docs(src): Improve the text regarding the allowed chars in an argument

The previous text seemed to suggest, that you could only use the special
chars if the argument was actually quoted, which was misleading.

src/lib.rs

@@ -37,13 +37,15 @@
 //! $$ \Sigma_{cmd} = \\{x | 0 \leqslant x \leqslant 9\\} \cup \\{x | "a" \leqslant x \leqslant "z"\\} \cup \\{x | "A" \leqslant x \leqslant "Z"\\} \cup \\{"\\_", "\text{-}", "."\\} $$
 //!
 //! ## Argument
-//! Arguments are similar to the command, although they can also contain spaces and quotes,
+//! Arguments constructed from the same alphabet as the commands, but can contain additional chars
-//! if it's quoted and additional characters (here notated as "$\\dots{}$"):
+//! listed in the [trinitry.pest](../../../src/trinitry.pest) file.
-//! $$ \Sigma_{args-quoted} = \Sigma_{cmd} \cup \\{"\\text{"}", "\\ ", \\dots{}\\} $$
+//! $$ \Sigma_{args} = \Sigma_{cmd} \cup{} \\{\\dots{}\\} $$
-//! $$ \Sigma_{args-single-quoted} = \Sigma_{cmd} \cup \\{"'", "\\ ", \\dots{}\\} $$
+//!
-//! $$ \Sigma_{args} = \Sigma_{cmd} \cup \\{\\dots{}\\} $$
+//! Besides the extra chars outlined above the arguments can also contain
-//! Look at the [trinitry.pest](../../../src/trinitry.pest) file for a full list of the additional
+//! spaces and quotes, if they are quoted. Quoted args are either double quoted, and can thus
-//! allowed characters.
+//! contain single quotes, or single quoted, and can contain double quotes.
+//! $$ \Sigma_{args-double-quoted} = \Sigma_{args} \cup \\{"\\text{\\texttt{'}}", "\\ "} $$
+//! $$ \Sigma_{args-single-quoted} = \Sigma_{args} \cup \\{"\\text{\\texttt{"}}", "\\ "} $$
 //!
 //! # Examples
 //! ## Command
@@ -61,7 +63,7 @@
 //! ```text
 //! lua "function() print('Hi!') end"
 //! ```
-//! Whilst this would not be valid (that is, it would very likely not be what you want):
+//! Whilst this would not be valid (it is actually valid, but results in something, you likely did not expect):
 //! ```text
 //! lua "function() print("Hi!") end"
 //! ```

src/trinitry.pest

@@ -18,12 +18,32 @@
 // and the Lesser GNU General Public License along with this program.
 // If not, see <https://www.gnu.org/licenses/>.
 
-chars = { ASCII_ALPHANUMERIC | "_" | "-" | "."  }
+command_chars = { ASCII_ALPHANUMERIC | "_" | "-" | "."  }
 
-// TODO(@soispha): Are these all the valid characters? <2023-11-01>
+argument_chars = {
-argument_chars = { chars | "(" | ")" | "{" | "}" | "<" | ">" | "?" | "!" | "+" | "^" | "@"
+            command_chars |
-| "&" | "*" | "~" | "|" | "=" | "," | "\\" | "/" }
+            "("   |
-whitespace = _{ " " } // lower case to avoid special treatment of 'WHITESPACE'
+            ")"   |
+            "{"   |
+            "}"   |
+            "<"   |
+            ">"   |
+            "?"   |
+            "!"   |
+            "+"   |
+            "^"   |
+            "@"   |
+            "&"   |
+            "*"   |
+            "~"   |
+            "|"   |
+            "="   |
+            ","   |
+            "\\"  |
+            "/"
+}
+
+whitespace = _{ " " } // lower case to avoid the special treatment of `WHITESPACE`
 
 quote = _{ "\"" }
 q = _{ quote }
@@ -33,7 +53,7 @@ sq = _{ single_quote }
 
 
 
-command = { chars+ }
+command = { command_chars+ }
 
 arg_quoted = { q ~ (!q ~ (argument_chars | " " | "'" ))+ ~ q }
 arg_single_quoted = { sq ~ (!sq ~ (argument_chars | " " | "\"" ))+ ~ sq }
@@ -43,3 +63,6 @@ argument = { whitespace+ ~ (arg_quoted | arg_single_quoted | arg )}
 
 
 trinitry = { SOI ~ #command = command ~ (#argument = argument)* ~ EOI }
+
+// better than no syntax highlight:
+// vim: ft=javascript