Date literals (#4619)

* Date literals

* update deps

* Add date+duration

crates/nu-protocol/src/ast/expr.rs

@@ -1,3 +1,5 @@
+use chrono::FixedOffset;
+
 use super::{Call, CellPath, Expression, FullCellPath, Operator, RangeOperator};
 use crate::{ast::ImportPattern, BlockId, Signature, Span, Spanned, Unit, VarId};
 
@@ -26,6 +28,7 @@ pub enum Expr {
     Record(Vec<(Expression, Expression)>),
     Keyword(Vec<u8>, Span, Box<Expression>),
     ValueWithUnit(Box<Expression>, Spanned<Unit>),
+    DateTime(chrono::DateTime<FixedOffset>),
     Filepath(String),
     GlobPattern(String),
     String(String),

crates/nu-protocol/src/ast/expression.rs

@@ -142,6 +142,7 @@ impl Expression {
                 false
             }
             Expr::CellPath(_) => false,
+            Expr::DateTime(_) => false,
             Expr::ExternalCall(head, args) => {
                 if head.has_in_variable(working_set) {
                     return true;
@@ -301,6 +302,7 @@ impl Expression {
                 }
             }
             Expr::CellPath(_) => {}
+            Expr::DateTime(_) => {}
             Expr::ExternalCall(head, args) => {
                 head.replace_in_variable(working_set, new_var_id);
                 for arg in args {
@@ -443,6 +445,7 @@ impl Expression {
                 }
             }
             Expr::CellPath(_) => {}
+            Expr::DateTime(_) => {}
             Expr::ExternalCall(head, args) => {
                 head.replace_span(working_set, replaced, new_span);
                 for arg in args {

crates/nu-protocol/src/syntax_shape.rs

@@ -55,6 +55,9 @@ pub enum SyntaxShape {
     /// A duration value is allowed, eg `19day`
     Duration,
 
+    /// A datetime value, eg `2022-02-02` or `2019-10-12T07:20:50.52+00:00`
+    DateTime,
+
     /// An operator
     Operator,
 
@@ -94,6 +97,7 @@ impl SyntaxShape {
             SyntaxShape::Block(_) => Type::Block,
             SyntaxShape::CellPath => Type::Unknown,
             SyntaxShape::Custom(custom, _) => custom.to_type(),
+            SyntaxShape::DateTime => Type::Date,
             SyntaxShape::Duration => Type::Duration,
             SyntaxShape::Expression => Type::Unknown,
             SyntaxShape::Filepath => Type::String,
@@ -145,6 +149,7 @@ impl Display for SyntaxShape {
             SyntaxShape::Record => write!(f, "record"),
             SyntaxShape::Filesize => write!(f, "filesize"),
             SyntaxShape::Duration => write!(f, "duration"),
+            SyntaxShape::DateTime => write!(f, "datetime"),
             SyntaxShape::Operator => write!(f, "operator"),
             SyntaxShape::RowCondition => write!(f, "condition"),
             SyntaxShape::MathExpression => write!(f, "variable"),

crates/nu-protocol/src/value/mod.rs

@@ -1306,6 +1306,17 @@ impl Value {
                 val: lhs - rhs,
                 span,
             }),
+            (Value::Date { val: lhs, .. }, Value::Date { val: rhs, .. }) => {
+                let result = lhs.signed_duration_since(*rhs);
+
+                match result.num_nanoseconds() {
+                    Some(v) => Ok(Value::Duration { val: v, span }),
+                    None => Err(ShellError::OperatorOverflow(
+                        "subtraction operation overflowed".into(),
+                        span,
+                    )),
+                }
+            }
             (Value::Date { val: lhs, .. }, Value::Duration { val: rhs, .. }) => {
                 match lhs.checked_sub_signed(chrono::Duration::nanoseconds(*rhs)) {
                     Some(val) => Ok(Value::Date { val, span }),