Add \c support

Author: coke

solutions/rakudo/Configurable-REPL.md

@@ -16,22 +16,39 @@ Each which supports the following interpolations:
 | Sequence | Prompt Expansion |
 |--|--|
 | `\a` | alert / bell character |
+| `\c` | color - see below for options |
 | `\e` | escape character |
 | `\i` | index - the current iteration of the REPL, which can be referred to later as, e.g. `$*1` |
 | `\l` | `$*RAKU.version` |
 | `\L` | `$*RAKU.gist` |
 | `\n` | newline |
-| `\t` | time - see below for more options |
+| `\t` | time - see below for options |
 | `\v` | `$*RAKU.compiler.version` |
 | `\V` | `$*RAKU.gist` |
 
-The escape character allows us to generate ANSI colors, e.g.
+## \c formatting
+
+Provide some common ANSI codes with short names. Defaults to `reset` if a bare `\c` is used,
+and multiple arguments can be separated with a `;`, e.g.
 
 ```
-RAKUDO_REPL_PROMPT='[\e[0;31m\i\e[0m] >'
+\c{bold;red}
 ```
 
-Would generate a prompt similar to the default except the index would appear in red.
+### formatting
+
+> reset, normal, bold, dim, italic, underline, blink, inverse, hiddne, strikethrough
+
+### foreground colors
+
+> black, red, green, yellow, blue, magenta, cyan, white, default
+
+### background colors
+
+> bg:black, bg:red, bg:green, bg:yellow, bg:blue, bg:magenta, bg:cyan, bg:white, bg:default
+
+Not all escape sequences have aliases - you can always use 
+`\e`  to manually generate codes.
 
 ## \t formatting
 
@@ -55,7 +72,6 @@ Would generate a prompt containing, e.g. `06:18 > `
 
 # Future Development
 
-* Support for colors directly - needs a list of ANSI codes/colors in core.
 * More strftime support - perhaps even invoking it directly instead of manually mapping.
 * Support `RAKUDO_REPL_COMMAND` to support arbitrary code invocation