ParZig

A parser combinator library for Zig.

Install

• Git submodule

  git submodule add https://github.com/notCalle/parzig lib/parzig

  const parzig = Pkg { .name = "parzig", .path = "lib/parzig/exports.zig" };

• Import declaration for zkg

  pub const parzig = zkg.import.git(
      "https://github.com/notCalle/parzig",
      "main",
      null,
  );

Examples

• Party Ghosts vs Ghost Parties

  usingnamespace @import("parzig");
  
  const Ghost = Char('👻');
  const Party = Char('🥳');
  
  const ghost = "👻";
  const party = "🥳";
  
  test "ghost party" {
      const GhostParty = Ghost.Seq(Party));
      const ghost_party = ghost ++ party;
      const party_ghost = party ++ ghost;
  
      std.testing.expectEqualSlices(
          u8,
          ghost_party,
          GhostParty.parse(ghost_party).value().?,
      );
  
      std.testing.expect(.None == GhostParty.parse(party_ghost));
  }

• Numeric expression evaluator

  usingnamespace @import("parzig");
  
  const Expression = Parser(struct {
      pub fn parse(input: Input) Result(i32) {
          return Term.Opt(AddSub.Seq(Term)).Map(evalExpression);
      }
  });
  
  const Term = Parser(struct {
      pub fn parse(input: Input) Result(i32) {
          return Factor.Opt(MulDiv.Seq(Factor)).Map(evalTerm);
      }
  });
  
  const Factor = Parser(struct {
      pub fn parse(input: Input) Result(i32) {
          return Opt(Char('-')).Seq(Number.Or(Paren)).Map(evalFactor);
      }
  });
  
  const Number = Parser(struct {
      pub fn parse(input: Input) Result(i32) {
          return CharRange('0', '9').Many1.Map(evalNumber);
      }
  });
  
  const Paren = Parser(struct {
      pub fn parse(input: Input) Result(i32) {
          return Char('(').Seq(Expression).Seq(Char(')')).Map(evalParen);
      }
  });
  
  // ...
  
  test "" {
      std.testing.expectEqual(
          Result(i32).some(7, ""),
          Expression.parse("-(1-2)*3+4"),
      );
  }