Merge pull request #24 from mist-go/generics

Generics
2026-05-08 18:20:42 +02:00
parent 91bee0c4fc 65f4c5278d
commit 0bf32b16cd
4 changed files with 464 additions and 112 deletions
@@ -3,13 +3,13 @@ use serde::Serialize;
 #[derive(Debug, Clone, Serialize)]
 pub struct Identifier(pub String);

-#[derive(Debug, Clone, Serialize)]
+#[derive(Debug, Clone, Serialize, Default)]
 pub struct FieldList(pub Vec<(Identifier, Visibility, TypeExpr)>);

-#[derive(Debug, Clone, Serialize)]
+#[derive(Debug, Clone, Serialize, Default)]
 pub struct ParamList(pub Vec<VarDecl>);

-#[derive(Debug, Clone, Serialize)]
+#[derive(Debug, Clone, Serialize, Default)]
 pub struct Block(pub Vec<Statement>);

 #[derive(Debug, Clone, Serialize)]
@@ -62,6 +62,8 @@ pub enum BinaryOp {
    GreaterThan,
    LessThanOrEqual,
    GreaterThanOrEqual,
+    And,
+    Or,
 }

 #[derive(Debug, Clone, Serialize)]
@@ -75,10 +77,12 @@ pub enum TopLevelKind {
    EnumDecl {
        visibility: Visibility,
        name: Identifier,
+        generics: Generics,
        fields: Vec<EnumItem>,
    },
    StructDecl {
        visibility: Visibility,
+        generics: Generics,
        name: Identifier,
        fields: FieldList,
    },
@@ -86,12 +90,16 @@ pub enum TopLevelKind {
    ClassDecl {
        visibility: Visibility,
        name: Identifier,
+        generics: Generics,
        fields: Vec<VarDeclStmt>,
        constructor: ClassConstructor,
        methods: Vec<FunctionDecl>,
    },
 }

+#[derive(Debug, Clone, Serialize, Default)]
+pub struct Generics(pub Vec<(Identifier, Vec<Path>)>);
+
 #[derive(Debug, Clone, Serialize)]
 pub enum Pattern {
    NamedTuple(Path, Vec<Identifier>),
@@ -112,6 +120,7 @@ pub enum EnumItem {
 #[derive(Debug, Clone, Serialize)]
 pub struct ClassConstructor {
    pub visibility: Visibility,
+    pub generics: Generics,
    pub params: ParamList,
    pub body: Block,
 }
@@ -120,6 +129,7 @@ pub struct ClassConstructor {
 pub struct FunctionDecl {
    pub visibility: Visibility,
    pub name: Identifier,
+    pub generics: Generics,
    pub params: ParamList,
    pub return_type: TypeExpr,
    pub body: Block,
@@ -1,59 +1,121 @@
+// ======================================================
+// LEXICAL
+// ======================================================
+
 WHITESPACE = _{ " " | "\t" | "\r" | "\n" }
 COMMENT    = _{ "//" ~ (!"\n" ~ ANY)* }

-program = { SOI ~ top_level* ~ EOI }
+// ------------------------------------------------------
+// PRIMITIVES
+// ------------------------------------------------------

-// primitives
 identifier = @{ (ASCII_ALPHA | "_") ~ (ASCII_ALPHANUMERIC | "_")* }
-integer     = @{ ASCII_DIGIT+ }
-float       = @{ ASCII_DIGIT+ ~ "." ~ ASCII_DIGIT+ }
-boolean     =  { "true" | "false" }
-string_lit  =  { "\"" ~ inner_str ~ "\"" }
-inner_str   = @{ (!"\"" ~ ("\\\"" | ANY))* }
-static_path =  { identifier ~ ("::" ~ identifier)* }

-// pattern
-tuple_pattern       =  { "(" ~ (identifier ~ ("," ~ identifier)*)? ~ ")" }
-named_tuple_pattern =  { static_path ~ "(" ~ (identifier ~ ("," ~ identifier)*)? ~ ")" }
-struct_pattern      =  { static_path ~ "{" ~ (identifier ~ ("," ~ identifier)*)? ~ "}" }
-pattern             = _{ named_tuple_pattern | tuple_pattern | struct_pattern | literal | static_path }
+integer = @{ ASCII_DIGIT+ }
+
+float = @{
+    ASCII_DIGIT+ ~ "." ~ ASCII_DIGIT+
+}
+
+boolean = {
+    "true"
+  | "false"
+}
+
+string_lit = {
+    "\"" ~ inner_str ~ "\""
+}
+
+inner_str = @{
+    (!"\"" ~ ("\\\"" | ANY))*
+}
+
+semicolon = _{ ";" }
+
+static_path = {
+    identifier ~ ("::" ~ identifier)*
+}
+
+// ======================================================
+// PROGRAM
+// ======================================================
+
+program = {
+    SOI ~ top_level* ~ EOI
+}
+
+// ======================================================
+// MODIFIERS
+// ======================================================

 export  = { "public" }
 mutable = { "mut" }
 var     = { "var" }
-var_decl  =  { (var | type_expr) ~ mutable? ~ pattern }
-semicolon = _{ ";" }

-// ================= CLASS =================
-class_constructor = {
-    export? ~ "constructor" ~ "(" ~ param_list? ~ ")" ~ block
+// ======================================================
+// GENERICS
+// ======================================================
+generic  = { identifier ~ (":" ~ static_path ~ ("+" ~ static_path)*)? }
+generics = { "<" ~ (generic ~ ("," ~ generic)*)? ~ ">" }
+
+// ======================================================
+// TYPES
+// ======================================================
+
+tuple_type = {
+    "(" ~ (type_expr ~ ("," ~ type_expr)*)? ~ ")"
 }

-class_fields = { var_decl_statement* }
-
-self_param = { "self" ~ mutable? ~ deref_px? }
-
-method = {
-    export? ~ type_expr ~ identifier ~ "(" ~ self_param? ~ param_list? ~ ")" ~ block
+path_type = {
+    static_path ~ ("<" ~ (type_expr ~ ("," ~ type_expr)*)? ~ ">")?
 }

-class_decl = {
-    export? ~ "class" ~ identifier ~ "{" ~ class_fields ~ class_constructor ~ method* ~ "}"
+ref_type = {
+    mutable? ~ "*"
 }

-// ================= TOP LEVEL =================
+type_expr = {
+    (path_type | tuple_type) ~ ref_type*
+}

-enum_named  = { identifier }
-enum_tuple  = { identifier ~ tuple_type }
-enum_struct = { identifier ~ "{" ~ field_list ~ "}" }
+// ======================================================
+// LITERALS
+// ======================================================

-enum_field = _{ enum_tuple | enum_struct | enum_named }
+literal = {
+    float
+  | integer
+  | boolean
+  | string_lit
+}

-enum_fields = _{ enum_field ~ ("," ~ enum_field)* ~ ","? }
+// ======================================================
+// PATTERNS
+// ======================================================

-enum_decl = { export? ~ "enum" ~ identifier ~ "{" ~ enum_fields ~ "}" }
+tuple_pattern = {
+    "(" ~ (identifier ~ ("," ~ identifier)*)? ~ ")"
+}

-top_level = { (attributes ~ (import | function_decl | struct_decl | enum_decl | class_decl | mod_package)) | mod_attribute }
+named_tuple_pattern = {
+    static_path ~ "(" ~ (identifier ~ ("," ~ identifier)*)? ~ ")"
+}
+
+struct_pattern = {
+    static_path ~ "{" ~ (identifier ~ ("," ~ identifier)*)? ~ "}"
+}
+
+pattern = _{
+    named_tuple_pattern
+  | tuple_pattern
+  | struct_pattern
+  | literal
+  | static_path
+}
+
+// ======================================================
+// ATTRIBUTES / META
+// ======================================================

 attribute = {
    "#" ~ "[" ~ meta ~ "]"
@@ -71,30 +133,132 @@ meta_list = {
    meta ~ ("," ~ meta)* ~ ","?
 }

-attributes = { attribute* }
+attributes = {
+    attribute*
+}

-import = { "use" ~ "<" ~ static_path ~ ">" ~ semicolon }
+// ======================================================
+// DECLARATION HELPERS
+// ======================================================

-mod_package = { "mod" ~ identifier ~ semicolon }
+var_decl = {
+    (var | type_expr) ~ mutable? ~ pattern
+}

-field_list = { field ~ ("," ~ field)* ~ ","? }
-field      = { export? ~ type_expr ~ identifier }
+field = {
+    export? ~ type_expr ~ identifier
+}

-param_list = { var_decl ~ ("," ~ var_decl)* ~ ","? }
+field_list = {
+    field ~ ("," ~ field)* ~ ","?
+}
+
+param_list = {
+    var_decl ~ ("," ~ var_decl)* ~ ","?
+}
+
+// ======================================================
+// IMPORTS / MODULES
+// ======================================================
+
+import = {
+    "use" ~ "<" ~ static_path ~ ">" ~ semicolon
+}
+
+mod_package = {
+    "mod" ~ identifier ~ semicolon
+}
+
+// ======================================================
+// STRUCTS
+// ======================================================

 struct_decl = {
-    export? ~ "struct" ~ identifier ~ "{" ~ field_list? ~ "}"
+    export? ~ "struct" ~ identifier ~ generics? ~ "{" ~ field_list? ~ "}"
 }

+// ======================================================
+// ENUMS
+// ======================================================
+
+enum_named = {
+    identifier
+}
+
+enum_tuple = {
+    identifier ~ tuple_type
+}
+
+enum_struct = {
+    identifier ~ "{" ~ field_list ~ "}"
+}
+
+enum_field = _{
+    enum_tuple
+  | enum_struct
+  | enum_named
+}
+
+enum_fields = _{
+    enum_field ~ ("," ~ enum_field)* ~ ","?
+}
+
+enum_decl = {
+    export? ~ "enum" ~ identifier ~ generics? ~ "{" ~ enum_fields ~ "}"
+}
+
+// ======================================================
+// CLASSES
+// ======================================================
+
+class_constructor = {
+    export? ~ "constructor" ~ generics? ~ "(" ~ param_list? ~ ")" ~ block
+}
+
+class_fields = {
+    var_decl_statement*
+}
+
+self_param = {
+    "self" ~ mutable? ~ deref_px?
+}
+
+method = {
+    export? ~ type_expr ~ identifier ~ generics? ~ "(" ~ self_param? ~ param_list? ~ ")" ~ block
+}
+
+class_decl = {
+    export? ~ "class" ~ identifier ~ generics? ~ "{" ~ class_fields ~ class_constructor ~ method* ~ "}"
+}
+
+// ======================================================
+// FUNCTIONS
+// ======================================================
+
 function_decl = {
    export? ~ type_expr ~ identifier ~ "(" ~ param_list? ~ ")" ~ block
 }

-// ================= STATEMENTS =================
+// ======================================================
+// TOP LEVEL
+// ======================================================

-block = { "{" ~ statement_list ~ "}" }
+top_level = {
+    (attributes ~ (import | function_decl | struct_decl | enum_decl | class_decl | mod_package))
+  | mod_attribute
+}

-statement_list = { statement* }
+// ======================================================
+// STATEMENTS
+// ======================================================
+
+block = {
+    "{" ~ statement_list ~ "}"
+}
+
+statement_list = {
+    statement*
+}

 statement = _{
    expr_stmt
@@ -111,28 +275,54 @@ statement = _{
  | block
 }

-// --- basic statements ---
+// ------------------------------------------------------
+// BASIC STATEMENTS
+// ------------------------------------------------------

-expr_stmt = { expr ~ semicolon }
+expr_stmt = {
+    expr ~ semicolon
+}

-return_stmt = { "return" ~ expr? ~ semicolon }
+return_stmt = {
+    "return" ~ expr? ~ semicolon
+}

-break_stmt = { "break" ~ semicolon }
+break_stmt = {
+    "break" ~ semicolon
+}

-continue_stmt = { "continue" ~ semicolon }
+continue_stmt = {
+    "continue" ~ semicolon
+}

-var_decl_statement = { var_decl ~ ("=" ~ expr)? ~ semicolon }
+var_decl_statement = {
+    var_decl ~ ("=" ~ expr)? ~ semicolon
+}

-assign_statement = { expr ~ "=" ~ expr ~ semicolon }
+assign_statement = {
+    expr ~ "=" ~ expr ~ semicolon
+}

-else_if = { "else" ~ "if" ~ "(" ~ expr ~ ")" ~ statement }
+// ------------------------------------------------------
+// CONDITIONALS
+// ------------------------------------------------------

-else_if_list = { else_if* }
+else_if = {
+    "else" ~ "if" ~ "(" ~ expr ~ ")" ~ statement
+}
+
+else_if_list = {
+    else_if*
+}

 if_stmt = {
    "if" ~ "(" ~ expr ~ ")" ~ statement ~ else_if_list ~ ("else" ~ statement)?
 }

+// ------------------------------------------------------
+// LOOPS
+// ------------------------------------------------------
+
 while_stmt = {
    "while" ~ "(" ~ expr ~ ")" ~ statement
 }
@@ -145,31 +335,42 @@ for_stmt = {
    "for" ~ "(" ~ mutable? ~ pattern ~ "in" ~ expr ~ ")" ~ statement
 }

-match_item = { pattern ~ "=>" ~ block }
+// ------------------------------------------------------
+// MATCH
+// ------------------------------------------------------
+
+match_item = {
+    pattern ~ "=>" ~ block
+}

 match_stmt = {
    "match" ~ "(" ~ expr ~ ")" ~ "{" ~ match_item* ~ "}"
 }

-// ================= EXPRESSIONS =================
-tuple_type = { "(" ~ (type_expr ~ ("," ~ type_expr)*)? ~ ")" }
-path_type  = { static_path ~ ("<" ~ (type_expr ~ ("," ~ type_expr)*)? ~ ">")? }
-ref_type   = { mutable? ~ "*" }
-type_expr  = { (path_type | tuple_type) ~ ref_type* }
+// ======================================================
+// EXPRESSIONS
+// ======================================================
+
+// ------------------------------------------------------
+// TUPLES
+// ------------------------------------------------------
+
+tuple = {
+    "(" ~ (expr ~ ("," ~ expr)*)? ~ ")"
+}
+
+// ------------------------------------------------------
+// MACROS
+// ------------------------------------------------------

 macro_inner_v = {
    "(" ~ macro_inner_v* ~ ")"
  | (!("(" | ")") ~ ANY)
 }

-tuple = { "(" ~ (expr ~ ("," ~ expr)*)? ~ ")" }
-
-literal = {
-    float
-  | integer
-  | boolean
-  | string_lit
-}
+// ------------------------------------------------------
+// PRIMARY EXPRESSIONS
+// ------------------------------------------------------

 primary = {
    literal
@@ -177,6 +378,38 @@ primary = {
  | tuple
 }

+// ------------------------------------------------------
+// POSTFIX EXPRESSIONS
+// ------------------------------------------------------
+
+field_px = {
+    "." ~ identifier
+}
+
+call_px = {
+    "(" ~ (expr ~ ("," ~ expr)*)? ~ ")"
+}
+
+macro_call_px = {
+    "!" ~ "(" ~ macro_inner_v* ~ ")"
+}
+
+struct_field_decl = {
+    identifier ~ ":" ~ expr
+}
+
+struct_px = {
+    "{" ~ (struct_field_decl ~ ("," ~ struct_field_decl)*)? ~ ","? ~ "}"
+}
+
+index_px = {
+    "[" ~ expr ~ "]"
+}
+
+binary_px = {
+    bin_op ~ expr
+}
+
 postfix = {
    field_px
  | call_px
@@ -186,14 +419,29 @@ postfix = {
  | binary_px
 }

-field_px          = { "." ~ identifier }
-call_px           = { "(" ~ (expr ~ ("," ~ expr)*)? ~ ")" }
-macro_call_px     = { "!" ~ "(" ~ macro_inner_v* ~ ")" }
-struct_px         = { "{" ~ (struct_field_decl ~ ("," ~ struct_field_decl)*)? ~ ","? ~ "}" }
-index_px          = { "[" ~ expr ~ "]" }
-binary_px         = { bin_op ~ expr }
-bin_op            = { "<=" | ">=" | "==" | "!=" | "+" | "-" | "*" | "/" | "%" | "<" | ">" }
-struct_field_decl = { identifier ~ ":" ~ expr }
+// ------------------------------------------------------
+// PREFIX EXPRESSIONS
+// ------------------------------------------------------
+
+deref_px = {
+    "*"
+}
+
+mut_ref_px = {
+    "&" ~ mutable
+}
+
+ref_px = {
+    "&"
+}
+
+new_px = {
+    "new"
+}
+
+not_px = {
+    "!"
+}

 prefix = {
    deref_px
@@ -203,13 +451,33 @@ prefix = {
  | not_px
 }

-deref_px   = { "*" }
-mut_ref_px = { "&" ~ mutable }
-ref_px     = { "&" }
-new_px     = { "new" }
-not_px     = { "!" }
+prefix_list = {
+    prefix*
+}

-prefix_list = { prefix* }
+// ------------------------------------------------------
+// OPERATORS
+// ------------------------------------------------------
+
+bin_op = {
+    "<="
+  | ">="
+  | "=="
+  | "!="
+  | "&&"
+  | "||"
+  | "+"
+  | "-"
+  | "*"
+  | "/"
+  | "%"
+  | "<"
+  | ">"
+}
+
+// ------------------------------------------------------
+// EXPRESSIONS
+// ------------------------------------------------------

 expr = {
    prefix_list ~ primary ~ postfix*
@@ -211,18 +211,45 @@ impl From<pest::iterators::Pair<'_, Rule>> for ClassConstructor {

        let visibility = Visibility::from(&mut inner);

+        let generics = consume_rule(&mut inner, Rule::generics)
+            .map(Generics::from)
+            .unwrap_or_default();
+
        let params = consume_rule(&mut inner, Rule::param_list)
            .map(ParamList::from)
            .unwrap_or_else(|| ParamList(Vec::new()));

        Self {
            visibility,
+            generics,
            params,
            body: Block::from(inner.next().unwrap()),
        }
    }
 }

+impl From<pest::iterators::Pair<'_, Rule>> for Generics {
+    fn from(pair: pest::iterators::Pair<'_, Rule>) -> Self {
+        let rule = pair.as_rule();
+        let inner = pair.clone().into_inner();
+
+        match rule {
+            Rule::generics => Generics(
+                inner
+                    .map(|pair| {
+                        let mut inner = pair.into_inner();
+                        (
+                            Identifier::from(inner.next().unwrap()),
+                            inner.map(Path::from).collect(),
+                        )
+                    })
+                    .collect(),
+            ),
+            _ => unimplemented!("{rule:#?}"),
+        }
+    }
+}
+
 impl From<pest::iterators::Pair<'_, Rule>> for TopLevelKind {
    fn from(pair: pest::iterators::Pair<'_, Rule>) -> Self {
        let rule = pair.as_rule();
@@ -233,22 +260,21 @@ impl From<pest::iterators::Pair<'_, Rule>> for TopLevelKind {

            Rule::function_decl => TopLevelKind::FunctionDecl(FunctionDecl::from(pair)),

-            Rule::struct_decl => {
-                let visibility = Visibility::from(&mut inner);
-                let name = Identifier::from(inner.next().unwrap());
-                let fields_pair = inner.next().unwrap();
-                let fields = FieldList::from(fields_pair);
-
-                TopLevelKind::StructDecl {
-                    visibility,
-                    name,
-                    fields,
-                }
-            }
+            Rule::struct_decl => TopLevelKind::StructDecl {
+                visibility: Visibility::from(&mut inner),
+                name: Identifier::from(inner.next().unwrap()),
+                generics: consume_rule(&mut inner, Rule::generics)
+                    .map(Generics::from)
+                    .unwrap_or_default(),
+                fields: inner.next().map(FieldList::from).unwrap_or_default(),
+            },

            Rule::class_decl => TopLevelKind::ClassDecl {
                visibility: Visibility::from(&mut inner),
                name: Identifier::from(inner.next().unwrap()),
+                generics: consume_rule(&mut inner, Rule::generics)
+                    .map(Generics::from)
+                    .unwrap_or_default(),
                fields: inner
                    .next()
                    .unwrap()
@@ -262,6 +288,9 @@ impl From<pest::iterators::Pair<'_, Rule>> for TopLevelKind {
            Rule::enum_decl => TopLevelKind::EnumDecl {
                visibility: Visibility::from(&mut inner),
                name: Identifier::from(inner.next().unwrap()),
+                generics: consume_rule(&mut inner, Rule::generics)
+                    .map(Generics::from)
+                    .unwrap_or_default(),
                fields: inner.map(EnumItem::from).collect(),
            },

@@ -498,6 +527,8 @@ impl From<pest::iterators::Pair<'_, Rule>> for Postfix {
                    ">" => BinaryOp::GreaterThan,
                    "<=" => BinaryOp::LessThanOrEqual,
                    ">=" => BinaryOp::GreaterThanOrEqual,
+                    "&&" => BinaryOp::And,
+                    "||" => BinaryOp::Or,

                    _ => {
                        unimplemented!("Binary operator not implemented yet: {}", op_pair.as_str())
@@ -592,12 +623,13 @@ impl From<pest::iterators::Pair<'_, Rule>> for VarDecl {
 impl From<pest::iterators::Pair<'_, Rule>> for FunctionDecl {
    fn from(pair: pest::iterators::Pair<'_, Rule>) -> Self {
        let mut inner = pair.into_inner();
-
        let visibility = Visibility::from(&mut inner);
-
        let return_type = TypeExpr::from(inner.next().unwrap());
-
        let name = Identifier::from(inner.next().unwrap());
+        let generics = consume_rule(&mut inner, Rule::generics)
+            .map(Generics::from)
+            .unwrap_or_default();
+
        let self_param = consume_rule(&mut inner, Rule::self_param).map(|param| {
            let mut param_inner = param.into_inner();
            let name = Pattern::Id(Identifier(String::from("self")));
@@ -642,6 +674,7 @@ impl From<pest::iterators::Pair<'_, Rule>> for FunctionDecl {
        Self {
            visibility,
            name,
+            generics,
            params,
            return_type,
            body,
@@ -1,6 +1,6 @@
 use parser::ast::{
-    Attribute, BinaryOp, Block, EnumItem, Expression, FunctionDecl, Identifier, Literal, Path,
-    Pattern, Postfix, Prefix, Statement, StatementBranch, TopLevel, TopLevelKind, TypeExpr,
+    Attribute, BinaryOp, Block, EnumItem, Expression, FunctionDecl, Generics, Identifier, Literal,
+    Path, Pattern, Postfix, Prefix, Statement, StatementBranch, TopLevel, TopLevelKind, TypeExpr,
    TypeExprKind, TypePostfix, VarAssignStmt, VarDecl, VarDeclStmt, Visibility,
 };

@@ -238,6 +238,8 @@ impl GetRust for Postfix {
                    BinaryOp::GreaterThan => ">",
                    BinaryOp::LessThanOrEqual => "<=",
                    BinaryOp::GreaterThanOrEqual => ">=",
+                    BinaryOp::And => "&&",
+                    BinaryOp::Or => "||",
                };
                format!(" {} {}", op_str, rhs.get_rust())
            }
@@ -314,12 +316,14 @@ impl ToRust for TopLevelKind {
            Self::StructDecl {
                visibility,
                name,
+                generics,
                fields,
            } => {
                cg.addln(&format!(
-                    "{}struct {} {{",
+                    "{}struct {}{} {{",
                    visibility.get_rust(),
-                    name.get_rust()
+                    name.get_rust(),
+                    generics.get_rust()
                ));
                cg.indent += 1;

@@ -334,12 +338,14 @@ impl ToRust for TopLevelKind {
            Self::EnumDecl {
                visibility,
                name,
+                generics,
                fields,
            } => {
                cg.addln(&format!(
-                    "{}enum {} {{",
+                    "{}enum {}{} {{",
                    visibility.get_rust(),
-                    name.get_rust()
+                    name.get_rust(),
+                    generics.get_rust()
                ));
                cg.indent += 1;

@@ -353,15 +359,17 @@ impl ToRust for TopLevelKind {
            Self::ClassDecl {
                visibility,
                name,
+                generics,
                fields,
                constructor,
                methods,
            } => {
                // Struct decl
                cg.addln(&format!(
-                    "{}struct {} {{",
+                    "{}struct {}{} {{",
                    visibility.get_rust(),
-                    name.get_rust()
+                    name.get_rust(),
+                    generics.get_rust()
                ));
                cg.indent += 1;

@@ -386,8 +394,9 @@ impl ToRust for TopLevelKind {
                    .join(", ");

                cg.add_indentedln(&format!(
-                    "{}fn new({}) -> Self {{",
+                    "{}fn new{}({}) -> Self {{",
                    constructor.visibility.get_rust(),
+                    constructor.generics.get_rust(),
                    params_str
                ));
                cg.indent += 1;
@@ -422,8 +431,9 @@ impl ToRust for TopLevelKind {

                // Constructor function
                cg.add_indentedln(&format!(
-                    "{}fn construct_class(&mut self, {}) {{",
+                    "{}fn construct_class{}(&mut self, {}) {{",
                    constructor.visibility.get_rust(),
+                    constructor.generics.get_rust(),
                    params_str
                ));
                cg.indent += 1;
@@ -577,9 +587,10 @@ impl ToRust for FunctionDecl {
            .join(", ");

        cg.add_indentedln(&format!(
-            "{}fn {}({}) -> {} {{",
+            "{}fn {}{}({}) -> {} {{",
            self.visibility.get_rust(),
            self.name.get_rust(),
+            self.generics.get_rust(),
            params_str,
            self.return_type.get_rust()
        ));
@@ -701,6 +712,36 @@ impl GetRust for Pattern {
    }
 }

+impl GetRust for Generics {
+    fn get_rust(&self) -> String {
+        if self.0.len() == 0 {
+            String::new()
+        } else {
+            format!(
+                "<{}>",
+                self.0
+                    .iter()
+                    .map(|generic| generic.0.get_rust()
+                        + &(if generic.1.len() == 0 {
+                            String::new()
+                        } else {
+                            format!(
+                                ": {}",
+                                generic
+                                    .1
+                                    .iter()
+                                    .map(Path::get_rust)
+                                    .collect::<Vec<_>>()
+                                    .join("+")
+                            )
+                        }))
+                    .collect::<Vec<_>>()
+                    .join(", ")
+            )
+        }
+    }
+}
+
 pub fn get_static_type_path(path: &Path) -> String {
    let rust_path = path.get_rust();