impl from str for column and scalar

datafusion/src/logical_plan/expr.rs

@@ -30,7 +30,9 @@ use aggregates::{AccumulatorFunctionImplementation, StateTypeFunction};
 use arrow::{compute::can_cast_types, datatypes::DataType};
 use functions::{ReturnTypeFunction, ScalarFunctionImplementation, Signature};
 use std::collections::{HashMap, HashSet};
+use std::convert::Infallible;
 use std::fmt;
+use std::str::FromStr;
 use std::sync::Arc;
 
 /// A named reference to a qualified field in a schema.
@@ -153,6 +155,14 @@ impl From<&str> for Column {
     }
 }
 
+impl FromStr for Column {
+    type Err = Infallible;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        Ok(s.into())
+    }
+}
+
 impl fmt::Display for Column {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match &self.relation {

datafusion/src/scalar.rs

@@ -27,6 +27,8 @@ use arrow::{
         TimestampSecondType, UInt16Type, UInt32Type, UInt64Type, UInt8Type,
     },
 };
+use std::convert::Infallible;
+use std::str::FromStr;
 use std::{convert::TryFrom, fmt, iter::repeat, sync::Arc};
 
 /// Represents a dynamically typed, nullable single value.
@@ -854,6 +856,14 @@ impl From<&str> for ScalarValue {
     }
 }
 
+impl FromStr for ScalarValue {
+    type Err = Infallible;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        Ok(s.into())
+    }
+}
+
 macro_rules! impl_try_from {
     ($SCALAR:ident, $NATIVE:ident) => {
         impl TryFrom<ScalarValue> for $NATIVE {