feat: initial commit

src/parser.rs

@@ -0,0 +1,40 @@
+use std::fmt::Display;
+use std::any::type_name;
+use crate::error::EnvError;
+use std::str::FromStr;
+
+pub trait Number: FromStr<Err: Display> {}
+
+impl Number for i8 {}
+impl Number for i16 {}
+impl Number for i32 {}
+impl Number for i64 {}
+impl Number for i128 {}
+impl Number for isize {}
+impl Number for u8 {}
+impl Number for u16 {}
+impl Number for u32 {}
+impl Number for u64 {}
+impl Number for u128 {}
+impl Number for usize {}
+impl Number for f32 {}
+impl Number for f64 {}
+
+pub fn parse_bool(value: &str) -> Result<bool, EnvError> {
+    if value.to_lowercase() == "t" { return Ok(true) }
+    if value.to_lowercase() == "f" { return Ok(false) }
+    if value == "1" { return Ok(true) }
+    if value == "0" { return Ok(false) }
+
+    match value.parse::<bool>() {
+        Ok(value) => Ok(value),
+        Err(e) => Err(EnvError::invalid("bool", value, &e.to_string()))
+    }
+}
+
+pub fn parse_number<T: Number>(value: &str) -> Result<T, EnvError> {
+    match value.parse::<T>() {
+        Ok(value) => Ok(value),
+        Err(e) => Err(EnvError::invalid(type_name::<T>(), value, &e.to_string()))
+    }
+}