generate largest-series-product tests

exercises/practice/largest-series-product/test.fut

@@ -1,66 +1,76 @@
 import "largest_series_product"
 
--- Finds the largest product if span equals length
+-- finds the largest product if span equals length
 -- ==
 -- input { "29" 2 }
 -- output { 18 }
 
--- Can find the largest product of 2 with numbers in order
+-- can find the largest product of 2 with numbers in order
 -- ==
 -- input { "0123456789" 2 }
 -- output { 72 }
 
--- Can find the largest product of 2
+-- can find the largest product of 2
 -- ==
 -- input { "576802143" 2 }
 -- output { 48 }
 
--- Can find the largest product of 3 with numbers in order
+-- can find the largest product of 3 with numbers in order
 -- ==
 -- input { "0123456789" 3 }
 -- output { 504 }
 
--- Can find the largest product of 3
+-- can find the largest product of 3
 -- ==
 -- input { "1027839564" 3 }
 -- output { 270 }
 
--- Can find the largest product of 5 with numbers in order
+-- can find the largest product of 5 with numbers in order
 -- ==
 -- input { "0123456789" 5 }
 -- output { 15120 }
 
--- Can get the largest product of a big number
+-- can get the largest product of a big number
 -- ==
 -- input { "73167176531330624919225119674426574742355349194934" 6 }
 -- output { 23520 }
 
--- Reports zero if the only digits are zero
+-- reports zero if the only digits are zero
 -- ==
 -- input { "0000" 2 }
 -- output { 0 }
 
--- Reports zero if all spans include zero
+-- reports zero if all spans include zero
 -- ==
 -- input { "99099" 3 }
 -- output { 0 }
 
--- Rejects span longer than string length
+-- rejects span longer than string length
 -- ==
 -- input { "123" 4 }
 -- error: Error*
 
--- Rejects empty string and nonzero span
+-- reports 1 for empty string and empty product (0 span)
+-- ==
+-- input { "" 0 }
+-- output { 1 }
+
+-- reports 1 for nonempty string and empty product (0 span)
+-- ==
+-- input { "123" 0 }
+-- output { 1 }
+
+-- rejects empty string and nonzero span
 -- ==
 -- input { "" 1 }
 -- error: Error*
 
--- Rejects invalid character in digits
+-- rejects invalid character in digits
 -- ==
 -- input { "1234a5" 2 }
 -- error: Error*
 
--- Rejects negative span
+-- rejects negative span
 -- ==
 -- input { "12345" -1 }
 -- error: Error*

generators/exercises/largest_series_product.py

@@ -0,0 +1,15 @@
+def gen_test_case(prop, description, inp, expected, f):
+    digits = inp["digits"]
+    span = inp["span"]
+    f.write(f"-- {description}\n")
+    f.write("-- ==\n")
+    f.write(f'-- input {{ "{digits}" {span} }}\n')
+    if isinstance(expected, dict):
+        f.write("-- error: Error*\n\n")
+    else:
+        f.write(f"-- output {{ {expected} }}\n\n")
+
+
+def gen_main(f):
+    f.write("let main (digits: []u8) (span: i32) : i32 =\n")
+    f.write("  largest_product digits span\n")