Cleaned up type conversions, functions, removed return type restricti…

…ons, added `passmissing()` to handle `missing` values, reserving `catch()` for parsing failures.

src/Tidier.jl

@@ -15,9 +15,9 @@ using Reexport
 @reexport using ShiftedArrays: lag, lead
 
 export Tidier_set, across, desc, n, row_number, starts_with, ends_with, matches, if_else, case_when, ntile, 
-      @select, @transmute, @rename, @mutate, @summarize, @summarise, @filter, @group_by, @ungroup, @slice, 
-      @arrange, @distinct, @pull, @left_join, @right_join, @inner_join, @full_join, @pivot_wider, @pivot_longer, 
-      @bind_rows, @bind_cols, @clean_names, @count, @tally, @drop_na, @glimpse, as_float, as_integer, as_string
+      as_float, as_integer, as_string, @select, @transmute, @rename, @mutate, @summarize, @summarise, @filter,
+      @group_by, @ungroup, @slice, @arrange, @distinct, @pull, @left_join, @right_join, @inner_join, @full_join,
+      @pivot_wider, @pivot_longer, @bind_rows, @bind_cols, @clean_names, @count, @tally, @drop_na, @glimpse
 
 # Package global variables
 const code = Ref{Bool}(false) # output DataFrames.jl code?

src/docstrings.jl

@@ -1869,4 +1869,82 @@ Groups: a [100]
 .b             Int64          1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
 .c             String         a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, a,
 ```
+"""
+
+const docstring_as_float =
+"""
+    as_float(value)
+
+Convert a number or string to a Float64 data type.
+
+This is a useful helper for type conversions. Missing values are propagated.
+  
+# Arguments
+- `value`: An `AbstractString`, `Number`, or `missing` value.
+
+# Examples
+```jldoctest 
+julia> as_float(1)
+1.0
+
+julia> as_float("1.5")
+1.5
+
+julia> as_float(missing)
+missing
+```
+"""
+
+const docstring_as_integer =
+"""
+    as_integer(value)
+
+Convert a number or string to an Int64 data type.
+
+This is a useful helper for type conversions. Missing values are propagated. Any values after the decimal point are removed.
+  
+# Arguments
+- `value`: An `AbstractString`, `Number`, or `missing` value.
+
+# Examples
+```jldoctest 
+julia> as_integer(1)
+1
+
+julia> as_integer(1.5)
+1
+
+julia> as_integer("2")
+2
+
+julia> as_integer("2.5")
+2
+
+julia> as_integer(missing)
+missing
+```
+"""
+
+const docstring_as_string =
+"""
+    as_string(value)
+
+Convert a number or string to a String data type.
+
+This is a useful helper for type conversions. Missing values are propagated.
+  
+# Arguments
+- `value`: An `AbstractString`, `Number`, or `missing` value.
+
+# Examples
+```jldoctest 
+julia> as_string(1)
+"1"
+
+julia> as_string(1.5)
+"1.5"
+
+julia> as_string(missing)
+missing
+```
 """

src/type_conversions.jl

@@ -1,36 +1,47 @@
-
-function as_float(value)::Union{AbstractFloat, Missing}
+"""
+$docstring_as_float
+"""
+function as_float(value)
     try
-        convert(AbstractFloat, value)
+        passmissing(convert)(Float64, value)
     catch
-        missing
+        missing # if parsing failure
     end
 end
 
-function as_float(value::String)::Union{Float64, Missing}
+function as_float(value::AbstractString)
     try
-        parse(Float64, value)
+        passmissing(parse)(Float64, value)
     catch
-        missing
+        missing # if parsing failure
     end
 end
 
-function as_integer(value)::Union{Integer, Missing}
+"""
+$docstring_as_integer
+"""
+function as_integer(value)
     try
-        convert(Integer, value)
+        passmissing(floor)(value) |>      
+        x -> passmissing(convert)(Int64, x)
     catch
-        missing
+        missing # if parsing failure
     end
 end
 
-function as_integer(value::String)::Union{Int64, Missing}
+function as_integer(value::AbstractString)
     try
-        parse(Int64, value)
+        passmissing(parse)(Float64, value) |>
+        x -> passmissing(floor)(x) |>      
+        x -> passmissing(convert)(Int64, x)
     catch
-        missing
+        missing # if parsing failure
     end
 end
 
-function as_string(value)::String
-    string(value)
+"""
+$docstring_as_string
+"""
+function as_string(value)
+  passmissing(string)(value)
 end