A blazing-fast, high-fidelity port of the historic AWK data extraction and reporting tool from C to Rust.

Built cooperatively by Francesco Tinti and Antigravity (Google Deepmind).

rawk is a fully functional interpreter that mimics POSIX AWK and parts of GNU Awk (gawk) while bringing modern memory safety, performance, and deterministic parsing thanks to Rust.

• Formal Grammar Parsing: Replaced historical Yacc/Lex combinations with modern PEG (Parsing Expression Grammars) using the pest crate, including a fully compliant PrattParser for operator precedence.
• Dynamic Typing: rawk intelligently manages numeric and string types, fully replicating AWK's famous implicit coercion capabilities.
• Flow Control & User Functions: Complete support for if/else, while, do/while, for (in), break, continue, next, return, exit, and user-defined functions with local scoping support.
• Extended Built-ins:
  • Math: sin, cos, exp, log, sqrt, int, rand, srand, atan2
  • Bitwise (gawk extension): and, or, xor, lshift, rshift
  • Time (gawk extension): systime, strftime
  • Strings: length, tolower, toupper, substr, index, split, sub, gsub, match (updates RSTART/RLENGTH), sprintf
• Advanced I/O & Pipes: Native support for output redirects (> file, >> file), pipeline execution to bash children (print "hello" | "cat -n"), and extended getline with streaming file cache.
• Global Magic Variables: Built-in support for FS, OFS, RS, ORS, NR, FNR, NF, SUBSEP, ARGC, ARGV, and dynamic environment capturing in ENVIRON.
• Associative Arrays: True hash map arrays supporting multi-dimensional key simulation via SUBSEP and item removal (delete).

• cli.rs: CLI argument parsing via clap.
• awk.pest: The definitive PEG grammar for the language.
• parser.rs: Transforms token pairs into an Abstract Syntax Tree.
• ast.rs: The typed AST enumerations modeling the language structures.
• types.rs: Holds the evaluation context, dynamic types, I/O caches, and the random number generator.
• runner.rs: The virtual machine executing the AST natively in Rust.

Just like traditional AWK:

# Direct scripts
echo "foo,bar" | cargo run -- -F "," '{ print $2 }'

# Script files
cargo run -- -f my_script.awk input.txt

# Pipe outputs to system commands!
echo "1\n2\n3" | cargo run -- '{ print $0 | "cat -n" }'

cargo build --release
cargo test                                        # 109 testcase XML + property test + integrazione
cargo run -- -f program.awk file.txt
cargo run --bin diffrun -- tests/testsuite.xml    # confronto vs /usr/bin/awk

Quality gates:

• cargo clippy --all-targets -- -D warnings
• cargo fmt --check
• bash scripts/checks.sh (tutti i verification gate del piano di adeguamento idiomatico)

This code was written as part of an iterative AI pair-programming project aiming to explore limits in translating untyped, legacy C CLI utilities to deterministic Rust ecosystems.