Rewrite SQL system to allow for transpiling SQL, and implement PoC

interpreter/src/context.rs

@@ -1,6 +1,6 @@
 #[cfg(feature = "advanced")]
 use super::processing::advanced::{DefaultAnalyzer, MusicAnalyzer};
-use super::processing::database::{DatabaseQuerier, SQLiteExecutor};
+use super::processing::database::{DatabaseQuerier, SQLiteTranspileExecutor};
 #[cfg(feature = "mpd")]
 use super::processing::database::{MpdExecutor, MpdQuerier};
 use super::processing::general::{
@@ -22,7 +22,7 @@ pub struct Context {
 impl Default for Context {
     fn default() -> Self {
         Self {
-            database: Box::new(SQLiteExecutor::default()),
+            database: Box::new(SQLiteTranspileExecutor::default()),
             variables: Box::new(OpStorage::default()),
             filesystem: Box::new(FilesystemExecutor::default()),
             #[cfg(feature = "advanced")]

interpreter/src/lang/vocabulary/filters/field_like_filter.rs

@@ -22,11 +22,7 @@ pub struct FieldLikeFilter {
 
 impl FieldLikeFilter {
     fn sanitise_string(s: &str) -> String {
-        #[cfg(feature = "unidecode")]
-        let s = unidecode::unidecode(s);
-        s.replace(|c: char| c.is_whitespace() || c == '_' || c == '-', "")
-            .replace(|c: char| !(c.is_whitespace() || c.is_alphanumeric()), "")
-            .to_lowercase()
+        super::utility::sanitise_string(s)
     }
 }
 

interpreter/src/lang/vocabulary/filters/utility.rs

@@ -4,6 +4,15 @@ use crate::lang::utility::assert_token_raw;
 use crate::lang::SyntaxError;
 use crate::tokens::Token;
 
+#[inline]
+pub fn sanitise_string(s: &str) -> String {
+    #[cfg(feature = "unidecode")]
+    let s = unidecode::unidecode(s);
+    s.replace(|c: char| c.is_whitespace() || c == '_' || c == '-', "")
+        .replace(|c: char| !(c.is_whitespace() || c.is_alphanumeric()), "")
+        .to_lowercase()
+}
+
 pub fn assert_comparison_operator(tokens: &mut VecDeque<Token>) -> Result<[i8; 2], SyntaxError> {
     let token1 = tokens.pop_front().unwrap();
     match token1 {

interpreter/src/processing/mod.rs

@@ -11,7 +11,7 @@ mod variables;
 pub mod database {
     #[cfg(feature = "mpd")]
     pub use super::mpd::{MpdExecutor, MpdQuerier};
-    pub use super::sql::{DatabaseQuerier, QueryResult, SQLiteExecutor};
+    pub use super::sql::{DatabaseQuerier, QueryResult, SQLiteExecutor, SQLiteTranspileExecutor};
 }
 
 pub mod general {

interpreter/src/processing/sql/executor.rs

@@ -30,6 +30,7 @@ pub trait DatabaseQuerier: Debug {
     /// `"folder" = "path"` - path to root music directory
     /// `"database" = "uri"` - connection URI for database (for SQLite this is just a filepath)
     /// `"generate" = "true"|"yes"|"false"|"no"` - whether to populate the database using the music directory
+    /// it is up to the specific implementation to use/ignore these parameters
     fn init_with_params(&mut self, params: &HashMap<String, String>) -> Result<(), RuntimeMsg>;
 }
 
@@ -305,24 +306,25 @@ fn rows_to_item(
 pub struct SQLiteTranspileExecutor;
 
 impl DatabaseQuerier for SQLiteTranspileExecutor {
-    fn raw(&mut self, query: &str) -> QueryResult {
+    fn raw(&mut self, _query: &str) -> QueryResult {
+        // TODO
         Err(RuntimeMsg("Unimplemented".to_owned()))
     }
 
     fn artist_like(&mut self, query: &str) -> QueryResult {
-        Err(RuntimeMsg("Unimplemented".to_owned()))
+        Ok(Box::new(super::SimpleSqlQuery::emit("artist", query)))
     }
 
     fn album_like(&mut self, query: &str) -> QueryResult {
-        Err(RuntimeMsg("Unimplemented".to_owned()))
+        Ok(Box::new(super::SimpleSqlQuery::emit("album", query)))
     }
 
     fn song_like(&mut self, query: &str) -> QueryResult {
-        Err(RuntimeMsg("Unimplemented".to_owned()))
+        Ok(Box::new(super::SimpleSqlQuery::emit("title", query)))
     }
 
     fn genre_like(&mut self, query: &str) -> QueryResult {
-        Err(RuntimeMsg("Unimplemented".to_owned()))
+        Ok(Box::new(super::SimpleSqlQuery::emit("genre", query)))
     }
 
     fn init_with_params(&mut self, _params: &HashMap<String, String>) -> Result<(), RuntimeMsg> {

interpreter/src/processing/sql/mod.rs

@@ -0,0 +1,5 @@
+mod executor;
+mod simple_emit;
+
+pub use executor::*;
+pub use simple_emit::SimpleSqlQuery;

interpreter/src/processing/sql/simple_emit.rs

@@ -0,0 +1,114 @@
+use std::fmt::{Debug, Display, Error, Formatter};
+use std::iter::Iterator;
+
+use crate::Context;
+
+use crate::lang::{IteratorItem, Op, PseudoOp};
+use crate::lang::{RuntimeError, RuntimeOp, TypePrimitive};
+use crate::processing::general::FileIter;
+
+#[derive(Debug)]
+pub struct SimpleSqlQuery {
+    context: Option<Context>,
+    file_iter: Option<FileIter>,
+    field_name: String,
+    val: String,
+    has_tried: bool,
+}
+
+impl SimpleSqlQuery {
+    pub fn emit(field: &str, value: &str) -> Self {
+        Self {
+            context: None,
+            file_iter: None,
+            field_name: field.to_owned(),
+            val: crate::lang::vocabulary::filters::utility::sanitise_string(value),
+            has_tried: false,
+        }
+    }
+}
+
+impl Display for SimpleSqlQuery {
+    fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
+        write!(f, "{}(`{}`)", self.field_name, self.val)
+    }
+}
+
+impl std::clone::Clone for SimpleSqlQuery {
+    fn clone(&self) -> Self {
+        Self {
+            context: None,
+            file_iter: None,
+            field_name: self.field_name.clone(),
+            val: self.val.clone(),
+            has_tried: self.has_tried,
+        }
+    }
+}
+
+impl Iterator for SimpleSqlQuery {
+    type Item = IteratorItem;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.file_iter.is_none() {
+            if self.has_tried {
+                return None;
+            } else {
+                self.has_tried = true;
+            }
+            let iter = self.context.as_mut().unwrap().filesystem.raw(
+                None,
+                None,
+                true,
+            );
+            self.file_iter = Some(match iter {
+                Ok(x) => x,
+                Err(e) => return Some(Err(e.with(RuntimeOp(PseudoOp::from_printable(self))))),
+            });
+        }
+        while let Some(item) = self.file_iter.as_mut().unwrap().next() {
+            match item {
+                Ok(item) => {
+                    // apply filter
+                    if let Some(TypePrimitive::String(field_val)) = item.field(&self.field_name) {
+                        if crate::lang::vocabulary::filters::utility::sanitise_string(field_val).contains(&self.val) {
+                            return Some(Ok(item));
+                        }
+                    }
+                },
+                Err(e) => return Some(Err(RuntimeError {
+                    line: 0,
+                    op: PseudoOp::from_printable(self),
+                    msg: e,
+                }))
+            }
+        }
+        None
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.file_iter.as_ref().map(|x| x.size_hint()).unwrap_or_default()
+    }
+}
+
+impl Op for SimpleSqlQuery {
+    fn enter(&mut self, ctx: Context) {
+        self.context = Some(ctx)
+    }
+
+    fn escape(&mut self) -> Context {
+        self.context.take().unwrap()
+    }
+
+    fn is_resetable(&self) -> bool {
+        true
+    }
+
+    fn reset(&mut self) -> Result<(), RuntimeError> {
+        Ok(())
+    }
+
+    fn dup(&self) -> Box<dyn Op> {
+        Box::new(self.clone())
+    }
+}