[−][src]Trait shelp::LangInterface
LangInterface is a trait used by Repl to provide dependent specific features.
Implement only the functions which you want, since there are default implementations for all of them.
Provided methods
pub fn print_line(
stdout: &mut Stdout,
lines: &[String],
index: usize
) -> Result<()>[src]
stdout: &mut Stdout,
lines: &[String],
index: usize
) -> Result<()>
Given the lines of text, this function should print the line at index. This should be overridden if you want to lint the output in the repl.
Why are all lines given, not just what needs to be printed?
Earlier, only the line that needed to be printed was given, but this caused issues while linting multi-line programs which had specific things over multiple lines. For example take the following lines:
<some-code> /* Multi line Comment */
This probably would not be linted properly, since in line 2, the context that the word 'line'
is within a comment is lost. For correct behaviour (subject to language linting rules), all
the lines should be processed, but only lines[index] should be written to stdout.
pub fn get_indent(lines: &[String]) -> usize[src]
Given the lines up to the place a new line is being added, this function should give the indentation of the new line.
For example, take the following [rust] code (note █ represents the cursor):
if true { █ // <------------- PRESSED ENTER HERE }
Here the lines would be give: ['if true {', '}'], and the expected indent would be 4
such that the code would become:
if true { █ // CURSOR HERE }
This is also used to detect if a new line should be added, or whether the command should be returned for execution. Take the following example:
if true { █ // <------------- PRESSED ENTER HERE
The indentation here would be 4 since its the start of the new block. So a new line will
be added instead of returning all the lines for processing.
if true { █ // CURSOR HERE