module cli import ( term strings ) const ( BASE_INDENT = 2 ABBREV_INDENT = 5 DESCRIPTION_INDENT = 20 ) fn help_flag() Flag { return Flag{ flag: .bool, name: 'help', abbrev: 'h', description: 'Prints help information', } } fn help_cmd() Command { return Command{ name: 'help', description: 'Prints help information', execute: help_func, parent: 0 } } fn help_func(help_cmd Command) { cmd := help_cmd.parent full_name := cmd.full_name() mut help := '' help += 'Usage: ${full_name}' if cmd.flags.len > 0 { help += ' [FLAGS]'} if cmd.commands.len > 0 { help += ' [COMMANDS]'} help += '\n\n' if cmd.description != '' { help += '${cmd.description}\n\n' } if cmd.flags.len > 0 { help += 'Flags:\n' for flag in cmd.flags { mut flag_name := '' if flag.abbrev != '' { abbrev_indent := ' '.repeat(max(ABBREV_INDENT-(flag.abbrev.len+1), 1)) flag_name = '-${flag.abbrev}${abbrev_indent}--${flag.name}' } else { abbrev_indent := ' '.repeat(max(ABBREV_INDENT-(flag.abbrev.len), 1)) flag_name = '${abbrev_indent}--${flag.name}' } mut required := '' if flag.required { required = ' (required)' } base_indent := ' '.repeat(BASE_INDENT) description_indent := ' '.repeat(max(DESCRIPTION_INDENT-flag_name.len, 1)) help += '${base_indent}${flag_name}${description_indent}' + pretty_description(flag.description + required) + '\n' } help += '\n' } if cmd.commands.len > 0 { help += 'Commands:\n' for command in cmd.commands { base_indent := ' '.repeat(BASE_INDENT) description_indent := ' '.repeat(max(DESCRIPTION_INDENT-command.name.len, 1)) help += '${base_indent}${command.name}${description_indent}' + pretty_description(command.description) + '\n' } help += '\n' } print(help) } // pretty_description resizes description text depending on terminal width. // Essentially, smart wrap-around fn pretty_description(s string) string { width, _ := term.get_terminal_size() // Don't prettify if the terminal is that small, it won't be pretty anyway. if s.len + DESCRIPTION_INDENT < width || DESCRIPTION_INDENT > width { return s } indent := ' '.repeat(DESCRIPTION_INDENT + 1) chars_per_line := width - DESCRIPTION_INDENT // Give us enough room, better a little bigger than smaller mut acc := strings.new_builder(((s.len / chars_per_line) + 1) * (width + 1)) mut i := chars_per_line - 1 mut j := 0 for ; i < s.len ; i += chars_per_line - 1 { for s.str[i] != ` ` { i-- } // indent was already done the first iteration if j != 0 { acc.write(indent) } acc.writeln(s[j..i]) j = i } // We need this even though it should never happen if j != 0 { acc.write(indent) } acc.write(s[j..]) return acc.str() } fn max(a, b int) int { return if a > b {a} else {b} }