Add variant of field filter which ignores missing field and comparison errors

mps-interpreter/src/interpretor.rs

@@ -158,6 +158,7 @@ pub(crate) fn standard_vocab(vocabulary: &mut MpsLanguageDictionary) {
     vocabulary
         .add(crate::lang::vocabulary::filters::empty_filter())
         .add(crate::lang::vocabulary::filters::field_filter())
+        .add(crate::lang::vocabulary::filters::field_filter_maybe())
         .add(crate::lang::vocabulary::sql_function_factory())
         .add(crate::lang::vocabulary::simple_sql_function_factory())
         .add(crate::lang::vocabulary::CommentStatementFactory)

mps-interpreter/src/lang/vocabulary/filters/field_filter.rs

@@ -14,24 +14,46 @@ use crate::MpsContext;
 use crate::MpsMusicItem;
 
 #[derive(Debug, Clone)]
-enum VariableOrValue {
+pub(super) enum VariableOrValue {
     Variable(String),
     Value(MpsTypePrimitive),
 }
 
 #[derive(Debug, Clone)]
 pub struct FieldFilter {
-    field_name: String,
+    pub(super) field_name: String,
-    val: VariableOrValue,
+    pub(super) field_errors: FieldFilterErrorHandling,
-    comparison: [i8; 2],
+    pub(super) comparison_errors: FieldFilterErrorHandling,
+    pub(super) val: VariableOrValue,
+    pub(super) comparison: [i8; 2],
+}
+
+#[derive(Debug, Clone)]
+pub enum FieldFilterErrorHandling {
+    Error, // return error
+    Ignore, // return Ok(false) when error encountered
+    Include, // return Ok(true) when error encountered
+}
+
+#[inline(always)]
+fn comparison_op(c: &[i8; 2]) -> &str {
+    match c {
+        [-1, -1] => "<",
+        [0, 0] => "==",
+        [1, 1] => ">",
+        [0, -1] => "<=",
+        [0, 1] => ">=",
+        [-1, 1] => "!=",
+        _ => "??"
+    }
 }
 
 impl Display for FieldFilter {
     fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
-        // TODO display other comparison operators correctly
+        let comp_op = comparison_op(&self.comparison);
         match &self.val {
-            VariableOrValue::Variable(name) => write!(f, "{} == {}", self.field_name, name),
+            VariableOrValue::Variable(name) => write!(f, "{} {} {}", self.field_name, comp_op, name),
-            VariableOrValue::Value(t) => write!(f, "{} == {}", self.field_name, t),
+            VariableOrValue::Value(t) => write!(f, "{} {} {}", self.field_name, comp_op, t),
         }
     }
 }
@@ -56,11 +78,19 @@ impl MpsFilterPredicate for FieldFilter {
             VariableOrValue::Value(val) => Ok(val),
         }?;
         if let Some(field) = music_item_lut.get(&self.field_name) {
-            let compare = field.compare(variable).map_err(|e| RuntimeError {
+            let compare_res = field.compare(variable);
+            if let Err(e) = compare_res {
+                match self.comparison_errors {
+                    FieldFilterErrorHandling::Error => Err(RuntimeError {
                         line: 0,
                         op: op(),
                         msg: e,
-            })?;
+                    }),
+                    FieldFilterErrorHandling::Ignore => Ok(false),
+                    FieldFilterErrorHandling::Include => Ok(true),
+                }
+            } else {
+                let compare = compare_res.unwrap();
                 let mut is_match = false;
                 for comparator in self.comparison {
                     if comparator == compare {
@@ -69,12 +99,17 @@ impl MpsFilterPredicate for FieldFilter {
                     }
                 }
                 Ok(is_match)
+            }
         } else {
-            Err(RuntimeError {
+            match self.field_errors {
+                FieldFilterErrorHandling::Error => Err(RuntimeError {
                     line: 0,
                     op: op(),
                     msg: format!("Field {} does not exist", &self.field_name),
-            })
+                }),
+                FieldFilterErrorHandling::Ignore => Ok(false),
+                FieldFilterErrorHandling::Include => Ok(true),
+            }
         }
     }
 
@@ -121,6 +156,8 @@ impl MpsFilterFactory<FieldFilter> for FieldFilterFactory {
             let value = VariableOrValue::Value(assert_type(tokens)?);
             Ok(FieldFilter {
                 field_name: field,
+                field_errors: FieldFilterErrorHandling::Error,
+                comparison_errors: FieldFilterErrorHandling::Error,
                 val: value,
                 comparison: compare_operator,
             })
@@ -135,6 +172,8 @@ impl MpsFilterFactory<FieldFilter> for FieldFilterFactory {
             )?);
             Ok(FieldFilter {
                 field_name: field,
+                field_errors: FieldFilterErrorHandling::Error,
+                comparison_errors: FieldFilterErrorHandling::Error,
                 val: variable,
                 comparison: compare_operator,
             })

mps-interpreter/src/lang/vocabulary/filters/field_filter_maybe.rs

@@ -0,0 +1,88 @@
+use std::collections::VecDeque;
+
+use super::utility::assert_comparison_operator;
+use super::{FieldFilter, FieldFilterErrorHandling, field_filter::VariableOrValue};
+use crate::lang::utility::{assert_token, assert_type, check_is_type, assert_token_raw};
+use crate::lang::MpsLanguageDictionary;
+use crate::lang::{MpsFilterFactory, MpsFilterStatementFactory};
+use crate::lang::SyntaxError;
+use crate::tokens::MpsToken;
+
+pub struct FieldFilterMaybeFactory;
+
+impl MpsFilterFactory<FieldFilter> for FieldFilterMaybeFactory {
+    fn is_filter(&self, tokens: &VecDeque<&MpsToken>) -> bool {
+        let tokens_len = tokens.len();
+        (tokens_len == 4 // field > variable OR field < variable
+            && tokens[0].is_name()
+            && (tokens[1].is_interrogation() || tokens[1].is_exclamation())
+            && (tokens[2].is_open_angle_bracket() || tokens[2].is_close_angle_bracket())
+            && (tokens[3].is_name() || check_is_type(&tokens[3])))
+            || (tokens_len == 5 // field >= variable OR field <= variable OR field != variable
+            && tokens[0].is_name()
+            && (tokens[1].is_interrogation() || tokens[1].is_exclamation())
+            && (tokens[2].is_open_angle_bracket() || tokens[2].is_close_angle_bracket() || tokens[2].is_equals() || tokens[2].is_exclamation())
+            && tokens[3].is_equals()
+            && (tokens[4].is_name() || check_is_type(&tokens[4])))
+    }
+
+    fn build_filter(
+        &self,
+        tokens: &mut VecDeque<MpsToken>,
+        _dict: &MpsLanguageDictionary,
+    ) -> Result<FieldFilter, SyntaxError> {
+        let field = assert_token(
+            |t| match t {
+                MpsToken::Name(n) => Some(n),
+                _ => None,
+            },
+            MpsToken::Name("field_name".into()),
+            tokens,
+        )?;
+        let error_f;
+        let error_c;
+        if tokens[0].is_interrogation() {
+            error_f = FieldFilterErrorHandling::Ignore;
+            error_c = FieldFilterErrorHandling::Ignore;
+            assert_token_raw(MpsToken::Interrogation, tokens)?;
+        } else {
+            error_f = FieldFilterErrorHandling::Include;
+            error_c = FieldFilterErrorHandling::Include;
+            assert_token_raw(MpsToken::Exclamation, tokens)?;
+        }
+        let compare_operator = assert_comparison_operator(tokens)?;
+        if check_is_type(&tokens[0]) {
+            let value = VariableOrValue::Value(assert_type(tokens)?);
+            Ok(FieldFilter {
+                field_name: field,
+                field_errors: error_f,
+                comparison_errors: error_c,
+                val: value,
+                comparison: compare_operator,
+            })
+        } else {
+            let variable = VariableOrValue::Variable(assert_token(
+                |t| match t {
+                    MpsToken::Name(n) => Some(n),
+                    _ => None,
+                },
+                MpsToken::Name("variable_name".into()),
+                tokens,
+            )?);
+            Ok(FieldFilter {
+                field_name: field,
+                field_errors: error_f,
+                comparison_errors: error_c,
+                val: variable,
+                comparison: compare_operator,
+            })
+        }
+    }
+}
+
+pub type FieldFilterMaybeStatementFactory = MpsFilterStatementFactory<FieldFilter, FieldFilterMaybeFactory>;
+
+#[inline(always)]
+pub fn field_filter_maybe() -> FieldFilterMaybeStatementFactory {
+    FieldFilterMaybeStatementFactory::new(FieldFilterMaybeFactory)
+}

mps-interpreter/src/lang/vocabulary/filters/mod.rs

@@ -1,10 +1,12 @@
 mod empty_filter;
 mod field_filter;
+mod field_filter_maybe;
 pub(crate) mod utility;
 
 pub use empty_filter::{
     empty_filter, EmptyFilter, EmptyFilterFactory, EmptyFilterStatementFactory,
 };
 pub use field_filter::{
-    field_filter, FieldFilter, FieldFilterFactory, FieldFilterStatementFactory,
+    field_filter, FieldFilter, FieldFilterFactory, FieldFilterStatementFactory, FieldFilterErrorHandling,
 };
+pub use field_filter_maybe::{field_filter_maybe, FieldFilterMaybeFactory, FieldFilterMaybeStatementFactory};

mps-interpreter/src/tokens/tokenizer.rs

@@ -260,7 +260,7 @@ impl ReaderStateMachine {
                 ' ' => Self::EndToken {},
                 '\n' | ';' => Self::EndStatement {},
                 '\0' => Self::EndOfFile {},
-                '(' | ')' | ',' | '=' | '<' | '>' | '.' => Self::SingleCharToken { out: input },
+                '(' | ')' | ',' | '=' | '<' | '>' | '.' | '!' | '?' => Self::SingleCharToken { out: input },
                 _ => Self::Regular { out: input },
             },
             Self::Escaped { inside } => match inside {

mps-interpreter/tests/single_line.rs

@@ -159,6 +159,30 @@ fn execute_fieldfilter_line() -> Result<(), Box<dyn MpsLanguageError>> {
     )
 }
 
+#[test]
+fn execute_fieldfiltermaybe_line() -> Result<(), Box<dyn MpsLanguageError>> {
+    execute_single_line(
+        "files(`~/Music/MusicFlac/Bruno Mars/24K Magic/`).(year? >= 2000)",
+        false,
+        true,
+    )?;
+    execute_single_line(
+        "files(`~/Music/MusicFlac/Bruno Mars/24K Magic/`).(year? <= 2020)",
+        false,
+        true,
+    )?;
+    execute_single_line(
+        "files(`~/Music/MusicFlac/Bruno Mars/24K Magic/`).(year! == 2016)",
+        false,
+        true,
+    )?;
+    execute_single_line(
+        "files(`~/Music/MusicFlac/Bruno Mars/24K Magic/`).(year! != `test`)",
+        false,
+        true,
+    )
+}
+
 #[test]
 fn execute_files_line() -> Result<(), Box<dyn MpsLanguageError>> {
     execute_single_line(