config: change default config to use toml-based configuration

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

@@ -0,0 +1,42 @@
+use {
+    crate::{
+        config::{
+            parser::{DataType, ParseResult, Parser, UnexpectedDataType},
+            parsers::{StringParser, StringParserError},
+        },
+        toml::{
+            toml_span::{Span, Spanned},
+            toml_value::Value,
+        },
+    },
+    indexmap::IndexMap,
+    thiserror::Error,
+};
+
+#[derive(Debug, Error)]
+pub enum EnvParserError {
+    #[error(transparent)]
+    Expected(#[from] UnexpectedDataType),
+    #[error(transparent)]
+    String(#[from] StringParserError),
+}
+
+pub struct EnvParser;
+
+impl Parser for EnvParser {
+    type Value = Vec<(String, String)>;
+    type Error = EnvParserError;
+    const EXPECTED: &'static [DataType] = &[DataType::Table];
+
+    fn parse_table(
+        &mut self,
+        _span: Span,
+        table: &IndexMap<Spanned<String>, Spanned<Value>>,
+    ) -> ParseResult<Self> {
+        let mut envs = vec![];
+        for (k, v) in table {
+            envs.push((k.value.to_string(), v.parse_map(&mut StringParser)?));
+        }
+        Ok(envs)
+    }
+}