diff --git a/Cargo.lock b/Cargo.lock
index a06ce06..842179f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -10,11 +10,6 @@ name = "autocfg"
 version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "byteorder"
-version = "1.3.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "cfg-if"
 version = "0.1.9"
@@ -28,7 +23,7 @@ dependencies = [
  "libc 0.2.60 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-integer 0.1.41 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.98 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -46,7 +41,8 @@ version = "0.1.0"
 dependencies = [
  "chrono 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
+ "nom 5.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.98 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
  "zip 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -61,6 +57,18 @@ name = "itoa"
 version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "lexical-core"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ryu 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "stackvector 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "static_assertions 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.60"
@@ -68,16 +76,30 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "libflate"
-version = "0.1.25"
+version = "0.1.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "adler32 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "crc32fast 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rle-decode-fast 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "take_mut 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "memchr"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "nom"
+version = "5.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lexical-core 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "num-integer"
 version = "0.1.41"
@@ -126,27 +148,48 @@ name = "rle-decode-fast"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "rustc_version"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "ryu"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
-name = "serde"
-version = "1.0.97"
+name = "semver"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "serde_derive 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
+ "semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "semver-parser"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "serde"
+version = "1.0.98"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "serde_derive 1.0.98 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.97"
+version = "1.0.98"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.44 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -156,12 +199,26 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "itoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "ryu 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.98 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "stackvector"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "static_assertions"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "syn"
-version = "0.15.40"
+version = "0.15.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -189,6 +246,24 @@ name = "unicode-xid"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "unreachable"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "version_check"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "void"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "winapi"
 version = "0.3.7"
@@ -214,21 +289,23 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "crc32fast 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "libflate 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libflate 0.1.26 (registry+https://github.com/rust-lang/crates.io-index)",
  "podio 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [metadata]
 "checksum adler32 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7e522997b529f05601e05166c07ed17789691f562762c7f3b987263d2dedee5c"
 "checksum autocfg 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "22130e92352b948e7e82a49cdb0aa94f2211761117f29e052dd397c1ac33542b"
-"checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
 "checksum cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "b486ce3ccf7ffd79fdeb678eac06a9e6c09fc88d33836340becb8fffe87c5e33"
 "checksum chrono 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)" = "77d81f58b7301084de3b958691458a53c3f7e0b1d702f77e550b6a88e3a88abe"
 "checksum crc32fast 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ba125de2af0df55319f41944744ad91c71113bf74a4646efff39afe1f6842db1"
 "checksum hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "805026a5d0141ffc30abb3be3173848ad46a1b1664fe632428479619a3644d77"
 "checksum itoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "501266b7edd0174f8530248f87f99c88fbe60ca4ef3dd486835b8d8d53136f7f"
+"checksum lexical-core 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b8b0f90c979adde96d19eb10eb6431ba0c441e2f9e9bdff868b2f6f5114ff519"
 "checksum libc 0.2.60 (registry+https://github.com/rust-lang/crates.io-index)" = "d44e80633f007889c7eff624b709ab43c92d708caad982295768a7b13ca3b5eb"
-"checksum libflate 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)" = "90c6f86f4b0caa347206f916f8b687b51d77c6ef8ff18d52dd007491fd580529"
+"checksum libflate 0.1.26 (registry+https://github.com/rust-lang/crates.io-index)" = "45c97cf62125b79dcac52d506acdc4799f21a198597806947fd5f40dc7b93412"
+"checksum memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "88579771288728879b57485cc7d6b07d648c9f0141eb955f8ab7f9d45394468e"
+"checksum nom 5.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e9761d859320e381010a4f7f8ed425f2c924de33ad121ace447367c713ad561b"
 "checksum num-integer 0.1.41 (registry+https://github.com/rust-lang/crates.io-index)" = "b85e541ef8255f6cf42bbfe4ef361305c6c135d10919ecc26126c4e5ae94bc09"
 "checksum num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "6ba9a427cfca2be13aa6f6403b0b7e7368fe982bfa16fccc450ce74c46cd9b32"
 "checksum podio 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "780fb4b6698bbf9cf2444ea5d22411cef2953f0824b98f33cf454ec5615645bd"
@@ -236,14 +313,22 @@ dependencies = [
 "checksum quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)" = "6ce23b6b870e8f94f81fb0a363d65d86675884b34a09043c81e5562f11c1f8e1"
 "checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
 "checksum rle-decode-fast 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cabe4fa914dec5870285fa7f71f602645da47c486e68486d2b4ceb4a343e90ac"
+"checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 "checksum ryu 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c92464b447c0ee8c4fb3824ecc8383b81717b9f1e74ba2e72540aef7b9f82997"
-"checksum serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)" = "d46b3dfedb19360a74316866cef04687cd4d6a70df8e6a506c63512790769b72"
-"checksum serde_derive 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)" = "c22a0820adfe2f257b098714323563dd06426502abbbce4f51b72ef544c5027f"
+"checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
+"checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
+"checksum serde 1.0.98 (registry+https://github.com/rust-lang/crates.io-index)" = "7fe5626ac617da2f2d9c48af5515a21d5a480dbd151e01bb1c355e26a3e68113"
+"checksum serde_derive 1.0.98 (registry+https://github.com/rust-lang/crates.io-index)" = "01e69e1b8a631f245467ee275b8c757b818653c6d704cdbcaeb56b56767b529c"
 "checksum serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)" = "051c49229f282f7c6f3813f8286cc1e3323e8051823fce42c7ea80fe13521704"
-"checksum syn 0.15.40 (registry+https://github.com/rust-lang/crates.io-index)" = "bc945221ccf4a7e8c31222b9d1fc77aefdd6638eb901a6ce457a3dc29d4c31e8"
+"checksum stackvector 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "1c4725650978235083241fab0fdc8e694c3de37821524e7534a1a9061d1068af"
+"checksum static_assertions 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b4f8de36da215253eb5f24020bfaa0646613b48bf7ebe36cdfa37c3b3b33b241"
+"checksum syn 0.15.44 (registry+https://github.com/rust-lang/crates.io-index)" = "9ca4b3b69a77cbe1ffc9e198781b7acb0c7365a883670e8f1c1bc66fba79a5c5"
 "checksum take_mut 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f764005d11ee5f36500a149ace24e00e3da98b0158b3e2d53a7495660d3f4d60"
 "checksum time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "db8dcfca086c1143c9270ac42a2bbd8a7ee477b78ac8e45b19abfb0cbede4b6f"
 "checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
+"checksum unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "382810877fe448991dfc7f0dd6e3ae5d58088fd0ea5e35189655f84e6814fa56"
+"checksum version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
+"checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 "checksum winapi 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)" = "f10e386af2b13e47c89e7236a7a14a086791a2b88ebad6df9bf42040195cf770"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
diff --git a/Cargo.toml b/Cargo.toml
index 4814f9d..f82368b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,6 +14,9 @@ features = ["serde"]
 [dependencies.hex]
 version = "*"
 
+[dependencies.nom]
+version = "5"
+
 [dependencies.serde]
 version = "*"
 features = ["derive"]
diff --git a/src/main.rs b/src/main.rs
index 78619d0..9f027d0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,6 +2,7 @@
 
 pub mod archive;
 pub mod error;
+pub mod query;
 
 use std::env::args;
 use std::time::Instant;
diff --git a/src/query/mod.rs b/src/query/mod.rs
new file mode 100644
index 0000000..8a6bd6b
--- /dev/null
+++ b/src/query/mod.rs
@@ -0,0 +1,6 @@
+//! Query module.
+
+mod optimizer;
+mod parser;
+
+pub use self::parser::parse;
diff --git a/src/query/optimizer.rs b/src/query/optimizer.rs
new file mode 100644
index 0000000..3ffbc33
--- /dev/null
+++ b/src/query/optimizer.rs
@@ -0,0 +1,87 @@
+//! Query optimizer.
+
+use std::str::FromStr;
+
+use chrono::prelude::*;
+
+use super::parser::{Operator, Source};
+use crate::archive::Story;
+use crate::error::{Error, Result};
+
+use Operator::*;
+use Source::*;
+
+type Filter = Box<dyn Fn(&Story) -> bool + Sync>;
+
+type IntFn = Box<dyn Fn(&Story) -> i64 + Sync>;
+type StrFn = Box<dyn Fn(&Story) -> &str + Sync>;
+type DtuFn = Box<dyn Fn(&Story) -> &Option<DateTime<Utc>> + Sync>;
+
+macro_rules! ok {
+    ($func:expr) => {
+        Ok(Box::new($func))
+    };
+}
+
+pub fn optimize(src: Source, op: Operator, value: &str) -> Result<Filter> {
+    match src {
+        StrFn(f) => strfn(f, op, value),
+        IntFn(f) => intfn(f, op, value),
+        DtuFn(f) => dtufn(f, op, value),
+    }
+}
+
+fn strfn(f: StrFn, op: Operator, value: &str) -> Result<Filter> {
+    let value: String = match op {
+        Fuzzy => value.to_lowercase(),
+        _ => value.to_owned(),
+    };
+
+    match op {
+        Exact => ok!(move |s| f(s) == &value),
+        Fuzzy => ok!(move |s| f(s).to_lowercase().contains(&value)),
+        _ => Err(Error::query("Invalid operation for text type")),
+    }
+}
+
+fn intfn(f: IntFn, op: Operator, value: &str) -> Result<Filter> {
+    let value: i64 = value.parse().map_err(|e| match e {
+        _ => Error::query("Invalid value for number type"),
+    })?;
+
+    match op {
+        Exact => ok!(move |s| f(s) == value),
+        Fuzzy => ok!(move |s| f(s) == value),
+        LessThan => ok!(move |s| f(s) < value),
+        MoreThan => ok!(move |s| f(s) > value),
+    }
+}
+
+fn dtufn(f: DtuFn, op: Operator, value: &str) -> Result<Filter> {
+    let parsed = DateTime::from_str(value);
+
+    let value: DateTime<Utc> = parsed.map_err(|e| match e {
+        _ => Error::query("Invalid value for date type"),
+    })?;
+
+    let date = value.date();
+
+    match op {
+        Exact => ok!(move |s| match f(s) {
+            Some(dt) => dt == &value,
+            None => false,
+        }),
+        Fuzzy => ok!(move |s| match f(s) {
+            Some(dt) => dt.date() == date,
+            None => false,
+        }),
+        LessThan => ok!(move |s| match f(s) {
+            Some(dt) => dt < &value,
+            None => false,
+        }),
+        MoreThan => ok!(move |s| match f(s) {
+            Some(dt) => dt > &value,
+            None => false,
+        }),
+    }
+}
diff --git a/src/query/parser.rs b/src/query/parser.rs
new file mode 100644
index 0000000..83e2dc0
--- /dev/null
+++ b/src/query/parser.rs
@@ -0,0 +1,215 @@
+//! Query parser.
+
+use chrono::prelude::*;
+
+use nom::character::complete::*;
+use nom::error::ErrorKind as NomErrorKind;
+use nom::sequence::*;
+use nom::*;
+
+use super::optimizer::optimize;
+use crate::archive::Story;
+use crate::error::*;
+
+type Filter = Box<dyn Fn(&Story) -> bool + Sync>;
+
+pub enum Source {
+    IntFn(Box<dyn Fn(&Story) -> i64 + Sync>),
+    StrFn(Box<dyn Fn(&Story) -> &str + Sync>),
+    DtuFn(Box<dyn Fn(&Story) -> &Option<DateTime<Utc>> + Sync>),
+}
+
+pub enum Operator {
+    Exact,
+    Fuzzy,
+    LessThan,
+    MoreThan,
+}
+
+macro_rules! sfn {
+    ($func:expr) => {
+        |_| Source::StrFn(Box::new($func))
+    };
+}
+
+macro_rules! ifn {
+    ($func:expr) => {
+        |_| Source::IntFn(Box::new($func))
+    };
+}
+
+macro_rules! dfn {
+    ($func:expr) => {
+        |_| Source::DtuFn(Box::new($func))
+    };
+}
+
+named!(source<&str, Source>, preceded!(space0, alt!(
+    tag!("id") => { ifn!(|s| s.id as i64) } |
+
+    tag!("story") => { sfn!(|s| &s.title) } |
+    tag!("title") => { sfn!(|s| &s.title) } |
+
+    tag!("description") => { sfn!(|s| &s.description_html) } |
+    tag!("short description") => { sfn!(|s| &s.short_description) } |
+    tag!("url") => { sfn!(|s| &s.url) } |
+
+    tag!("modified") => { dfn!(|s| &s.date_modified) } |
+    tag!("published") => { dfn!(|s| &s.date_published) } |
+    tag!("updated") => { dfn!(|s| &s.date_updated) } |
+
+    tag!("chapters") => { ifn!(|s| s.num_chapters as i64) } |
+    tag!("comments") => { ifn!(|s| s.num_comments as i64) } |
+    tag!("dislikes") => { ifn!(|s| s.num_dislikes as i64) } |
+    tag!("likes") => { ifn!(|s| s.num_likes as i64) } |
+    tag!("total views") => { ifn!(|s| s.total_num_views as i64) } |
+    tag!("views") => { ifn!(|s| s.num_views as i64) } |
+    tag!("words") => { ifn!(|s| s.num_words as i64) } |
+
+    tag!("author") => { sfn!(|s| &s.author.name) } |
+    tag!("author name") => { sfn!(|s| &s.author.name) } |
+
+    tag!("author id") => { ifn!(|s| s.author.id as i64) } |
+    tag!("author joined") => { dfn!(|s| &s.author.date_joined) } |
+
+    tag!("path") => { sfn!(|s| &s.archive.path) } |
+    tag!("archive") => { sfn!(|s| &s.archive.path) } |
+    tag!("archive path") => { sfn!(|s| &s.archive.path) } |
+
+    tag!("entry checked") => { dfn!(|s| &s.archive.date_checked) } |
+    tag!("entry created") => { dfn!(|s| &s.archive.date_created) } |
+    tag!("entry fetched") => { dfn!(|s| &s.archive.date_fetched) } |
+    tag!("entry updated") => { dfn!(|s| &s.archive.date_updated) }
+)));
+
+named!(operator<&str, Operator>, preceded!(space0, alt!(
+    tag!("=") => { |_| Operator::Exact } |
+    tag!(":") => { |_| Operator::Fuzzy } |
+    tag!("<") => { |_| Operator::LessThan } |
+    tag!(">") => { |_| Operator::MoreThan }
+)));
+
+fn unescape(input: &str) -> String {
+    input
+        .replace("\\)", ")")
+        .replace("\\,", ",")
+        .replace("\\|", "|")
+        .replace("\\\\", "\\")
+}
+
+named!(value<&str, &str>,
+    escaped!(none_of!("),|\\"), '\\', one_of!("),|\\"))
+);
+
+named!(target<&str, String>, preceded!(space0,
+    map!(value, |value| unescape(value.trim()))
+));
+
+fn item(input: &str) -> IResult<&str, Filter> {
+    let result = tuple((source, operator, target))(input)?;
+    let (left, (src, op, value)) = result;
+
+    let filter = optimize(src, op, &value).map_err(|e| match e {
+        _ => Err::Failure((input, NomErrorKind::Permutation)),
+    })?;
+
+    Ok((left, filter))
+}
+
+named!(parens<&str, Filter>, alt!(
+    delimited!(
+        preceded!(space0, tag!("(")),
+        preceded!(space0, call!(ofunc)),
+        preceded!(space0, tag!(")"))
+    ) |
+    call!(item)
+));
+
+fn negate(input: &str) -> IResult<&str, Filter> {
+    let (left, filter) = parens(input)?;
+
+    Ok((left, Box::new(move |s| !filter(s))))
+}
+
+named!(nlist<&str, Filter>, preceded!(space0, alt!(
+    preceded!(char('!'), call!(negate)) | call!(parens)
+)));
+
+named!(alist<&str, Vec<Filter>>, separated_nonempty_list!(
+    preceded!(space0, char(',')), call!(nlist)
+));
+
+fn afunc(input: &str) -> IResult<&str, Filter> {
+    let (left, mut filters) = alist(input)?;
+
+    if filters.len() == 1 {
+        return Ok((left, filters.remove(0)));
+    }
+
+    let filter: Filter = Box::new(move |story| {
+        for filter in filters.iter() {
+            if !filter(story) {
+                return false;
+            }
+        }
+
+        true
+    });
+
+    Ok((left, filter))
+}
+
+named!(olist<&str, Vec<Filter>>, separated_nonempty_list!(
+    preceded!(space0, char('|')), call!(afunc)
+));
+
+fn ofunc(input: &str) -> IResult<&str, Filter> {
+    let (left, mut filters) = olist(input)?;
+
+    if filters.len() == 1 {
+        return Ok((left, filters.remove(0)));
+    }
+
+    let filter: Filter = Box::new(move |story| {
+        for filter in filters.iter() {
+            if filter(story) {
+                return true;
+            }
+        }
+
+        false
+    });
+
+    Ok((left, filter))
+}
+
+fn format_error(query: &str, input: &str, error: NomErrorKind) -> String {
+    let description = error.description().to_lowercase();
+    let position = query.len() - input.len();
+
+    format!("Invalid {} at {}", description, position)
+}
+
+fn translate_error(query: &str, error: Err<(&str, NomErrorKind)>) -> Error {
+    let message = match error {
+        Err::Error((i, e)) => format_error(query, i, e),
+        Err::Failure((i, e)) => format_error(query, i, e),
+        Err::Incomplete(_) => String::from("Incomplete input"),
+    };
+
+    Error::query(message)
+}
+
+fn translate_incomplete(query: &str, input: &str) -> Error {
+    let position = query.len() - input.len();
+
+    Error::query(format!("Incomplete input at {}", position))
+}
+
+pub fn parse(query: &str) -> Result<Filter> {
+    match ofunc(query.trim()) {
+        Ok(("", filter)) => Ok(filter),
+        Ok((i, _)) => Err(translate_incomplete(query, i)),
+        Err(e) => Err(translate_error(query, e)),
+    }
+}