config: change default config to use toml-based configuration

toml-config/src/toml/toml_value.rs

@@ -0,0 +1,63 @@
+use {
+    crate::toml::toml_span::Spanned,
+    indexmap::IndexMap,
+    std::{
+        cmp::Ordering,
+        fmt::{Debug, Formatter},
+    },
+};
+
+pub enum Value {
+    String(String),
+    Integer(i64),
+    Float(f64),
+    Boolean(bool),
+    Array(Vec<Spanned<Value>>),
+    Table(IndexMap<Spanned<String>, Spanned<Value>>),
+}
+
+impl Value {
+    pub fn name(&self) -> &'static str {
+        match self {
+            Value::String(_) => "a string",
+            Value::Integer(_) => "an integer",
+            Value::Float(_) => "a float",
+            Value::Boolean(_) => "a boolean",
+            Value::Array(_) => "an array",
+            Value::Table(_) => "a table",
+        }
+    }
+}
+
+impl Debug for Value {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Value::String(v) => v.fmt(f),
+            Value::Integer(v) => v.fmt(f),
+            Value::Float(v) => v.fmt(f),
+            Value::Boolean(v) => v.fmt(f),
+            Value::Array(v) => v.fmt(f),
+            Value::Table(v) => v.fmt(f),
+        }
+    }
+}
+
+impl PartialEq for Value {
+    fn eq(&self, other: &Self) -> bool {
+        match (self, other) {
+            (Value::String(v1), Value::String(v2)) => v1 == v2,
+            (Value::Integer(v1), Value::Integer(v2)) => v1 == v2,
+            (Value::Float(v1), Value::Float(v2)) => {
+                if v1.is_nan() && v2.is_nan() {
+                    true
+                } else {
+                    v1.total_cmp(v2) == Ordering::Equal
+                }
+            }
+            (Value::Boolean(v1), Value::Boolean(v2)) => v1 == v2,
+            (Value::Array(v1), Value::Array(v2)) => v1 == v2,
+            (Value::Table(v1), Value::Table(v2)) => v1 == v2,
+            _ => false,
+        }
+    }
+}