Rhyme and Meter

A collection of C++ methods for checking validating poetic rhmye and meter. Compiled to WebAssembly and used in Strictly, my rhyme and meter checker.

Intro

Uses my Phonetic library to get pronunciations using the CMU Pronouncing Dictionary. For the rhyme checking, we calcuate a "rhyme distance", using a notion of "vowel distance", "consonant distance" and techniques from bio-informatics to align string sequences.

The meter checking is a minimum validation that a certain meter could match a certain line, without trying to guess what the actual meter of the text is.

More information here.

Build

Includes my Phonetic library as a sub-module. Use:

git submodule update --init --recursive

to load load that library and CMU Pronouncing Dictionary data.

You can use CMake to compile:

mkdir build
cd build
cmake ..
make

This will also build tests/tests Catch-2 test file.

This can also be easily compiled to WebAssembly using Emscripten:

mdkir build
cd build
emcmake cmake ..
emmake make

This will generate rhyme-and-meter.js, rhyme-and-meter.wasm, and rhmye-and-meter.data. Using these you'll be able to call these methods directly from Javascript:

• Rhyme_and_Meter::check_syllable_validity()
• Rhyme_and_Meter::check_meter_validity()
• Rhyme_and_Meter::get_end_rhyme_distance()
• levenshtein_distance()

(Note:rhmye-and-meter.data expects to be found in the root folder of your web project.)

To use these functions in Javascript you can do something like this:

// Initialize the WebAssembly module
Module().then((Module) => {
	console.log("module initialized")

	// Create an instance of Rhyme_and_Meter class
	rhyme_and_meter = new Module.Rhyme_and_Meter();
    
	const result_object = rhmye_and_meter.get_end_rhyme_distance(string1, string2);

    if (result.is_valid) {
        //blah blah blah
    }
    
    // Or, for functions not in a class:
    const distance = Module.levenshtein_distance(string1, string2);
})

Usage

See header files for documentation of each method. See tests for methods in action.

Rhyme_and_Meter::check_syllable_validity()

Checks whether a line of text could match a syllable count.

Returns a Check_Validity_Result object, containing a bool is_valid and a vector of unrecognized words.

Rhyme_and_Meter::check_meter_validity()

Checks whether a line of text could match a meter, given as a string of 'x' and '/', where 'x' is an unstessed syllable and '/' is a stressed syllable. E.g. iambic penatmeter would be rendered as "x/x/x/x/x/".

Returns a Check_Validity_Result object, containing a bool is_valid and a vector of unrecognized words.

Rhyme_and_Meter::get_end_rhyme_distance()

Compares the end rhymes of two lines and returns the "rhyme distance". Currently, this takes as its comparison unit the at the shortest rhyming-part from between the last word of the two lines.

Scoring, roughly:

0     => perfect rhyme!
1-5   => pretty dang close!
6-10  => close!
11-20 => further!
20+   => noisy!

(Note / TODO: these number guides probably need to be updated now.)

levenshtein_distance()

Compares two space-separated strings of CMUdict arpabet phones.