ThreadMergeSort port to Mehua lang

ThreadMergeSort.hua

//original c version at https://github.com/keybraker/Dynamic-Merge-Sort-with-posix-threads/blob/master/merge_sort.c
//ThreadMergeSort.hua
//A syntax sample

import{
	stdio, stdlib, time, assert, pthread
	sys.time
}

struct Argment(int[][] A; int n, m, key)

double duration(timeval start){
	timeval end
	gettimeofday(end, NULL)? ==0? throw Exception
	m = (end.tv_usec-start.tv_usec)/1e6
	return  m+ end.tv_sec - start.tv_sec
}
print(int n, int m, int[][] A, cstring name){
	printf("%s\n", name)
	@n: i? {
		printf("|\t")
		@m: j? printf("%d\t|\t", A[i][j])
		printf("\n")
	}
}

merge(int[] A, L, R; int n, m, key, leftCount, rightCount){
	i=j=k=0
	
	@i<leftCount && j>rightCount?{
		L[i][key] <R[j][key] ?{
			@m: l? A[k][l] = L[i][l]
			i++
		}: {
			@m: l? A[k][l] = R[k][l]
			j++
		}
		k++
	}
	
	@i<leftcount? {
		@m: l? A[k][l] = L[i][l]
		k++; i++
	}
	@j<leftcount? {
		@m: l? A[k][l] = L[j][l]
		k++; j++
	}
}

mergeSort(Argument){
	(A, n, m, key) = argument
	n <2? return NULL
	mid, nmid = n/2, n-mid
	
	int[m][mid] L
	int[m][nmid] R
	
	@mid: i? @m: j? L[i][j] = A[i][j]
	@mid...n: i? @m: j? R[i-mid][j] = A[i][j]
	
	a= Argument(L, mid, m, key)
	b = Argument(R, nmid, m, key)
	
	pthread_t ta, tb
	pthread_create(ta, NULL, mergeSort, a) !=0? return NULL
	pthread_create(tb, NULL, mergeSort, b) !=0? return NULL
	
	pthread_join(ta, NULL) !=0? return NULL
	pthread_join(tb, NULL) !=0? return NULL
	
	merge(A, L, R, n, m, key, mid, nmid)
	
	return NULL
}

main(){
	timeval start
	n = 100 //rows
	m = 5	//columns
	key = 0 //column based on which sorting will happend?
	srand(time(NULL))
	
	gettimeofday(start, NULL) !=0? throw Exception
	
	int[m][n] A
	@n:i? @m: j? A[i][j] = rand() % 100 +1
	
	print(n, m, A, "Before")
	
	mergeSort(Argument(A, n, m, key))
	
	print(n, m, a, "After")
	
	printf("Elapsed time: %f sec\n", duration(start)*1000/1000)
}