Input range -> take -> filter -> chain: Take gets applied *after* filter

[dlangBugzillaToGithub]

qigezx+dc40d6nao940k reported this on 2024-09-20T13:14:28Z

Transfered from https://issues.dlang.org/show_bug.cgi?id=24775

Description

InputRange.take(n).filter.chain logically transforms it into InputRange.filter.take(n-1).chain and thus takes the wrong number of elements

Example:
----
import std.stdio;
import std.algorithm;
import std.range;

auto inputRangeFactory(){
	int i = 0;
	int gen(){
		return i++;
	}
	return generate!gen();
}

void main(){

	// [10, 11, 12, 13, 14, 15, 16, 17, 18, 100]
	inputRangeFactory.take(10).filter!"a>8".chain(only(100)).writeln;
	
	// Unless filter would discard all taken elements
	// [100]
	inputRangeFactory.take(10).filter!"a>9".chain(only(100)).writeln;
	
	// Adding "array" somewhere in the middle fixes it
	// [9,100]
	inputRangeFactory.take(10).array.filter!"a>8".chain(only(100)).writeln;
	inputRangeFactory.take(10).filter!"a>8".array.chain(only(100)).writeln;
}
------

$ dmd --version
DMD64 D Compiler v2.109.1

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