Clarify what happens when variable isn't specified.

Closes #132

R/col_types.R

@@ -9,7 +9,8 @@
 #'   If a list, it must contain one "\code{\link{collector}}" for each column.
 #'   If you only want to read a subset of the columns, you can use a named list
 #'   (where the names give the column names). If a column is not mentioned by
-#'   name, it will not be included in the output.
+#'   name, it will be parsed with the default collector (as determined by
+#'   reading the first 100 rows).
 #'
 #'   Alternatively, you can use a compact string representation where each
 #'   character represents one column: c = character, d = double, i = integer,

man/col_types_standardise.Rd

@@ -16,7 +16,8 @@ col_types_standardise(col_types, col_names, guessed_types)
   If a list, it must contain one "\code{\link{collector}}" for each column.
   If you only want to read a subset of the columns, you can use a named list
   (where the names give the column names). If a column is not mentioned by
-  name, it will not be included in the output.
+  name, it will be parsed with the default collector (as determined by
+  reading the first 100 rows).
 
   Alternatively, you can use a compact string representation where each
   character represents one column: c = character, d = double, i = integer,

man/read_delim.Rd

@@ -67,7 +67,8 @@ a single quote, \code{\"}.}
   If a list, it must contain one "\code{\link{collector}}" for each column.
   If you only want to read a subset of the columns, you can use a named list
   (where the names give the column names). If a column is not mentioned by
-  name, it will not be included in the output.
+  name, it will be parsed with the default collector (as determined by
+  reading the first 100 rows).
 
   Alternatively, you can use a compact string representation where each
   character represents one column: c = character, d = double, i = integer,

man/read_fwf.Rd

@@ -41,7 +41,8 @@ use \code{fwf_positions}.}
   If a list, it must contain one "\code{\link{collector}}" for each column.
   If you only want to read a subset of the columns, you can use a named list
   (where the names give the column names). If a column is not mentioned by
-  name, it will not be included in the output.
+  name, it will be parsed with the default collector (as determined by
+  reading the first 100 rows).
 
   Alternatively, you can use a compact string representation where each
   character represents one column: c = character, d = double, i = integer,

man/read_log.Rd

@@ -39,7 +39,8 @@ read_log(file, col_names = FALSE, col_types = NULL, skip = 0,
   If a list, it must contain one "\code{\link{collector}}" for each column.
   If you only want to read a subset of the columns, you can use a named list
   (where the names give the column names). If a column is not mentioned by
-  name, it will not be included in the output.
+  name, it will be parsed with the default collector (as determined by
+  reading the first 100 rows).
 
   Alternatively, you can use a compact string representation where each
   character represents one column: c = character, d = double, i = integer,

man/read_table.Rd

@@ -39,7 +39,8 @@ read_table(file, col_names = TRUE, col_types = NULL, na = "NA",
   If a list, it must contain one "\code{\link{collector}}" for each column.
   If you only want to read a subset of the columns, you can use a named list
   (where the names give the column names). If a column is not mentioned by
-  name, it will not be included in the output.
+  name, it will be parsed with the default collector (as determined by
+  reading the first 100 rows).
 
   Alternatively, you can use a compact string representation where each
   character represents one column: c = character, d = double, i = integer,

man/type_convert.Rd

@@ -18,7 +18,8 @@ type_convert(df, col_types = NULL)
   If a list, it must contain one "\code{\link{collector}}" for each column.
   If you only want to read a subset of the columns, you can use a named list
   (where the names give the column names). If a column is not mentioned by
-  name, it will not be included in the output.
+  name, it will be parsed with the default collector (as determined by
+  reading the first 100 rows).
 
   Alternatively, you can use a compact string representation where each
   character represents one column: c = character, d = double, i = integer,