diff --git a/Cargo.lock b/Cargo.lock
index d400682..fe8d84a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -47,6 +47,14 @@ name = "bitflags"
 version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "bstr"
+version = "0.2.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "memchr 2.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "byteorder"
 version = "1.3.2"
@@ -91,6 +99,25 @@ dependencies = [
  "time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "crossbeam-channel"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-utils 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "maybe-uninit 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "doc-comment"
 version = "0.3.1"
@@ -140,6 +167,35 @@ dependencies = [
  "syn 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "globset"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "aho-corasick 0.7.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bstr 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "ignore"
+version = "0.4.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-channel 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "globset 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 2.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "same-file 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thread_local 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "walkdir 2.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-util 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.3.2"
@@ -158,6 +214,14 @@ name = "libc"
 version = "0.2.66"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "log"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "lrlex"
 version = "0.6.0"
@@ -219,6 +283,11 @@ name = "macro-attr"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "maybe-uninit"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "memchr"
 version = "2.3.2"
@@ -309,6 +378,7 @@ dependencies = [
  "lrlex 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lrpar 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rerun_except 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "snafu 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -333,6 +403,14 @@ name = "regex-syntax"
 version = "0.6.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "rerun_except"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "ignore 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rmp"
 version = "0.8.9"
@@ -383,6 +461,14 @@ dependencies = [
  "syn 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi-util 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "semver"
 version = "0.1.20"
@@ -553,6 +639,16 @@ dependencies = [
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "walkdir"
+version = "2.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "same-file 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-util 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.8"
@@ -567,6 +663,14 @@ name = "winapi-i686-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
@@ -579,25 +683,32 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum backtrace-sys 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)" = "5d6575f128516de27e3ce99689419835fce9643a9b215a14d2b5b685be018491"
 "checksum bincode 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "5753e2a71534719bf3f4e57006c3a4f0d2c672a4b676eec84161f763eca87dbf"
 "checksum bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+"checksum bstr 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "502ae1441a0a5adb8fbd38a5955a6416b9493e92b465de5e4a9bde6a539c2c48"
 "checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
 "checksum cactus 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "0713c9ecac2733e4c61a93157674eee620ba377d263714a6083d7a8be13468eb"
 "checksum cc 1.0.50 (registry+https://github.com/rust-lang/crates.io-index)" = "95e28fa049fda1c330bcf9d723be7663a899c4679724b34c81e9f5a326aab8cd"
 "checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 "checksum cfgrammar 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "38ba3189f7cc6ccd37f6ce141b6c5a2670cbe8191ce12e937c24871cf26fd1be"
 "checksum chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "31850b4a4d6bae316f7a09e691c944c28299298837edc0a03f755618c23cbc01"
+"checksum crossbeam-channel 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "cced8691919c02aac3cb0a1bc2e9b73d89e832bf9a06fc579d4e71b68a2da061"
+"checksum crossbeam-utils 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c3c7c73a2d1e9fc0886a08b93e98eb643461230d5f1925e4036204d5f2e261a8"
 "checksum doc-comment 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "923dea538cea0aa3025e8685b20d6ee21ef99c4f77e954a30febbaac5ec73a97"
 "checksum error-chain 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3ab49e9dcb602294bc42f9a7dfc9bc6e936fca4418ea300dbfb84fe16de0b7d9"
 "checksum filetime 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "1ff6d4dab0aa0c8e6346d46052e93b13a16cf847b54ed357087c35011048cc7d"
 "checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
 "checksum getopts 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)" = "14dbbfd5c71d70241ecf9e6f13737f7b5ce823821063188d7e46c41d371eebd5"
 "checksum getset 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f62a139c59ae846c3964c392f12aac68f1997d1a40e9d3b40a89a4ab553e04a0"
+"checksum globset 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "925aa2cac82d8834e2b2a4415b6f6879757fb5c0928fc445ae76461a12eed8f2"
+"checksum ignore 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)" = "522daefc3b69036f80c7d2990b28ff9e0471c683bad05ca258e0a01dd22c5a1e"
 "checksum indexmap 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "076f042c5b7b98f31d205f1249267e12a6518c1481e9dae9764af19b707d2292"
 "checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 "checksum libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)" = "d515b1f41455adea1313a4a2ac8a8a477634fbae63cc6100e3aebb207ce61558"
+"checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
 "checksum lrlex 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "480f51804dcbff3209f226f8e51b7802fd31b98c8bf5927e6c91b0e330164029"
 "checksum lrpar 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0e2365adfdbcd180f4ed5266f2ae622b9ba78ef96ab16234d8c2ce580267c4e1"
 "checksum lrtable 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3ce78b4d45f3a59856731881206e03aadd0e1493c644f0f08b769a867a6f3a36"
 "checksum macro-attr 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "00e51c6f0e2bf862b01b3d784fc32b02feb248a69062c51fb0b6d14cd526cc2a"
+"checksum maybe-uninit 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "60302e4db3a61da70c0cb7991976248362f30319e88850c487b9b95bbf059e00"
 "checksum memchr 2.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "53445de381a1f436797497c61d851644d0e8e88e6140f22872ad33a704933978"
 "checksum newtype_derive 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "ac8cd24d9f185bb7223958d8c1ff7a961b74b1953fd05dba7cc568a63b3861ec"
 "checksum num-integer 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "3f6ea62e9d81a77cd3ee9a2a5b9b609447857f3d358704331e4ef39eb247fcba"
@@ -610,12 +721,14 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
 "checksum regex 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "322cf97724bea3ee221b78fe25ac9c46114ebb51747ad5babd51a2fc6a8235a8"
 "checksum regex-syntax 0.6.14 (registry+https://github.com/rust-lang/crates.io-index)" = "b28dfe3fe9badec5dbf0a79a9cccad2cfc2ab5484bdb3e44cbd1ae8b3ba2be06"
+"checksum rerun_except 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f74370ce9660eea246c8c15aa4e30e836438a3ff9dc24af4ae1d3c6c6a0a3c1e"
 "checksum rmp 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)" = "0f10b46df14cf1ee1ac7baa4d2fbc2c52c0622a4b82fa8740e37bc452ac0184f"
 "checksum rmp-serde 0.14.3 (registry+https://github.com/rust-lang/crates.io-index)" = "4c1ee98f14fe8b8e9c5ea13d25da7b2a1796169202c57a09d7288de90d56222b"
 "checksum rustc-demangle 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)" = "4c691c0e608126e00913e33f0ccf3727d5fc84573623b8d65b2df340b5201783"
 "checksum rustc_version 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "c5f5376ea5e30ce23c03eb77cbe4962b988deead10910c372b226388b594c084"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 "checksum rustversion 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b3bba175698996010c4f6dce5e7f173b6eb781fce25d2cfc45e27091ce0b79f6"
+"checksum same-file 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
 "checksum semver 0.1.20 (registry+https://github.com/rust-lang/crates.io-index)" = "d4f410fedcf71af0345d7607d246e7ad15faaadd49d240ee3b24e5dc21a820ac"
 "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"
@@ -637,6 +750,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum vergen 2.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "93fb2d57fbc535fcd45548c99b141d2d960995daaf04b864c4d9fe1ea011c819"
 "checksum version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
 "checksum vob 2.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "5430ea8977e2f0ed62cd37239cd713415022b240095c2f9187c32823015ae52f"
+"checksum walkdir 2.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "777182bc735b6424e1a57516d35ed72cb8019d85c8c9bf536dccb3445c1a2f7d"
 "checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+"checksum winapi-util 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "4ccfbf554c6ad11084fb7517daca16cfdcaccbdadba4fc336f032a8b12c2ad80"
 "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 10cca2b..bd6cdeb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,3 +23,4 @@ regex = "*"
 cfgrammar = "0.6"
 lrlex = "0.6"
 lrpar = "0.6"
+rerun_except = "0.1"
diff --git a/build.rs b/build.rs
index baeff5e..efc0667 100644
--- a/build.rs
+++ b/build.rs
@@ -1,6 +1,7 @@
 use cfgrammar::yacc::YaccKind;
 use lrlex::LexerBuilder;
 use lrpar::{CTParserBuilder};
+use rerun_except::rerun_except;
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let lex_rule_ids_map = CTParserBuilder::new()
@@ -9,5 +10,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     LexerBuilder::new()
         .rule_ids_map(lex_rule_ids_map)
         .process_file_in_src("vm/obj/syn/lexer.l")?;
+    rerun_except(&[
+        "examples/*.asm",
+        "tests/*.asm",
+    ]).unwrap();
     Ok(())
 }