feat: Function dot syntax (#3369)

```
>> CREATE TEMP TABLE t (a INT, b TEXT);
┌─────────────────────┐
│ Query success       │
│ No columns returned │
└─────────────────────┘

>> INSERT INTO t VALUES (3, 'cat'), (4, 'dog'), (NULL, 'mouse'), (5, NULL);
┌───────────────┐
│ rows_inserted │
│ UInt64        │
├───────────────┤
│             4 │
└───────────────┘

>> SELECT b.upper() FROM t;
┌───────┐
│ upper │
│ Utf8  │
├───────┤
│ CAT   │
│ NULL  │
│ MOUSE │
│ DOG   │
└───────┘

>> SELECT t.b.upper() AS my_upper, my_upper.repeat(t.a) AS my_repeat, my_repeat.lower() AS my_lower FROM t;
┌──────────┬───────────┬──────────┐
│ my_upper │ my_repeat │ my_lower │
│ Utf8     │ Utf8      │ Utf8     │
├──────────┼───────────┼──────────┤
│ MOUSE    │ NULL      │ NULL     │
│ NULL     │ NULL      │ NULL     │
│ CAT      │ CATCATCAT │ catcatc… │
│ DOG      │ DOGDOGDO… │ dogdogd… │
└──────────┴───────────┴──────────┘
```

Actual chaining later.

crates/rayexec_execution/src/config/session.rs

@@ -15,6 +15,7 @@ pub struct SessionConfig {
     pub partitions: u64,
     pub batch_size: u64,
     pub verify_optimized_plan: bool,
+    pub enable_function_chaining: bool,
 }
 
 impl SessionConfig {
@@ -30,6 +31,7 @@ impl SessionConfig {
             partitions: executor.default_partitions() as u64,
             batch_size: 4096,
             verify_optimized_plan: false,
+            enable_function_chaining: true,
         }
     }
 
@@ -103,6 +105,7 @@ static GET_SET_FUNCTIONS: LazyLock<HashMap<&'static str, SettingFunctions>> = La
     insert_setting::<AllowNestedLoopJoin>(&mut map);
     insert_setting::<Partitions>(&mut map);
     insert_setting::<BatchSize>(&mut map);
+    insert_setting::<EnableFunctionChaining>(&mut map);
 
     map
 });
@@ -218,6 +221,23 @@ impl SessionSetting for VerifyOptimizedPlan {
     }
 }
 
+pub struct EnableFunctionChaining;
+
+impl SessionSetting for EnableFunctionChaining {
+    const NAME: &'static str = "enable_function_chaining";
+    const DESCRIPTION: &'static str = "If function chaining syntax is enabled.";
+
+    fn set_from_scalar(scalar: ScalarValue, conf: &mut SessionConfig) -> Result<()> {
+        let val = scalar.try_as_bool()?;
+        conf.enable_function_chaining = val;
+        Ok(())
+    }
+
+    fn get_as_scalar(conf: &SessionConfig) -> OwnedScalarValue {
+        conf.enable_function_chaining.into()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -230,6 +250,7 @@ mod tests {
             partitions: 8,
             batch_size: 4096,
             verify_optimized_plan: false,
+            enable_function_chaining: true,
         }
     }
 

crates/rayexec_execution/src/engine/session.rs

@@ -30,7 +30,7 @@ use crate::logical::logical_set::VariableOrAll;
 use crate::logical::operator::{LogicalOperator, Node};
 use crate::logical::planner::plan_statement::StatementPlanner;
 use crate::logical::resolver::resolve_context::ResolveContext;
-use crate::logical::resolver::{ResolveMode, ResolvedStatement, Resolver};
+use crate::logical::resolver::{ResolveConfig, ResolveMode, ResolvedStatement, Resolver};
 use crate::optimizer::Optimizer;
 use crate::runtime::time::Timer;
 use crate::runtime::{PipelineExecutor, Runtime};
@@ -243,6 +243,9 @@ where
             &tx,
             &self.context,
             self.registry.get_file_handlers(),
+            ResolveConfig {
+                enable_function_chaining: self.config.enable_function_chaining,
+            },
         )
         .resolve_statement(stmt.statement.clone())
         .await?;

crates/rayexec_execution/src/logical/binder/bind_query/bind_select_list.rs

@@ -1,17 +1,18 @@
 use std::collections::HashMap;
 
-use rayexec_error::Result;
+use rayexec_error::{RayexecError, Result};
 use rayexec_parser::ast;
 
 use super::select_expr_expander::ExpandedSelectExpr;
 use super::select_list::SelectList;
 use crate::expr::column_expr::ColumnExpr;
 use crate::expr::Expression;
 use crate::logical::binder::bind_context::{BindContext, BindScopeRef};
-use crate::logical::binder::column_binder::DefaultColumnBinder;
+use crate::logical::binder::column_binder::{DefaultColumnBinder, ExpressionColumnBinder};
 use crate::logical::binder::expr_binder::{BaseExpressionBinder, RecursionContext};
 use crate::logical::binder::table_list::TableRef;
 use crate::logical::resolver::resolve_context::ResolveContext;
+use crate::logical::resolver::ResolvedMeta;
 
 #[derive(Debug)]
 pub struct SelectListBinder<'a> {
@@ -77,13 +78,19 @@ impl<'a> SelectListBinder<'a> {
         // Bind the expressions.
         let expr_binder = BaseExpressionBinder::new(self.current, self.resolve_context);
         let mut exprs = Vec::with_capacity(projections.len());
-        for proj in projections {
+        for (idx, proj) in projections.into_iter().enumerate() {
             match proj {
                 ExpandedSelectExpr::Expr { expr, .. } => {
+                    let mut col_binder = SelectAliasColumnBinder {
+                        current_idx: idx,
+                        alias_map: &alias_map,
+                        previous_exprs: &exprs,
+                    };
+
                     let expr = expr_binder.bind_expression(
                         bind_context,
                         &expr,
-                        &mut DefaultColumnBinder,
+                        &mut col_binder,
                         RecursionContext {
                             allow_windows: true,
                             allow_aggregates: true,
@@ -242,3 +249,76 @@ impl<'a> SelectListBinder<'a> {
         Ok(())
     }
 }
+
+/// Column binder that allows binding to previously defined user aliases.
+///
+/// If an ident isn't found in the alias map, then default column binding is
+/// used.
+///
+/// Aliases are only checked if normal column binding cannot find a column.
+#[derive(Debug, Clone, Copy)]
+struct SelectAliasColumnBinder<'a> {
+    /// Index of the expression we're currently planning in the select list.
+    ///
+    /// Used to determine if an alias is valid to use.
+    current_idx: usize,
+    /// User provided aliases.
+    alias_map: &'a HashMap<String, usize>,
+    /// Previously planned expressions.
+    previous_exprs: &'a [Expression],
+}
+
+impl ExpressionColumnBinder for SelectAliasColumnBinder<'_> {
+    fn bind_from_root_literal(
+        &mut self,
+        bind_scope: BindScopeRef,
+        bind_context: &mut BindContext,
+        literal: &ast::Literal<ResolvedMeta>,
+    ) -> Result<Option<Expression>> {
+        DefaultColumnBinder.bind_from_root_literal(bind_scope, bind_context, literal)
+    }
+
+    fn bind_from_ident(
+        &mut self,
+        bind_scope: BindScopeRef,
+        bind_context: &mut BindContext,
+        ident: &ast::Ident,
+        _recur: RecursionContext,
+    ) -> Result<Option<Expression>> {
+        let col = ident.as_normalized_string();
+
+        match DefaultColumnBinder.bind_column(bind_scope, bind_context, None, &col)? {
+            Some(expr) => Ok(Some(expr)),
+            None => {
+                match self.alias_map.get(&col) {
+                    Some(&col_idx) => {
+                        if col_idx < self.current_idx {
+                            // Valid alias reference, use the existing expression.
+                            let aliased_expr =
+                                self.previous_exprs.get(col_idx).ok_or_else(|| {
+                                    RayexecError::new("Missing select expression?")
+                                        .with_field("idx", col_idx)
+                                })?;
+
+                            Ok(Some(aliased_expr.clone()))
+                        } else {
+                            // Not a valid alias expression.
+                            Err(RayexecError::new(format!("'{col}' can only be referenced after it's been defined in the SELECT list")))
+                        }
+                    }
+                    None => Ok(None),
+                }
+            }
+        }
+    }
+
+    fn bind_from_idents(
+        &mut self,
+        bind_scope: BindScopeRef,
+        bind_context: &mut BindContext,
+        idents: &[ast::Ident],
+        recur: RecursionContext,
+    ) -> Result<Option<Expression>> {
+        DefaultColumnBinder.bind_from_idents(bind_scope, bind_context, idents, recur)
+    }
+}

crates/rayexec_execution/src/logical/binder/column_binder.rs

@@ -89,7 +89,11 @@ impl ExpressionColumnBinder for DefaultColumnBinder {
 }
 
 impl DefaultColumnBinder {
-    fn bind_column(
+    /// Binds a column with the given name and optional table alias.
+    ///
+    /// This will handle appending correlated columns to the bind context as
+    /// necessary.
+    pub fn bind_column(
         &self,
         bind_scope: BindScopeRef,
         bind_context: &mut BindContext,

crates/rayexec_execution/src/logical/resolver/expr_resolver.rs

@@ -12,6 +12,7 @@ use crate::database::catalog_entry::CatalogEntryType;
 use crate::logical::binder::expr_binder::BaseExpressionBinder;
 use crate::logical::operator::LocationRequirement;
 
+#[derive(Debug)]
 pub struct ExpressionResolver<'a> {
     resolver: &'a Resolver<'a>,
 }
@@ -237,7 +238,10 @@ impl<'a> ExpressionResolver<'a> {
                 op,
                 right: Box::new(Box::pin(self.resolve_expression(*right, resolve_context)).await?),
             }),
-            ast::Expr::Function(func) => self.resolve_function(func, resolve_context).await,
+            ast::Expr::Function(func) => {
+                self.resolve_scalar_or_aggregate_function(func, resolve_context)
+                    .await
+            }
             ast::Expr::Subquery(subquery) => self.resolve_subquery(subquery, resolve_context).await,
             ast::Expr::Exists {
                 subquery,
@@ -556,20 +560,82 @@ impl<'a> ExpressionResolver<'a> {
         }
     }
 
-    async fn resolve_function(
+    async fn resolve_scalar_or_aggregate_function(
         &self,
-        func: Box<ast::Function<Raw>>,
+        mut func: Box<ast::Function<Raw>>,
         resolve_context: &mut ResolveContext,
     ) -> Result<ast::Expr<ResolvedMeta>> {
         // TODO: Search path (with system being the first to check)
-        if func.reference.0.len() != 1 {
-            return Err(RayexecError::new(
-                "Qualified function names not yet supported",
-            ));
+        let (catalog, schema, func_name) = match func.reference.0.len() {
+            0 => return Err(RayexecError::new("Missing idents for function reference")), // Shouldn't happen.
+            1 => (
+                "system".to_string(),
+                "glare_catalog".to_string(),
+                func.reference.0[0].as_normalized_string(),
+            ),
+            2 => (
+                "system".to_string(),
+                func.reference.0[0].as_normalized_string(),
+                func.reference.0[1].as_normalized_string(),
+            ),
+            3 => (
+                func.reference.0[0].as_normalized_string(),
+                func.reference.0[1].as_normalized_string(),
+                func.reference.0[2].as_normalized_string(),
+            ),
+            _ => {
+                // TODO: This could technically be from chained syntax on a
+                // fully qualified column.
+                return Err(RayexecError::new("Too many idents for function reference")
+                    .with_field("idents", func.reference.to_string()));
+            }
+        };
+
+        let context = self.resolver.context;
+
+        // See if we can resolve the catalog & schema. If we can't assume we're
+        // using chained function syntax.
+        //
+        // TODO: Make `get_database` return Option.
+        // TODO: We should be exhaustive about what's part of the qualified
+        //       function call vs what's part of the column.
+        let is_qualified = func.reference.0.len() > 1;
+        if self.resolver.config.enable_function_chaining
+            && is_qualified
+            && (!context.database_exists(&catalog)
+                || context
+                    .get_database(&catalog)?
+                    .catalog
+                    .get_schema(self.resolver.tx, &schema)?
+                    .is_none())
+        {
+            let unqualified_name = func.reference.0.pop().unwrap(); // Length checked above.
+            let unqualified_ref = ast::ObjectReference(vec![unqualified_name]);
+
+            let mut prefix_ref = std::mem::replace(&mut func.reference, unqualified_ref);
+
+            // Now add the prefix we took from the reference as the first
+            // argument to the function.
+
+            // TODO: Expr binder should probably take of this for us.
+            let arg_expr = match prefix_ref.0.len() {
+                1 => ast::Expr::Ident(prefix_ref.0.pop().unwrap()),
+                _ => ast::Expr::CompoundIdent(prefix_ref.0),
+            };
+
+            func.args.insert(
+                0,
+                ast::FunctionArg::Unnamed {
+                    arg: ast::FunctionArgExpr::Expr(arg_expr),
+                },
+            );
+
+            // Now try to resolve with just the unqualified reference.
+            let resolved =
+                Box::pin(self.resolve_scalar_or_aggregate_function(func, resolve_context)).await?;
+
+            return Ok(resolved);
         }
-        let func_name = &func.reference.0[0].as_normalized_string();
-        let catalog = "system";
-        let schema = "glare_catalog";
 
         let filter = self
             .resolve_optional_expression(func.filter.map(|e| *e), resolve_context)
@@ -582,16 +648,14 @@ impl<'a> ExpressionResolver<'a> {
         };
         let args = Box::pin(self.resolve_function_args(func.args, resolve_context)).await?;
 
-        let schema_ent = self
-            .resolver
-            .context
-            .get_database(catalog)?
+        let schema_ent = context
+            .get_database(&catalog)?
             .catalog
-            .get_schema(self.resolver.tx, schema)?
+            .get_schema(self.resolver.tx, &schema)?
             .ok_or_else(|| RayexecError::new(format!("Missing schema: {schema}")))?;
 
         // Check if this is a special function.
-        if let Some(special) = SpecialBuiltinFunction::try_from_name(func_name) {
+        if let Some(special) = SpecialBuiltinFunction::try_from_name(&func_name) {
             let resolve_idx = resolve_context
                 .functions
                 .push_resolved(ResolvedFunction::Special(special), LocationRequirement::Any);
@@ -606,7 +670,7 @@ impl<'a> ExpressionResolver<'a> {
         }
 
         // Now check scalars.
-        if let Some(scalar) = schema_ent.get_scalar_function(self.resolver.tx, func_name)? {
+        if let Some(scalar) = schema_ent.get_scalar_function(self.resolver.tx, &func_name)? {
             // TODO: Allow unresolved scalars?
             // TODO: This also assumes scalars (and aggs) are the same everywhere, which
             // they probably should be for now.
@@ -624,7 +688,7 @@ impl<'a> ExpressionResolver<'a> {
         }
 
         // Now check aggregates.
-        if let Some(aggregate) = schema_ent.get_aggregate_function(self.resolver.tx, func_name)? {
+        if let Some(aggregate) = schema_ent.get_aggregate_function(self.resolver.tx, &func_name)? {
             // TODO: Allow unresolved aggregates?
             let resolve_idx = resolve_context.functions.push_resolved(
                 ResolvedFunction::Aggregate(
@@ -651,7 +715,7 @@ impl<'a> ExpressionResolver<'a> {
                 CatalogEntryType::ScalarFunction,
                 CatalogEntryType::AggregateFunction,
             ],
-            func_name,
+            &func_name,
         ))
     }