perspective_viewer/exprtk/
cursor.rs

1// ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
2// ┃ ██████ ██████ ██████       █      █      █      █      █ █▄  ▀███ █       ┃
3// ┃ ▄▄▄▄▄█ █▄▄▄▄▄ ▄▄▄▄▄█  ▀▀▀▀▀█▀▀▀▀▀ █ ▀▀▀▀▀█ ████████▌▐███ ███▄  ▀█ █ ▀▀▀▀▀ ┃
4// ┃ █▀▀▀▀▀ █▀▀▀▀▀ █▀██▀▀ ▄▄▄▄▄ █ ▄▄▄▄▄█ ▄▄▄▄▄█ ████████▌▐███ █████▄   █ ▄▄▄▄▄ ┃
5// ┃ █      ██████ █  ▀█▄       █ ██████      █      ███▌▐███ ███████▄ █       ┃
6// ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┫
7// ┃ Copyright (c) 2017, the Perspective Authors.                              ┃
8// ┃ ╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌ ┃
9// ┃ This file is part of the Perspective library, distributed under the terms ┃
10// ┃ of the [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0). ┃
11// ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
12
13use perspective_client::ExprValidationError;
14use yew::prelude::*;
15
16/// A tokenizer cursor for ExprTK parsing.
17///
18/// Because ExprTK reports errors in column/row coordinates and visually needs
19/// to be applied to an entire token rather than a single character, we need
20/// fairly obnoxious counter logic to figure out how to generate the resulting
21/// syntax-highlighted HTML. The `Counter<'a>` struct encpsulates this logic,
22/// generating a `NodeRef` to any autocomplete-able `<span>` tokens, as well
23/// as other convenient data for HTML rendering, and can be called incrementally
24/// while iterating tokens after parsing.
25pub struct Cursor<'a> {
26    row: u32,
27    col: u32,
28    index: u32,
29    pub err: &'a Option<ExprValidationError>,
30    pub txt: &'a str,
31    pub noderef: NodeRef,
32    pub auto: Option<String>,
33}
34
35impl<'a> Cursor<'a> {
36    pub fn new(err: &'a Option<ExprValidationError>) -> Self {
37        Self {
38            row: 1,
39            col: 0,
40            index: 0,
41            err,
42            txt: "",
43            auto: None,
44            noderef: NodeRef::default(),
45        }
46    }
47
48    /// Is the cursor currently overlapping a token with an error?
49    pub const fn is_error(&self) -> bool {
50        if let Some(err) = &self.err {
51            err.line + 1 == self.row
52                && err.column >= self.col
53                && err.column < (self.col + self.txt.len() as u32)
54        } else {
55            false
56        }
57    }
58
59    /// Is the cursor currently overlapping an  autocomplete-able token?
60    pub const fn is_autocomplete(&self, position: u32) -> bool {
61        position > self.index && position <= self.index + self.txt.len() as u32
62    }
63
64    /// TODO this is alot of type backage for what could just be `num_rows()`.
65    pub fn map_rows<T, F: Fn(u32) -> T>(self, f: F) -> impl Iterator<Item = T> {
66        (0..self.row).map(f)
67    }
68
69    /// Increment the counter column by `size` characters.
70    pub fn increment_column(&mut self, size: u32) {
71        self.col += size;
72        self.index += size;
73    }
74
75    /// Increment to the next line, typewriter-style.
76    pub fn increment_line(&mut self) {
77        self.row += 1;
78        self.col = 0;
79        self.index += 1;
80    }
81}
perspective_viewer/exprtk/cursor.rs

perspective_viewer/exprtk/
cursor.rs
