4d: Parsing (Tracing)

+last

Further trace.

Compares two line-column pairs, .zyc and .naz, producing whichever is further along.

Accepts

.zyc is a $hair.

.naz is a $hair.

Produces

A $hair.

Source

++  last  |=  [zyc=hair naz=hair]
          ^-  hair
          ?:  =(p.zyc p.naz)
            ?:((gth q.zyc q.naz) zyc naz)
          ?:((gth p.zyc p.naz) zyc naz)

Examples

> (last [1 1] [1 2])
[p=1 q=2]

> (last [2 1] [1 2])
[p=2 q=1]

> (last [0 0] [99 0])
[p=99 q=0]

> (last [7 7] [7 7])
[p=7 q=7]

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+lust

Detect newline.

Advances .naz by a row if the .weq is a newline, or by a column if .weq is any other character.

Accepts

.weq is a +char.

.naz is a $hair.

Produces

A $hair.

Source

++  lust  |=  [weq=char naz=hair]
          ^-  hair
          ?:(=(`@`10 weq) [+(p.naz) 1] [p.naz +(q.naz)])

Examples

> (lust 'a' [1 1])
[p=1 q=2]

> (lust `@t`10 [1 1])
[p=2 q=1]

> (lust '9' [10 10])
[p=10 q=11]

> (roll "maze" [.(+<+ [1 1])]:lust)
[1 5]

> %-  roll  :_  [.(+<+ [1 1])]:lust
  """
  Sam
  lokes
  """
[2 6]

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