93 lines
2.2 KiB
Rust
93 lines
2.2 KiB
Rust
use winnow::prelude::*;
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mod parser;
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mod parser_ast;
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mod parser_lexer;
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#[cfg(test)]
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mod test_parser;
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#[cfg(test)]
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mod test_parser_ast;
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#[cfg(test)]
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mod test_parser_lexer;
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fn main() -> Result<(), lexopt::Error> {
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let args = Args::parse()?;
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let input = args.input.as_deref().unwrap_or("1 + 1");
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if let Err(err) = calc(input, args.implementation) {
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println!("FAILED");
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println!("{err}");
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}
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Ok(())
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}
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fn calc(
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input: &str,
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imp: Impl,
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) -> Result<(), winnow::error::ParseError<&str, winnow::error::ContextError>> {
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println!("{input} =");
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match imp {
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Impl::Eval => {
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let result = parser::expr.parse(input)?;
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println!(" {result}");
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}
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Impl::Ast => {
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let result = parser_ast::expr.parse(input)?;
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println!(" {:#?}={}", result, result.eval());
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}
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Impl::Lexer => {
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let tokens = parser_lexer::tokens.parse(input)?;
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println!(" {tokens:#?}");
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let tokens = parser_lexer::Tokens::new(&tokens);
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let result = parser_lexer::expr.parse(tokens).unwrap();
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println!(" {:#?}={}", result, result.eval());
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}
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}
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Ok(())
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}
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#[derive(Default)]
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struct Args {
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input: Option<String>,
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implementation: Impl,
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}
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enum Impl {
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Eval,
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Ast,
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Lexer,
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}
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impl Default for Impl {
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fn default() -> Self {
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Self::Eval
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}
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}
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impl Args {
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fn parse() -> Result<Self, lexopt::Error> {
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use lexopt::prelude::*;
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let mut res = Args::default();
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let mut args = lexopt::Parser::from_env();
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while let Some(arg) = args.next()? {
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match arg {
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Long("impl") => {
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res.implementation = args.value()?.parse_with(|s| match s {
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"eval" => Ok(Impl::Eval),
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"ast" => Ok(Impl::Ast),
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"lexer" => Ok(Impl::Lexer),
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_ => Err("expected `eval`, `ast`"),
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})?;
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}
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Value(input) => {
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res.input = Some(input.string()?);
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}
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_ => return Err(arg.unexpected()),
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}
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}
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Ok(res)
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}
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}
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