diff options
Diffstat (limited to 'dice-lang/lang-process.md')
| -rw-r--r-- | dice-lang/lang-process.md | 65 |
1 files changed, 0 insertions, 65 deletions
diff --git a/dice-lang/lang-process.md b/dice-lang/lang-process.md deleted file mode 100644 index 1175fca..0000000 --- a/dice-lang/lang-process.md +++ /dev/null @@ -1,65 +0,0 @@ -# Top level reader loop -First, a command is read in from the user under a prompt - -Next, it is checked if the first token of the command (split on " ") -corresponds to an action name -* If it does, the corresponding action is executed, and the next command is - read -* If it doesn't, the command is parsed as a language command and executed - -This continues until the command "quit" (non case-sensitive) is read - -# Known actions -The currently implemented actions are: -* env: print out the contents of the enviroment. Takes no arguments -* inline: inline variables out of the definition of specified variables. Takes - at least two arguments - * The first is the name of the variable to do inlining in - * The second is the name of the variable to bind the inlined expression to - * The third and following are the names of the variables to inline in the - variable you are inlining. If you don't give any, it will inline every - variable - -## Details on inlining -The way the inlining process works is simple. The tree for the variable to be -inlined is read, and then each variable reference is inlined if it is marked as -one of the variable references to inline. This only occurs one layer deep - -# Parsing language commands -Once it is decided to parse a command as a language command, it goes through -four steps: -* Preparation -* AST Building -* AST Transformation -* AST Evaluation - -# Command preparation -Command preparation means turning the raw space-seperated tokens into tokens -suitable for feeding the AST builder. It involves the following steps: -* The first is operator expansion, which turns a token like 4+4 into the three - tokens 4, +, and 4 -* The next is token deaffixation which turns a token like (4 into the tokens ( - and 4. However, ((4 will become (( 4, not ( ( 4, because (( is a different - nesting level than ( -* Next, any blank tokens that have been created as a result of the process are - disposed of -* Finally, the entire expression is shunted, turning it from infix notation to - postfix notation. The only real special thing about this is that (( is a - different nesting level than (. The token precedence levels are (sorted from - lower to higher precedence): - * Math precedence - * + & - - * * & / - * - * Dice precedence - * d - * c - * Expression precedence - * => - * := - -# AST Building -AST building is a slightly more complex process, as the tree is traversed -twice: once to build the tree, and then again to convert the tokens from -strings into data tokens. The only really finicky part about the first tree is -arrays, because arrays are still in infix form at this point. |