Build fn child unwrap; some tests.

ast-generator/src/build_fn_gen.rs

@@ -1,5 +1,6 @@
 use crate::spec::{
-    BuildBooleanOn, ChildSpec, SingleChildToBuild, StructBuildSpec, VecChildToBuild,
+    BuildBooleanOn, ChildSpec, SingleBooleanChildToBuild, SingleChildToBuild,
+    SingleTypeChildToBuild, StructBuildSpec, VecChild, VecChildToBuild,
 };
 use convert_case::{Case, Casing};
 use proc_macro2::TokenStream;
@@ -9,33 +10,45 @@ pub fn make_build_fn_name(s: &str) -> String {
     format!("build_{}", s.to_case(Case::Snake))
 }
 
-fn make_child_holder(child_spec: &ChildSpec) -> Option<TokenStream> {
+fn make_vec_child_holder(vec_child: &VecChild) -> TokenStream {
-    match child_spec {
-        ChildSpec::SkipChild(_) => None,
-        ChildSpec::VecChild(vec_child) => {
     let (child_ident, child_type_ident) = match vec_child.build() {
         VecChildToBuild::Type(vec_type_child) => (
             format_ident!("{}", vec_type_child.var_name()),
             format_ident!("{}", vec_type_child.build()),
         ),
     };
-            Some(quote! {
+    quote! {
-                let mut #child_ident: Vec<#child_type_ident> = vec![]
+        let mut #child_ident: Vec<Box<#child_type_ident>> = vec![]
-            })
     }
-        ChildSpec::SingleChild(single_child) => match single_child.build() {
+}
-            SingleChildToBuild::Type(single_type_child) => {
+
+fn make_single_type_child_holder(single_type_child: &SingleTypeChildToBuild) -> TokenStream {
     let child_ident = format_ident!("{}", single_type_child.var_name());
     let child_type_ident = format_ident!("{}", single_type_child.build());
-                Some(quote! {
+    quote! {
-                    let mut #child_ident: Option<#child_type_ident> = None;
+        let mut #child_ident: Option<Box<#child_type_ident>> = None
-                })
+    }
+}
+
+fn make_single_boolean_child_holder(
+    single_boolean_child: &SingleBooleanChildToBuild,
+) -> TokenStream {
+    let child_ident = format_ident!("{}", single_boolean_child.var_name());
+    quote! {
+        let mut #child_ident: bool = false
+    }
+}
+
+fn make_child_holder(child_spec: &ChildSpec) -> Option<TokenStream> {
+    match child_spec {
+        ChildSpec::SkipChild(_) => None,
+        ChildSpec::VecChild(vec_child) => Some(make_vec_child_holder(vec_child)),
+        ChildSpec::SingleChild(single_child) => match single_child.build() {
+            SingleChildToBuild::Type(single_type_child) => {
+                Some(make_single_type_child_holder(single_type_child))
             }
             SingleChildToBuild::Boolean(boolean_child) => {
-                let child_ident = format_ident!("{}", boolean_child.var_name());
+                Some(make_single_boolean_child_holder(boolean_child))
-                Some(quote! {
-                    let #child_ident: bool = false
-                })
             }
         },
     }
@@ -52,7 +65,7 @@ fn make_match_action(child_spec: &ChildSpec) -> TokenStream {
                 ),
             };
             quote! {
-                #child_name_ident.push(#build_fn_ident(inner_pair))
+                #child_name_ident.push(Box::new(#build_fn_ident(inner_pair)))
             }
         }
         ChildSpec::SingleChild(single_child) => match single_child.build() {
@@ -60,7 +73,7 @@ fn make_match_action(child_spec: &ChildSpec) -> TokenStream {
                 let child_name_ident = format_ident!("{}", single_type_child.var_name());
                 let build_fn_ident = format_ident!("{}", single_type_child.with());
                 quote! {
-                    #child_name_ident = Some(#build_fn_ident(inner_pair))
+                    #child_name_ident = Some(Box::new(#build_fn_ident(inner_pair)))
                 }
             }
             SingleChildToBuild::Boolean(single_boolean_child) => {
@@ -90,6 +103,57 @@ fn make_rule_matcher(child_spec: &ChildSpec) -> TokenStream {
     }
 }
 
+fn make_child_arg(child_spec: &ChildSpec) -> Option<TokenStream> {
+    match child_spec {
+        ChildSpec::SkipChild(_) => None,
+        ChildSpec::VecChild(vec_child) => {
+            let child_ident = match vec_child.build() {
+                VecChildToBuild::Type(vec_type_child) => {
+                    format_ident!("{}", vec_type_child.var_name())
+                }
+            };
+            Some(quote! { #child_ident })
+        }
+        ChildSpec::SingleChild(single_child) => match single_child.build() {
+            SingleChildToBuild::Type(single_type_child) => {
+                let child_ident = format_ident!("{}", single_type_child.var_name());
+                if single_type_child.optional() {
+                    Some(quote! { #child_ident })
+                } else if let Some(or_else) = single_type_child.or_else() {
+                    let child_type_ident = format_ident!("{}", single_type_child.build());
+                    let or_else_ident = format_ident!("{}", or_else);
+                    Some(quote! {
+                        #child_ident.unwrap_or_else(|| Box::new(#child_type_ident::#or_else_ident()))
+                    })
+                } else {
+                    Some(quote! { #child_ident.unwrap() })
+                }
+            }
+            SingleChildToBuild::Boolean(single_boolean_child) => {
+                let child_ident = format_ident!("{}", single_boolean_child.var_name());
+                Some(quote! { #child_ident })
+            }
+        },
+    }
+}
+
+fn make_return_value_stream(build_spec: &StructBuildSpec) -> TokenStream {
+    let type_ident = format_ident!("{}", build_spec.build());
+    let child_args = build_spec
+        .children()
+        .iter()
+        .map(|child| make_child_arg(child))
+        .filter(|child_arg| child_arg.is_some())
+        .map(|child_arg| child_arg.unwrap())
+        .collect::<Vec<_>>();
+
+    quote! {
+        #type_ident::new(
+            #(#child_args,)*
+        )
+    }
+}
+
 pub fn make_struct_build_fn(build_spec: &StructBuildSpec) -> TokenStream {
     let build_fn_ident = format_ident!("{}", build_spec.with());
     let pair_ident = format_ident!("{}_pair", build_spec.build().to_case(Case::Snake));
@@ -117,11 +181,66 @@ pub fn make_struct_build_fn(build_spec: &StructBuildSpec) -> TokenStream {
         }
     };
 
+    let new_stream = make_return_value_stream(build_spec);
+
     quote! {
         fn #build_fn_ident(#pair_ident: Pair<Rule>) -> #return_type_ident {
             #(#child_holders;)*
 
             #iter_stream
+
+            #new_stream
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::spec::VecTypeChildToBuild;
+
+    #[test]
+    fn vec_child_holder() {
+        let vec_child = VecChild::new(
+            "test_child",
+            "Test",
+            VecChildToBuild::Type(VecTypeChildToBuild::new(
+                "TestType",
+                "test_child",
+                "build_test_child",
+            )),
+        );
+        assert_eq!(
+            make_vec_child_holder(&vec_child).to_string(),
+            quote! {
+                let mut test_child: Vec<Box<TestType>> = vec![]
+            }
+            .to_string()
+        );
+    }
+
+    #[test]
+    fn single_type_child_holder() {
+        let single_type_child = SingleTypeChildToBuild::from_build_or_rule("TestType", None, false);
+        assert_eq!(
+            make_single_type_child_holder(&single_type_child).to_string(),
+            quote! {
+                let mut test_type: Option<Box<TestType>> = None
+            }
+            .to_string()
+        );
+    }
+
+    #[test]
+    fn single_boolean_child_holder() {
+        let single_boolean_child =
+            SingleBooleanChildToBuild::new("test_child", BuildBooleanOn::RulePresent);
+        assert_eq!(
+            make_single_boolean_child_holder(&single_boolean_child).to_string(),
+            quote! {
+                let mut test_child: bool = false
+            }
+            .to_string()
+        );
+    }
+}

ast-generator/src/deserialize.rs

@@ -46,9 +46,10 @@ fn get_vec_child(name: &str, rule: &str, build: &Yaml) -> ChildSpec {
     ))
 }
 
-fn get_single_child_to_build(name: &str, rule: &str, build: &Yaml) -> SingleChildToBuild {
+fn get_single_child_to_build(name: &str, rule: &str, optional: bool, build: &Yaml) -> SingleChildToBuild {
     if build.is_hash() {
-        let r#type = build["type"].as_str().unwrap();
+        match build["type"].as_str() {
+            Some(r#type) => {
                 let var_name = build["var"]
                     .as_str()
                     .map(|s| s.to_string())
@@ -62,19 +63,41 @@ fn get_single_child_to_build(name: &str, rule: &str, build: &Yaml) -> SingleChil
                 } else {
                     todo!("currently on boolean types with on: rule_present are supported")
                 }       
+            },
+            None => {
+                let or_else = build["or_else"]
+                    .as_str()
+                    .map(|s| s.to_string())
+                    .or_else(|| {
+                        let or_else_default = build["or_else_default"]
+                            .as_bool()
+                            .unwrap_or_else(|| false);
+                        if or_else_default {
+                            Some(String::from("default"))
+                        } else {
+                            None
+                        }
+                    });
+                SingleChildToBuild::Type(SingleTypeChildToBuild::from_build_or_rule(
+                    rule,
+                    or_else,
+                    optional,
+                ))
+            }
+        }
     } else {
         match build.as_str() {
-            Some(s) => SingleChildToBuild::Type(SingleTypeChildToBuild::from_build_or_rule(s)),
+            Some(s) => SingleChildToBuild::Type(SingleTypeChildToBuild::from_build_or_rule(s, None, optional)),
-            None => SingleChildToBuild::Type(SingleTypeChildToBuild::from_build_or_rule(rule)),
+            None => SingleChildToBuild::Type(SingleTypeChildToBuild::from_build_or_rule(rule, None, optional)),
         }
     }
 }
 
-fn get_single_child(name: &str, rule: &str, build: &Yaml) -> ChildSpec {
+fn get_single_child(name: &str, rule: &str, optional: bool, build: &Yaml) -> ChildSpec {
     ChildSpec::SingleChild(SingleChild::new(
         name,
         rule,
-        get_single_child_to_build(name, rule, build),
+        get_single_child_to_build(name, rule, optional, build),
     ))
 }
 
@@ -92,18 +115,25 @@ fn get_child_specs(children: &Yaml) -> Vec<ChildSpec> {
                     .map(|(name, props)| (name.as_str().unwrap(), props))
                     .unwrap();
 
-                let rule = props["rule"].as_str().unwrap();
+                let rule = props["rule"]
+                    .as_str()
+                    .map(|s| s.to_string())
+                    .unwrap_or(name.to_case(Case::Pascal));
 
                 if get_skip(&props["skip"]) {
-                    return ChildSpec::SkipChild(SkipChild::new(name, rule));
+                    return ChildSpec::SkipChild(SkipChild::new(name, &rule));
                 }
 
                 let build = &props["build"];
 
                 if get_vec(&props["vec"]) {
-                    get_vec_child(name, rule, build)
+                    get_vec_child(name, &rule, build)
                 } else {
-                    get_single_child(name, rule, build)
+                    let optional = props["optional"]
+                        .as_bool()
+                        .unwrap_or_else(|| false);
+                    
+                    get_single_child(name, &rule, optional, build)
                 }
             } else {
                 ChildSpec::SingleChild(SingleChild::from_name_snake(child_spec.as_str().unwrap()))

ast-generator/src/lib.rs

@@ -9,6 +9,7 @@ use proc_macro2::TokenStream;
 use quote::quote;
 use spec::BuildSpec;
 use syn::File;
+use syn::spanned::Spanned;
 
 fn debug_built_spec(build_spec: &BuildSpec, token_stream: &TokenStream) {
     println!("*** BuildSpec ***");

ast-generator/src/spec.rs

@@ -233,6 +233,8 @@ impl SingleChild {
             rule: name.to_case(Case::Pascal),
             build: SingleChildToBuild::Type(SingleTypeChildToBuild::from_build_or_rule(
                 &name.to_case(Case::Pascal),
+                None,
+                false,
             )),
         }
     }
@@ -272,14 +274,22 @@ pub struct SingleTypeChildToBuild {
     build: String,
     var_name: String,
     with: String,
+    or_else: Option<String>,
+    optional: bool,
 }
 
 impl SingleTypeChildToBuild {
-    pub fn from_build_or_rule(build_or_rule: &str) -> Self {
+    pub fn from_build_or_rule(
+        build_or_rule: &str,
+        or_else: Option<String>,
+        optional: bool,
+    ) -> Self {
         Self {
             build: build_or_rule.to_string(),
             var_name: build_or_rule.to_case(Case::Snake),
             with: make_build_fn_name(build_or_rule),
+            or_else,
+            optional,
         }
     }
 
@@ -297,6 +307,16 @@ impl SingleTypeChildToBuild {
     pub fn with(&self) -> &str {
         &self.with
     }
+
+    /// The default fn to call when unwrapping the child (before passing as arg to new).
+    pub fn or_else(&self) -> Option<&str> {
+        self.or_else.as_deref()
+    }
+
+    /// If the type should be wrapped in an Option.
+    pub fn optional(&self) -> bool {
+        self.optional
+    }
 }
 
 #[derive(Debug)]

ast-generator/src/type_gen.rs

@@ -64,9 +64,15 @@ fn handle_single_type_child(
     let child_ident_mut = format_ident!("{}_mut", single_type_child.var_name());
     let child_type_ident = format_ident!("{}", single_type_child.build());
     member_names.push(child_ident.clone());
+    if single_type_child.optional() {
+        annotated_members.push(quote! {
+            #child_ident: Option<Box<#child_type_ident>>
+        });
+    } else {
         annotated_members.push(quote! {
             #child_ident: Box<#child_type_ident>
-    });
+        })
+    }
     accessors.push(quote! {
         pub fn #child_ident(&self) -> &#child_type_ident {
             self.#child_ident.as_ref()

sketching/september_2025/adder/adder.dm

@@ -0,0 +1,5 @@
+use math::add
+
+fn main()
+    println add(1, 2) // 3
+end

sketching/september_2025/adder/math/add.dm

@@ -0,0 +1,3 @@
+mod math
+
+pub fn add(a: Int, b: Int) = a + b

src/parser/ast.schema.yaml

@@ -78,18 +78,32 @@ $defs:
     properties:
       rule:
         type: string
+        description: The type to build, in Pascal case.
+      optional:
+        type: boolean
+        description: If true, this child will be stored as an Option.
       build:
         oneOf:
           - type: string
           - $ref: "#/$defs/SingleChildBuildDefinition"
-    required:
-      - rule
   SingleChildBuildDefinition:
     type: object
     additionalProperties: false
     description: A definition of what exactly to build for a given child rule.
     oneOf:
+      - $ref: "#/$defs/BuildSingleTypeChild"
       - $ref: "#/$defs/BuildBooleanChild"
+  BuildSingleTypeChild:
+    type: object
+    additionalProperties: false
+    description: A definition of a single-type child to build.
+    properties:
+      or_else:
+        type: string
+        description: The method name to call upon the built-type if the rule is not found. Takes precedence over "or_else_default".
+      or_else_default:
+        type: boolean
+        description: Whether to call the default method on the built-type if the rule is not found.
   BuildBooleanChild:
     type: object
     additionalProperties: false

src/parser/ast.yaml

@@ -1,19 +1,21 @@
 # $schema: ./ast.schema.yaml
+# Top-level constructs
 CompilationUnit:
   children:
-    - namespace
+    - parent_mod
     - use_statements:
         rule: UseStatement
         vec: true
     - module_level_declarations:
         rule: ModuleLevelDeclaration
-Namespace:
+        vec: true
+ParentMod:
   children:
-    - ns_kw:
+    - mod_kw:
-        rule: Ns
+        rule: Mod
         skip: true
     - fqn:
-        rule: Fqn
+        rule: FullyQualifiedName
 UseStatement:
   children:
     - use_kw:
@@ -24,17 +26,49 @@ UseStatement:
         vec: true
     - suffix:
         rule: UseStatementSuffix
+UseStatementPrefix:
+  children:
+    - identifier
+UseStatementSuffix:
+  rules:
+    - Identifier
+    - rule: Star
+      build: UseStatementStarSuffix
+    - UseList
+UseList:
+  children:
+    - identifiers:
+        rule: Identifier
+        vec: true
+
+# Level declarations
 ModuleLevelDeclaration:
   rules:
-    - rule: Module
+    - Module
-      build: ModuleDeclaration
+    - Interface
-    - rule: Interface
+    - Class
-      build: InterfaceDeclaration
+    - Function
-    - rule: Class
-      build: ClassDeclaration
-    - FunctionDefinition
     - PlatformFunction
-ModuleDeclaration:
+InterfaceLevelDeclaration:
+  rules:
+    - CompanionModule
+    - Interface
+    - Class
+    - InterfaceFunction
+    - InterfaceDefaultFunction
+    - InterfaceOperatorFunction
+    - InterfaceDefaultOperatorFunction
+ClassLevelDeclaration:
+  children:
+    - CompanionModule
+    - Interface
+    - Class
+    - Function
+    - OperatorFunction
+    - PlatformFunction
+
+# Main organizational constructs
+Module:
   children:
     - is_public:
         rule: Pub
@@ -49,7 +83,47 @@ ModuleDeclaration:
     - declarations:
         rule: ModuleLevelDeclaration
         vec: true
-ClassDeclaration:
+    - end_kw:
+        rule: End
+        skip: true
+CompanionModule:
+  children:
+    - companion_kw:
+        rule: Companion
+        skip: true
+    - mod_kw:
+        rule: Mod
+        skip: true
+    - declarations:
+        rule: ModuleLevelDeclaration
+        vec: true
+    - end_kw:
+        rule: End
+        skip: true
+Interface:
+  children:
+    - is_public:
+        rule: Pub
+        build:
+          type: boolean
+          on: rule_present
+    - int_kw:
+        rule: IntKw
+        skip: true
+    - identifier
+    - generic_parameters:
+        build:
+          or_else_default: true
+    - implements_list:
+        build:
+          or_else_default: true
+    - declarations:
+        rule: InterfaceLevelDeclaration
+        vec: true
+    - end_kw:
+        rule: End
+        skip: true
+Class:
   children:
     - is_public:
         rule: Pub
@@ -60,22 +134,27 @@ ClassDeclaration:
         rule: ClassKw
         skip: true
     - identifier
-    - generic_parameters
+    - generic_parameters:
-    - class_constructor
+        build:
-    - implements_list
+          or_else_default: true
+    - class_constructor:
+        build:
+          or_else_default: true
+    - implements_list:
+        build:
+          or_else_default: true
     - class_level_declarations:
         rule: ClassLevelDeclaration
         vec: true
-FunctionDeclaration:
+
+# Function constructs
+Function:
   children:
     - is_public:
         rule: Pub
         build:
           type: boolean
           on: rule_present
-    - modifier:
-        rule: Modifier
-        build: FunctionModifier
     - fn_kw:
         rule: Fn
         skip: true
@@ -83,5 +162,47 @@ FunctionDeclaration:
         rule: GenericParameters
     - identifier
     - parameters
-    - return_type
+    - return_type:
+        build:
+          or_else: void
     - function_body
+OperatorFunction:
+  children:
+    - is_public:
+        rule: Pub
+        build:
+          type: boolean
+          on: rule_present
+    - op_kw:
+        rule: Op
+        skip: true
+    - generics:
+        rule: GenericParameters
+        build:
+          or_else_default: true
+    - operator
+    - parameters
+    - return_type:
+        build:
+          or_else: void
+    - function_body
+PlatformFunction:
+  children:
+    - is_public:
+        rule: Pub
+        build:
+          type: boolean
+          on: rule_present
+    - platform_kw:
+        rule: Platform
+        skip: true
+    - fn_kw:
+        rule: Fn
+        skip: true
+    - generics:
+        rule: GenericParameters
+        build:
+          or_else_default: true
+    - identifier
+    - parameters
+    - return_type

src/parser/deimos.pest

@@ -30,6 +30,8 @@ Alias = { "alias" }
 True = { "true" }
 False = { "false" }
 Use = { "use" }
+End = { "end" }
+Companion = { "comp" }
 
 // Keywords: primitive types
 Byte = { "Byte" }
@@ -322,22 +324,31 @@ RefList = {
 
 CompilationUnit = {
       SOI
-    ~ ( Namespace ~ Semicolon )?
+    ~ ParentMod?
-    ~ ( UseStatement ~ Semicolon )*
+    ~ ( UseStatement | ModuleLevelDeclaration )*
-    ~ ModuleLevelDeclaration*
     ~ EOI
 }
 
-Namespace = {
+ParentMod = {
-      Ns
+      Mod
     ~ FullyQualifiedName
 }
 
 UseStatement = {
       Use
-    ~ Identifier
+    ~ UseStatementPrefix*
-    ~ ( "::" ~ Identifier )*
+    ~ UseStatementSuffix
-    ~ ( "::" ~ ( Star | UseList ) )?
+}
+
+UseStatementPrefix = {
+      Identifier
+    ~ "::"
+}
+
+UseStatementSuffix = {
+      Identifier
+    | Star
+    | UseList
 }
 
 UseList = {
@@ -353,12 +364,12 @@ ModuleLevelDeclaration = {
       Module
     | Interface
     | Class
-    | FunctionDefinition
+    | Function
     | PlatformFunction
 }
 
 InterfaceLevelDeclaration = {
-      Module
+      CompanionModule
     | Interface
     | Class
     | InterfaceFunction
@@ -368,14 +379,12 @@ InterfaceLevelDeclaration = {
 }
 
 ClassLevelDeclaration = {
-      Module
+      CompanionModule
     | Interface
     | Class
-    | FunctionDefinition
+    | Function
-    | OperatorFunctionDefinition
+    | OperatorFunction
     | PlatformFunction
-    | Property
-    | Field
 }
 
 // Main organizational constructs
@@ -384,7 +393,15 @@ Module = {
       Pub?
     ~ Mod
     ~ Identifier
-    ~ "{" ~ ModuleLevelDeclaration* ~ "}"
+    ~ ModuleLevelDeclaration*
+    ~ End
+}
+
+CompanionModule = {
+      Companion
+    ~ Mod
+    ~ ModuleLevelDeclaration*
+    ~ End
 }
 
 Interface = {
@@ -393,7 +410,8 @@ Interface = {
     ~ Identifier
     ~ GenericParameters?
     ~ ImplementsList?
-    ~ ( "{" ~ InterfaceLevelDeclaration* ~ "}" )?
+    ~ InterfaceLevelDeclaration*
+    ~ End
 }
 
 Class = {
@@ -403,14 +421,14 @@ Class = {
     ~ GenericParameters?
     ~ ClassConstructor?
     ~ ImplementsList?
-    ~ ( "{" ~ ClassLevelDeclaration* ~ "}" )?
+    ~ ClassLevelDeclaration*
+    ~ End
 }
 
 // Function constructs
 
-FunctionDefinition = {
+Function = {
       Pub?
-    ~ FunctionModifier?
     ~ Fn
     ~ GenericParameters?
     ~ Identifier
@@ -419,9 +437,8 @@ FunctionDefinition = {
     ~ FunctionBody
 }
 
-OperatorFunctionDefinition = {
+OperatorFunction = {
       Pub?
-    ~ FunctionModifier?
     ~ Op
     ~ GenericParameters?
     ~ Operator
@@ -432,14 +449,12 @@ OperatorFunctionDefinition = {
 
 PlatformFunction = {
       Pub?
-    ~ FunctionModifier?
     ~ Platform
     ~ Fn
     ~ GenericParameters?
     ~ Identifier
     ~ Parameters
     ~ ReturnType
-    ~ ";"
 }
 
 InterfaceFunction = {
@@ -482,13 +497,7 @@ InterfaceDefaultOperatorFunction = {
     ~ FunctionBody
 }
 
-FunctionModifier = {
+// Function Components
-      Static
-    | Cons
-    | Mut ~ Ref
-    | Mut
-    | Ref
-}
 
 FunctionBody = {
       FunctionAliasBody