diff --git a/.gitignore b/.gitignore
index 5c20209..7157292 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
 parser.out.ts
+new.ast.out.ts
+
diff --git a/ast b/ast
index c99b4cc..7619893 100644
--- a/ast
+++ b/ast
@@ -1,20 +1,27 @@
 
 Statement {
-    Enum(enum_: Enum)
-    Node(node: Node)
+    Enum(Enum)
+    Node(Node)
 }
 
 Enum(name: Name, nodes: Node[])
 
 Node(name: Name, params: Param[])
 
-Param(name: Name, type_: Type)
-
-Type {
-    Name(name: Name)
-    Optional(type_: Type)
-    Multiple(type_: Type)
+Param {
+    Named(name: Name, type_: Type)
+    Unnamed(Type)
 }
 
-Name(value: string)
+Type {
+    Name(Name)
+    Optional(Type)
+    Multiple(Type)
+}
+
+Name(
+    string,
+    line: number,
+    col: number,
+)
 
diff --git a/ast.out.ts b/ast.out.ts
index 99ab9da..fca5482 100644
--- a/ast.out.ts
+++ b/ast.out.ts
@@ -1,14 +1,14 @@
 // Generated file by ast_generator
 export type EnumStatement = {
     kind: "Enum";
-    enum_: Enum;
+    [0]: Enum;
 };
-export const EnumStatement = (enum_: Enum): EnumStatement => ({ kind: "Enum", enum_ });
+export const EnumStatement = (v0: Enum): EnumStatement => ({ kind: "Enum", [0]: v0 });
 export type NodeStatement = {
     kind: "Node";
-    node: Node;
+    [0]: Node;
 };
-export const NodeStatement = (node: Node): NodeStatement => ({ kind: "Node", node });
+export const NodeStatement = (v0: Node): NodeStatement => ({ kind: "Node", [0]: v0 });
 export type Statement = EnumStatement | NodeStatement;
 export type Enum = {
     name: Name;
@@ -20,29 +20,38 @@ export type Node = {
     params: Param[];
 };
 export const Node = (name: Name, params: Param[]): Node => ({ name, params });
-export type Param = {
+export type NamedParam = {
+    kind: "Named";
     name: Name;
     type_: Type;
 };
-export const Param = (name: Name, type_: Type): Param => ({ name, type_ });
+export const NamedParam = (name: Name, type_: Type): NamedParam => ({ kind: "Named", name, type_ });
+export type UnnamedParam = {
+    kind: "Unnamed";
+    [0]: Type;
+};
+export const UnnamedParam = (v0: Type): UnnamedParam => ({ kind: "Unnamed", [0]: v0 });
+export type Param = NamedParam | UnnamedParam;
 export type NameType = {
     kind: "Name";
-    name: Name;
+    [0]: Name;
 };
-export const NameType = (name: Name): NameType => ({ kind: "Name", name });
+export const NameType = (v0: Name): NameType => ({ kind: "Name", [0]: v0 });
 export type OptionalType = {
     kind: "Optional";
-    type_: Type;
+    [0]: Type;
 };
-export const OptionalType = (type_: Type): OptionalType => ({ kind: "Optional", type_ });
+export const OptionalType = (v0: Type): OptionalType => ({ kind: "Optional", [0]: v0 });
 export type MultipleType = {
     kind: "Multiple";
-    type_: Type;
+    [0]: Type;
 };
-export const MultipleType = (type_: Type): MultipleType => ({ kind: "Multiple", type_ });
+export const MultipleType = (v0: Type): MultipleType => ({ kind: "Multiple", [0]: v0 });
 export type Type = NameType | OptionalType | MultipleType;
 export type Name = {
-    value: string;
+    [0]: string;
+    line: number;
+    col: number;
 };
-export const Name = (value: string): Name => ({ value });
+export const Name = (v0: string, line: number, col: number): Name => ({ [0]: v0, line, col });
 
diff --git a/ast_generator.ts b/ast_generator.ts
index c429e4b..01a65a9 100644
--- a/ast_generator.ts
+++ b/ast_generator.ts
@@ -4,7 +4,7 @@ import {
 } from "https://deno.land/x/nearley@2.19.7-deno/mod.ts";
 
 import compiledParserGrammar from "./parser.out.ts";
-import { Enum, Name, Node, Param, Statement, Type } from "./ast.out.ts";
+import { Enum, Name, NamedParam, Node, Statement, Type } from "./ast.out.ts";
 
 class TypescriptGenerator {
     private result = "";
@@ -14,10 +14,10 @@ class TypescriptGenerator {
         for (const statement of ast) {
             switch (statement.kind) {
                 case "Enum":
-                    this.generateEnum(statement.enum_);
+                    this.generateEnum(statement[0]);
                     break;
                 case "Node":
-                    this.generateNode(statement.node);
+                    this.generateNode(statement[0]);
                     break;
             }
         }
@@ -49,22 +49,47 @@ class TypescriptGenerator {
         if (kind) {
             this.result += `    kind: "${kind}";\n`;
         }
-        for (const param of node.params) {
-            this.result += `    ${this.makeParam(param)};\n`;
+        for (
+            const [param, index] of node.params
+                .map((v, i) => [v, i] as const)
+        ) {
+            switch (param.kind) {
+                case "Named":
+                    this.result += `    ${this.makeNamedParam(param)};\n`;
+                    break;
+                case "Unnamed":
+                    this.result += `    [${index}]: ${
+                        this.makeType(param[0])
+                    };\n`;
+            }
         }
         this.result += "};\n";
-        const fnParams = node.params.map((param) => this.makeParam(param)).join(
-            ", ",
-        );
+        const fnParams = node.params
+            .map((param, index) => {
+                switch (param.kind) {
+                    case "Named":
+                        return this.makeNamedParam(param);
+                    case "Unnamed":
+                        return `v${index}: ${this.makeType(param[0])}`;
+                }
+            })
+            .join(", ");
         const fields = [
             ...(kind ? [`kind: "${kind}"`] : []),
-            ...node.params.map((param) => this.makeName(param.name)),
+            ...node.params.map((param, index) => {
+                switch (param.kind) {
+                    case "Named":
+                        return this.makeName(param.name);
+                    case "Unnamed":
+                        return `[${index}]: v${index}`;
+                }
+            }),
         ].join(", ");
         this.result +=
             `export const ${name} = (${fnParams}): ${name} => ({ ${fields} });\n`;
     }
 
-    private makeParam(param: Param): string {
+    private makeNamedParam(param: NamedParam): string {
         const name = this.makeName(param.name);
         const type_ = this.makeType(param.type_);
         return `${name}: ${type_}`;
@@ -73,16 +98,16 @@ class TypescriptGenerator {
     private makeType(type_: Type): string {
         switch (type_.kind) {
             case "Name":
-                return this.makeName(type_.name);
+                return this.makeName(type_[0]);
             case "Optional":
-                return `${this.makeType(type_.type_)} | null`;
+                return `${this.makeType(type_[0])} | null`;
             case "Multiple":
-                return `${this.makeType(type_.type_)}[]`;
+                return `${this.makeType(type_[0])}[]`;
         }
     }
 
     private makeName(name: Name): string {
-        return name.value;
+        return name[0];
     }
 }
 
diff --git a/deno.lock b/deno.lock
new file mode 100644
index 0000000..ef44ba6
--- /dev/null
+++ b/deno.lock
@@ -0,0 +1,9 @@
+{
+  "version": "3",
+  "remote": {
+    "https://deno.land/x/moo@0.5.1-deno.2/mod.ts": "fbccad242a370172385c0545886e8051ab4c2cc86b4635798fcf490db718af4e",
+    "https://deno.land/x/moo@0.5.1-deno.2/moo.js": "90e55b04d273feb1ccf0bd7f20df24259715bbfbbffe0e462882c5c5caeb232b",
+    "https://deno.land/x/nearley@2.19.7-deno/lib/nearley.js": "4d69e17885788c78f0aa4776de6ce587a99e1562468fb826c5a5b649a59b9d43",
+    "https://deno.land/x/nearley@2.19.7-deno/mod.ts": "a52f8fe208afc6790bd4167e433f397c578838547bf7161eef144810c28d57db"
+  }
+}
diff --git a/parser.ne b/parser.ne
index a9bb7f5..7333152 100644
--- a/parser.ne
+++ b/parser.ne
@@ -55,7 +55,12 @@ params -> _ (param paramTail (_ ","):? _):? {% v => v[1] ? [v[1][0], ...v[1][1]]
 
 paramTail -> ("," _ param):* {% v => v[0].map(w => w[2]) %}
 
-param -> name _ ":" _ type {% v => ast.Param(v[0], v[4]) %}
+param   ->  namedParam {% id %}
+        |   unnamedParam {% id %}
+
+namedParam -> name _ ":" _ type {% v => ast.NamedParam(v[0], v[4]) %}
+
+unnamedParam -> type {% v => ast.UnnamedParam(v[0]) %}
 
 type -> optional {% id %}
     |   multiple {% id %}
@@ -65,7 +70,7 @@ optional -> type "?" {% v => ast.OptionalType(v[0]) %}
 
 multiple -> type "[" "]" {% v => ast.MultipleType(v[0]) %}
 
-name -> %name {% v => ast.Name(v[0]) %}
+name -> %name {% v => ast.Name(v[0].value, v[0].line, v[0].col) %}
 
 _           ->  __:?
 __          ->  (%whitespace|%newline|%singeLineComment|%multiLineComment):+