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302da1a3d3
Lots of new unit-tests increase code coverage. Lots of refactoring, cleanup and simlpification to reduce code size. Fixes for Bug 223564 and 245807 Updates to dirdeps.mk and meta2deps.py
42 lines
1.4 KiB
Makefile
42 lines
1.4 KiB
Makefile
# $NetBSD: hanoi-include.mk,v 1.1 2020/10/03 17:30:54 rillig Exp $
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#
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# Implements the Towers of Hanoi puzzle, thereby demonstrating a bunch of
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# useful programming techniques:
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#
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# * default assignment using the ?= assignment operator
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# * including the same file recursively
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# * extracting the current value of a variable using the .for loop
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# * using shell commands for calculations since make is a text processor
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# * using the :: dependency operator for adding commands to a target
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# * on-the-fly variable assignment expressions using the ::= modifier
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#
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# usage:
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# env N=3 make -f hanoi-include.mk
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# endless loop:
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# make -f hanoi-include.mk N=3
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N?= 5 # Move this number of disks ...
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FROM?= A # ... from this stack ...
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VIA?= B # ... via this stack ...
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TO?= C # ... to this stack.
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.if $N == 1
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. for from to in ${FROM} ${TO}
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all::
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@echo "Move the upper disk from stack ${from} to stack ${to}."
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. endfor
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.else
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_:= ${N::!=expr $N - 1} ${TMP::=${VIA}} ${VIA::=${TO}} ${TO::=${TMP}}
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. include "${.PARSEDIR}/${.PARSEFILE}"
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_:= ${N::!=expr $N + 1} ${TMP::=${VIA}} ${VIA::=${TO}} ${TO::=${TMP}}
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. for from to in ${FROM} ${TO}
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all::
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@echo "Move the upper disk from stack ${from} to stack ${to}."
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. endfor
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_:= ${N::!=expr $N - 1} ${TMP::=${VIA}} ${VIA::=${FROM}} ${FROM::=${TMP}}
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. include "${.PARSEDIR}/${.PARSEFILE}"
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_:= ${N::!=expr $N + 1} ${TMP::=${VIA}} ${VIA::=${FROM}} ${FROM::=${TMP}}
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.endif
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