Static Pattern Rules and Filter -- Errors and naive fix

[a1exlism]

Issue: part Static Pattern Rules and Filter example not works well, refer to issue 40.

Refer issue 40 and the issue was fixed by commmit b7e9438.

However, the code was reversed after the new design commitment.
May the code change to this below due to 54?

obj_files = foo.result bar.o lose.o
src_files = foo.raw bar.c lose.c

all: $(obj_files)

$(filter %.o,$(obj_files)): %.o: %.c
	cc -c $< -o $@
	echo "target: $@ prereq: $<"
$(filter %.result,$(obj_files)): %.result: %.raw
	cc -c $< -o $@
	echo "target: $@ prereq: $<" 

$(src_files):
	touch $@

clean:
	rm -f $(src_files) $(obj_files)

But unfortunately, the implicit rule failed to work in this example, and no X.result file is generated.

[theicfire]

Thanks! Yeah it looks like I need the .PHONY: all in this example. Fixed here: e7a44a1

I don't need to explicitly run the cc commands like you've shown, because I don't even need output in this example.