oak 0.8.0

A typed parser generator syntax extension for Parsing Expression Grammar (PEG).
Documentation 
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// Copyright 2016 Pierre Talbot (IRCAM)

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at

//     http://www.apache.org/licenses/LICENSE-2.0

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use back::compiler::*;

pub struct StrLiteralCompiler
{
  literal: String
}

impl StrLiteralCompiler
{
  pub fn recognizer(literal: String) -> StrLiteralCompiler {
    StrLiteralCompiler {
      literal: literal
    }
  }

  pub fn parser(literal: String) -> StrLiteralCompiler {
    StrLiteralCompiler::recognizer(literal)
  }
}

impl CompileExpr for StrLiteralCompiler
{
  fn compile_expr<'a>(&self, _context: &mut Context<'a>,
    continuation: Continuation) -> syn::Expr
  {
    let lit = self.literal.as_str();
    continuation
      .map_success(|success, failure| parse_quote!(
        if state.consume_prefix(#lit) {
          #success
        }
        else {
          state.error(#lit);
          #failure
        }
      ))
      .unwrap_success()
  }
}