Remove Value::MatchPattern (#11356)

# Description
`Value::MatchPattern` implies that `MatchPattern`s are first-class
values. This PR removes this case, and commands must now instead use
`Expr::MatchPattern` to extract `MatchPattern`s just like how the
`match` command does using `Expr::MatchBlock`.

# User-Facing Changes
Breaking API change for `nu_protocol` crate.

crates/nu-cmd-lang/src/core_commands/describe.rs

@@ -290,7 +290,6 @@ fn describe_value(
         | Value::Date { .. }
         | Value::Range { .. }
         | Value::String { .. }
-        | Value::MatchPattern { .. }
         | Value::Nothing { .. } => Value::record(
             record!(
                 "type" => Value::string(value.get_type().to_string(), head),

crates/nu-cmd-lang/src/example_support.rs

@@ -278,9 +278,6 @@ impl<'a> std::fmt::Debug for DebuggableValue<'a> {
                 let rec = val.collect().map_err(|_| std::fmt::Error)?;
                 write!(f, "LazyRecord({:?})", DebuggableValue(&rec))
             }
-            Value::MatchPattern { val, .. } => {
-                write!(f, "MatchPattern({:?})", val)
-            }
         }
     }
 }

crates/nu-color-config/src/style_computer.rs

@@ -131,8 +131,7 @@ impl<'a> StyleComputer<'a> {
             Value::Closure { .. }
             | Value::CustomValue { .. }
             | Value::Error { .. }
-            | Value::LazyRecord { .. }
+            | Value::LazyRecord { .. } => TextStyle::basic_left(),
-            | Value::MatchPattern { .. } => TextStyle::basic_left(),
         }
     }
 

crates/nu-command/src/database/commands/into_sqlite.rs

@@ -260,7 +260,6 @@ fn nu_value_to_string(value: Value, separator: &str) -> String {
         Value::Binary { val, .. } => format!("{val:?}"),
         Value::CellPath { val, .. } => val.to_string(),
         Value::CustomValue { val, .. } => val.value_string(),
-        Value::MatchPattern { val, .. } => format!("{:?}", val),
     }
 }
 

crates/nu-command/src/debug/explain.rs

@@ -259,6 +259,5 @@ pub fn debug_string_without_formatting(value: &Value) -> String {
         Value::Binary { val, .. } => format!("{val:?}"),
         Value::CellPath { val, .. } => val.to_string(),
         Value::CustomValue { val, .. } => val.value_string(),
-        Value::MatchPattern { val, .. } => format!("{:?}", val),
     }
 }

crates/nu-command/src/filters/find.rs

@@ -516,7 +516,6 @@ fn value_should_be_printed(
             Err(_) => false,
         },
         Value::Binary { .. } => false,
-        Value::MatchPattern { .. } => false,
     });
     if invert {
         match_found = !match_found;

crates/nu-command/src/formats/to/json.rs

@@ -127,10 +127,7 @@ pub fn value_to_json_value(v: &Value) -> Result<nu_json::Value, ShellError> {
 
         Value::List { vals, .. } => nu_json::Value::Array(json_list(vals)?),
         Value::Error { error, .. } => return Err(*error.clone()),
-        Value::Closure { .. }
+        Value::Closure { .. } | Value::Block { .. } | Value::Range { .. } => nu_json::Value::Null,
-        | Value::Block { .. }
-        | Value::Range { .. }
-        | Value::MatchPattern { .. } => nu_json::Value::Null,
         Value::Binary { val, .. } => {
             nu_json::Value::Array(val.iter().map(|x| nu_json::Value::U64(*x as u64)).collect())
         }

crates/nu-command/src/formats/to/nuon.rs

@@ -241,12 +241,6 @@ pub fn value_to_string(
                 ))
             }
         }
-        Value::MatchPattern { .. } => Err(ShellError::UnsupportedInput {
-            msg: "match patterns are currently not nuon-compatible".to_string(),
-            input: "value originates from here".into(),
-            msg_span: span,
-            input_span: v.span(),
-        }),
         Value::Nothing { .. } => Ok("null".to_string()),
         Value::Range { val, .. } => Ok(format!(
             "{}..{}{}",

crates/nu-command/src/formats/to/text.rs

@@ -148,7 +148,6 @@ fn local_into_string(value: Value, separator: &str, config: &Config) -> String {
         Value::Binary { val, .. } => format!("{val:?}"),
         Value::CellPath { val, .. } => val.to_string(),
         Value::CustomValue { val, .. } => val.value_string(),
-        Value::MatchPattern { val, .. } => format!("{:?}", val),
     }
 }
 

crates/nu-command/src/formats/to/toml.rs

@@ -94,7 +94,6 @@ fn helper(engine_state: &EngineState, v: &Value) -> Result<toml::Value, ShellErr
                 .collect::<Result<Vec<toml::Value>, ShellError>>()?,
         ),
         Value::CustomValue { .. } => toml::Value::String("<Custom Value>".to_string()),
-        Value::MatchPattern { .. } => toml::Value::String("<Match Pattern>".to_string()),
     })
 }
 

crates/nu-command/src/formats/to/yaml.rs

@@ -97,7 +97,6 @@ pub fn value_to_yaml_value(v: &Value) -> Result<serde_yaml::Value, ShellError> {
                 .collect::<Result<Vec<serde_yaml::Value>, ShellError>>()?,
         ),
         Value::CustomValue { .. } => serde_yaml::Value::Null,
-        Value::MatchPattern { .. } => serde_yaml::Value::Null,
     })
 }
 

crates/nu-protocol/src/eval_base.rs

@@ -277,8 +277,8 @@ pub trait Eval {
             Expr::GlobPattern(pattern) => {
                 Self::eval_glob_pattern(state, mut_state, pattern.clone(), expr.span)
             }
-            Expr::MatchPattern(pattern) => Ok(Value::match_pattern(*pattern.clone(), expr.span)),
+            Expr::MatchPattern(_) // match patterns are handled directly by commands
-            Expr::MatchBlock(_) // match blocks are handled by `match`
+            | Expr::MatchBlock(_) // match blocks are handled by `match`
             | Expr::VarDecl(_)
             | Expr::ImportPattern(_)
             | Expr::Signature(_)

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

@@ -1,6 +1,6 @@
 use std::path::PathBuf;
 
-use crate::ast::{CellPath, MatchPattern, PathMember};
+use crate::ast::{CellPath, PathMember};
 use crate::engine::{Block, Closure};
 use crate::{Range, Record, ShellError, Spanned, Value};
 use chrono::{DateTime, FixedOffset};
@@ -535,32 +535,3 @@ impl FromValue for Spanned<Closure> {
         }
     }
 }
-
-impl FromValue for Spanned<MatchPattern> {
-    fn from_value(v: Value) -> Result<Self, ShellError> {
-        let span = v.span();
-        match v {
-            Value::MatchPattern { val, .. } => Ok(Spanned { item: *val, span }),
-            v => Err(ShellError::CantConvert {
-                to_type: "Match pattern".into(),
-                from_type: v.get_type().to_string(),
-                span: v.span(),
-                help: None,
-            }),
-        }
-    }
-}
-
-impl FromValue for MatchPattern {
-    fn from_value(v: Value) -> Result<Self, ShellError> {
-        match v {
-            Value::MatchPattern { val, .. } => Ok(*val),
-            v => Err(ShellError::CantConvert {
-                to_type: "Match pattern".into(),
-                from_type: v.get_type().to_string(),
-                span: v.span(),
-                help: None,
-            }),
-        }
-    }
-}

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

@@ -7,7 +7,7 @@ mod record;
 mod stream;
 mod unit;
 
-use crate::ast::{Bits, Boolean, CellPath, Comparison, MatchPattern, PathMember};
+use crate::ast::{Bits, Boolean, CellPath, Comparison, PathMember};
 use crate::ast::{Math, Operator};
 use crate::engine::{Closure, EngineState};
 use crate::ShellError;
@@ -150,12 +150,6 @@ pub enum Value {
         // please use .span() instead of matching this span value
         internal_span: Span,
     },
-    MatchPattern {
-        val: Box<MatchPattern>,
-        // note: spans are being refactored out of Value
-        // please use .span() instead of matching this span value
-        internal_span: Span,
-    },
 }
 
 impl Clone for Value {
@@ -223,10 +217,6 @@ impl Clone for Value {
                 internal_span: *internal_span,
             },
             Value::CustomValue { val, internal_span } => val.clone_value(*internal_span),
-            Value::MatchPattern { val, internal_span } => Value::MatchPattern {
-                val: val.clone(),
-                internal_span: *internal_span,
-            },
         }
     }
 }
@@ -507,18 +497,6 @@ impl Value {
         }
     }
 
-    pub fn as_match_pattern(&self) -> Result<&MatchPattern, ShellError> {
-        match self {
-            Value::MatchPattern { val, .. } => Ok(val.as_ref()),
-            x => Err(ShellError::CantConvert {
-                to_type: "match-pattern".into(),
-                from_type: x.get_type().to_string(),
-                span: self.span(),
-                help: None,
-            }),
-        }
-    }
-
     /// Get the span for the current value
     pub fn span(&self) -> Span {
         match self {
@@ -539,7 +517,6 @@ impl Value {
             | Value::CellPath { internal_span, .. }
             | Value::CustomValue { internal_span, .. }
             | Value::LazyRecord { internal_span, .. }
-            | Value::MatchPattern { internal_span, .. }
             | Value::Error { internal_span, .. } => *internal_span,
         }
     }
@@ -563,8 +540,7 @@ impl Value {
             | Value::Nothing { internal_span, .. }
             | Value::Binary { internal_span, .. }
             | Value::CellPath { internal_span, .. }
-            | Value::CustomValue { internal_span, .. }
+            | Value::CustomValue { internal_span, .. } => *internal_span = new_span,
-            | Value::MatchPattern { internal_span, .. } => *internal_span = new_span,
             Value::Error { .. } => (),
         }
 
@@ -621,7 +597,6 @@ impl Value {
             Value::Binary { .. } => Type::Binary,
             Value::CellPath { .. } => Type::CellPath,
             Value::CustomValue { val, .. } => Type::Custom(val.typetag_name().into()),
-            Value::MatchPattern { .. } => Type::MatchPattern,
         }
     }
 
@@ -727,7 +702,6 @@ impl Value {
             Value::Binary { val, .. } => format!("{val:?}"),
             Value::CellPath { val, .. } => val.to_string(),
             Value::CustomValue { val, .. } => val.value_string(),
-            Value::MatchPattern { val, .. } => format!("<Pattern: {:?}>", val),
         }
     }
 
@@ -782,7 +756,6 @@ impl Value {
             Value::Binary { val, .. } => format!("{val:?}"),
             Value::CellPath { val, .. } => val.to_string(),
             Value::CustomValue { val, .. } => val.value_string(),
-            Value::MatchPattern { .. } => "<Pattern>".into(),
         }
     }
 
@@ -890,7 +863,6 @@ impl Value {
             Value::Binary { val, .. } => format!("{val:?}"),
             Value::CellPath { val, .. } => val.to_string(),
             Value::CustomValue { val, .. } => val.value_string(),
-            Value::MatchPattern { val, .. } => format!("<Pattern {:?}>", val),
         }
     }
 
@@ -1834,13 +1806,6 @@ impl Value {
         }
     }
 
-    pub fn match_pattern(val: MatchPattern, span: Span) -> Value {
-        Value::MatchPattern {
-            val: Box::new(val),
-            internal_span: span,
-        }
-    }
-
     /// Note: Only use this for test data, *not* live data, as it will point into unknown source
     /// when used in errors.
     pub fn test_bool(val: bool) -> Value {
@@ -1942,12 +1907,6 @@ impl Value {
     pub fn test_lazy_record(val: Box<dyn for<'a> LazyRecord<'a>>) -> Value {
         Value::lazy_record(val, Span::test_data())
     }
-
-    /// Note: Only use this for test data, *not* live data, as it will point into unknown source
-    /// when used in errors.
-    pub fn test_match_pattern(val: MatchPattern) -> Value {
-        Value::match_pattern(val, Span::test_data())
-    }
 }
 
 impl Default for Value {
@@ -1992,7 +1951,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Int { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2013,7 +1971,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Float { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2034,7 +1991,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Filesize { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2055,7 +2011,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Duration { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2076,7 +2031,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Date { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2097,7 +2051,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Range { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2118,7 +2071,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::String { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2139,7 +2091,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Record { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2179,7 +2130,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::List { vals: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2200,7 +2150,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Block { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2221,7 +2170,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Closure { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2242,7 +2190,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Nothing { .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2263,7 +2210,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Error { .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2284,7 +2230,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Less),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::Binary { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2305,7 +2250,6 @@ impl PartialOrd for Value {
                 Value::Binary { val: rhs, .. } => lhs.partial_cmp(rhs),
                 Value::CellPath { .. } => Some(Ordering::Less),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::CellPath { val: lhs, .. }, rhs) => match rhs {
                 Value::Bool { .. } => Some(Ordering::Greater),
@@ -2326,7 +2270,6 @@ impl PartialOrd for Value {
                 Value::Binary { .. } => Some(Ordering::Greater),
                 Value::CellPath { val: rhs, .. } => lhs.partial_cmp(rhs),
                 Value::CustomValue { .. } => Some(Ordering::Less),
-                Value::MatchPattern { .. } => Some(Ordering::Less),
             },
             (Value::CustomValue { val: lhs, .. }, rhs) => lhs.partial_cmp(rhs),
             (Value::LazyRecord { val, .. }, rhs) => {
@@ -2336,27 +2279,6 @@ impl PartialOrd for Value {
                     None
                 }
             }
-            (Value::MatchPattern { .. }, rhs) => match rhs {
-                Value::Bool { .. } => Some(Ordering::Greater),
-                Value::Int { .. } => Some(Ordering::Greater),
-                Value::Float { .. } => Some(Ordering::Greater),
-                Value::Filesize { .. } => Some(Ordering::Greater),
-                Value::Duration { .. } => Some(Ordering::Greater),
-                Value::Date { .. } => Some(Ordering::Greater),
-                Value::Range { .. } => Some(Ordering::Greater),
-                Value::String { .. } => Some(Ordering::Greater),
-                Value::Record { .. } => Some(Ordering::Greater),
-                Value::LazyRecord { .. } => Some(Ordering::Greater),
-                Value::List { .. } => Some(Ordering::Greater),
-                Value::Block { .. } => Some(Ordering::Greater),
-                Value::Closure { .. } => Some(Ordering::Greater),
-                Value::Nothing { .. } => Some(Ordering::Greater),
-                Value::Error { .. } => Some(Ordering::Greater),
-                Value::Binary { .. } => Some(Ordering::Greater),
-                Value::CellPath { .. } => Some(Ordering::Greater),
-                Value::CustomValue { .. } => Some(Ordering::Greater),
-                Value::MatchPattern { .. } => None,
-            },
         }
     }
 }