Module response/select_lines

A select lines response gives students a sequence of lines of code and asks them to choose the ones that are correct and should become part of a final solution. The relative ordering of the lines is fixed, but each may be turned on/off. Lines may be "forced", meaning they cannot be turned off and are always included in the final solution. A "line" may in fact contain several lines if its specified content contains newline characters.

The response is rendered as a sequence of lines with checkboxes. Clicking a line toggles whether it is selected or not. Students may also preview their final solution, composed of only the selected lines.

Here's an example of a question with a select lines response.

export const Question_Sample_Select_Lines : QuestionSpecification = {
  question_id: "sample_select_lines",
  tags: [],
  points: 9,
  mk_description:
`
Compose a poem by selecting from the lines below.
Click all lines that should be included. You are not able to change the
relative ordering of the lines. You may use the buttons to toggle between
viewing all choices or just the ones you have selected to preview your
chosen code. When finished, the **selected lines should form a working
function** that performs a **deep copy** where appropriate and **avoids
undefined behavior or memory leaks**. Some lines contain **mistakes**
or are **unnecessary** for the function - these lines should not be selected.
`,
  response: {
    kind: "select_lines",
    code_language: "cpp",
    header: "A profound poem:",
    choices: [
      {
        kind: "item",
        text: "Roses are red",
        forced: false
      },
      {
        kind: "item",
        text: "Roses are pink",
        forced: true
      },
      {
        kind: "item",
        text: "Violets are blue",
        forced: false
      },
      {
        kind: "item",
        text: "Violets are purple",
        forced: false
      },
      {
        kind: "item",
        text: "This question is easy",
        forced: false
      },
      {
        kind: "item",
        text: "This question is tough",
        forced: false
      },
      {
        kind: "item",
        text: "But you already knew",
        forced: false
      },
      {
        kind: "item",
        text: "Nothing rhymes with purple",
        forced: false
      },
    ],
    footer: "The end",
    sample_solution: [1, 2, 4, 6]
  }
}

A submission for a select lines response is an array of numbers corresponding to the indices of selected lines. See SLSubmission for details.