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v/vlib/cli/help.v

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