Package com.singularsys.extensions.structure

Provides limited support for block style programming with for, if and while statements.

See: Description

Interface Summary

Interface	Description
GrammaticalRuleI	Indicates rules for parsing structured code.

Class Summary

Class	Description
BlockRule	Parse a statement block { sequence }.
ControlNode	A node representing a control statement such as break or continue.
ControlRule	Parses break and continue statements <ControlRule> ::= | <word> <separator> A successful parse returns a ControlNode
ExpressionRule	Parses an expression.
IfNode	A node representing an if statement.
JavaForRule	Parses a java-style for loop for(i=0;i<10;++i) x+=i;.
JavaIfRule	Parse a java style if statement: if(expr) statement [ else statement ] <JavaInRule> ::= || <if> <open> <expression> <close> <statement> || <if> <open> <expression> <close> <statement> <else> <statement>
JavaWhileRule	Parse a Java-style while loop while(x<10) x=x+1; <JavaWhileRule> ::= <while> <open> <expression> <close> <statement> A successful parse will return a LoopNode.
LoopNode	A node represents a looping construct such as a for or while loop.
PossiblyTerminatedExpressionRule	Parse an expression followed by an optional separator.
SequenceNode	A node representing a sequence of expressions.
SequenceRule	Parses a sequence of statements <SequenceRule> ::= (<statement>)* A successful parses will return a SequenceNode with one child per statement.
SequenceSeparatorRule	Parses a sequence of statements separated by a separator <SequenceRule> ::= <statement> (<sep> <statement>)* <sep>?
StandardStructuredParser	A structured parser with a java like grammar.
StatementRule	Parse a single statement from a list of possibilities.
StructuredEvaluator	An evaluator which works with structured programming.
StructuredGrammarParser	A grammar parser which works with structured programming.
StructuredParser	Base class for defining a parser for structured code.
StructureNode	Base class for all structure nodes, defines an eval method.
TerminatedExpressionRule	Parse an expression followed by a separator.

Enum Summary

Enum	Description
LoopNode.ControlValues	Special values to indicate break and continue statements Used by ControlRule and ControlNode.

Package com.singularsys.extensions.structure Description

Provides limited support for block style programming with for, if and while statements.

The structure package provides limited support for block style programming with if, for and while statements. The exact syntax can be configurable to give a Java, Pascal or Basic like syntax. It is not intended to be a fully featured parser more a way to add some structured programming elements like simple loops to Jep code.

The StandardStructuredParser provides a ready made parser with a java-like syntax. It supports:

• Statements separated by semi-colons x=5; y=x^2;
• Blocks enclosed in curly-brackets { x=5; y=6; }
• If statements if(x==5) {y=6;} else {y=7;}
• For statements for(j=0;j<=10;++j) x+=j;
• While statements while(x<10) x+=2;
• Break and continue statements inside looks.

Alternative syntaxes can be built up using the StructuredGrammerParser and a set of GrammaticalRuleI. Rules are provided for most types of statements.

The StructuredEvaluator is used to evaluate sequences of expressions after parsing.

Since:

Jep 3.5 / Extensions 2.0

See Also:

StructuredConsole, Documentation