Conditions

[no-vici]

Thank you for your hard work and a great plugin that saves people lot of typing time.

I've been messing about with ConTeXt, and I can't use the features that VimTeX offers like in_math(), in_text() etc. However, I have tried to replicate some of those features with a few Lua functions. I have a feeling that my is_inside_env(name) is still not quite right and missing something.

If anyone has the experience of how VimTeX handles its in_inside function, please share yours with me.

-- This module contains functions to check if the cursor is in a particular environment
local M = {}

-- Get the current line number and column
local function get_cursor_pos()
    local cursor = vim.api.nvim_win_get_cursor(0)
    return tonumber(cursor[1]), tonumber(cursor[2])
end

-- Function to check if a pattern exists in a given location
local function contains_pattern(location, pattern)
    return location:find(pattern) ~= nil
end

-- Check if the current line is inside an inline math environment
function M.in_inline_math()
    local current_row, current_col = get_cursor_pos()
    local line = vim.api.nvim_buf_get_lines(0, current_row - 1, current_row, false)[1]

    local before_found = contains_pattern(line:sub(1, current_col), "$")
    local after_found = contains_pattern(line:sub(current_col + 1), "$")

    return before_found and after_found
end

-- Function to check for patterns in a given location
local function contains_patterns(location, patterns)
    for _, pattern in ipairs(patterns) do
        if contains_pattern(location, pattern) then
            return true
        end
    end
    return false
end

-- Check for math start and stop patterns above or below the current line
local function check_math_patterns(direction, start_patterns, stop_patterns)
    local math_mode = false
    local current_row = get_cursor_pos()

    local line_num = current_row
    -- -1 or 1 depending on the direction
    local increment = (direction == "above" or direction == "before") and -1 or 1

    while line_num > 0 and line_num <= vim.api.nvim_buf_line_count(0) do
        local line = vim.api.nvim_buf_get_lines(0, line_num - 1, line_num, false)[1]
        if line:len() > 0 then
            local start_found = contains_patterns(line, start_patterns)
            local stop_found = contains_patterns(line, stop_patterns)
            if start_found and not stop_found then
                math_mode = true
                break
            elseif stop_found and not start_found then
                math_mode = false
                break
            end
        end
        line_num = line_num + increment
    end

    return math_mode
end

-- Check if the current line is inside an environment within the range of 40 lines.
-- Checking the whole buffer is not very efficient.
local function is_inside_env(name)
    local current_row = get_cursor_pos()
    local lines = vim.api.nvim_buf_get_lines(0, math.max(current_row - 20, 0), math.min(current_row + 20, -1), false)

    local start_tag = "\\start" .. name
    local stop_tag = "\\stop" .. name

    local inside = false
    for _, line in ipairs(lines) do
        if line:find(start_tag) then
            inside = true
        end
        if line:find(stop_tag) then
            inside = false
        end
    end

    return inside
end

-- Check if the cursor is inside a math zone
function M.in_math()
    return check_math_patterns("above", {"\\startformula"}, {"\\stopformula"}) or check_math_patterns("below", {"\\startformula"}, {"\\stopformula"})
end

-- Check if the cursor is inside a text zone
function M.in_text()
    return is_inside_env("text") and not M.in_math()
end

-- Check if the cursor is inside tikzpicture
function M.in_tikz()
    return is_inside_env("tikzpicture")
end

-- Check if the cursor is inside an itemize or enumerate
function M.in_bullets()
    return is_inside_env("itemize") or is_inside_env("enumerate")
end

-- Check if the cursor is inside MPcode
function M.in_MPcode()
    return is_inside_env("MPcode")
end

return M