feat: add fancy-regex

__misc/fancy-regex/Cargo.lock

@@ -0,0 +1,81 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "aho-corasick"
+version = "0.7.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7404febffaa47dac81aa44dba71523c9d069b1bdc50a77db41195149e17f68e5"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "bit-set"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e11e16035ea35e4e5997b393eacbf6f63983188f7a2ad25bfb13465f5ad59de"
+dependencies = [
+ "bit-vec",
+]
+
+[[package]]
+name = "bit-vec"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f0dc55f2d8a1a85650ac47858bb001b4c0dd73d79e3c455a842925e68d29cd3"
+
+[[package]]
+name = "fancy-regex"
+version = "0.1.0"
+dependencies = [
+ "fancy-regex 0.4.1",
+]
+
+[[package]]
+name = "fancy-regex"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "36996e5f56f32ca51a937f325094fa450b32df871af1a89be331b7145b931bfc"
+dependencies = [
+ "bit-set",
+ "regex",
+]
+
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+
+[[package]]
+name = "memchr"
+version = "2.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
+
+[[package]]
+name = "regex"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "38cf2c13ed4745de91a5eb834e11c00bcc3709e773173b2ce4c56c9fbde04b9c"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+ "thread_local",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b181ba2dcf07aaccad5448e8ead58db5b742cf85dfe035e2227f137a539a189"
+
+[[package]]
+name = "thread_local"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d40c6d1b69745a6ec6fb1ca717914848da4b44ae29d9b3080cbee91d72a69b14"
+dependencies = [
+ "lazy_static",
+]

__misc/fancy-regex/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "fancy-regex"
+version = "0.1.0"
+authors = ["Hatter Jiang <jht5945@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+fancy-regex = "0.4.1"
+

__misc/fancy-regex/README.md

@@ -0,0 +1,6 @@
+https://github.com/fancy-regex/fancy-regex
+
+A Rust library for compiling and matching regular expressions. It uses a hybrid regex implementation designed to support a relatively rich set of features. In particular, it uses backtracking to implement "fancy" features such as look-around and backtracking, which are not supported in purely NFA-based implementations (exemplified by RE2, and implemented in Rust in the regex crate).
+
+
+

__misc/fancy-regex/src/main.rs

@@ -0,0 +1,104 @@
+use fancy_regex::internal::{analyze, compile, run_trace, Insn, Prog};
+use fancy_regex::*;
+use std::env;
+use std::str::FromStr;
+
+fn main() {
+    let mut args = env::args().skip(1);
+    if let Some(cmd) = args.next() {
+        if cmd == "parse" {
+            if let Some(re) = args.next() {
+                let e = Expr::parse_tree(&re);
+                println!("{:#?}", e);
+            }
+        } else if cmd == "analyze" {
+            if let Some(re) = args.next() {
+                let tree = Expr::parse_tree(&re).unwrap();
+                let a = analyze(&tree);
+                println!("{:#?}", a);
+            }
+        } else if cmd == "compile" {
+            if let Some(re) = args.next() {
+                let r = Regex::new(&re).unwrap();
+                r.debug_print();
+            }
+        } else if cmd == "run" {
+            let re = args.next().expect("expected regexp argument");
+            let r = Regex::new(&re).unwrap();
+            let text = args.next().expect("expected text argument");
+            let mut pos = 0;
+            if let Some(pos_str) = args.next() {
+                pos = usize::from_str(&pos_str).unwrap();
+            }
+            if let Some(caps) = r.captures_from_pos(&text, pos).unwrap() {
+                print!("captures:");
+                for i in 0..caps.len() {
+                    print!(" {}:", i);
+                    if let Some(m) = caps.get(i) {
+                        print!("[{}..{}] \"{}\"", m.start(), m.end(), m.as_str());
+                    } else {
+                        print!("_");
+                    }
+                }
+                println!("");
+                for cap in caps.iter() {
+                    println!("iterate {:?}", cap);
+                }
+            } else {
+                println!("no match");
+            }
+        } else if cmd == "trace" {
+            if let Some(re) = args.next() {
+                let prog = prog(&re);
+                if let Some(s) = args.next() {
+                    run_trace(&prog, &s, 0).unwrap();
+                }
+            }
+        } else if cmd == "trace-inner" {
+            if let Some(re) = args.next() {
+                let tree = Expr::parse_tree(&re).unwrap();
+                let a = analyze(&tree).unwrap();
+                let p = compile(&a).unwrap();
+                if let Some(s) = args.next() {
+                    run_trace(&p, &s, 0).unwrap();
+                }
+            }
+        } else if cmd == "graph" {
+            let re = args.next().expect("expected regexp argument");
+            graph(&re);
+        } else {
+            println!("commands: parse|analyze|compile|graph <expr>, run|trace|trace-inner <expr> <input>");
+        }
+    }
+}
+
+fn graph(re: &str) {
+    let prog = prog(re);
+    println!("digraph G {{");
+    for (i, insn) in prog.body.iter().enumerate() {
+        let label = format!("{:?}", insn)
+            .replace(r#"\"#, r#"\\"#)
+            .replace(r#"""#, r#"\""#);
+        println!(r#"{:3} [label="{}: {}"];"#, i, i, label);
+        match *insn {
+            Insn::Split(a, b) => {
+                println!("{:3} -> {};", i, a);
+                println!("{:3} -> {};", i, b);
+            }
+            Insn::Jmp(target) => {
+                println!("{:3} -> {};", i, target);
+            }
+            Insn::End => {}
+            _ => {
+                println!("{:3} -> {};", i, i + 1);
+            }
+        }
+    }
+    println!("}}");
+}
+
+fn prog(re: &str) -> Prog {
+    let tree = Expr::parse_tree(re).expect("Expected parsing regex to work");
+    let result = analyze(&tree).expect("Expected analyze to succeed");
+    compile(&result).expect("Expected compile to succeed")
+}