From b388d04bfaec53a8cc969f1832d832727f28d22e Mon Sep 17 00:00:00 2001
From: elkowar <5300871+elkowar@users.noreply.github.com>
Date: Sat, 5 Jun 2021 18:35:43 +0200
Subject: [PATCH] asdf

---
 Cargo.lock    |  7 +++++
 Cargo.toml    |  1 +
 src/config.rs | 80 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/lexer.rs  | 85 ---------------------------------------------------
 src/main.rs   | 18 +++++++++++
 5 files changed, 106 insertions(+), 85 deletions(-)
 create mode 100644 src/config.rs
 delete mode 100644 src/lexer.rs

diff --git a/Cargo.lock b/Cargo.lock
index 7806c6c..5d6f7ea 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -9,6 +9,12 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "anyhow"
+version = "1.0.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28b2cd92db5cbd74e8e5028f7e27dd7aa3090e89e4f2a197cc7c8dfb69c7063b"
+
 [[package]]
 name = "arrayref"
 version = "0.3.6"
@@ -266,6 +272,7 @@ checksum = "e4a24736216ec316047a1fc4252e27dabb04218aa4a3f37c6e7ddbf1f9782b54"
 name = "nomwut"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "itertools",
  "lalrpop",
  "lalrpop-util",
diff --git a/Cargo.toml b/Cargo.toml
index d938bfb..8824444 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,6 +12,7 @@ build = "build.rs"
 lalrpop-util = "0.19.5"
 regex = "1"
 itertools = "0.10"
+anyhow = "1.0"
 
 [build-dependencies]
 lalrpop = "0.19.5"
diff --git a/src/config.rs b/src/config.rs
new file mode 100644
index 0000000..27f7293
--- /dev/null
+++ b/src/config.rs
@@ -0,0 +1,80 @@
+use std::collections::HashMap;
+
+use super::*;
+use anyhow::*;
+
+type VarName = String;
+type AttrValue = String;
+type AttrName = String;
+
+pub enum AstError {
+    UnexpectedNode,
+    InvalidDefinition,
+    WrongExprType,
+}
+
+impl From<WrongExprType> for AstError {
+    fn from(_: WrongExprType) -> Self {
+        AstError::WrongExprType
+    }
+}
+
+pub trait FromExpr: Sized {
+    fn from_expr(e: Expr) -> Result<Self, AstError>;
+    fn from_sp(e: Sp<Expr>) -> Result<Self, AstError> {
+        Self::from_expr(e.1)
+    }
+}
+
+pub enum DefType {
+    Widget,
+}
+
+impl FromExpr for DefType {
+    fn from_expr(e: Expr) -> Result<Self, AstError> {
+        if let Expr::Symbol(sym) = e {
+            match sym.as_str() {
+                "defwidget" => Ok(DefType::Widget),
+                _ => Err(AstError::InvalidDefinition),
+            }
+        } else {
+            Err(AstError::UnexpectedNode)
+        }
+    }
+}
+
+pub struct Definitional<T> {
+    def_type: DefType,
+    name: String,
+    attrs: HashMap<AttrName, Sp<Expr>>,
+    children: Vec<T>,
+}
+
+impl<T: FromExpr> FromExpr for Definitional<T> {
+    fn from_expr(e: Expr) -> Result<Self, AstError> {
+        if let Expr::List(list) = e {
+            let mut iter = list.into_iter();
+            let def_type = DefType::from_sp(iter.next().unwrap())?;
+            let name = iter.next().unwrap().1.str()?;
+            let mut attrs = HashMap::new();
+            while let Some(Sp(_, Expr::Keyword(x), _)) = iter.next() {
+                attrs.insert(x, iter.next().unwrap());
+            }
+
+            let children = iter.map(T::from_sp).collect::<Result<Vec<_>, AstError>>()?;
+            Ok(Definitional {
+                def_type,
+                name,
+                attrs,
+                children,
+            })
+        } else {
+            Err(AstError::UnexpectedNode)
+        }
+    }
+}
+
+pub struct WidgetDefinition {
+    name: String,
+    argnames: Vec<VarName>,
+}
diff --git a/src/lexer.rs b/src/lexer.rs
deleted file mode 100644
index 8deea40..0000000
--- a/src/lexer.rs
+++ /dev/null
@@ -1,85 +0,0 @@
-use std::str::CharIndices;
-
-pub type Spanned<Tok, Loc, Error> = Result<(Loc, Tok, Loc), Error>;
-
-#[derive(Copy, Clone, Debug)]
-pub enum Tok {
-    LPren,
-    RPren,
-    Space,
-    Int(i32),
-}
-
-#[derive(Debug, Copy, Clone)]
-pub enum LexicalError {
-    InvalidDigit,
-    UnknownToken,
-}
-
-impl std::fmt::Display for LexicalError {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{:?}", self)
-    }
-}
-
-pub struct Lexer<'input> {
-    chars: CharIndices<'input>,
-}
-
-impl<'input> Lexer<'input> {
-    pub fn new(input: &'input str) -> Self {
-        Lexer {
-            chars: input.char_indices(),
-        }
-    }
-}
-
-impl<'input> Iterator for Lexer<'input> {
-    type Item = Spanned<Tok, usize, LexicalError>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        let c = self.chars.next();
-        match c {
-            Some((i, '(')) => Some(Ok((i, Tok::LPren, i + 1))),
-            Some((i, ')')) => Some(Ok((i, Tok::RPren, i + 1))),
-            Some((i, s)) if s.is_whitespace() => {
-                let mut last_space = i;
-                loop {
-                    match self.chars.next() {
-                        Some((i, next)) if next.is_whitespace() => {
-                            last_space = i;
-                        }
-                        _ => {
-                            break;
-                        }
-                    }
-                }
-                Some(Ok((i, Tok::Space, last_space + 1)))
-            }
-            Some((i, s)) if s.is_digit(10) || s == '-' => {
-                let mut end = i;
-                let mut digits = String::new();
-
-                loop {
-                    match self.chars.next() {
-                        Some((i, next)) if next.is_digit(10) => {
-                            end = i;
-                            digits.push(next);
-                        }
-                        _ => {
-                            break;
-                        }
-                    }
-                }
-
-                let num = match digits.parse::<i32>() {
-                    Ok(num) => num,
-                    Err(_err) => return Some(Err(LexicalError::InvalidDigit)),
-                };
-                Some(Ok((i, Tok::Int(num), end + 1)))
-            }
-            Some((_, _)) => Some(Err(LexicalError::UnknownToken)),
-            None => None,
-        }
-    }
-}
diff --git a/src/main.rs b/src/main.rs
index 99bbd5d..e9ea411 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,9 @@
 #![allow(unused_imports)]
+#![allow(unused)]
+
+mod config;
+
+use std::ops::Deref;
 
 use itertools::Itertools;
 
@@ -17,6 +22,9 @@ impl<T: std::fmt::Display> std::fmt::Display for Sp<T> {
     }
 }
 
+#[derive(Debug, Clone, Copy)]
+pub struct WrongExprType;
+
 #[derive(Debug)]
 pub enum Expr {
     List(Vec<Sp<Expr>>),
@@ -28,6 +36,16 @@ pub enum Expr {
     Comment,
 }
 
+impl Expr {
+    fn str(self) -> Result<String, WrongExprType> {
+        use Expr::*;
+        match self {
+            Str(x) => Ok(x),
+            _ => Err(WrongExprType),
+        }
+    }
+}
+
 impl std::fmt::Display for Expr {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         use Expr::*;