vt.md
In cli: Helpers for Developing Command Line Interfaces

empty input

Code
  vt_output("", width = 20, height = 2)$segment
Output
  [1] "                    " "                    "

raw input

Code
  vt_output(charToRaw("foobar"), width = 20, height = 2)$segment
Output
  [1] "foobar              " "                    "

overflow

Code
  vt_output(strrep("1234567890", 2), width = 19, height = 2)$segment
Output
  [1] "1234567890123456789" "0                  "

control characters

Code
  vt_output("foo\nbar", width = 20, height = 2)$segment
Output
  [1] "foo                 " "bar                 "

Code
  vt_output("foobar\rbaz", width = 20, height = 2)$segment
Output
  [1] "bazbar              " "                    "

scroll up

Code
  vt_output(strrep("1234567890", 5), width = 20, height = 2)$segment
Output
  [1] "12345678901234567890" "1234567890          "

Code
  vt_output(paste0(1:10, "\n"), width = 10, height = 5)$segment
Output
  [1] "7         " "8         " "9         " "10        " "          "

ANSI SGR [ansi]

Code
  vt_output("12\033[31m34\033[1m56\033[39m78\033[21m90", width = 20, height = 2)
Output
    lineno segmentno              segment  bold italic underline strikethrough
  1      1         1                   12 FALSE  FALSE     FALSE         FALSE
  2      1         1                   34 FALSE  FALSE     FALSE         FALSE
  3      1         1                   56  TRUE  FALSE     FALSE         FALSE
  4      1         1                   78  TRUE  FALSE     FALSE         FALSE
  5      1         1         90           FALSE  FALSE     FALSE         FALSE
  6      2         1                      FALSE  FALSE     FALSE         FALSE
    blink inverse color background_color link link_params
  1 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  2 FALSE   FALSE     1             <NA> <NA>        <NA>
  3 FALSE   FALSE     1             <NA> <NA>        <NA>
  4 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  5 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  6 FALSE   FALSE  <NA>             <NA> <NA>        <NA>

Code
  vt_output(style_bold("I'm bold"), width = 20, height = 2)
Output
    lineno segmentno              segment  bold italic underline strikethrough
  1      1         1             I'm bold  TRUE  FALSE     FALSE         FALSE
  2      1         1                      FALSE  FALSE     FALSE         FALSE
  3      2         1                      FALSE  FALSE     FALSE         FALSE
    blink inverse color background_color link link_params
  1 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  2 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  3 FALSE   FALSE  <NA>             <NA> <NA>        <NA>

Code
  vt_output(style_italic("I'm italic"), width = 20, height = 2)
Output
    lineno segmentno              segment  bold italic underline strikethrough
  1      1         1           I'm italic FALSE   TRUE     FALSE         FALSE
  2      1         1                      FALSE  FALSE     FALSE         FALSE
  3      2         1                      FALSE  FALSE     FALSE         FALSE
    blink inverse color background_color link link_params
  1 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  2 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  3 FALSE   FALSE  <NA>             <NA> <NA>        <NA>

Code
  vt_output(style_underline("I'm underlined"), width = 20, height = 2)
Output
    lineno segmentno              segment  bold italic underline strikethrough
  1      1         1       I'm underlined FALSE  FALSE      TRUE         FALSE
  2      1         1                      FALSE  FALSE     FALSE         FALSE
  3      2         1                      FALSE  FALSE     FALSE         FALSE
    blink inverse color background_color link link_params
  1 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  2 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  3 FALSE   FALSE  <NA>             <NA> <NA>        <NA>

Code
  vt_output(style_strikethrough("I'm strikethrough"), width = 20, height = 2)
Output
    lineno segmentno              segment  bold italic underline strikethrough
  1      1         1    I'm strikethrough FALSE  FALSE     FALSE          TRUE
  2      1         1                      FALSE  FALSE     FALSE         FALSE
  3      2         1                      FALSE  FALSE     FALSE         FALSE
    blink inverse color background_color link link_params
  1 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  2 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  3 FALSE   FALSE  <NA>             <NA> <NA>        <NA>

Code
  vt_output(style_inverse("I'm inverse"), width = 20, height = 2)
Output
    lineno segmentno              segment  bold italic underline strikethrough
  1      1         1          I'm inverse FALSE  FALSE     FALSE         FALSE
  2      1         1                      FALSE  FALSE     FALSE         FALSE
  3      2         1                      FALSE  FALSE     FALSE         FALSE
    blink inverse color background_color link link_params
  1 FALSE    TRUE  <NA>             <NA> <NA>        <NA>
  2 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  3 FALSE   FALSE  <NA>             <NA> <NA>        <NA>

hyperlinks

Code
  link <- style_hyperlink("text", "url")
  vt_output(c("pre ", st_from_bel(link), " post"), width = 20, height = 2)
Output
    lineno segmentno              segment  bold italic underline strikethrough
  1      1         1                 pre  FALSE  FALSE     FALSE         FALSE
  2      1         1                 text FALSE  FALSE     FALSE         FALSE
  3      1         1          post        FALSE  FALSE     FALSE         FALSE
  4      2         1                      FALSE  FALSE     FALSE         FALSE
    blink inverse color background_color link link_params
  1 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  2 FALSE   FALSE  <NA>             <NA>  url            
  3 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  4 FALSE   FALSE  <NA>             <NA> <NA>        <NA>

Code
  link <- style_hyperlink("text", "url", params = c(f = "x", g = "y"))
  vt_output(c("pre ", st_from_bel(link), " post"), width = 20, height = 2)
Output
    lineno segmentno              segment  bold italic underline strikethrough
  1      1         1                 pre  FALSE  FALSE     FALSE         FALSE
  2      1         1                 text FALSE  FALSE     FALSE         FALSE
  3      1         1          post        FALSE  FALSE     FALSE         FALSE
  4      2         1                      FALSE  FALSE     FALSE         FALSE
    blink inverse color background_color link link_params
  1 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  2 FALSE   FALSE  <NA>             <NA>  url f = x:g = y
  3 FALSE   FALSE  <NA>             <NA> <NA>        <NA>
  4 FALSE   FALSE  <NA>             <NA> <NA>        <NA>

erase in line

Code
  vt_output("foobar\033[3D\033[K", width = 10, height = 2)$segment
Output
  [1] "foo       " "          "
Code
  vt_output("foobar\033[3D\033[0K", width = 10, height = 2)$segment
Output
  [1] "foo       " "          "
Code
  vt_output("foobar\033[3D\033[1K", width = 10, height = 2)$segment
Output
  [1] "    ar    " "          "
Code
  vt_output("foobar\033[3D\033[2K", width = 10, height = 2)$segment
Output
  [1] "          " "          "

erase in screen

Code
  vt_output("foo\nfoobar\nfoobar2\033[A\033[4D\033[J", width = 10, height = 4)$
    segment
Output
  [1] "foo       " "foo       " "          " "          "
Code
  vt_output("foo\nfoobar\nfoobar2\033[A\033[4D\033[0J", width = 10, height = 4)$
    segment
Output
  [1] "foo       " "foo       " "          " "          "
Code
  vt_output("foo\nfoobar\nfoobar2\033[A\033[4D\033[1J", width = 10, height = 4)$
    segment
Output
  [1] "          " "    ar    " "foobar2   " "          "
Code
  vt_output("foo\nfoobar\nfoobar2\033[A\033[4D\033[2Jx", width = 10, height = 4)$
    segment
Output
  [1] "          " "   x      " "          " "          "
Code
  vt_output("foo\nfoobar\nfoobar2\033[A\033[4D\033[3Jx", width = 10, height = 4)$
    segment
Output
  [1] "          " "   x      " "          " "          "