd"
+
 [[package]]
 name = "is_terminal_polyfill"
 version = "1.70.1"
@@ -190,6 +198,12 @@ version = "0.2.167"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09d6582e104315a817dff97f75133544b2e094ee22447d2acf4a74e189ba06fc"
 
+[[package]]
+name = "log"
+version = "0.4.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13dc2df351e3202783a1fe0d44375f7295ffb4049267b0f3018346dc122a1d94"
+
 [[package]]
 name = "memchr"
 version = "2.7.4"
@@ -204,9 +218,9 @@ checksum = "1261fe7e33c73b354eab43b1273a57c8f967d0391e80353e51f764ac02cf6775"
 
 [[package]]
 name = "pest"
-version = "2.7.14"
+version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "879952a81a83930934cbf1786752d6dedc3b1f29e8f8fb2ad1d0a36f377cf442"
+checksum = "198db74531d58c70a361c42201efde7e2591e976d518caf7662a47dc5720e7b6"
 dependencies = [
  "memchr",
  "thiserror",
@@ -215,9 +229,9 @@ dependencies = [
 
 [[package]]
 name = "pest_derive"
-version = "2.7.14"
+version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d214365f632b123a47fd913301e14c946c61d1c183ee245fa76eb752e59a02dd"
+checksum = "d725d9cfd79e87dccc9341a2ef39d1b6f6353d68c4b33c177febbe1a402c97c5"
 dependencies = [
  "pest",
  "pest_generator",
@@ -225,9 +239,9 @@ dependencies = [
 
 [[package]]
 name = "pest_generator"
-version = "2.7.14"
+version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb55586734301717aea2ac313f50b2eb8f60d2fc3dc01d190eefa2e625f60c4e"
+checksum = "db7d01726be8ab66ab32f9df467ae8b1148906685bbe75c82d1e65d7f5b3f841"
 dependencies = [
  "pest",
  "pest_meta",
@@ -238,9 +252,9 @@ dependencies = [
 
 [[package]]
 name = "pest_meta"
-version = "2.7.14"
+version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b75da2a70cf4d9cb76833c990ac9cd3923c9a8905a8929789ce347c84564d03d"
+checksum = "7f9f832470494906d1fca5329f8ab5791cc60beb230c74815dff541cbd2b5ca0"
 dependencies = [
  "once_cell",
  "pest",
@@ -324,18 +338,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.69"
+version = "2.0.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
+checksum = "567b8a2dae586314f7be2a752ec7474332959c6460e02bde30d702a66d488708"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.69"
+version = "2.0.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
+checksum = "7f7cf42b4507d8ea322120659672cf1b9dbb93f8f2d4ecfd6e51350ff5b17a1d"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -12,7 +12,9 @@ name = "dmc"
 path = "src/bin/dmc/main.rs"
 
 [dependencies]
-pest = "2.7.14"
+pest = { version = "2.8.0" }
 clap = { version = "4.5.23", features = ["derive"] }
-pest_derive = "2.7.14"
+pest_derive = { version = "2.8.0", features = ["grammar-extras"] }
 codespan-reporting = "0.12.0"
+log = "0.4.27"
+indoc = "2.0.6"

sketching/may_2025/closure.dm

@@ -0,0 +1,8 @@
+fn main() {
+    let x = 42;
+    let cl = mut |&mut x| { i ->
+        let result = x + i;
+        x = x + 1;
+        result
+    };
+}

sketching/may_2025/if.dm

@@ -0,0 +1,9 @@
+fn main(args: Array<String>) {
+    if (args[0] == 'test') {
+        println('test');
+    } else if (args[0] == 'foo') {
+        println('foo');
+    } else {
+        println('not test');
+    }
+}

sketching/may_2025/name_one.dm

@@ -1,13 +1,17 @@
 ns greeter
 
-fn main() {
+fn main(x: String) {
     let x = 'Hello';
     let y = 'World';
     {
-        let x = 'Hello';
-        let test = 'Test';
-        let test = 'Again';
+        let test = 'test';
+        let x = 'x';
+        let y = 'y';
+        let z = 'z';
+        let test = 'oops.';
     };
-    x = y;
-    let x = 'Hello!';
+}
+
+pub mod test {
+
 }

src/ast/mod.rs

@@ -1,4 +1,4 @@
-use crate::compile::name_analysis::Symbol;
+use crate::name_analysis::symbol::Symbol;
 use pest::Parser;
 use std::range::Range;
 
@@ -55,15 +55,17 @@ pub enum SuffixUnaryOperator {
 #[derive(Debug, Clone)]
 pub struct Identifier {
     pub name: String,
+    pub file_id: usize,
     pub range: Range<usize>,
     scope_id: Option<usize>,
     symbol: Option<Symbol>,
 }
 
 impl Identifier {
-    pub fn new(name: &str, range: Range<usize>) -> Self {
+    pub fn new(name: &str, file_id: usize, range: Range<usize>) -> Self {
         Identifier {
             name: name.to_string(),
+            file_id,
             range,
             scope_id: None,
             symbol: None,
@@ -90,16 +92,18 @@ impl Identifier {
 #[derive(Debug)]
 pub struct FullyQualifiedName {
     pub identifiers: Vec<Identifier>,
+    pub file_id: usize,
     pub range: Range<usize>,
     scope_id: Option<usize>,
     symbol: Option<Symbol>,
 }
 
 impl FullyQualifiedName {
-    pub fn new(identifiers: Vec<Identifier>, range: Range<usize>) -> Self {
+    pub fn new(identifiers: Vec<Identifier>, file_id: usize, range: Range<usize>) -> Self {
         FullyQualifiedName {
             identifiers,
             range,
+            file_id,
             scope_id: None,
             symbol: None,
         }
@@ -241,8 +245,8 @@ impl Default for Parameters {
 
 #[derive(Debug)]
 pub struct Parameter {
-    identifier: Identifier,
-    type_use: TypeUse,
+    pub identifier: Identifier,
+    pub type_use: TypeUse,
 }
 
 /* Return Type */
@@ -491,15 +495,17 @@ pub struct IfStatement {
 
 #[derive(Debug)]
 pub struct IfElseStatement {
-    pub condition: Expression,
-    pub then_block: BlockStatement,
+    pub if_statement: IfStatement,
     pub else_ifs: ElseIfs,
-    pub else_block: BlockStatement,
+    pub else_block: Option<ElseBlock>,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Default)]
 pub struct ElseIfs(pub Vec<IfStatement>);
 
+#[derive(Debug)]
+pub struct ElseBlock(pub BlockStatement);
+
 #[derive(Debug)]
 pub struct WhileStatement {
     pub condition: Expression,
@@ -571,7 +577,51 @@ pub struct CallArguments(pub Vec<CallArgument>);
 pub struct CallArgument(pub Box<Expression>);
 
 #[derive(Debug)]
-pub struct Closure {}
+pub struct Closure {
+    pub modifier: Option<ClosureModifier>,
+    pub is_move: bool,
+    pub captures: ClosureCaptures,
+    pub parameters: ClosureParameters,
+    pub statements: Vec<Statement>,
+    pub expression: Option<Box<Expression>>,
+}
+
+#[derive(Debug)]
+pub enum ClosureModifier {
+    Cons,
+    Mut,
+}
+
+#[derive(Debug, Default)]
+pub struct ClosureCaptures(pub Vec<ClosureCapture>);
+
+impl ClosureCaptures {
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+}
+
+#[derive(Debug)]
+pub struct ClosureCapture {
+    pub borrow_count: usize,
+    pub is_mutable: bool,
+    pub identifier: Box<Identifier>,
+}
+
+#[derive(Debug, Default)]
+pub struct ClosureParameters(pub Vec<ClosureParameter>);
+
+impl ClosureParameters {
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+}
+
+#[derive(Debug)]
+pub struct ClosureParameter {
+    pub identifier: Identifier,
+    pub type_use: Option<TypeUse>,
+}
 
 #[derive(Debug)]
 pub struct ObjectAccess {
@@ -595,5 +645,47 @@ pub enum Literal {
     Double(f64),
     USize(usize),
     String(String),
+    DString(DString),
+    BacktickString(DString),
     Boolean(bool),
 }
+
+#[derive(Debug)]
+pub struct DString(pub Vec<DStringPart>);
+
+#[derive(Debug)]
+pub enum DStringPart {
+    String(String),
+    Expression(Box<Expression>),
+}
+
+impl DStringPart {
+    pub fn from_string(s: &str) -> DStringPart {
+        DStringPart::String(String::from(s))
+    }
+
+    pub fn from_expression(e: Expression) -> DStringPart {
+        DStringPart::Expression(Box::new(e))
+    }
+
+    pub fn is_string(&self) -> bool {
+        match self {
+            DStringPart::String(_) => true,
+            _ => false,
+        }
+    }
+
+    pub fn unwrap_string(self) -> String {
+        match self {
+            DStringPart::String(s) => s,
+            _ => panic!(),
+        }
+    }
+
+    pub fn is_expression(&self) -> bool {
+        match self {
+            DStringPart::Expression(_) => true,
+            _ => false,
+        }
+    }
+}

src/ast/pretty_print.rs

@@ -19,6 +19,7 @@ impl PrettyPrint for Operator {
 
 impl PrettyPrint for BinaryOperator {
     fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.write_indented("BinaryOperator(")?;
         use BinaryOperator::*;
         match self {
             Or => writer.write("||"),
@@ -36,12 +37,15 @@ impl PrettyPrint for BinaryOperator {
             Modulo => writer.write("%"),
             LeftShift => writer.write("<<"),
             RightShift => writer.write(">>"),
-        }
+        }?;
+        writer.writeln(")")?;
+        Ok(())
     }
 }
 
 impl PrettyPrint for PrefixUnaryOperator {
     fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.write_indented("PrefixUnaryOperator(")?;
         use PrefixUnaryOperator::*;
         match self {
             Spread => writer.write("..."),
@@ -50,17 +54,22 @@ impl PrettyPrint for PrefixUnaryOperator {
             Mut => writer.write("mut"),
             Not => writer.write("!"),
             Negative => writer.write("-"),
-        }
+        }?;
+        writer.writeln(")")?;
+        Ok(())
     }
 }
 
 impl PrettyPrint for SuffixUnaryOperator {
     fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.write_indented("SuffixUnaryOperator(")?;
         use SuffixUnaryOperator::*;
         match self {
             PlusPlus => writer.write("++"),
             MinusMinus => writer.write("--"),
-        }
+        }?;
+        writer.write(")")?;
+        Ok(())
     }
 }
 
@@ -663,6 +672,7 @@ impl PrettyPrint for IfStatement {
     fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
         writer.writeln_indented("IfStatement")?;
         writer.increase_indent();
+        writer.increase_indent();
         self.condition.pretty_print(writer)?;
         self.then_block.pretty_print(writer)?;
         writer.decrease_indent();
@@ -674,13 +684,33 @@ impl PrettyPrint for IfElseStatement {
     fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
         writer.writeln_indented("IfElseStatement")?;
         writer.increase_indent();
-        self.condition.pretty_print(writer)?;
-        self.then_block.pretty_print(writer)?;
-        for else_if in &self.else_ifs.0 {
-            else_if.condition.pretty_print(writer)?;
-            else_if.then_block.pretty_print(writer)?;
+        self.if_statement.pretty_print(writer)?;
+        self.else_ifs.pretty_print(writer)?;
+        if let Some(else_block) = &self.else_block {
+            else_block.pretty_print(writer)?;
         }
-        self.else_block.pretty_print(writer)?;
+        writer.decrease_indent();
+        Ok(())
+    }
+}
+
+impl PrettyPrint for ElseIfs {
+    fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.writeln_indented("ElseIfs")?;
+        writer.increase_indent();
+        for if_statement in &self.0 {
+            if_statement.pretty_print(writer)?;
+        }
+        writer.decrease_indent();
+        Ok(())
+    }
+}
+
+impl PrettyPrint for ElseBlock {
+    fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.writeln_indented("ElseBlock")?;
+        writer.increase_indent();
+        self.0.pretty_print(writer)?;
         writer.decrease_indent();
         Ok(())
     }
@@ -820,7 +850,88 @@ impl PrettyPrint for CallArgument {
 
 impl PrettyPrint for Closure {
     fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
-        todo!()
+        writer.writeln_indented(&format!("Closure(is_move = {})", self.is_move))?;
+        writer.increase_indent();
+        if let Some(modifier) = &self.modifier {
+            modifier.pretty_print(writer)?;
+        }
+        self.captures.pretty_print(writer)?;
+        self.parameters.pretty_print(writer)?;
+        if !self.statements.is_empty() {
+            writer.writeln_indented("ClosureStatements")?;
+            writer.increase_indent();
+            for statement in &self.statements {
+                statement.pretty_print(writer)?;
+            }
+            writer.decrease_indent();
+        }
+        if let Some(expression) = &self.expression {
+            expression.pretty_print(writer)?;
+        }
+        writer.decrease_indent();
+        Ok(())
+    }
+}
+
+impl PrettyPrint for ClosureModifier {
+    fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.writeln_indented(&format!(
+            "ClosureModifier({})",
+            match self {
+                ClosureModifier::Mut => "mut",
+                ClosureModifier::Cons => "cons",
+            }
+        ))
+    }
+}
+
+impl PrettyPrint for ClosureCaptures {
+    fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.writeln_indented("ClosureCaptures")?;
+        writer.increase_indent();
+        for capture in &self.0 {
+            capture.pretty_print(writer)?;
+        }
+        writer.decrease_indent();
+        Ok(())
+    }
+}
+
+impl PrettyPrint for ClosureCapture {
+    fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.writeln_indented(&format!(
+            "ClosureCapture(borrow_count = {}, is_mutable = {})",
+            self.borrow_count, self.is_mutable
+        ))?;
+        writer.increase_indent();
+        self.identifier.pretty_print(writer)?;
+        writer.decrease_indent();
+        Ok(())
+    }
+}
+
+impl PrettyPrint for ClosureParameters {
+    fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.writeln_indented("ClosureParameters")?;
+        writer.increase_indent();
+        for parameter in &self.0 {
+            parameter.pretty_print(writer)?;
+        }
+        writer.decrease_indent();
+        Ok(())
+    }
+}
+
+impl PrettyPrint for ClosureParameter {
+    fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.writeln_indented("ClosureParameter")?;
+        writer.increase_indent();
+        self.identifier.pretty_print(writer)?;
+        if let Some(type_use) = &self.type_use {
+            type_use.pretty_print(writer)?;
+        }
+        writer.decrease_indent();
+        Ok(())
     }
 }
 
@@ -877,7 +988,31 @@ impl PrettyPrint for Literal {
             Double(d) => writer.writeln_indented(&format!("Double({})", d)),
             USize(u) => writer.writeln_indented(&format!("USize({})", u)),
             String(s) => writer.writeln_indented(&format!("String({})", s)),
+            DString(d_string) => d_string.pretty_print(writer),
+            BacktickString(d_string) => d_string.pretty_print(writer),
             Boolean(b) => writer.writeln_indented(&format!("Boolean({})", b)),
         }
     }
 }
+
+impl PrettyPrint for DString {
+    fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.writeln_indented("DString")?;
+        writer.increase_indent();
+        for part in &self.0 {
+            part.pretty_print(writer)?;
+        }
+        Ok(())
+    }
+}
+
+impl PrettyPrint for DStringPart {
+    fn pretty_print(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.writeln_indented("DStringPart")?;
+        writer.increase_indent();
+        match self {
+            DStringPart::String(s) => writer.writeln_indented(&format!("String({})", s)),
+            DStringPart::Expression(e) => e.pretty_print(writer),
+        }
+    }
+}

src/ast/unparse.rs

@@ -653,9 +653,7 @@ impl Unparse for FunctionBody {
             }
             Block(body) => {
                 writer.writeln("{")?;
-                writer.increase_indent();
                 body.unparse_inner(writer)?;
-                writer.decrease_indent();
                 writer.writeln_indented("}")
             }
             Alias(identifier) => {
@@ -826,9 +824,9 @@ impl Unparse for ReturnStatement {
 
 impl Unparse for IfStatement {
     fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
-        writer.write_indented("if ")?;
+        writer.write_indented("if (")?;
         self.condition.unparse(writer)?;
-        writer.writeln(" {")?;
+        writer.writeln(") {")?;
         self.then_block.unparse_inner(writer)?;
         writer.writeln_indented("}")?;
         Ok(())
@@ -837,15 +835,11 @@ impl Unparse for IfStatement {
 
 impl Unparse for IfElseStatement {
     fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
-        writer.write_indented("if ")?;
-        self.condition.unparse(writer)?;
-        writer.writeln(" {")?;
-        self.then_block.unparse_inner(writer)?;
-        writer.write_indented("} ")?;
+        self.if_statement.unparse(writer)?;
         self.else_ifs.unparse(writer)?;
-        writer.writeln("else {")?;
-        self.else_block.unparse_inner(writer)?;
-        writer.writeln_indented("}")?;
+        if let Some(else_block) = &self.else_block {
+            else_block.unparse(writer)?;
+        }
         Ok(())
     }
 }
@@ -853,16 +847,24 @@ impl Unparse for IfElseStatement {
 impl Unparse for ElseIfs {
     fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
         for if_statement in &self.0 {
-            writer.write(" else if ")?;
+            writer.write_indented("else if (")?;
             if_statement.condition.unparse(writer)?;
-            writer.writeln(" {")?;
+            writer.writeln(") {")?;
             if_statement.then_block.unparse_inner(writer)?;
-            writer.write_indented("} ")?;
+            writer.writeln_indented("}")?;
         }
         Ok(())
     }
 }
 
+impl Unparse for ElseBlock {
+    fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.write_indented("else ")?;
+        self.0.unparse(writer)?;
+        Ok(())
+    }
+}
+
 impl Unparse for WhileStatement {
     fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
         writer.write_indented("while ")?;
@@ -994,7 +996,100 @@ impl Unparse for CallArgument {
 
 impl Unparse for Closure {
     fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
-        writer.write("{{ -> TODO }}")
+        if let Some(modifier) = &self.modifier {
+            match modifier {
+                ClosureModifier::Cons => writer.write("cons "),
+                ClosureModifier::Mut => writer.write("mut "),
+            }?;
+        }
+        if self.is_move {
+            writer.write("move ")?;
+        }
+        if !self.captures.is_empty() {
+            self.captures.unparse(writer)?;
+            writer.write(" ")?;
+        }
+
+        writer.write("{ ")?;
+
+        if !self.parameters.is_empty() {
+            self.parameters.unparse(writer)?;
+            writer.write(" -> ")?;
+        }
+
+        if !self.statements.is_empty() {
+            writer.write("\n")?;
+            writer.increase_indent();
+            for statement in &self.statements {
+                statement.unparse(writer)?;
+            }
+            writer.decrease_indent();
+        }
+        if let Some(expression) = &self.expression {
+            if self.statements.is_empty() {
+                expression.unparse(writer)?;
+                writer.write(" }")?;
+            } else {
+                writer.increase_indent();
+                writer.write_indented("")?;
+                expression.unparse(writer)?;
+                writer.write("\n")?;
+                writer.decrease_indent();
+                writer.write_indented("}")?;
+            }
+        } else if !self.statements.is_empty() {
+            writer.write_indented(" }")?;
+        } else {
+            writer.write(" }")?;
+        }
+        Ok(())
+    }
+}
+
+impl Unparse for ClosureCaptures {
+    fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.write("|")?;
+        for (i, capture) in self.0.iter().enumerate() {
+            capture.unparse(writer)?;
+            if i != self.0.len() - 1 {
+                writer.write(", ")?;
+            }
+        }
+        writer.write("|")?;
+        Ok(())
+    }
+}
+
+impl Unparse for ClosureCapture {
+    fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        for _ in 0..self.borrow_count {
+            writer.write("&")?;
+        }
+        if self.is_mutable {
+            writer.write("mut ")?;
+        }
+        self.identifier.unparse(writer)?;
+        Ok(())
+    }
+}
+
+impl Unparse for ClosureParameters {
+    fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        for parameter in &self.0 {
+            parameter.unparse(writer)?;
+        }
+        Ok(())
+    }
+}
+
+impl Unparse for ClosureParameter {
+    fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        self.identifier.unparse(writer)?;
+        if let Some(type_use) = &self.type_use {
+            writer.write(": ")?;
+            type_use.unparse(writer)?;
+        }
+        Ok(())
     }
 }
 
@@ -1042,7 +1137,33 @@ impl Unparse for Literal {
             Double(d) => writer.write(&format!("{}", d)),
             USize(u) => writer.write(&format!("{}", u)),
             String(s) => writer.write(&format!("\"{}\"", s)),
+            DString(d_string) => d_string.unparse(writer),
+            BacktickString(d_string) => d_string.unparse(writer),
             Boolean(b) => writer.write(&format!("{}", b)),
         }
     }
 }
+
+impl Unparse for DString {
+    fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        writer.write("\"")?;
+        for part in &self.0 {
+            part.unparse(writer)?;
+        }
+        writer.write("\"")?;
+        Ok(())
+    }
+}
+
+impl Unparse for DStringPart {
+    fn unparse(&self, writer: &mut IndentWriter) -> std::io::Result<()> {
+        match self {
+            DStringPart::String(s) => writer.write(s),
+            DStringPart::Expression(e) => {
+                writer.write("${")?;
+                e.unparse(writer)?;
+                writer.write("}")
+            }
+        }
+    }
+}

src/bin/dmc/name_analysis.rs

@@ -2,7 +2,8 @@ use codespan_reporting::files::SimpleFiles;
 use codespan_reporting::term;
 use codespan_reporting::term::termcolor::{ColorChoice, StandardStream};
 use deimos::ast::build::build_ast;
-use deimos::compile::name_analysis::{analyze_names, SymbolTable};
+use deimos::name_analysis::analyze_names;
+use deimos::name_analysis::symbol_table::SymbolTable;
 use deimos::parser::{DeimosParser, Rule};
 use pest::Parser;
 use std::path::Path;
@@ -16,7 +17,7 @@ pub fn name_analysis(path: &Path) -> Result<(), Box<dyn std::error::Error>> {
     match parse_result {
         Ok(mut pairs) => {
             let compilation_unit_pair = pairs.next().unwrap();
-            let mut compilation_unit = build_ast(compilation_unit_pair);
+            let mut compilation_unit = build_ast(file_id, compilation_unit_pair);
             let mut symbol_table = SymbolTable::new();
             let diagnostics = analyze_names(file_id, &mut compilation_unit, &mut symbol_table);
             if diagnostics.is_empty() {

src/bin/dmc/p3.rs

@@ -11,7 +11,7 @@ pub fn pretty_print_parse(path: &PathBuf) {
     match parse_result {
         Ok(mut pairs) => {
             let compilation_unit_pair = pairs.next().unwrap();
-            let compilation_unit = build_ast(compilation_unit_pair);
+            let compilation_unit = build_ast(0, compilation_unit_pair);
             let mut indent_writer = IndentWriter::new(0, "  ", Box::new(std::io::stdout()));
             compilation_unit
                 .pretty_print(&mut indent_writer)

src/bin/dmc/unparse.rs

@@ -11,7 +11,7 @@ pub fn unparse(path: &PathBuf) {
     match parse_result {
         Ok(mut pairs) => {
             let compilation_unit_pair = pairs.next().unwrap();
-            let compilation_unit = build_ast(compilation_unit_pair);
+            let compilation_unit = build_ast(0, compilation_unit_pair);
             let mut writer = IndentWriter::new(0, "  ", Box::new(std::io::stdout()));
             compilation_unit
                 .unparse(&mut writer)

src/compile/mod.rs

@@ -1 +0,0 @@
-pub mod name_analysis;

src/compile/name_analysis.rs

@@ -1,540 +0,0 @@
-use crate::ast::named::Named;
-use crate::ast::*;
-use codespan_reporting::diagnostic::{Diagnostic, Label};
-use std::collections::HashMap;
-use std::fmt::Display;
-
-#[derive(Debug, Clone)]
-pub enum Symbol {
-    Function(FunctionSymbol),
-    Variable(VariableSymbol),
-}
-
-impl Symbol {
-    pub fn name(&self) -> &str {
-        match self {
-            Symbol::Function(s) => s.declared_name.as_str(),
-            Symbol::Variable(s) => s.name.as_str(),
-        }
-    }
-}
-
-impl Display for Symbol {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        use Symbol::*;
-        match self {
-            Function(function_symbol) => write!(f, "{}", function_symbol),
-            Variable(variable_symbol) => write!(f, "{}", variable_symbol),
-        }
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct FunctionSymbol {
-    pub fqn: String,
-    pub declared_name: String,
-    pub is_public: bool,
-}
-
-impl Display for FunctionSymbol {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(
-            f,
-            "FunctionSymbol(fqn = {}, declared_name = {}, is_public = {})",
-            self.fqn, self.declared_name, self.is_public
-        )
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct VariableSymbol {
-    pub name: String,
-    pub is_mutable: bool,
-}
-
-impl Display for VariableSymbol {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(
-            f,
-            "VariableSymbol(name = {}, is_mutable = {})",
-            self.name, self.is_mutable
-        )
-    }
-}
-
-#[derive(Default)]
-pub struct Scope {
-    parent: Option<usize>,
-    symbols: HashMap<String, Symbol>,
-    debug_name: String,
-}
-
-#[derive(Default)]
-pub struct SymbolTable {
-    scopes: Vec<Scope>,
-    current_scope_id: usize,
-}
-
-/// Contains a vec of scopes, like a flattened tree
-impl SymbolTable {
-    pub fn new() -> Self {
-        let mut t = SymbolTable::default();
-        t.scopes.push(Scope::default());
-        t.current_scope_id = 0;
-        t
-    }
-
-    pub fn current_scope_id(&self) -> usize {
-        self.current_scope_id
-    }
-
-    pub fn push_scope(&mut self, debug_name: &str) {
-        let id = self.scopes.len();
-        self.scopes.push(Scope {
-            symbols: HashMap::new(),
-            parent: Some(self.current_scope_id),
-            debug_name: debug_name.to_string(),
-        });
-        self.current_scope_id = id;
-    }
-
-    pub fn pop_scope(&mut self) {
-        if let Some(parent_id) = self.scopes[self.current_scope_id].parent {
-            self.current_scope_id = parent_id;
-        }
-    }
-
-    pub fn insert(&mut self, name: String, symbol: Symbol) -> Result<(), String> {
-        if let Some(current_symbol) = self.scopes[self.current_scope_id].symbols.get(&name) {
-            Err(format!(
-                "Symbol '{}' already defined in current scope.",
-                current_symbol.name()
-            ))
-        } else {
-            self.scopes[self.current_scope_id]
-                .symbols
-                .insert(name, symbol);
-            Ok(())
-        }
-    }
-
-    pub fn lookup(&self, name: &str, scope_id: usize) -> Result<&Symbol, String> {
-        let mut scope_opt = Some(&self.scopes[scope_id]);
-        while let Some(scope) = scope_opt {
-            if let Some(symbol) = scope.symbols.get(name) {
-                return Ok(symbol);
-            }
-            scope_opt = if let Some(parent_id) = scope.parent {
-                Some(&self.scopes[parent_id])
-            } else {
-                None
-            };
-        }
-        Err(format!("Symbol '{}' not found in current scope.", name))
-    }
-}
-
-impl Display for SymbolTable {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        for (i, scope) in self.scopes.iter().enumerate() {
-            writeln!(f, "Scope {} {}", i, scope.debug_name)?;
-            for (name, symbol) in &scope.symbols {
-                writeln!(f, "  {}({})", name, symbol)?;
-            }
-        }
-        Ok(())
-    }
-}
-
-struct FqnContext {
-    stack: Vec<String>,
-}
-
-impl FqnContext {
-    fn new() -> Self {
-        FqnContext { stack: Vec::new() }
-    }
-
-    fn push(&mut self, name: String) {
-        self.stack.push(name);
-    }
-
-    fn pop(&mut self) {
-        self.stack.pop();
-    }
-
-    fn current(&self) -> String {
-        let mut acc = String::new();
-        for (i, name) in self.stack.iter().enumerate() {
-            acc.push_str(name);
-            if i != self.stack.len() - 1 {
-                acc.push_str("::")
-            }
-        }
-        acc
-    }
-
-    fn resolve(&self, name: &str) -> String {
-        let mut acc = String::new();
-        if !self.stack.is_empty() {
-            acc.push_str(&self.current());
-            acc.push_str("::");
-        }
-        acc.push_str(name);
-        acc
-    }
-}
-
-pub fn analyze_names(
-    file_id: usize,
-    compilation_unit: &mut CompilationUnit,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    let mut diagnostics = vec![];
-
-    let mut fqn_context = FqnContext::new();
-    if let Some(namespace) = &compilation_unit.namespace {
-        fqn_context.push(namespace.name().to_string());
-    }
-
-    for declaration in &mut compilation_unit.declarations {
-        diagnostics.extend(gather_module_level_declaration(
-            file_id,
-            declaration,
-            symbol_table,
-            &mut fqn_context,
-        ));
-    }
-
-    assert_eq!(symbol_table.current_scope_id, 0);
-
-    for declaration in &mut compilation_unit.declarations {
-        diagnostics.extend(resolve_module_level_declaration(file_id, declaration, symbol_table));
-    }
-
-    diagnostics
-}
-
-fn gather_module_level_declaration(
-    file_id: usize,
-    declaration: &mut ModuleLevelDeclaration,
-    symbol_table: &mut SymbolTable,
-    fqn_context: &mut FqnContext,
-) -> Vec<Diagnostic<usize>> {
-    use ModuleLevelDeclaration::*;
-    match declaration {
-        Function(function_definition) => {
-            gather_function_definition(file_id, function_definition, symbol_table, fqn_context)
-        }
-        _ => todo!(),
-    }
-}
-
-fn gather_function_definition(
-    file_id: usize,
-    function: &mut FunctionDefinition,
-    symbol_table: &mut SymbolTable,
-    fqn_context: &mut FqnContext,
-) -> Vec<Diagnostic<usize>> {
-    let mut diagnostics = vec![];
-
-    let declared_name = function.identifier.name().to_string();
-    let resolved_name = fqn_context.resolve(&declared_name);
-
-    let insert_result = symbol_table.insert(
-        declared_name.clone(),
-        Symbol::Function(FunctionSymbol {
-            fqn: resolved_name.clone(),
-            declared_name,
-            is_public: function.is_public,
-        }),
-    );
-    if let Err(msg) = insert_result {
-        diagnostics.push(
-            Diagnostic::error()
-                .with_message(msg)
-                .with_label(Label::primary(file_id, function.identifier.range)),
-        )
-    }
-
-    function
-        .identifier
-        .set_scope_id(symbol_table.current_scope_id());
-
-    symbol_table.push_scope(&format!("FunctionScope({})", resolved_name));
-    // TODO: params
-    diagnostics.extend(gather_function_body(
-        file_id,
-        &mut function.body,
-        symbol_table,
-        fqn_context,
-    ));
-    symbol_table.pop_scope();
-
-    diagnostics
-}
-
-fn gather_function_body(
-    file_id: usize,
-    function_body: &mut FunctionBody,
-    symbol_table: &mut SymbolTable,
-    fqn_context: &mut FqnContext,
-) -> Vec<Diagnostic<usize>> {
-    use FunctionBody::*;
-    match function_body {
-        Block(block) => gather_block_statement(file_id, block, symbol_table, fqn_context),
-        _ => todo!(),
-    }
-}
-
-fn gather_block_statement(
-    file_id: usize,
-    block: &mut BlockStatement,
-    symbol_table: &mut SymbolTable,
-    fqn_context: &mut FqnContext,
-) -> Vec<Diagnostic<usize>> {
-    let mut diagnostics = vec![];
-    symbol_table.push_scope("BlockStatementScope");
-    for statement in &mut block.statements {
-        diagnostics.extend(gather_statement(
-            file_id,
-            statement,
-            symbol_table,
-            fqn_context,
-        ));
-    }
-    symbol_table.pop_scope();
-    diagnostics
-}
-
-fn gather_statement(
-    file_id: usize,
-    statement: &mut Statement,
-    symbol_table: &mut SymbolTable,
-    fqn_context: &mut FqnContext,
-) -> Vec<Diagnostic<usize>> {
-    use Statement::*;
-    match statement {
-        BlockStatement(block) => gather_block_statement(file_id, block, symbol_table, fqn_context),
-        VariableDeclarationStatement(variable_declaration) => {
-            gather_variable_declaration(file_id, variable_declaration, symbol_table)
-        }
-        AssignStatement(assign_statement) => {
-            gather_assign_statement(assign_statement, symbol_table, fqn_context)
-        }
-        _ => todo!(),
-    }
-}
-
-fn gather_variable_declaration(
-    file_id: usize,
-    variable_declaration: &mut VariableDeclarationStatement,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    let mut diagnostics = vec![];
-    let variable_name = variable_declaration.identifier.name().to_string();
-
-    let insert_result = symbol_table.insert(
-        variable_name.clone(),
-        Symbol::Variable(VariableSymbol {
-            name: variable_name,
-            is_mutable: variable_declaration.is_mutable,
-        }),
-    );
-
-    if let Err(msg) = insert_result {
-        diagnostics.push(
-            Diagnostic::error()
-                .with_message(msg)
-                .with_label(Label::primary(
-                    file_id,
-                    variable_declaration.identifier.range,
-                )),
-        );
-    }
-
-    variable_declaration
-        .identifier
-        .set_scope_id(symbol_table.current_scope_id());
-
-    diagnostics
-}
-
-fn gather_assign_statement(
-    assign_statement: &mut AssignStatement,
-    symbol_table: &mut SymbolTable,
-    fqn_context: &mut FqnContext,
-) -> Vec<Diagnostic<usize>> {
-    let mut diagnostics = vec![];
-    diagnostics.extend(gather_expression(
-        &mut assign_statement.lhs,
-        symbol_table,
-        fqn_context,
-    ));
-    diagnostics.extend(gather_expression(
-        &mut assign_statement.rhs,
-        symbol_table,
-        fqn_context,
-    ));
-    diagnostics
-}
-
-fn gather_expression(
-    expression: &mut Expression,
-    symbol_table: &mut SymbolTable,
-    fqn_context: &mut FqnContext,
-) -> Vec<Diagnostic<usize>> {
-    use Expression::*;
-    match expression {
-        FullyQualifiedName(fully_qualified_name) => {
-            gather_fully_qualified_name(fully_qualified_name, symbol_table)
-        }
-        _ => {
-            vec![]
-        }
-    }
-}
-
-fn gather_fully_qualified_name(
-    fully_qualified_name: &mut FullyQualifiedName,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    fully_qualified_name.set_scope_id(symbol_table.current_scope_id());
-    vec![]
-}
-
-/* Resolve */
-
-fn resolve_module_level_declaration(
-    file_id: usize,
-    declaration: &mut ModuleLevelDeclaration,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    use ModuleLevelDeclaration::*;
-    match declaration {
-        Function(function_definition) => {
-            resolve_function_definition(file_id, function_definition, symbol_table)
-        }
-        _ => todo!(),
-    }
-}
-
-fn resolve_function_definition(
-    file_id: usize,
-    function_definition: &mut FunctionDefinition,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    resolve_function_body(file_id, &mut function_definition.body, symbol_table)
-}
-
-fn resolve_function_body(
-    file_id: usize,
-    function_body: &mut FunctionBody,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    use FunctionBody::*;
-    match function_body {
-        Block(block) => resolve_block(file_id, block, symbol_table),
-        _ => todo!(),
-    }
-}
-
-fn resolve_block(
-    file_id: usize,
-    block_statement: &mut BlockStatement,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    block_statement
-        .statements
-        .iter_mut()
-        .flat_map(|statement| resolve_statement(file_id, statement, symbol_table))
-        .collect()
-}
-
-fn resolve_statement(
-    file_id: usize,
-    statement: &mut Statement,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    use Statement::*;
-    match statement {
-        BlockStatement(block) => resolve_block(file_id, block, symbol_table),
-        VariableDeclarationStatement(variable_declaration) => {
-            resolve_variable_declaration(file_id, variable_declaration, symbol_table)
-        }
-        AssignStatement(assign_statement) => {
-            resolve_assign_statement(file_id, assign_statement, symbol_table)
-        }
-        CallStatement(call_statement) => resolve_call_statement(file_id, call_statement, symbol_table),
-        _ => todo!(),
-    }
-}
-
-fn resolve_variable_declaration(
-    file_id: usize,
-    variable_declaration: &mut VariableDeclarationStatement,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    if let Some(initializer) = &mut variable_declaration.initializer {
-        resolve_expression(file_id, initializer, symbol_table)
-    } else {
-        vec![]
-    }
-}
-
-fn resolve_assign_statement(
-    file_id: usize,
-    assign_statement: &mut AssignStatement,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    let mut diagnostics = vec![];
-    diagnostics.extend(resolve_expression(file_id, &mut assign_statement.lhs, symbol_table));
-    diagnostics.extend(resolve_expression(file_id, &mut assign_statement.rhs, symbol_table));
-    diagnostics
-}
-
-fn resolve_call_statement(
-    file_id: usize,
-    call_statement: &mut CallStatement,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    resolve_expression(file_id, &mut call_statement.0, symbol_table)
-}
-
-fn resolve_expression(
-    file_id: usize,
-    expression: &mut Expression,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    use Expression::*;
-    match expression {
-        FullyQualifiedName(fqn) => resolve_fully_qualified_name(file_id, fqn, symbol_table),
-        Literal(_) => vec![],
-        _ => todo!(),
-    }
-}
-
-fn resolve_fully_qualified_name(
-    file_id: usize,
-    fully_qualified_name: &mut FullyQualifiedName,
-    symbol_table: &mut SymbolTable,
-) -> Vec<Diagnostic<usize>> {
-    let lookup_result = symbol_table.lookup(
-        fully_qualified_name.name().as_ref(),
-        fully_qualified_name.scope_id().expect(&format!(
-            "FullyQualifiedName has no scope_id set: {:?}",
-            fully_qualified_name
-        )),
-    );
-    match lookup_result {
-        Ok(symbol) => {
-            fully_qualified_name.set_symbol(symbol.clone());
-            vec![]
-        }
-        Err(e) => vec![
-            Diagnostic::error()
-            .with_message(e)
-                .with_label(Label::primary(file_id, fully_qualified_name.range))
-        ],
-    }
-}

src/diagnostic/mod.rs

@@ -0,0 +1,3 @@
+use codespan_reporting::diagnostic::Diagnostic;
+
+pub type DmDiagnostic = Diagnostic<usize>;

src/lib.rs

@@ -1,8 +1,9 @@
 #![feature(new_range_api)]
 #![allow(warnings)]
 pub mod ast;
-pub mod compile;
+pub mod diagnostic;
 pub mod module;
+pub mod name_analysis;
 pub mod object_file;
 pub mod parser;
 pub mod util;

src/name_analysis/fqn_context.rs

@@ -0,0 +1,38 @@
+pub(super) struct FqnContext {
+    stack: Vec<String>,
+}
+
+impl FqnContext {
+    pub fn new() -> Self {
+        FqnContext { stack: Vec::new() }
+    }
+
+    pub fn push(&mut self, name: String) {
+        self.stack.push(name);
+    }
+
+    pub fn pop(&mut self) {
+        self.stack.pop();
+    }
+
+    pub fn current(&self) -> String {
+        let mut acc = String::new();
+        for (i, name) in self.stack.iter().enumerate() {
+            acc.push_str(name);
+            if i != self.stack.len() - 1 {
+                acc.push_str("::")
+            }
+        }
+        acc
+    }
+
+    pub fn resolve(&self, name: &str) -> String {
+        let mut acc = String::new();
+        if !self.stack.is_empty() {
+            acc.push_str(&self.current());
+            acc.push_str("::");
+        }
+        acc.push_str(name);
+        acc
+    }
+}

src/name_analysis/gather.rs

@@ -0,0 +1,319 @@
+use crate::ast::named::Named;
+use crate::ast::*;
+use crate::name_analysis::fqn_context::FqnContext;
+use crate::name_analysis::symbol::{FunctionSymbol, ModuleSymbol, SourceDefinition, Symbol, VariableSymbol};
+use crate::name_analysis::symbol_table::{SymbolInsertError, SymbolTable};
+use crate::name_analysis::DiagnosticsContainer;
+use codespan_reporting::diagnostic::{Diagnostic, Label};
+use std::range::Range;
+
+fn handle_insert_error(
+    err: SymbolInsertError,
+    error_symbol_name: &str,
+    error_file_id: usize,
+    error_range: Range<usize>,
+    symbol_types: &str,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    match err {
+        SymbolInsertError::SymbolAlreadyDefined(s) => {
+            let already_defined_definition = s.definition();
+
+            diagnostics.add(
+                Diagnostic::error()
+                    .with_message(format!(
+                        "{} symbol '{}' already defined in the current scope.",
+                        symbol_types, error_symbol_name,
+                    ))
+                    .with_label(
+                        Label::primary(error_file_id, error_range)
+                            .with_message("Symbol duplicated here."),
+                    )
+                    .with_label(
+                        Label::secondary(
+                            already_defined_definition.file_id(),
+                            already_defined_definition.range(),
+                        )
+                        .with_message("Symbol defined here."),
+                    ),
+            );
+        }
+    }
+}
+
+pub(super) fn gather_module_level_declaration(
+    declaration: &mut ModuleLevelDeclaration,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    use ModuleLevelDeclaration::*;
+    match declaration {
+        Module(module_declaration) => {
+            gather_module_declaration(module_declaration, symbol_table, fqn_context, diagnostics);
+        }
+        Function(function_definition) => {
+            gather_function_definition(function_definition, symbol_table, fqn_context, diagnostics)
+        }
+        _ => todo!(),
+    }
+}
+
+fn gather_module_declaration(
+    declaration: &mut ModuleDeclaration,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    // 1. Add mod identifier symbol
+    // 2. Update fqn context
+    // 3. Push scope
+    // 4. Process declarations
+    // 5. Pop scope
+
+    let module_name = declaration.identifier.name();
+
+    let insert_result = symbol_table.insert(
+        &module_name,
+        Symbol::Module(ModuleSymbol::new(
+            &fqn_context.resolve(&module_name),
+            &module_name,
+            declaration.is_public,
+            &declaration.identifier,
+        )),
+    );
+
+    if let Err(err) = insert_result {
+        handle_insert_error(
+            err,
+            &module_name,
+            declaration.identifier.file_id,
+            declaration.identifier.range,
+            "module/type",
+            diagnostics,
+        )
+    }
+
+    fqn_context.push(module_name.to_string());
+
+    symbol_table.push_scope(&format!("Module '{}' Scope", module_name));
+    for inner_declaration in &mut declaration.declarations {
+        gather_module_level_declaration(inner_declaration, symbol_table, fqn_context, diagnostics);
+    }
+    symbol_table.pop_scope()
+}
+
+fn gather_function_definition(
+    function: &mut FunctionDefinition,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    let declared_name = function.identifier.name();
+    let resolved_name = fqn_context.resolve(&declared_name);
+
+    let insert_result = symbol_table.insert(
+        &declared_name,
+        Symbol::Function(FunctionSymbol::new(
+            &resolved_name,
+            &declared_name,
+            function.is_public,
+            &function.identifier,
+        )),
+    );
+
+    if let Err(err) = insert_result {
+        handle_insert_error(
+            err,
+            &declared_name,
+            function.identifier.file_id,
+            function.identifier.range,
+            "function/variable",
+            diagnostics,
+        )
+    }
+
+    function
+        .identifier
+        .set_scope_id(symbol_table.current_scope_id());
+
+    symbol_table.push_scope(&format!("FunctionScope({})", resolved_name));
+    gather_parameters(
+        &mut function.parameters,
+        symbol_table,
+        fqn_context,
+        diagnostics,
+    );
+    gather_function_body(&mut function.body, symbol_table, fqn_context, diagnostics);
+    symbol_table.pop_scope();
+}
+
+fn gather_parameters(
+    parameters: &mut Parameters,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    for parameter in &mut parameters.0 {
+        gather_parameter(parameter, symbol_table, fqn_context, diagnostics);
+    }
+}
+
+fn gather_parameter(
+    parameter: &mut Parameter,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    let parameter_name = parameter.identifier.name();
+
+    let insert_result = symbol_table.insert(
+        &parameter_name,
+        Symbol::Variable(VariableSymbol::new(
+            &parameter_name,
+            false,
+            SourceDefinition::from_identifier(&parameter.identifier),
+        )),
+    );
+
+    if let Err(err) = insert_result {
+        handle_insert_error(
+            err,
+            &parameter_name,
+            parameter.identifier.file_id,
+            parameter.identifier.range,
+            "function/variable",
+            diagnostics,
+        )
+    }
+
+    parameter
+        .identifier
+        .set_scope_id(symbol_table.current_scope_id());
+}
+
+fn gather_function_body(
+    function_body: &mut FunctionBody,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    use crate::ast::FunctionBody::*;
+    match function_body {
+        Block(block) => gather_block_statement_inner(block, symbol_table, fqn_context, diagnostics),
+        _ => todo!(),
+    }
+}
+
+fn gather_block_statement(
+    block: &mut BlockStatement,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    symbol_table.push_scope("BlockStatementScope");
+    gather_block_statement_inner(block, symbol_table, fqn_context, diagnostics);
+    symbol_table.pop_scope();
+}
+
+fn gather_block_statement_inner(
+    block: &mut BlockStatement,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    for statement in &mut block.statements {
+        gather_statement(statement, symbol_table, fqn_context, diagnostics);
+    }
+    if let Some(expression) = &mut block.expression {
+        gather_expression(expression, symbol_table, diagnostics);
+    }
+}
+
+fn gather_statement(
+    statement: &mut Statement,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    use crate::ast::Statement::*;
+    match statement {
+        BlockStatement(block) => {
+            gather_block_statement(block, symbol_table, fqn_context, diagnostics)
+        }
+        VariableDeclarationStatement(variable_declaration) => {
+            gather_variable_declaration(variable_declaration, symbol_table, diagnostics)
+        }
+        AssignStatement(assign_statement) => {
+            gather_assign_statement(assign_statement, symbol_table, fqn_context, diagnostics)
+        }
+        _ => todo!(),
+    }
+}
+
+fn gather_variable_declaration(
+    variable_declaration: &mut VariableDeclarationStatement,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    let variable_name = variable_declaration.identifier.name();
+
+    let insert_result = symbol_table.insert(
+        &variable_name,
+        Symbol::Variable(VariableSymbol::new( 
+            &variable_name,
+            variable_declaration.is_mutable,
+            SourceDefinition::from_identifier(&variable_declaration.identifier),
+        )),
+    );
+
+    if let Err(err) = insert_result {
+        handle_insert_error(
+            err,
+            &variable_name,
+            variable_declaration.identifier.file_id,
+            variable_declaration.identifier.range,
+            "function/variable",
+            diagnostics,
+        )
+    }
+
+    variable_declaration
+        .identifier
+        .set_scope_id(symbol_table.current_scope_id());
+
+    if let Some(initializer) = &mut variable_declaration.initializer {
+        gather_expression(initializer, symbol_table, diagnostics);
+    }
+}
+
+fn gather_assign_statement(
+    assign_statement: &mut AssignStatement,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    gather_expression(&mut assign_statement.lhs, symbol_table, diagnostics);
+    gather_expression(&mut assign_statement.rhs, symbol_table, diagnostics);
+}
+
+fn gather_expression(
+    expression: &mut Expression,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    use crate::ast::Expression::*;
+    match expression {
+        FullyQualifiedName(fully_qualified_name) => {
+            gather_fully_qualified_name(fully_qualified_name, symbol_table);
+        }
+        _ => {}
+    }
+}
+
+fn gather_fully_qualified_name(
+    fully_qualified_name: &mut FullyQualifiedName,
+    symbol_table: &mut SymbolTable,
+) {
+    fully_qualified_name.set_scope_id(symbol_table.current_scope_id());
+}

src/name_analysis/mod.rs

@@ -0,0 +1,128 @@
+use crate::ast::named::Named;
+use crate::ast::{CompilationUnit, Identifier};
+use crate::diagnostic::DmDiagnostic;
+use crate::name_analysis::fqn_context::FqnContext;
+use crate::name_analysis::gather::gather_module_level_declaration;
+use crate::name_analysis::resolve::resolve_module_level_declaration;
+use crate::name_analysis::symbol_table::SymbolTable;
+use codespan_reporting::diagnostic::{Diagnostic, Label};
+use log::debug;
+
+mod fqn_context;
+mod gather;
+mod resolve;
+pub mod symbol;
+pub mod symbol_table;
+
+pub(self) struct DiagnosticsContainer {
+    file_id: usize,
+    diagnostics: Vec<DmDiagnostic>,
+}
+
+impl DiagnosticsContainer {
+    pub fn new(file_id: usize) -> DiagnosticsContainer {
+        DiagnosticsContainer {
+            file_id,
+            diagnostics: vec![],
+        }
+    }
+
+    pub fn add(&mut self, diagnostic: DmDiagnostic) {
+        self.diagnostics.push(diagnostic);
+    }
+
+    pub fn add_error_at_identifier(&mut self, msg: &str, identifier: &Identifier) {
+        self.diagnostics.push(
+            Diagnostic::error()
+                .with_message(msg)
+                .with_label(Label::primary(self.file_id, identifier.range)),
+        );
+    }
+}
+
+impl Into<Vec<DmDiagnostic>> for DiagnosticsContainer {
+    fn into(self) -> Vec<DmDiagnostic> {
+        self.diagnostics
+    }
+}
+
+pub fn analyze_names(
+    file_id: usize,
+    compilation_unit: &mut CompilationUnit,
+    symbol_table: &mut SymbolTable,
+) -> Vec<DmDiagnostic> {
+    let mut diagnostics = DiagnosticsContainer::new(file_id);
+
+    let mut fqn_context = FqnContext::new();
+    if let Some(namespace) = &compilation_unit.namespace {
+        fqn_context.push(namespace.name().to_string());
+    }
+
+    for declaration in &mut compilation_unit.declarations {
+        gather_module_level_declaration(
+            declaration,
+            symbol_table,
+            &mut fqn_context,
+            &mut diagnostics,
+        );
+    }
+
+    assert_eq!(symbol_table.current_scope_id(), 0);
+
+    for declaration in &mut compilation_unit.declarations {
+        resolve_module_level_declaration(declaration, symbol_table, &mut diagnostics);
+    }
+
+    diagnostics.into()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::ast::build::build_ast;
+    use crate::parser::{DeimosParser, Rule};
+    use codespan_reporting::files::SimpleFiles;
+    use codespan_reporting::term;
+    use codespan_reporting::term::termcolor::{ColorChoice, StandardStream};
+    use pest::Parser;
+
+    fn assert_no_diagnostics(src: &str) {
+        let mut files = SimpleFiles::new();
+        let test_file_id = files.add("test.dm", src);
+
+        let parse_result = DeimosParser::parse(Rule::CompilationUnit, src);
+        if let Err(err) = &parse_result {
+            panic!("{:?}", err);
+        }
+
+        let compilation_unit_pair = parse_result.unwrap().next().unwrap();
+        let mut ast = build_ast(test_file_id, compilation_unit_pair);
+
+        let mut symbol_table = SymbolTable::new();
+
+        let diagnostics = analyze_names(test_file_id, &mut ast, &mut symbol_table);
+
+        if !diagnostics.is_empty() {
+            let writer = StandardStream::stderr(ColorChoice::Always);
+            let config = term::Config::default();
+
+            for diagnostic in &diagnostics {
+                term::emit(&mut writer.lock(), &config, &files, &diagnostic).unwrap();
+            }
+
+            eprintln!("{}", symbol_table);
+            panic!("Diagnostics was not empty!");
+        }
+    }
+
+    #[test]
+    fn params_seen() {
+        assert_no_diagnostics(
+            r#"
+            fn main(args: Array<String>) {
+                let x = args;
+            }
+            "#,
+        )
+    }
+}

src/name_analysis/resolve.rs

@@ -0,0 +1,143 @@
+use crate::ast::named::Named;
+use crate::ast::*;
+use crate::name_analysis::symbol_table::SymbolTable;
+use crate::name_analysis::DiagnosticsContainer;
+use codespan_reporting::diagnostic::{Diagnostic, Label};
+
+pub(super) fn resolve_module_level_declaration(
+    declaration: &mut ModuleLevelDeclaration,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    use crate::ast::ModuleLevelDeclaration::*;
+    match declaration {
+        Function(function_definition) => {
+            resolve_function_definition(function_definition, symbol_table, diagnostics)
+        }
+        _ => todo!(),
+    }
+}
+
+fn resolve_function_definition(
+    function_definition: &mut FunctionDefinition,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    resolve_function_body(&mut function_definition.body, symbol_table, diagnostics);
+}
+
+fn resolve_function_body(
+    function_body: &mut FunctionBody,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    use crate::ast::FunctionBody::*;
+    match function_body {
+        Block(block) => resolve_block(block, symbol_table, diagnostics),
+        _ => todo!(),
+    }
+}
+
+fn resolve_block(
+    block_statement: &mut BlockStatement,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    for statement in block_statement.statements.iter_mut() {
+        resolve_statement(statement, symbol_table, diagnostics);
+    }
+    if let Some(expression) = block_statement.expression.as_mut() {
+        resolve_expression(expression, symbol_table, diagnostics);
+    }
+}
+
+fn resolve_statement(
+    statement: &mut Statement,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    use crate::ast::Statement::*;
+    match statement {
+        BlockStatement(block) => resolve_block(block, symbol_table, diagnostics),
+        VariableDeclarationStatement(variable_declaration) => {
+            resolve_variable_declaration(variable_declaration, symbol_table, diagnostics)
+        }
+        AssignStatement(assign_statement) => {
+            resolve_assign_statement(assign_statement, symbol_table, diagnostics)
+        }
+        CallStatement(call_statement) => {
+            resolve_call_statement(call_statement, symbol_table, diagnostics)
+        }
+        _ => todo!(),
+    }
+}
+
+fn resolve_variable_declaration(
+    variable_declaration: &mut VariableDeclarationStatement,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    if let Some(initializer) = &mut variable_declaration.initializer {
+        resolve_expression(initializer, symbol_table, diagnostics)
+    }
+}
+
+fn resolve_assign_statement(
+    assign_statement: &mut AssignStatement,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    resolve_expression(&mut assign_statement.lhs, symbol_table, diagnostics);
+    resolve_expression(&mut assign_statement.rhs, symbol_table, diagnostics);
+}
+
+fn resolve_call_statement(
+    call_statement: &mut CallStatement,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    resolve_expression(&mut call_statement.0, symbol_table, diagnostics)
+}
+
+fn resolve_expression(
+    expression: &mut Expression,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    use crate::ast::Expression::*;
+    match expression {
+        FullyQualifiedName(fqn) => resolve_fully_qualified_name(fqn, symbol_table, diagnostics),
+        Literal(_) => {}
+        _ => todo!(),
+    }
+}
+
+fn resolve_fully_qualified_name(
+    fully_qualified_name: &mut FullyQualifiedName,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut DiagnosticsContainer,
+) {
+    let lookup_result = symbol_table.lookup(
+        fully_qualified_name.name().as_ref(),
+        fully_qualified_name.scope_id().expect(&format!(
+            "FullyQualifiedName has no scope_id set: {:?}",
+            fully_qualified_name
+        )),
+    );
+    match lookup_result {
+        Ok(symbol) => {
+            fully_qualified_name.set_symbol(symbol.clone());
+        }
+        Err(e) => diagnostics.add(
+            Diagnostic::error()
+                .with_message(format!(
+                    "No symbol with name '{}' found in current scope.",
+                    fully_qualified_name.name()
+                ))
+                .with_label(Label::primary(
+                    fully_qualified_name.file_id,
+                    fully_qualified_name.range,
+                )),
+        ),
+    }
+}

src/name_analysis/symbol.rs

@@ -0,0 +1,169 @@
+use crate::ast::Identifier;
+use std::fmt::Display;
+use std::range::Range;
+
+#[derive(Clone, Debug)]
+pub struct SourceDefinition {
+    file_id: usize,
+    range: Range<usize>,
+}
+
+impl SourceDefinition {
+    pub fn from_identifier(identifier: &Identifier) -> Self {
+        SourceDefinition {
+            file_id: identifier.file_id,
+            range: identifier.range,
+        }
+    }
+
+    pub fn file_id(&self) -> usize {
+        self.file_id
+    }
+
+    pub fn range(&self) -> Range<usize> {
+        self.range.clone()
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum Symbol {
+    Function(FunctionSymbol),
+    Variable(VariableSymbol),
+    Module(ModuleSymbol),
+}
+
+impl Symbol {
+    pub fn name(&self) -> &str {
+        match self {
+            Symbol::Function(s) => s.declared_name.as_str(),
+            Symbol::Variable(s) => s.name.as_str(),
+            Symbol::Module(s) => s.declared_name.as_str(),
+        }
+    }
+
+    pub fn definition(&self) -> &SourceDefinition {
+        match self {
+            Symbol::Function(s) => s.definition(),
+            Symbol::Module(s) => s.definition(),
+            Symbol::Variable(s) => s.definition(),
+        }
+    }
+}
+
+impl Display for Symbol {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        use Symbol::*;
+        match self {
+            Function(function_symbol) => write!(f, "{}", function_symbol),
+            Variable(variable_symbol) => write!(f, "{}", variable_symbol),
+            Module(module_symbol) => write!(f, "{}", module_symbol),
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct FunctionSymbol {
+    pub fqn: String,
+    pub declared_name: String,
+    pub is_public: bool,
+    definition: SourceDefinition,
+}
+
+impl FunctionSymbol {
+    pub fn new(
+        fqn: &str,
+        declared_name: &str,
+        is_public: bool,
+        identifier: &Identifier,
+    ) -> FunctionSymbol {
+        FunctionSymbol {
+            fqn: fqn.to_string(),
+            declared_name: declared_name.to_string(),
+            is_public,
+            definition: SourceDefinition::from_identifier(identifier),
+        }
+    }
+
+    fn definition(&self) -> &SourceDefinition {
+        &self.definition
+    }
+}
+
+impl Display for FunctionSymbol {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(
+            f,
+            "FunctionSymbol(fqn = {}, declared_name = {}, is_public = {})",
+            self.fqn, self.declared_name, self.is_public
+        )
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct VariableSymbol {
+    pub name: String,
+    pub is_mutable: bool,
+    definition: SourceDefinition,
+}
+
+impl VariableSymbol {
+    pub fn new(name: &str, is_mutable: bool, definition: SourceDefinition) -> Self {
+        VariableSymbol {
+            name: name.to_string(),
+            is_mutable,
+            definition,
+        }
+    }
+
+    pub fn definition(&self) -> &SourceDefinition {
+        &self.definition
+    }
+}
+
+impl Display for VariableSymbol {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(
+            f,
+            "VariableSymbol(name = {}, is_mutable = {})",
+            self.name, self.is_mutable
+        )
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct ModuleSymbol {
+    pub fqn: String,
+    pub declared_name: String,
+    pub is_public: bool,
+    definition: SourceDefinition,
+}
+
+impl ModuleSymbol {
+    pub fn new(
+        fqn: &str,
+        declared_name: &str,
+        is_public: bool,
+        identifier: &Identifier,
+    ) -> ModuleSymbol {
+        ModuleSymbol {
+            fqn: fqn.to_string(),
+            declared_name: declared_name.to_string(),
+            is_public,
+            definition: SourceDefinition::from_identifier(identifier),
+        }
+    }
+
+    pub fn definition(&self) -> &SourceDefinition {
+        &self.definition
+    }
+}
+
+impl Display for ModuleSymbol {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(
+            f,
+            "ModuleSymbol(name = {}, is_public = {})",
+            self.fqn, self.is_public
+        )
+    }
+}

src/name_analysis/symbol_table.rs

@@ -0,0 +1,129 @@
+use crate::name_analysis::symbol::Symbol;
+use std::collections::HashMap;
+use std::fmt::Display;
+use crate::name_analysis::symbol_table::SymbolInsertError::SymbolAlreadyDefined;
+use crate::name_analysis::symbol_table::SymbolLookupError::NoDefinition;
+
+pub struct Scope {
+    parent: Option<usize>,
+    function_and_variable_symbols: HashMap<String, Symbol>,
+    type_and_module_symbols: HashMap<String, Symbol>,
+    debug_name: String,
+}
+
+impl Scope {
+    pub fn new(parent: Option<usize>, debug_name: String) -> Scope {
+        Scope {
+            parent,
+            function_and_variable_symbols: HashMap::new(),
+            type_and_module_symbols: HashMap::new(),
+            debug_name,
+        }
+    }
+}
+
+pub enum SymbolInsertError {
+    SymbolAlreadyDefined(Symbol),
+}
+
+pub enum SymbolLookupError {
+    NoDefinition
+}
+
+pub struct SymbolTable {
+    scopes: Vec<Scope>,
+    current_scope_id: usize,
+}
+
+/// Contains a vec of scopes, like a flattened tree
+impl SymbolTable {
+    pub fn new() -> Self {
+        let mut t = SymbolTable {
+            scopes: vec![Scope::new(None, String::from("GlobalScope"))],
+            current_scope_id: 0,
+        };
+        t
+    }
+
+    pub fn current_scope_id(&self) -> usize {
+        self.current_scope_id
+    }
+
+    pub fn push_scope(&mut self, debug_name: &str) {
+        let id = self.scopes.len();
+        self.scopes
+            .push(Scope::new(Some(self.current_scope_id), debug_name.to_string()));
+        self.current_scope_id = id;
+    }
+
+    pub fn pop_scope(&mut self) {
+        if let Some(parent_id) = self.scopes[self.current_scope_id].parent {
+            self.current_scope_id = parent_id;
+        }
+    }
+
+    pub fn insert(&mut self, name: &str, symbol: Symbol) -> Result<(), SymbolInsertError> {
+        match symbol {
+            Symbol::Function(_) | Symbol::Variable(_) => {
+                self.insert_function_or_variable(name, symbol)
+            }
+            Symbol::Module(_) => self.insert_module_or_type(name, symbol),
+        }
+    }
+
+    fn insert_function_or_variable(&mut self, name: &str, symbol: Symbol) -> Result<(), SymbolInsertError> {
+        if let Some(defined_symbol) = self.scopes[self.current_scope_id]
+            .function_and_variable_symbols
+            .get(name)
+        {
+            Err(SymbolAlreadyDefined(defined_symbol.clone()))
+        } else {
+            self.scopes[self.current_scope_id]
+                .function_and_variable_symbols
+                .insert(name.to_string(), symbol);
+            Ok(())
+        }
+    }
+
+    fn insert_module_or_type(&mut self, name: &str, symbol: Symbol) -> Result<(), SymbolInsertError> {
+        if let Some(defined_symbol) = self.scopes[self.current_scope_id]
+            .type_and_module_symbols
+            .get(name)
+        {
+            Err(SymbolAlreadyDefined(defined_symbol.clone()))
+        } else {
+            self.scopes[self.current_scope_id]
+                .type_and_module_symbols
+                .insert(name.to_string(), symbol);
+            Ok(())
+        }
+    }
+
+    pub fn lookup(&self, name: &str, scope_id: usize) -> Result<&Symbol, SymbolLookupError> {
+        let mut scope_opt = Some(&self.scopes[scope_id]);
+        while let Some(scope) = scope_opt {
+            if let Some(symbol) = scope.function_and_variable_symbols.get(name) {
+                return Ok(symbol);
+            }
+            scope_opt = if let Some(parent_id) = scope.parent {
+                Some(&self.scopes[parent_id])
+            } else {
+                None
+            };
+        }
+        Err(NoDefinition)
+    }
+}
+
+impl Display for SymbolTable {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        writeln!(f, "SymbolTable(current_scope = {})", self.current_scope_id)?;
+        for (i, scope) in self.scopes.iter().enumerate() {
+            writeln!(f, "Scope {} {}", i, scope.debug_name)?;
+            for (name, symbol) in &scope.function_and_variable_symbols {
+                writeln!(f, "  {}({})", name, symbol)?;
+            }
+        }
+        Ok(())
+    }
+}

src/parser/deimos.pest

@@ -95,6 +95,7 @@ Borrow = { "&" }
 Star = { "*" }
 LeftShift = { "<<" }
 RightShift = { ">>" }
+Index = { "[]" }
 
 Operator = {
       Or
@@ -118,6 +119,9 @@ Operator = {
     | Spread
     | Borrow
     | Star
+    | LeftShift
+    | RightShift
+    | Index
 }
 
 // Names
@@ -429,9 +433,9 @@ FunctionModifier = {
 }
 
 FunctionBody = {
-      FunctionEqualsBody
+      FunctionAliasBody
+    | FunctionEqualsBody
     | BlockStatement
-    | FunctionAliasBody
 }
 
 FunctionEqualsBody = {
@@ -484,17 +488,19 @@ BlockStatement = {
 
 Statement = {
       (
-          BlockStatement
-        | VariableDeclaration
+          VariableDeclaration
         | AssignmentStatement
         | CallStatement
         | ReturnStatement
-        | IfStatement
+      )
+    ~ Semicolon
+    | (
+          BlockStatement
         | IfElseStatement
+        | IfStatement
         | WhileStatement
         | ForStatement
-      )?
-    ~ Semicolon
+      )
 }
 
 VariableDeclaration = {
@@ -530,30 +536,43 @@ ReturnStatement = {
 
 IfStatement = {
       If
+    ~ "("
     ~ Expression
+    ~ ")"
     ~ BlockStatement
 }
 
 IfElseStatement = {
-      If
-    ~ Expression
-    ~ BlockStatement
-    ~ ( Else ~ IfStatement )*
-    ~ Else
+      IfStatement
+    ~ ElseIf*
+    ~ ElseBlock?
+}
+
+ElseIf = {
+      Else
+    ~ IfStatement
+}
+
+ElseBlock = {
+      Else
     ~ BlockStatement
 }
 
 WhileStatement = {
       While
+    ~ "("
     ~ Expression
+    ~ ")"
     ~ BlockStatement
 }
 
 ForStatement = {
       For
-    ~ Expression
+    ~ "("
+    ~ Identifier
     ~ In
     ~ Expression
+    ~ ")"
     ~ BlockStatement
 }
 
@@ -652,9 +671,18 @@ ParenthesizedExpression = {
 }
 
 ObjectAccess = {
+      ( ObjectProperty | ObjectIndex )+
+}
+
+ObjectProperty = {
       "."
     ~ Identifier
-    ~ ( "." ~ Identifier )*
+}
+
+ObjectIndex = {
+      "["
+    ~ Expression
+    ~ "]"
 }
 
 // Calls
@@ -708,10 +736,8 @@ ClosureCaptures = {
 }
 
 ClosureCapture = {
-      (
-          Mut
-        | ( Borrow ~ Mut? )*
-      )?
+      Borrow*
+    ~ Mut?
     ~ Identifier
 }
 
@@ -782,14 +808,15 @@ StringChar = {
 DStringInner = @{ DStringChar+ }
 
 DStringChar = {
-      !( "\"" | "\\" ) ~ ANY
+      !( "\"" | "\\" | "${" ) ~ ANY
     | "\\" ~ ( "\"" | "\\" | "/" | "b" | "f" | "n" | "r" | "t" | "$" )
     | "\\" ~ ( "u" ~ ASCII_HEX_DIGIT{4} )
 }
 
 DStringExpression = {
-      "$"
-    ~ BlockStatement
+      "${"
+    ~ Expression
+    ~ "}"
 }
 
 BacktickString = {
@@ -802,7 +829,7 @@ BacktickString = {
 BacktickInner = @{ BacktickStringChar+ }
 
 BacktickStringChar = {
-      !( "\\`" | "\\" ) ~ ANY
+      !( "\\`" | "\\" | "${" ) ~ ANY
     | "\\" ~ ( "`" | "\\" | "/" | "b" | "f" | "n" | "r" | "t" | "$" )
     | "\\" ~ ( "u" ~ ASCII_HEX_DIGIT{4} )
 }

src/parser/mod.rs

@@ -7,8 +7,8 @@ pub struct DeimosParser;
 #[cfg(test)]
 mod deimos_parser_tests {
     use crate::parser::{DeimosParser, Rule};
-    use pest::iterators::Pair;
-    use pest::{Parser};
+    use indoc::indoc;
+    use pest::{parses_to, Parser};
 
     macro_rules! fail_rule {
         ($pair: expr; $rule:path) => {{
@@ -28,81 +28,156 @@ mod deimos_parser_tests {
         }};
     }
 
-    macro_rules! match_inner_rules {
-        ($pair:expr; $rule:path; $handle_last:expr) => {{
-            if let $rule = $pair.as_rule() {
-                $handle_last($pair);
-            } else {
-                fail_rule!($pair; $rule);
-            }
-        }};
-        ($pair:expr; $head_rule:path $(, $tail_rules:path )* ; $handle_last:expr) => {{
-            if let $head_rule = $pair.as_rule() {
-                let inner = $pair.into_inner().next().unwrap();
-                match_inner_rules!(
-                    inner;
-                    $( $tail_rules ),*;
-                    $handle_last
+    fn parses_to(rule: Rule, input: &str) {
+        let parse_result = DeimosParser::parse(rule, input);
+        if let Err(e) = parse_result {
+            panic!("Parsing failed.\n{}", e);
+        } else {
+            let mut pairs = parse_result.unwrap();
+            if input.trim() != pairs.as_str().trim() {
+                panic!(
+                    "Parsing did not consume entire input. Consumed only:\n{}",
+                    pairs.as_str()
                 );
-            } else {
-                fail_rule!($pair; $head_rule);
             }
-        }};
-    }
-
-    fn parse(rule: Rule, input: &str) -> Pair<Rule> {
-        let pair = DeimosParser::parse(rule, input)
-            .expect("Parsing failed.")
-            .next()
-            .unwrap();
-        dbg!(&pair);
-        pair
+            let first = pairs.next().unwrap();
+            match_rule!(first; rule)
+        }
     }
 
     #[test]
     fn hex_int() {
-        let pair = parse(Rule::IntLiteral, "0x1234abcd");
-        match_inner_rules!(pair; Rule::IntLiteral, Rule::NumberBase, Rule::HexadecimalBase; |hexadecimal_base: Pair<Rule>| {
-            assert_eq!(hexadecimal_base.as_str(), "0x1234abcd")
-        });
+        parses_to(Rule::IntLiteral, "0x1234abcd");
     }
 
     #[test]
     fn hex_long() {
-        let pair = parse(Rule::LongLiteral, "0x123456789abcdefL");
-        match_inner_rules!(pair; Rule::LongLiteral, Rule::NumberBase, Rule::HexadecimalBase; |hexadecimal_base: Pair<Rule>| {
-            assert_eq!(hexadecimal_base.as_str(), "0x123456789abcdef")
-        })
+        parses_to(Rule::LongLiteral, "0x123456789abcdefL");
     }
 
     #[test]
-    fn identifier_call_as_expression() {
-        parse(Rule::Expression, "foo()");
+    fn suffix_expression_call_single_identifier() {
+        parses_to(Rule::SuffixExpression, "foo()");
     }
 
-    mod smoke_screen_tests {
-        use crate::parser::deimos_parser_tests::parse;
-        use crate::parser::Rule;
+    #[test]
+    fn simple_interface() {
+        parses_to(Rule::CompilationUnit, "pub int Simple { fn foo() -> Void }");
+    }
 
-        #[test]
-        fn simple_interface() {
-            parse(Rule::CompilationUnit, "pub int Simple { fn foo() -> Void }");
-        }
+    #[test]
+    fn interface_with_op() {
+        parses_to(
+            Rule::CompilationUnit,
+            "pub int Callable { op () () -> Void }",
+        );
+    }
 
-        #[test]
-        fn interface_with_op() {
-            parse(
-                Rule::CompilationUnit,
-                "pub int Callable { op () () -> Void }",
-            );
-        }
+    #[test]
+    fn interface_with_alias() {
+        parses_to(
+            Rule::CompilationUnit,
+            indoc! {"
+                pub int Callable {
+                    fn call() -> Void
+                    def op () () -> Void alias call
+                }
+            "},
+        );
+    }
 
-        #[test]
-        fn interface_with_alias() {
-            parse(
-                Rule::CompilationUnit,
-                "pub int Callable {\n  fn call() -> Void\n  op () () -> Void alias call\n}",
-            );
-        }
+    #[test]
+    fn index_identifier() {
+        parses_to(Rule::SuffixExpression, "foo[0]");
+    }
+
+    #[test]
+    fn chained_index_call_on_identifier() {
+        parses_to(Rule::SuffixExpression, "foo[0]()");
+    }
+
+    #[test]
+    fn if_statement() {
+        parses_to(
+            Rule::IfStatement,
+            indoc! {"
+            if (foo == 42) {
+                bar()
+            }"},
+        )
+    }
+
+    #[test]
+    fn if_else_statement() {
+        parses_to(
+            Rule::IfElseStatement,
+            indoc! {"
+            if (foo == 42) {
+                bar()
+            } else {
+                baz()
+            }"},
+        )
+    }
+
+    #[test]
+    fn if_else_if_statement() {
+        parses_to(
+            Rule::IfElseStatement,
+            indoc! {"
+            if (foo == 42) {
+                bar()
+            } else if (foo == 16) {
+                baz()
+            }"},
+        )
+    }
+
+    #[test]
+    fn if_else_if_else_statement() {
+        parses_to(
+            Rule::IfElseStatement,
+            indoc! {"
+            if (foo == 42) {
+                foo()
+            } else if (foo == 16) {
+                baz()
+            } else {
+                fizz()
+            }"},
+        )
+    }
+    
+    #[test]
+    fn while_statement() {
+        parses_to(Rule::WhileStatement, "while (foo) { bar() }");
+    }
+    
+    #[test]
+    fn for_statement() {
+        parses_to(Rule::ForStatement, "for (foo in bar) { baz(foo); }");
+    }
+    
+    #[test]
+    fn if_statement_with_call_condition() {
+        parses_to(Rule::IfStatement, indoc! {"
+            if (foo()) {
+                bar()
+            }
+        "})
+    }
+    
+    #[test]
+    fn while_statement_with_call_condition() {
+        parses_to(Rule::WhileStatement, "while (foo()) { bar(); }")
+    }
+    
+    #[test]
+    fn for_statement_with_call_iterator() {
+        parses_to(Rule::ForStatement, indoc! {"
+            for (foo in bar()) {
+                baz(foo);
+            }
+        "})
     }
 }