tscript

tscript for t3kton script. Is a Turing complete scripting language that is designed to be executed in such a way it’s state can be fully serialized and stored in the database while when not being actively executed. The script is initially parsed and loaded by the Forman module. When a subcontractor instance for the site the script belongs to, the script is executed to the point where it requires external input/execution, at which point the data required for the external action is sent to subcontracor, and the script’s state is stored in the database. It will remain there until the results of that execution are returned. This way jobs for sites that do not have a subcontractor executing are not taking processing resources, as well as not requiring any type of message bus. When the script completes, the attached Structure/Foundation/Dependancy is changed state, if the script was a create or destroy script. If a non-terminal error occurs, the operator is given the ability to reset to retry. There is also an rollback option for when the external function supports rolling back (ie: cleaning up a half deployed vm). Some errors are terminal, at which point the execution job is put in the aborted state. The script can also be paused so it will not execute further. NOTE: this does not affect any external operations that may be on going, the script will not continue after the results are returned.

The functions avaible to thescript depend on the plugins installed and the type of Foundation in use.

built in functions

  • len( array ) - return length of the array
  • slice( array, start, end ) - returns a slice of the array from start to end (same start end rules as python)
  • pop( array, index=-1 ) - returns and removes index index from array
  • append( array, value ) - appends value to the end of the array
  • index( array, value ) - returns the index(offset) or value in array
  • pause( msg ) - pause the script with the message msg
  • error( msg ) - cause a non fatal error with the message msg
  • fatal_error( msg ) - cause a fatal error with the message msg
  • delay( seconds=0, minutes=0, hours=0 ) - delay execution of the script for the specified seconds, minutes, and/or hours

gramer

tscript uses the parsimonious parser, here is it’s grammar:

script              = lines
lines               = line*
line                = ( expression / ws_s ) comment? nl_p
expression          = ws_s ( jump_point / goto / function / ifelse / whiledo / block / assignment / infix / boolean / not_ / none / exists / other / array_map_item / array / map / variable / time / number_float / number_int / text ) ws_s
value_expression    = ws_s ( function / assignment / infix / boolean / not_ / none / exists / array_map_item / array / map / variable / time / number_float / number_int / text ) ws_s
constant_expression = ws_s ( boolean / none / time / number_float / number_int / text ) ws_s
comment             = "#" ~"[^\\r\\n]*"
jump_point          = ":" label
goto                = "goto " label
paramater_map       = ( ( ws_s label ws_s "=" value_expression "," )* ws_s label ws_s "=" value_expression )? ws_s
const_paramater_map = ( ( ws_s label ws_s "=" constant_expression "," )* ws_s label ws_s "=" constant_expression )? ws_s
block               = "begin(" const_paramater_map ")" lines ws_s "end"

whiledo             = "while" value_expression "do" em_p expression
other               = ( "continue" / "break" / "pass" )

ifelse              = "if" value_expression "then" em_p expression ( em_s "elif" value_expression "then" em_p expression )* ( em_s "else" em_p expression )?

not_                = ~"[Nn]ot" value_expression

time                = ~"([0-9]{1,2}:){1,3}[0-9]{1,2}"
number_float        = ~"[-+]?[0-9]+\.[0-9]+"
number_int          = ~"[-+]?[0-9]+"
text                = ( "'" ~"[^']*" "'" ) / ( '"' ~'[^"]*' '"' )
boolean             = ~"[Tt]rue" / ~"[Ff]alse"
none                = ~"[Nn]one"
exists              = "exists(" ws_s ( array_map_item / variable ) ws_s ")"

array               = "[" ( ( value_expression "," )* value_expression )? ws_s "]"
map                 = "{" paramater_map "}"

reserved            = ( "begin" / "end" / "while" / "do" / "goto" / "exists" / other ) !~"[a-zA-Z0-9_]"
variable            = !reserved ( label "." )? label !"("

function            = !reserved ( label "." )? label "(" paramater_map ")"
array_map_item      = variable "[" value_expression "]"

infix               = "(" value_expression ( "^" / "*" / "/" / "%" / "+" / "-" / "&" / "|" / "and"/ "or" / "==" / "!=" / "<=" / ">=" / ">" / "<" ) value_expression ")"

assignment          = ( array_map_item / variable ) ws_s "=" value_expression

label               = ~"[a-zA-Z][a-zA-Z0-9_]+"
ws_o                = ~"[ \\x09]"
ws_s                = ~"[ \\x09]*"
ws_p                = ~"[ \\x09]+"
nl_o                = ~"[\\x0d\\x0a]"
nl_s                = ~"[\\x0d\\x0a]*"
nl_p                = ~"[\\x0d\\x0a]+"
em_o                = ~"[\\x0d\\x0a \\x09]"
em_s                = ~"[\\x0d\\x0a \\x09]*"
em_p                = ~"[\\x0d\\x0a \\x09]+"