parser snippet expr_primary

parser.lua

-- Parse primary expression.
function expr_primary(ast, ls)
    local v, vk
    -- Parse prefix expression.
    if ls.token == '(' then
        local line = ls.linenumber
        ls:next()
        vk, v = 'expr', ast:expr_brackets(expr(ast, ls))
        lex_match(ls, ')', '(', line)
    elseif ls.token == 'TK_name' or (not LJ_52 and ls.token == 'TK_goto') then
        vk, v = 'var', var_lookup(ast, ls)
    else
        err_syntax(ls, "unexpected symbol")
    end
    while true do -- Parse multiple expression suffixes.
        local line = ls.linenumber
        if ls.token == '.' then
            vk, v = 'indexed', expr_field(ast, ls, v)
        elseif ls.token == '[' then
            local key = expr_bracket(ast, ls, true)
            vk, v = 'indexed', ast:expr_index(v, key)
        elseif ls.token == ':' then
            ls:next()
            local key = lex_str(ls)
            local args = parse_args(ast, ls)
            vk, v = 'call', ast:expr_method_call(v, key, args, line)
        elseif ls.token == '(' or ls.token == 'TK_string' or ls.token == '{' then
            local args = parse_args(ast, ls)
            vk, v = 'call', ast:expr_function_call(v, args, line)
        else
            break
        end
    end
    return v, vk
end