config: change default config to use toml-based configuration

toml-config/src/config/parsers/mode.rs

@@ -0,0 +1,47 @@
+use {
+    crate::{
+        config::{
+            context::Context,
+            extractor::{flt, opt, s32, Extractor, ExtractorError},
+            parser::{DataType, ParseResult, Parser, UnexpectedDataType},
+            Mode,
+        },
+        toml::{
+            toml_span::{DespanExt, Span, Spanned},
+            toml_value::Value,
+        },
+    },
+    indexmap::IndexMap,
+    thiserror::Error,
+};
+
+#[derive(Debug, Error)]
+pub enum ModeParserError {
+    #[error(transparent)]
+    Expected(#[from] UnexpectedDataType),
+    #[error(transparent)]
+    Extract(#[from] ExtractorError),
+}
+
+pub struct ModeParser<'a>(pub &'a Context<'a>);
+
+impl<'a> Parser for ModeParser<'a> {
+    type Value = Mode;
+    type Error = ModeParserError;
+    const EXPECTED: &'static [DataType] = &[DataType::Table];
+
+    fn parse_table(
+        &mut self,
+        span: Span,
+        table: &IndexMap<Spanned<String>, Spanned<Value>>,
+    ) -> ParseResult<Self> {
+        let mut ext = Extractor::new(self.0, span, table);
+        let (width, height, refresh_rate) =
+            ext.extract((s32("width"), s32("height"), opt(flt("refresh-rate"))))?;
+        Ok(Mode {
+            width: width.value,
+            height: height.value,
+            refresh_rate: refresh_rate.despan(),
+        })
+    }
+}