From 08cb1109c7c53b5c896037339e8d399a3a7bbad7 Mon Sep 17 00:00:00 2001
From: me <me@alloca.space>
Date: Fri, 19 Dec 2025 10:48:31 +0200
Subject: [PATCH] lexer positions

---
 readme.md                                     | 10 ++--
 src/parser/parser.rs                          |  4 +-
 src/parser/scanner.rs                         | 49 ++++++++++++++++---
 ...__parser__parser__tests__full_program.snap |  4 +-
 ...__parser__scanner__tests__scaffolding.snap | 17 ++++---
 src/parser/types.rs                           | 15 +++++-
 6 files changed, 74 insertions(+), 25 deletions(-)

diff --git a/readme.md b/readme.md
index dbb44ba..a3e4a2c 100644
--- a/readme.md
+++ b/readme.md
@@ -13,14 +13,14 @@ Ayin
 - first class functions
 
 ```
-let init = fn() {
+let setup = fn() {
   return {
-    player: { position: { x: 10, y: 20 }, },
-  }
+    .player: { .position: { .x: 10, .y: 20 }, },
+  };
 };
 
 let update = fn(state, events) {
-  return state';
+  return state;
 };
 
 let draw = fn(frame, state) {
@@ -28,7 +28,7 @@ let draw = fn(frame, state) {
 };
 
 let migrate = fn(state) {
-    return { player: { pos: state.player.position } };
+    return { .player: { .pos: state.player.position } };
 };
 ```
 
diff --git a/src/parser/parser.rs b/src/parser/parser.rs
index bd37e91..0f591f4 100644
--- a/src/parser/parser.rs
+++ b/src/parser/parser.rs
@@ -395,14 +395,14 @@ mod tests {
     #[test]
     fn full_program() {
         let program = "
-let init = fn() {
+let setup = fn() {
   return {
     .player: { .position: { .x: 10, .y: 20 }, },
   };
 };
 
 let update = fn(state, events) {
-  return state2;
+  return state;
 };
 
 let draw = fn(frame, state) {
diff --git a/src/parser/scanner.rs b/src/parser/scanner.rs
index a4eb480..d137256 100644
--- a/src/parser/scanner.rs
+++ b/src/parser/scanner.rs
@@ -1,7 +1,44 @@
 use super::types::*;
 use chumsky::text::Char;
 use log;
-use lyn::Scanner;
+use lyn;
+
+pub struct Scanner {
+    scanner: lyn::Scanner,
+    cursor: Pos,
+}
+
+impl Scanner {
+    pub fn new(string: &str) -> Scanner {
+        let scanner = lyn::Scanner::new(string);
+        Scanner {
+            scanner,
+            cursor: Pos { line: 1, column: 1 },
+        }
+    }
+    pub fn peek(&self) -> Option<&char> {
+        self.scanner.peek()
+    }
+    pub fn pop(&mut self) -> Option<&char> {
+        let ch = self.scanner.pop();
+        match ch {
+            Some(&'\n') => {
+                self.cursor.line += 1;
+                self.cursor.column = 1;
+            }
+            _ => {
+                self.cursor.column += 1;
+            }
+        }
+        //if let Some(chr) = ch {
+        //    println!("'{}' {}", chr, self.cursor);
+        //}
+        ch
+    }
+    pub fn cursor(&self) -> Pos {
+        self.cursor.clone()
+    }
+}
 
 pub fn scan(source: String) -> Tokens {
     let mut scanner = Scanner::new(&source);
@@ -214,14 +251,14 @@ let main = fn (x) {
     #[test]
     fn scaffolding() {
         let program = "
-let init = fn() {
+let setup = fn() {
   return {
-    player: { position: { x: 10, y: 20 }, },
-  }
+    .player: { .position: { .x: 10, .y: 20 }, },
+  };
 };
 
 let update = fn(state, events) {
-  return state';
+  return state;
 };
 
 let draw = fn(frame, state) {
@@ -229,7 +266,7 @@ let draw = fn(frame, state) {
 };
 
 let migrate = fn(state) {
-    return { player: { pos: state.player.position } },
+    return { .player: { .pos: state.player.position } };
 };
 "
         .to_string();
diff --git a/src/parser/snapshots/ayin__parser__parser__tests__full_program.snap b/src/parser/snapshots/ayin__parser__parser__tests__full_program.snap
index b4ce559..f1624ae 100644
--- a/src/parser/snapshots/ayin__parser__parser__tests__full_program.snap
+++ b/src/parser/snapshots/ayin__parser__parser__tests__full_program.snap
@@ -7,7 +7,7 @@ Ok(
         Definition {
             mutable: false,
             name: Name(
-                "init",
+                "setup",
             ),
             expr: Func(
                 Fn {
@@ -78,7 +78,7 @@ Ok(
                                 Some(
                                     Var(
                                         Name(
-                                            "state2",
+                                            "state",
                                         ),
                                     ),
                                 ),
diff --git a/src/parser/snapshots/ayin__parser__scanner__tests__scaffolding.snap b/src/parser/snapshots/ayin__parser__scanner__tests__scaffolding.snap
index 28ceab5..253c9ad 100644
--- a/src/parser/snapshots/ayin__parser__scanner__tests__scaffolding.snap
+++ b/src/parser/snapshots/ayin__parser__scanner__tests__scaffolding.snap
@@ -5,7 +5,7 @@ expression: result
 [
     Let,
     Identifier(
-        "init",
+        "setup",
     ),
     Equals,
     Fn,
@@ -14,17 +14,17 @@ expression: result
     OpenCurly,
     Return,
     OpenCurly,
-    Identifier(
+    Label(
         "player",
     ),
     Colon,
     OpenCurly,
-    Identifier(
+    Label(
         "position",
     ),
     Colon,
     OpenCurly,
-    Identifier(
+    Label(
         "x",
     ),
     Colon,
@@ -32,7 +32,7 @@ expression: result
         10,
     ),
     Comma,
-    Identifier(
+    Label(
         "y",
     ),
     Colon,
@@ -44,6 +44,7 @@ expression: result
     CloseCurly,
     Comma,
     CloseCurly,
+    Semicolon,
     CloseCurly,
     Semicolon,
     Let,
@@ -121,12 +122,12 @@ expression: result
     OpenCurly,
     Return,
     OpenCurly,
-    Identifier(
+    Label(
         "player",
     ),
     Colon,
     OpenCurly,
-    Identifier(
+    Label(
         "pos",
     ),
     Colon,
@@ -141,7 +142,7 @@ expression: result
     ),
     CloseCurly,
     CloseCurly,
-    Comma,
+    Semicolon,
     CloseCurly,
     Semicolon,
 ]
diff --git a/src/parser/types.rs b/src/parser/types.rs
index 7b9d9e4..28d9c0a 100644
--- a/src/parser/types.rs
+++ b/src/parser/types.rs
@@ -1,10 +1,21 @@
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct LocatedToken {
-    pub start: usize,
-    pub end: usize,
+    pub start: Pos,
+    pub end: Pos,
     pub token: Token,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Pos {
+    pub line: usize,
+    pub column: usize,
+}
+impl std::fmt::Display for Pos {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, "{}:{}", self.line, self.column)
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Token {
     Let,