Range extraction: Difference between revisions

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« 1 SF "" <span style="color:grey">@ initialize output string</span>

'''WHILE''' OVER SIZE '''REPEAT''' <span style="color:grey">@ while input list is not empty</span>

'''IF''' 1 FC?C '''THEN''' "," + '''END''' <span style="color:grey">@ do not append comma at first iteration</span>

'''IFERR''' OVER ΔLIST '''THEN END''' <span style="color:grey">@ if at least 2 items in input list</span>

'''IF''' DUP 1 2 SUB { 1 1 } == '''THEN''' <span style="color:grey">@ if 3 consecutive items </span>

ROT ROT OVER HEAD + "-" + <span style="color:grey">@ append range start to result string</span>

ROT 1 « 1 ≠ » DOLIST 1 POS <span style="color:grey">@ get rank of last consecutive number</span>

'''IF''' DUP NOT '''THEN''' DROP OVER SIZE '''END'''

ROT DUP2 SWAP 1 + OVER SIZE SUB <span style="color:grey">@ remove processed items from input list</span>

4 ROLLD SWAP GET + <span style="color:grey">@ append range end to result </span>

'''ELSE''' <span style="color:grey">@ else</span>

DROP OVER HEAD + SWAP TAIL SWAP <span style="color:grey">@ append first item and remove it from input </span>

'''END'''

'''END'''

SWAP DROP

» '<span style="color:blue">→RNG</span>' STO

{ -6, -3, -2, -1, 0, 1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20 } <span style="color:blue">→RNG</span>

{{out}}

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1: "-6,-3-1,3-5,7-11,14,15,17-20"