This is my attempt to document just what makes up "The IrcII Language" and
how epic uses the ircII language.  This could be used as a starting point
to replace ircII with something else.

The ircII language is a collection of:
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* A block parser that runs a string of "ircII statements"
* A statement tokenizer (identify statements in a block)
* A string macro-expander (including function-calling) and dequoter.
* A collection of user created ircII statements
 	(strings that are blocks, and can be used as commands or functions)
* A collection of user created ircII variables: strings that are macros.
* An expression parser that performs mathematical operations.
* A collection of built-in commands that can be used in ircII statements.
* A collection of built-in functions that can be used in irciI expandos.
* A stack of local variables which are constrained to an "atomic scope"

These are the atomic scopes of the ircII language
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* /DEFER runs a string (provided as an argument)
* /LOAD -PF runs a string (provided in a file)
* /EXEC runs a string (provided as argument to -ERROR, END, etc)
* /EXEC runs a string (provided as argument to WAIT %proc -CMD)
* Statemenet parser runs a string (aliases)
* call_function() runs a string (provided as argument to ALIAS)
* do_hook() runs a string (provided as argument to ON)
* key_exec() runs a string (user-created keybindings)
* /QUEUE -RUN runs a string (provided as an argument to QUEUE)
* /WAIT -CMD runs a command (provided as argument)
* /TIMER expiration runs a command (provided as argument to /TIMER)
* /SET runs a string (provided as argument to /ADDSET)
* /WHO callback runs a string (provided as argument to -LINE, -END, etc)
* /ISON callback runs a string (provided as argument to -ON, etc)
* /USERHOST callback runs a string (provided as argument to -CMD)

These run ircII code asynchronously, but not in an atomic scope
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* The SEND_LINE keybinding runs the input line as a statement
* /LOAD -STD runs statements (provided in a file)
* /SENDLINE runs a string as a statement (provided as argument)
* Sending message to "/CMD" runs the command + text as a statement
* Dumb mode input runs each line of input as statement (from stdin)
* Expression parser runs a string (the {} operator) (hides function_return)

These run ircII code, but expressly in an existing atomic scope
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* /EVAL and /XEVAL runs a string (provided as argument)
* /REDIRECT runs a string (provided as argument)
* /WAIT FOR runs a string (provided as argument)
* /INPUT runs a string (provided as an argument)
* /IF, /DO, /WHILE, /FOREACH run a string (provided as an argument)
* /FE, /FOR .. NEXT, /FOR .. IN, /FOR (,,) run a string (argument)
* /SWITCH, /REPEAT run a string (provided as argument)
* The PARSE_COMMAND keybinding runs a string (provided as argument)
* Perl, Ruby, and TCL can all call-back to ircII blocks

These call ircII expressions
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* Statements starting with @ or surrounded by () are expressions.
* The ${...} expando is an expression
* /IF, /DO, /WHILE, /FOR, /REPEAT all take expressions
* Perl, Ruby, and TCL can all call-back to ircII expressions

These call ircII functions directly
-----------------------------------
* Expression parser calls functions
* do_hook() calls the $cparse() function for implied hooks
* Perl, Ruby, and TCL can all call-back to ircII functions.
* /POP, /PUSH, /SHIFT, and /UNSHIFT call functions directly
* $tow(), $afterw() $fromw(), and $beforew() calls $findw() directly
* $uniq() calls $findw() directly

These try to expand $'s or dequote \'s in strings
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* Default values for arglists are expanded
* Each statement is expanded before the command is parsed
* Assignment operators in the expression parser expand the lval.
* The [] operator in expression parser are expanded.
* The operand of the ++ or -- operator is expanded
* For $[...]var, the ... value is expanded. 
* For $(...), the ... value is expanded
* The argument list to a function call is expanded.
* The first argument to $cparse() is expanded if it's double quoted.
* The wildcard pattern in flexible hooks is expanded
* The /FE command expands the word list
* The /FOR var IN (list) command expands the word list
* The /SWITCH command expands the wildcard patterns
* The input prompt is expanded
* The insides of []s in variable names are expanded.
* Stuff written to logfiles is expanded via /SET LOG_REWRITE
* /SET BANNER is expanded if /SET BANNER_EXPAND is on
* The /QUEUE command sometimes expands the commands it runs
* Stuff displayed to windows is expanded via /SET OUTPUT_REWRITE
* The status bar is expanded if /SET STATUS_DOES_EXPANDOS is on
* The %{3}F (status_activity) value is expanded

These places try to extract an lval (variable name) from a string
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* /ASSIGN ...
* /STUB ASSIGN ...
* /LOCAL ...
* The operand after the # or @ operator in the old math parser.
* The operand tokenizer in the math parser
* $unshift(...) and $push(...)