refactor into modules

Cargo.lock

@@ -2,6 +2,22 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aro"
+version = "0.1.0"
+dependencies = [
+ "nom",
+ "serde",
+ "serde_json",
+ "test-case",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "itoa"
 version = "1.0.4"
@@ -30,6 +46,30 @@ dependencies = [
  "minimal-lexical",
 ]
 
+[[package]]
+name = "proc-macro-error"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c"
+dependencies = [
+ "proc-macro-error-attr",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "version_check",
+]
+
+[[package]]
+name = "proc-macro-error-attr"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1be40180e52ecc98ad80b184934baf3d0d29f979574e439af5a55274b35f869"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "version_check",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.47"
@@ -54,15 +94,6 @@ version = "1.0.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4501abdff3ae82a1c1b477a17252eb69cee9e66eb915c1abaa4f44d873df9f09"
 
-[[package]]
-name = "scryfall-ygo"
-version = "0.1.0"
-dependencies = [
- "nom",
- "serde",
- "serde_json",
-]
-
 [[package]]
 name = "serde"
 version = "1.0.147"
@@ -105,8 +136,36 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "test-case"
+version = "2.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21d6cf5a7dffb3f9dceec8e6b8ca528d9bd71d36c9f074defb548ce161f598c0"
+dependencies = [
+ "test-case-macros",
+]
+
+[[package]]
+name = "test-case-macros"
+version = "2.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e45b7bf6e19353ddd832745c8fcf77a17a93171df7151187f26623f2b75b5b26"
+dependencies = [
+ "cfg-if",
+ "proc-macro-error",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ceab39d59e4c9499d4e5a8ee0e2735b891bb7308ac83dfb4e80cad195c9f6f3"
+
+[[package]]
+name = "version_check"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"

Cargo.toml

@@ -7,3 +7,4 @@ edition = "2021"
 serde_json = "1.0"
 serde = { version = "1.0", features = ["derive"] }
 nom = "7.1.3"
+test-case = "2.2.2"

src/data.rs

@@ -0,0 +1,119 @@
+use serde::Deserialize;
+use std::fmt::{self, Display};
+
+#[derive(Debug, Deserialize, PartialEq, Eq, Clone)]
+pub struct CardInfo {
+    pub data: Vec<Card>,
+}
+
+#[derive(Debug, Deserialize, PartialEq, Eq, Clone, Default)]
+pub struct Card {
+    pub id:          usize,
+    #[serde(rename = "type")]
+    pub card_type:   String,
+    pub name:        String,
+    #[serde(rename = "desc")]
+    pub text:        String,
+    // Will also be None for ?
+    pub atk:         Option<i32>,
+    pub def:         Option<i32>,
+    pub attribute:   Option<String>,
+    #[serde(rename = "race")]
+    pub r#type:      String,
+    // also includes rank
+    pub level:       Option<i32>,
+    #[serde(rename = "linkval")]
+    pub link_rating: Option<i32>,
+    #[serde(rename = "linkmarkers")]
+    pub link_arrows: Option<Vec<String>>,
+}
+
+impl Display for Card {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{} (", &self.name)?;
+        if let Some(level) = self.level {
+            write!(f, "Level {level} ")?;
+        } else if let Some(lr) = self.link_rating {
+            write!(f, "Link {lr} ")?;
+        }
+        if let Some(attr) = &self.attribute {
+            write!(f, "{attr}/")?;
+        }
+        write!(f, "{} {})", self.r#type, self.card_type)?;
+        if self.card_type.contains(&String::from("Monster")) {
+            match (self.atk, self.def) {
+                (Some(atk), Some(def)) => write!(f, " {atk} ATK / {def} DEF")?,
+                (Some(atk), None) if self.link_rating.is_some() => write!(f, "{atk} ATK")?,
+                (None, Some(def)) => write!(f, " ? ATK / {def} DEF")?,
+                (Some(atk), None) => write!(f, " {atk} ATK / ? DEF")?,
+                (None, None) => write!(f, " ? ATK / ? DEF")?,
+            }
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+
+    pub const RAW_SPELL: &str = r#"
+    {
+      "id": 41142615,
+      "name": "The Cheerful Coffin",
+      "type": "Spell Card",
+      "desc": "Discard up to 3 Monster Cards from your hand to the Graveyard.",
+      "race": "Normal"
+    }"#;
+
+    pub const RAW_MONSTER: &str = r#"
+    {
+       "id": 2326738,
+       "name": "Des Lacooda",
+       "type": "Effect Monster",
+       "desc": "Once per turn: You can change this card to face-down Defense Position. When this card is Flip Summoned: Draw 1 card.",
+       "atk": 500,
+       "def": 600,
+       "level": 3,
+       "race": "Zombie",
+       "attribute": "EARTH"
+    }"#;
+
+    #[test]
+    fn test_spell() {
+        let coffin: Card = serde_json::from_str(RAW_SPELL).unwrap();
+        assert_eq!(
+            coffin,
+            Card {
+                id: 41142615,
+                card_type: "Spell Card".to_owned(),
+                name: "The Cheerful Coffin".to_owned(),
+                text: "Discard up to 3 Monster Cards from your hand to the Graveyard.".to_owned(),
+                r#type: "Normal".to_owned(),
+                ..Default::default()
+            }
+        )
+    }
+
+    #[test]
+    fn test_monster() {
+        let munch: Card = serde_json::from_str(RAW_MONSTER).unwrap();
+        assert_eq!(
+            munch,
+            Card {
+                id: 2326738,
+                card_type: "Effect Monster".to_owned(),
+                name: "Des Lacooda".to_owned(),
+                text:
+                    "Once per turn: You can change this card to face-down Defense Position. When this card is Flip Summoned: Draw 1 card."
+                        .to_owned(),
+                atk: Some(500),
+                def: Some(600),
+                level: Some(3),
+                r#type: "Zombie".to_owned(),
+                attribute: Some("EARTH".to_owned()),
+                ..Default::default()
+            },
+        )
+    }
+}

src/filter.rs

@@ -0,0 +1,87 @@
+use crate::{
+    data::Card,
+    parser::{Field, Operator, Value, OPERATOR_CHARS},
+};
+
+/// A struct derived from `Card` that has all fields lowercased for easier search
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub struct SearchCard {
+    pub id:      usize,
+    card_type:   String,
+    name:        String,
+    text:        String,
+    atk:         Option<i32>,
+    def:         Option<i32>,
+    attribute:   Option<String>,
+    r#type:      String,
+    // also includes rank
+    level:       Option<i32>,
+    link_rating: Option<i32>,
+    link_arrows: Option<Vec<String>>,
+}
+
+impl From<&Card> for SearchCard {
+    fn from(card: &Card) -> Self {
+        Self {
+            id:          card.id,
+            card_type:   card.card_type.to_lowercase(),
+            name:        card.name.to_lowercase(),
+            text:        card.text.to_lowercase(),
+            atk:         card.atk,
+            def:         card.def,
+            attribute:   card.attribute.as_ref().map(|s| s.to_lowercase()),
+            r#type:      card.r#type.to_lowercase(),
+            level:       card.level,
+            link_rating: card.link_rating,
+            link_arrows: card.link_arrows.as_ref().map(|arrows| arrows.iter().map(|a| a.to_lowercase()).collect()),
+        }
+    }
+}
+
+pub type CardFilter = Box<dyn Fn(&SearchCard) -> bool>;
+pub type RawCardFilter = (Field, Operator, Value);
+
+pub fn fallback_filter(query: &str) -> Result<RawCardFilter, String> {
+    if query.contains(&OPERATOR_CHARS[..]) {
+        return Err(format!("Invalid query: {query}"));
+    }
+    #[cfg(debug_assertions)]
+    println!("Trying to match {query} as card name");
+    let q = query.to_lowercase();
+    Ok((Field::Name, Operator::Equals, Value::String(q)))
+}
+
+pub fn build_filter(query: RawCardFilter) -> Result<CardFilter, String> {
+    dbg!(&query);
+    Ok(match query {
+        (Field::Atk, op, Value::Numerical(n)) => Box::new(move |card| op.filter_number(card.atk, n)),
+        (Field::Def, op, Value::Numerical(n)) => Box::new(move |card| op.filter_number(card.def, n)),
+        // ? ATK/DEF is modeled as None in the source json. At least for some monsters.
+        // Let’s at least find those.
+        (Field::Atk, _, Value::String(s)) if s == "?" => Box::new(move |card| card.atk.is_none() && card.card_type.contains("monster")),
+        (Field::Def, _, Value::String(s)) if s == "?" => {
+            Box::new(move |card| card.def.is_none() && card.link_rating.is_none() && card.card_type.contains("monster"))
+        }
+        (Field::Level, op, Value::Numerical(n)) => Box::new(move |card| op.filter_number(card.level, n)),
+        (Field::Type, Operator::Equals, Value::String(s)) => Box::new(move |card| card.r#type == s),
+        (Field::Class, Operator::Equals, Value::String(s)) => Box::new(move |card| card.card_type.contains(&s)),
+        (Field::Text, Operator::Equals, Value::String(s)) => Box::new(move |card| card.text.contains(&s)),
+        (Field::Name, Operator::Equals, Value::String(s)) => Box::new(move |card| card.name.contains(&s)),
+        q => Err(format!("unknown query: {q:?}"))?,
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{data::tests::RAW_MONSTER, parser::parse_filters};
+
+    #[test]
+    fn level_filter_test() {
+        let lacooda = SearchCard::from(&serde_json::from_str::<Card>(RAW_MONSTER).unwrap());
+        let filter_level_3 = parse_filters("l=3").unwrap();
+        assert!(filter_level_3[0](&lacooda));
+        let filter_level_5 = parse_filters("l=5").unwrap();
+        assert!(!filter_level_5[0](&lacooda));
+    }
+}

src/main.rs

@@ -1,367 +1,21 @@
 #![feature(option_result_contains)]
-use nom::{
+use std::collections::HashMap;
-    branch::alt,
-    bytes::complete::{take_until1, take_while, take_while_m_n},
-    character::complete::{alphanumeric1, multispace0},
-    combinator::{complete, map_res, rest},
-    multi::many1,
-    sequence::{preceded, tuple},
-    IResult,
-};
-use serde::Deserialize;
-use std::{
-    collections::HashMap,
-    fmt::{self, Display},
-    str::FromStr,
-};
 
-type CardFilter = Box<dyn Fn(&SearchCard) -> bool>;
+use data::CardInfo;
-type RawCardFilter = (Field, Operator, Value);
+use filter::SearchCard;
+
+mod data;
+mod filter;
+mod parser;
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let cards = serde_json::from_reader::<_, CardInfo>(std::io::BufReader::new(std::fs::File::open("cards.json")?))?.data;
     let search_cards: Vec<_> = cards.iter().map(SearchCard::from).collect();
     let cards_by_id: HashMap<_, _> = cards.into_iter().map(|c| (c.id, c)).collect();
     let raw_query = std::env::args().nth(1).unwrap();
-    let query = parse_filters(&raw_query)?;
+    let query = parser::parse_filters(&raw_query)?;
-    search_cards.iter().filter(|card| query.iter().all(|q| q(card))).for_each(|c| println!("{}", cards_by_id.get(&c.id).unwrap()));
+    for c in search_cards.iter().filter(|card| query.iter().all(|q| q(card))) {
+        println!("{}", cards_by_id.get(&c.id).unwrap());
+    }
     Ok(())
 }
-
-fn parse_filters(input: &str) -> Result<Vec<CardFilter>, String> {
-    parse_raw_filters(input).map_err(|e| format!("Error while parsing filters “{input}”: {e:?}")).and_then(|(rest, v)| {
-        if rest.is_empty() {
-            Ok(v.into_iter().map(build_filter).collect::<Result<Vec<_>, _>>()?)
-        } else {
-            Err(format!("Input was not fully parsed. Left over: “{rest}”"))
-        }
-    })
-}
-
-fn parse_raw_filters(input: &str) -> IResult<&str, Vec<RawCardFilter>> {
-    many1(parse_raw_filter)(input)
-}
-
-fn parse_raw_filter(input: &str) -> IResult<&str, RawCardFilter> {
-    preceded(
-        multispace0,
-        alt((
-            complete(tuple((field, operator, value))),
-            map_res(take_until1(" "), |q| fallback_filter(q)),
-            // I would like to use `rest` here, but that results in a pattern that can be empty
-            // which can lead to infinite loops while parsing and is therefore disallowed by nom.
-            // I would need something like rest1 or a way to assert that the rest isn’t empty.
-            map_res(alphanumeric1, |q| fallback_filter(q)),
-        )),
-    )(input)
-}
-
-fn fallback_filter(query: &str) -> Result<RawCardFilter, String> {
-    if query.contains(&OPERATOR_CHARS[..]) {
-        return Err(format!("Invalid query: {query}"));
-    }
-    #[cfg(debug_assertions)]
-    println!("Trying to match {query} as card name");
-    let q = query.to_lowercase();
-    Ok((Field::Name, Operator::Equals, Value::String(q)))
-}
-
-fn build_filter(query: RawCardFilter) -> Result<CardFilter, String> {
-    dbg!(&query);
-    Ok(match query {
-        (Field::Atk, op, Value::Numerical(n)) => Box::new(move |card| op.filter_number(card.atk, n)),
-        (Field::Def, op, Value::Numerical(n)) => Box::new(move |card| op.filter_number(card.def, n)),
-        // ? ATK/DEF is modeled as None in the source json. At least for some monsters.
-        // Let’s at least find those.
-        (Field::Atk, _, Value::String(s)) if s == "?" => Box::new(move |card| card.atk.is_none() && card.card_type.contains("monster")),
-        (Field::Def, _, Value::String(s)) if s == "?" => {
-            Box::new(move |card| card.def.is_none() && card.link_rating.is_none() && card.card_type.contains("monster"))
-        }
-        (Field::Level, op, Value::Numerical(n)) => Box::new(move |card| op.filter_number(card.level, n)),
-        (Field::Type, Operator::Equals, Value::String(s)) => Box::new(move |card| card.r#type == s),
-        (Field::Class, Operator::Equals, Value::String(s)) => Box::new(move |card| card.card_type.contains(&s)),
-        (Field::Text, Operator::Equals, Value::String(s)) => Box::new(move |card| card.text.contains(&s)),
-        (Field::Name, Operator::Equals, Value::String(s)) => Box::new(move |card| card.name.contains(&s)),
-        q => Err(format!("unknown query: {q:?}"))?,
-    })
-}
-
-fn field(input: &str) -> IResult<&str, Field> {
-    map_res(take_while(char::is_alphabetic), str::parse)(input)
-}
-
-const OPERATOR_CHARS: &[char] = &['=', '<', '>', ':'];
-
-fn operator(input: &str) -> IResult<&str, Operator> {
-    map_res(take_while_m_n(1, 2, |c| OPERATOR_CHARS.contains(&c)), str::parse)(input)
-}
-
-fn value(input: &str) -> IResult<&str, Value> {
-    map_res(alt((take_until1(" "), rest)), |i: &str| match i.parse() {
-        Ok(n) => Ok(Value::Numerical(n)),
-        Err(_) if i.is_empty() => Err("empty filter argument"),
-        Err(_) => Ok(Value::String(i.to_lowercase())),
-    })(input)
-}
-
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-enum Field {
-    Atk,
-    Def,
-    Level,
-    Type,
-    Attribute,
-    Class,
-    Name,
-    Text,
-}
-
-impl FromStr for Field {
-    type Err = String;
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        Ok(match s.to_lowercase().as_ref() {
-            "atk" => Self::Atk,
-            "def" => Self::Def,
-            "level" | "l" => Self::Level,
-            "type" | "t" => Self::Type,
-            "attribute" | "attr" | "a" => Self::Attribute,
-            "c" | "class" => Self::Class,
-            "o" | "eff" | "text" | "effect" | "e" => Self::Text,
-            _ => Err(s.to_string())?,
-        })
-    }
-}
-
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-enum Operator {
-    Equals,
-    Less,
-    LessEqual,
-    Greater,
-    GreaterEqual,
-}
-
-impl Operator {
-    pub fn filter_number(&self, a: Option<i32>, b: i32) -> bool {
-        if let Some(a) = a {
-            match self {
-                Self::Equals => a == b,
-                Self::Less => a < b,
-                Self::LessEqual => a <= b,
-                Self::Greater => a > b,
-                Self::GreaterEqual => a >= b,
-            }
-        } else {
-            false
-        }
-    }
-}
-
-impl FromStr for Operator {
-    type Err = String;
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        Ok(match s {
-            "=" | "==" | ":" => Self::Equals,
-            ">=" | "=>" => Self::GreaterEqual,
-            "<=" | "=<" => Self::LessEqual,
-            ">" => Self::Greater,
-            "<" => Self::Less,
-            _ => Err(s.to_owned())?,
-        })
-    }
-}
-
-#[derive(Debug, PartialEq, Eq, Clone)]
-enum Value {
-    String(String),
-    Numerical(i32),
-}
-
-#[derive(Debug, Deserialize, PartialEq, Eq, Clone)]
-struct CardInfo {
-    data: Vec<Card>,
-}
-
-#[derive(Debug, Deserialize, PartialEq, Eq, Clone, Default)]
-struct Card {
-    id:          usize,
-    #[serde(rename = "type")]
-    card_type:   String,
-    name:        String,
-    #[serde(rename = "desc")]
-    text:        String,
-    // Will also be None for ?
-    atk:         Option<i32>,
-    def:         Option<i32>,
-    attribute:   Option<String>,
-    #[serde(rename = "race")]
-    r#type:      String,
-    // also includes rank
-    level:       Option<i32>,
-    #[serde(rename = "linkval")]
-    link_rating: Option<i32>,
-    #[serde(rename = "linkmarkers")]
-    link_arrows: Option<Vec<String>>,
-}
-
-/// A struct derived from `Card` that has all fields lowercased for easier search
-#[derive(Debug, PartialEq, Eq, Clone)]
-struct SearchCard {
-    id:          usize,
-    card_type:   String,
-    name:        String,
-    text:        String,
-    atk:         Option<i32>,
-    def:         Option<i32>,
-    attribute:   Option<String>,
-    r#type:      String,
-    // also includes rank
-    level:       Option<i32>,
-    link_rating: Option<i32>,
-    link_arrows: Option<Vec<String>>,
-}
-
-impl From<&Card> for SearchCard {
-    fn from(card: &Card) -> Self {
-        Self {
-            id:          card.id,
-            card_type:   card.card_type.to_lowercase(),
-            name:        card.name.to_lowercase(),
-            text:        card.text.to_lowercase(),
-            atk:         card.atk,
-            def:         card.def,
-            attribute:   card.attribute.as_ref().map(|s| s.to_lowercase()),
-            r#type:      card.r#type.to_lowercase(),
-            level:       card.level,
-            link_rating: card.link_rating,
-            link_arrows: card.link_arrows.as_ref().map(|arrows| arrows.iter().map(|a| a.to_lowercase()).collect()),
-        }
-    }
-}
-
-impl Display for Card {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "{} (", &self.name)?;
-        if let Some(level) = self.level {
-            write!(f, "Level {level} ")?;
-        } else if let Some(lr) = self.link_rating {
-            write!(f, "Link {lr} ")?;
-        }
-        if let Some(attr) = &self.attribute {
-            write!(f, "{attr}/")?;
-        }
-        write!(f, "{} {})", self.r#type, self.card_type)?;
-        if self.card_type.contains(&String::from("Monster")) {
-            match (self.atk, self.def) {
-                (Some(atk), Some(def)) => write!(f, " {atk} ATK / {def} DEF")?,
-                (Some(atk), None) if self.link_rating.is_some() => write!(f, "{atk} ATK")?,
-                (None, Some(def)) => write!(f, " ? ATK / {def} DEF")?,
-                (Some(atk), None) => write!(f, " {atk} ATK / ? DEF")?,
-                (None, None) => write!(f, " ? ATK / ? DEF")?,
-            }
-        }
-        Ok(())
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    const RAW_SPELL: &str = r#"
-    {
-      "id": 41142615,
-      "name": "The Cheerful Coffin",
-      "type": "Spell Card",
-      "desc": "Discard up to 3 Monster Cards from your hand to the Graveyard.",
-      "race": "Normal"
-    }"#;
-
-    const RAW_MONSTER: &str = r#"
-    {
-       "id": 2326738,
-       "name": "Des Lacooda",
-       "type": "Effect Monster",
-       "desc": "Once per turn: You can change this card to face-down Defense Position. When this card is Flip Summoned: Draw 1 card.",
-       "atk": 500,
-       "def": 600,
-       "level": 3,
-       "race": "Zombie",
-       "attribute": "EARTH"
-    }"#;
-
-    #[test]
-    fn test_spell() {
-        let coffin: Card = serde_json::from_str(RAW_SPELL).unwrap();
-        assert_eq!(
-            coffin,
-            Card {
-                id: 41142615,
-                card_type: "Spell Card".to_owned(),
-                name: "The Cheerful Coffin".to_owned(),
-                text: "Discard up to 3 Monster Cards from your hand to the Graveyard.".to_owned(),
-                r#type: "Normal".to_owned(),
-                ..Default::default()
-            }
-        )
-    }
-
-    #[test]
-    fn test_monster() {
-        let munch: Card = serde_json::from_str(RAW_MONSTER).unwrap();
-        assert_eq!(
-            munch,
-            Card {
-                id: 2326738,
-                card_type: "Effect Monster".to_owned(),
-                name: "Des Lacooda".to_owned(),
-                text:
-                    "Once per turn: You can change this card to face-down Defense Position. When this card is Flip Summoned: Draw 1 card."
-                        .to_owned(),
-                atk: Some(500),
-                def: Some(600),
-                level: Some(3),
-                r#type: "Zombie".to_owned(),
-                attribute: Some("EARTH".to_owned()),
-                ..Default::default()
-            },
-        )
-    }
-
-    #[test]
-    fn query_parsing_test() {
-        assert_eq!(parse_raw_filter("t:PYro"), Ok(("", (Field::Type, Operator::Equals, Value::String("pyro".into())))));
-        assert_eq!(parse_raw_filter("t=pyro"), Ok(("", (Field::Type, Operator::Equals, Value::String("pyro".into())))));
-        assert_eq!(parse_raw_filter("t==pyro"), Ok(("", (Field::Type, Operator::Equals, Value::String("pyro".into())))));
-        assert_eq!(parse_raw_filter("atk>=100"), Ok(("", (Field::Atk, Operator::GreaterEqual, Value::Numerical(100)))));
-        assert_eq!(parse_raw_filter("Necrovalley"), Ok(("", (Field::Name, Operator::Equals, Value::String("necrovalley".into())))));
-        assert_eq!(parse_raw_filter("l=10"), Ok(("", (Field::Level, Operator::Equals, Value::Numerical(10)))));
-
-        let (rest, filter) = parse_raw_filter("atk>=100 l:4").unwrap();
-        assert_eq!(filter, (Field::Atk, Operator::GreaterEqual, Value::Numerical(100)));
-        assert_eq!(parse_raw_filter(rest), Ok(("", (Field::Level, Operator::Equals, Value::Numerical(4)))));
-
-        assert_eq!(
-            parse_raw_filters("atk>=100 l:4"),
-            Ok((
-                "",
-                vec![(Field::Atk, Operator::GreaterEqual, Value::Numerical(100)), (Field::Level, Operator::Equals, Value::Numerical(4))]
-            ))
-        );
-
-        // These will fail during conversion
-        assert!(parse_filters("l===10").is_err());
-        assert!(parse_filters("t=").is_err());
-        assert!(parse_filters("=100").is_err());
-        assert!(parse_filters("atk<=>1").is_err());
-    }
-
-    #[test]
-    fn level_filter_test() {
-        let lacooda = SearchCard::from(&serde_json::from_str::<Card>(RAW_MONSTER).unwrap());
-        let filter_level_3 = parse_filters("l=3").unwrap();
-        assert!(filter_level_3[0](&lacooda));
-        let filter_level_5 = parse_filters("l=5").unwrap();
-        assert!(!filter_level_5[0](&lacooda));
-    }
-}

src/parser.rs

@@ -0,0 +1,166 @@
+use std::str::FromStr;
+
+use crate::filter::{build_filter, fallback_filter, CardFilter, RawCardFilter};
+use nom::{
+    branch::alt,
+    bytes::complete::{take_until1, take_while, take_while_m_n},
+    character::complete::multispace0,
+    combinator::{complete, map_res, rest, verify},
+    multi::many_m_n,
+    sequence::{preceded, tuple},
+    IResult,
+};
+
+pub fn parse_filters(input: &str) -> Result<Vec<CardFilter>, String> {
+    parse_raw_filters(input).map_err(|e| format!("Error while parsing filters “{input}”: {e:?}")).and_then(|(rest, v)| {
+        if rest.is_empty() {
+            v.into_iter().map(build_filter).collect()
+        } else {
+            Err(format!("Input was not fully parsed. Left over: “{rest}”"))
+        }
+    })
+}
+
+fn parse_raw_filters(input: &str) -> IResult<&str, Vec<RawCardFilter>> {
+    many_m_n(1, 32, parse_raw_filter)(input)
+}
+
+fn word_non_empty(input: &str) -> IResult<&str, &str> {
+    verify(alt((take_until1(" "), rest)), |s: &str| s.len() >= 2)(input)
+}
+
+fn parse_raw_filter(input: &str) -> IResult<&str, RawCardFilter> {
+    preceded(multispace0, alt((complete(tuple((field, operator, value))), map_res(word_non_empty, |q| fallback_filter(q)))))(input)
+}
+
+fn field(input: &str) -> IResult<&str, Field> {
+    map_res(take_while(char::is_alphabetic), str::parse)(input)
+}
+
+pub const OPERATOR_CHARS: &[char] = &['=', '<', '>', ':'];
+
+fn operator(input: &str) -> IResult<&str, Operator> {
+    map_res(take_while_m_n(1, 2, |c| OPERATOR_CHARS.contains(&c)), str::parse)(input)
+}
+
+fn value(input: &str) -> IResult<&str, Value> {
+    map_res(alt((take_until1(" "), rest)), |i: &str| match i.parse() {
+        Ok(n) => Ok(Value::Numerical(n)),
+        Err(_) if i.is_empty() => Err("empty filter argument"),
+        Err(_) => Ok(Value::String(i.to_lowercase())),
+    })(input)
+}
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum Field {
+    Atk,
+    Def,
+    Level,
+    Type,
+    Attribute,
+    Class,
+    Name,
+    Text,
+}
+
+impl FromStr for Field {
+    type Err = String;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match s.to_lowercase().as_ref() {
+            "atk" => Self::Atk,
+            "def" => Self::Def,
+            "level" | "l" => Self::Level,
+            "type" | "t" => Self::Type,
+            "attribute" | "attr" | "a" => Self::Attribute,
+            "c" | "class" => Self::Class,
+            "o" | "eff" | "text" | "effect" | "e" => Self::Text,
+            _ => Err(s.to_string())?,
+        })
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum Operator {
+    Equals,
+    Less,
+    LessEqual,
+    Greater,
+    GreaterEqual,
+}
+
+impl Operator {
+    pub fn filter_number(&self, a: Option<i32>, b: i32) -> bool {
+        if let Some(a) = a {
+            match self {
+                Self::Equals => a == b,
+                Self::Less => a < b,
+                Self::LessEqual => a <= b,
+                Self::Greater => a > b,
+                Self::GreaterEqual => a >= b,
+            }
+        } else {
+            false
+        }
+    }
+}
+
+impl FromStr for Operator {
+    type Err = String;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match s {
+            "=" | "==" | ":" => Self::Equals,
+            ">=" | "=>" => Self::GreaterEqual,
+            "<=" | "=<" => Self::LessEqual,
+            ">" => Self::Greater,
+            "<" => Self::Less,
+            _ => Err(s.to_owned())?,
+        })
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub enum Value {
+    String(String),
+    Numerical(i32),
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use test_case::test_case;
+
+    #[test_case("t=pyro" => Ok(("", (Field::Type, Operator::Equals, Value::String("pyro".into())))))]
+    #[test_case("t:PYro" => Ok(("", (Field::Type, Operator::Equals, Value::String("pyro".into())))); "input is lowercased")]
+    #[test_case("t==warrior" => Ok(("", (Field::Type, Operator::Equals, Value::String("warrior".into())))))]
+    #[test_case("atk>=100" => Ok(("", (Field::Atk, Operator::GreaterEqual, Value::Numerical(100)))))]
+    #[test_case("Necrovalley" => Ok(("", (Field::Name, Operator::Equals, Value::String("necrovalley".into())))))]
+    #[test_case("l=10" => Ok(("", (Field::Level, Operator::Equals, Value::Numerical(10)))))]
+    #[test_case("Ib" => Ok(("", (Field::Name, Operator::Equals, Value::String("ib".to_owned())))))]
+    fn successful_parsing_test(input: &str) -> IResult<&str, RawCardFilter> {
+        parse_raw_filter(input)
+    }
+
+    #[test_case("atk<=>1")]
+    #[test_case("l===10")]
+    #[test_case("t=")]
+    #[test_case("=100")]
+    #[test_case("a")]
+    fn unsuccessful_parsing_test(input: &str) {
+        assert!(parse_filters(input).is_err());
+    }
+
+    #[test]
+    fn sequential_parsing_test() {
+        let (rest, filter) = parse_raw_filter("atk>=100 l:4").unwrap();
+        assert_eq!(filter, (Field::Atk, Operator::GreaterEqual, Value::Numerical(100)));
+        assert_eq!(parse_raw_filter(rest), Ok(("", (Field::Level, Operator::Equals, Value::Numerical(4)))));
+
+        assert_eq!(
+            parse_raw_filters("atk>=100 l:4"),
+            Ok((
+                "",
+                vec![(Field::Atk, Operator::GreaterEqual, Value::Numerical(100)), (Field::Level, Operator::Equals, Value::Numerical(4))]
+            ))
+        );
+    }
+}