const TYPE_LITERAL = 117; // all literals, identifiers and unrecognised tokens
const ACTION_GOTO = 201;
+ const ACTION_PUSH = 202;
+ const ACTION_POP = 203;
// Sanity limit to avoid excessive memory usage
const STACK_LIMIT = 1000;
// $model : This is the main table for our state machine. For every state/token pair
// the desired action is defined.
+ //
+ // The state pushed onto the stack by ACTION_PUSH will be returned to by ACTION_POP.
+ //
+ // A given state/token pair MAY NOT specify both ACTION_POP and ACTION_GOTO.
+ // In the event of such mistake, ACTION_POP is used instead of ACTION_GOTO.
$model = [
// Statement - This is the initial state.
self::STATEMENT => [
self::TYPE_ADD_OP => [
self::ACTION_GOTO => self::EXPRESSION,
],
+ self::TYPE_BRACE_OPEN => [
+ // Use of '{' in statement context, creates a Block.
+ self::ACTION_PUSH => self::STATEMENT,
+ ],
+ self::TYPE_BRACE_CLOSE => [
+ // Ends a Block
+ self::ACTION_POP => true,
+ ],
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_RETURN => [
],
self::CONDITION => [
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::STATEMENT,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
],
self::ACTION_GOTO => self::PROPERTY_EXPRESSION,
],
self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::PROPERTY_ASSIGNMENT,
self::ACTION_GOTO => self::STATEMENT,
],
+ self::TYPE_BRACE_CLOSE => [
+ self::ACTION_POP => true,
+ ],
],
self::EXPRESSION => [
self::TYPE_SEMICOLON => [
self::ACTION_GOTO => self::STATEMENT,
],
self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
+ self::TYPE_BRACE_CLOSE => [
+ self::ACTION_POP => true,
+ ],
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_FUNC => [
self::ACTION_GOTO => self::STATEMENT,
],
self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
+ self::TYPE_BRACE_CLOSE => [
+ self::ACTION_POP => true,
+ ],
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_FUNC => [
self::ACTION_GOTO => self::EXPRESSION,
],
self::TYPE_HOOK => [
+ self::ACTION_PUSH => self::EXPRESSION,
self::ACTION_GOTO => self::EXPRESSION_TERNARY,
],
self::TYPE_COLON => [
self::ACTION_GOTO => self::STATEMENT,
],
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
+ self::TYPE_BRACE_CLOSE => [
+ self::ACTION_POP => true,
+ ],
],
self::EXPRESSION_FUNC => [
self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::STATEMENT,
],
],
self::EXPRESSION_TERNARY => [
self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_TERNARY_OP,
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_TERNARY_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_FUNC => [
self::ACTION_GOTO => self::EXPRESSION_TERNARY,
],
self::TYPE_HOOK => [
+ self::ACTION_PUSH => self::EXPRESSION_TERNARY,
self::ACTION_GOTO => self::EXPRESSION_TERNARY,
],
self::TYPE_COMMA => [
self::ACTION_GOTO => self::EXPRESSION_TERNARY,
],
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_TERNARY_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
+ self::TYPE_COLON => [
+ self::ACTION_POP => true,
+ ],
],
self::EXPRESSION_TERNARY_FUNC => [
self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::EXPRESSION_TERNARY_OP,
self::ACTION_GOTO => self::STATEMENT,
],
],
self::PAREN_EXPRESSION => [
self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::PAREN_EXPRESSION_OP,
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::PAREN_EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
+ self::TYPE_PAREN_CLOSE => [
+ self::ACTION_POP => true,
+ ],
self::TYPE_FUNC => [
self::ACTION_GOTO => self::PAREN_EXPRESSION_FUNC,
],
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::PAREN_EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
+ self::TYPE_PAREN_CLOSE => [
+ self::ACTION_POP => true,
+ ],
],
self::PAREN_EXPRESSION_FUNC => [
self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::PAREN_EXPRESSION_OP,
self::ACTION_GOTO => self::STATEMENT,
],
],
self::PROPERTY_EXPRESSION => [
self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::PROPERTY_EXPRESSION_OP,
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
+ self::TYPE_BRACE_CLOSE => [
+ self::ACTION_POP => true,
+ ],
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::PROPERTY_EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_FUNC => [
self::TYPE_COMMA => [
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
+ self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::PROPERTY_EXPRESSION_OP,
+ ],
+ self::TYPE_BRACE_CLOSE => [
+ self::ACTION_POP => true,
+ ],
self::TYPE_PAREN_OPEN => [
+ self::ACTION_PUSH => self::PROPERTY_EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
],
self::PROPERTY_EXPRESSION_FUNC => [
self::TYPE_BRACE_OPEN => [
+ self::ACTION_PUSH => self::PROPERTY_EXPRESSION_OP,
self::ACTION_GOTO => self::STATEMENT,
],
- ]
- ];
-
- // $push : This table contains the rules for when to push a state onto the stack.
- // The pushed state is the state to return to when the corresponding
- // closing token is found
- $push = [
- self::STATEMENT => [
- self::TYPE_BRACE_OPEN => self::STATEMENT,
- self::TYPE_PAREN_OPEN => self::EXPRESSION_OP
- ],
- self::CONDITION => [
- self::TYPE_PAREN_OPEN => self::STATEMENT
- ],
- self::PROPERTY_ASSIGNMENT => [
- self::TYPE_BRACE_OPEN => self::PROPERTY_ASSIGNMENT
- ],
- self::EXPRESSION => [
- self::TYPE_BRACE_OPEN => self::EXPRESSION_OP,
- self::TYPE_PAREN_OPEN => self::EXPRESSION_OP
- ],
- self::EXPRESSION_NO_NL => [
- self::TYPE_BRACE_OPEN => self::EXPRESSION_OP,
- self::TYPE_PAREN_OPEN => self::EXPRESSION_OP
- ],
- self::EXPRESSION_OP => [
- self::TYPE_HOOK => self::EXPRESSION,
- self::TYPE_PAREN_OPEN => self::EXPRESSION_OP
- ],
- self::EXPRESSION_FUNC => [
- self::TYPE_BRACE_OPEN => self::EXPRESSION_OP
- ],
- self::EXPRESSION_TERNARY => [
- self::TYPE_BRACE_OPEN => self::EXPRESSION_TERNARY_OP,
- self::TYPE_PAREN_OPEN => self::EXPRESSION_TERNARY_OP
- ],
- self::EXPRESSION_TERNARY_OP => [
- self::TYPE_HOOK => self::EXPRESSION_TERNARY,
- self::TYPE_PAREN_OPEN => self::EXPRESSION_TERNARY_OP
- ],
- self::EXPRESSION_TERNARY_FUNC => [
- self::TYPE_BRACE_OPEN => self::EXPRESSION_TERNARY_OP
- ],
- self::PAREN_EXPRESSION => [
- self::TYPE_BRACE_OPEN => self::PAREN_EXPRESSION_OP,
- self::TYPE_PAREN_OPEN => self::PAREN_EXPRESSION_OP
],
- self::PAREN_EXPRESSION_OP => [
- self::TYPE_PAREN_OPEN => self::PAREN_EXPRESSION_OP
- ],
- self::PAREN_EXPRESSION_FUNC => [
- self::TYPE_BRACE_OPEN => self::PAREN_EXPRESSION_OP
- ],
- self::PROPERTY_EXPRESSION => [
- self::TYPE_BRACE_OPEN => self::PROPERTY_EXPRESSION_OP,
- self::TYPE_PAREN_OPEN => self::PROPERTY_EXPRESSION_OP
- ],
- self::PROPERTY_EXPRESSION_OP => [
- self::TYPE_BRACE_OPEN => self::PROPERTY_EXPRESSION_OP,
- self::TYPE_PAREN_OPEN => self::PROPERTY_EXPRESSION_OP
- ],
- self::PROPERTY_EXPRESSION_FUNC => [
- self::TYPE_BRACE_OPEN => self::PROPERTY_EXPRESSION_OP
- ]
- ];
-
- // $pop : Rules for when to pop a state from the stack
- $pop = [
- self::STATEMENT => [ self::TYPE_BRACE_CLOSE => true ],
- self::PROPERTY_ASSIGNMENT => [ self::TYPE_BRACE_CLOSE => true ],
- self::EXPRESSION => [ self::TYPE_BRACE_CLOSE => true ],
- self::EXPRESSION_NO_NL => [ self::TYPE_BRACE_CLOSE => true ],
- self::EXPRESSION_OP => [ self::TYPE_BRACE_CLOSE => true ],
- self::EXPRESSION_TERNARY_OP => [ self::TYPE_COLON => true ],
- self::PAREN_EXPRESSION => [ self::TYPE_PAREN_CLOSE => true ],
- self::PAREN_EXPRESSION_OP => [ self::TYPE_PAREN_CLOSE => true ],
- self::PROPERTY_EXPRESSION => [ self::TYPE_BRACE_CLOSE => true ],
- self::PROPERTY_EXPRESSION_OP => [ self::TYPE_BRACE_CLOSE => true ]
];
// $semicolon : Rules for when a semicolon insertion is appropriate
$semicolon = [
self::EXPRESSION_NO_NL => [
- self::TYPE_UN_OP => true,
- self::TYPE_INCR_OP => true,
- self::TYPE_ADD_OP => true,
+ self::TYPE_UN_OP => true,
+ self::TYPE_INCR_OP => true,
+ self::TYPE_ADD_OP => true,
self::TYPE_BRACE_OPEN => true,
self::TYPE_PAREN_OPEN => true,
- self::TYPE_RETURN => true,
- self::TYPE_IF => true,
- self::TYPE_DO => true,
- self::TYPE_FUNC => true,
- self::TYPE_LITERAL => true
+ self::TYPE_RETURN => true,
+ self::TYPE_IF => true,
+ self::TYPE_DO => true,
+ self::TYPE_FUNC => true,
+ self::TYPE_LITERAL => true
],
self::EXPRESSION_OP => [
- self::TYPE_UN_OP => true,
- self::TYPE_INCR_OP => true,
+ self::TYPE_UN_OP => true,
+ self::TYPE_INCR_OP => true,
self::TYPE_BRACE_OPEN => true,
- self::TYPE_RETURN => true,
- self::TYPE_IF => true,
- self::TYPE_DO => true,
- self::TYPE_FUNC => true,
- self::TYPE_LITERAL => true
+ self::TYPE_RETURN => true,
+ self::TYPE_IF => true,
+ self::TYPE_DO => true,
+ self::TYPE_FUNC => true,
+ self::TYPE_LITERAL => true
]
];
$newlineFound = false;
// Now that we have output our token, transition into the new state.
- if ( isset( $push[$state][$type] ) && count( $stack ) < self::STACK_LIMIT ) {
- $stack[] = $push[$state][$type];
+ if ( isset( $model[$state][$type][self::ACTION_PUSH] ) &&
+ count( $stack ) < self::STACK_LIMIT
+ ) {
+ $stack[] = $model[$state][$type][self::ACTION_PUSH];
}
- if ( $stack && isset( $pop[$state][$type] ) ) {
+ if ( $stack && isset( $model[$state][$type][self::ACTION_POP] ) ) {
$state = array_pop( $stack );
} elseif ( isset( $model[$state][$type][self::ACTION_GOTO] ) ) {
$state = $model[$state][$type][self::ACTION_GOTO];