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Dr. Philip Cannata Programming Languages
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Programming Languages
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10
Java (Object Oriented)Java (Object Oriented)
ASPASP
RDF (Horn Clause Deduction, RDF (Horn Clause Deduction, Semantic Web)Semantic Web)
RelationRelation
Jython in JavaJython in Java
This CourseThis Course
High LevelHigh LevelLanguagesLanguages
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{ } a series of zero or more( ) must pick one from a list[ ] pick none or one from a list
expression -> term { ( + | - ) term } term -> factor { ( * | / ) factor }factor -> ( expression ) | number // the parenthesis are part of the grammar not the EBNFnumber -> { 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 }
6 * ( 11 – 7 ) / 3 + 100
High Level Overview of Grammar Concepts
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Abstract Syntax
Internal Parse Tree
int main ()
{
return 0 ;
}
Program (abstract syntax): Function = main; Return type = int params = Block: Return: Variable: return#main, LOCAL addr=0 IntValue: 0
Instance of a Programming Language:
We’ll be starting with javacc moving to ANTLR later
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$ lsMakefile Parser.jj test
Parser Files – javacc demo1 – similar to Chapter 1 in the Textbook but in java instead of scheme
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PARSER_BEGIN(Parser)
import java.io.*;import java.util.*;
public class Parser { public static void main(String args[]) throws ParseException { Parser parser = new Parser (System.in); parser.ae(); }}
PARSER_END(Parser )
SKIP :{ " " | "\t" | "\n" | "\r" | <"//" (~["\n","\r"])* ("\n"|"\r")>}
TOKEN:{ < LCURLY: "{" > | < RCURLY: "}" > | < MINUS: "-" > | < PLUS: "+" >
}
TOKEN: /* Literals */{ < INTEGER: (["0"-"9"])+ >}
TOKEN:{ <ERROR: ~[] >}
void ae() :{ Token n; }{ n = <INTEGER> { System.out.print("(num " + n +")"); } | list()}
void list() :{}{ LOOKAHEAD(2) <LCURLY> <PLUS> { System.out.print(" (add ");}
( ae() )* <RCURLY> { System.out.print(") "); } | <LCURLY> <MINUS> { System.out.print(" (sub ");} ( ae() )*
<RCURLY> { System.out.print(") "); }}
Parser
Grammar Production Rules
Tokens, Terminals
Syntax and Grammar – Parser.jj
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$ cat MakefileParser.class: Parser.java javac *java
Parser.java: Parser.jj javacc Parser.jj
clean: rm *.class ParseException.java Parser.java ParserConstants.java ParserTokenManager.java SimpleCharStream.java Token.java TokenMgrError.java
Parser Makefile - Makefile
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$ makejavacc Parser.jjJava Compiler Compiler Version 4.0 (Parser Generator)(type "javacc" with no arguments for help)Reading from file Parser.jj . . .File "TokenMgrError.java" does not exist. Will create one.File "ParseException.java" does not exist. Will create one.File "Token.java" does not exist. Will create one.File "SimpleCharStream.java" does not exist. Will create one.Parser generated successfully.javac *javaNote: Parser.java uses unchecked or unsafe operations.Note: Recompile with -Xlint:unchecked for details.
Making the Parser
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$ cat test; cat test | java -cp "." Parser{+ 4 5 {- {+ 1 2 3 } 6} 101 {+ 102}} (add (num 4)(num 5) (sub (add (num 1)(num 2)(num 3)) (num 6)) (num 101) (add (num 102)) )
Testing the Parser
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$ lsAbstractSyntax.java Makefile Parser.jj calc.sh test
$ cat calc.shcat testcat test | java Parsercat test | java Parser | sed -e "s/add/+/g" -e "s/sub/-/g" -e "s/(num//g" -e "s/\([0-9]\))/\1/g" | tr -s " " " " | sed "s/^ *//"cat test | java Parser | sed -e "s/add/+/g" -e "s/sub/-/g" -e "s/(num//g" -e "s/\([0-9]\))/\1/g" | clisp --silent | grep -v ">"
$ ./calc.sh{+ 4 5 {- {+ 1 2 3} 6} 101 {+ 102}} (add (num 4) (num 5) (sub (add (num 1) (num 2) (num 3)) (num 6)) (num 101) (add (num 102)))(+ 4 5 (- (+ 1 2 3) 6) 101 (+ 102))212
New
Parser Files – javacc demo2 – similar to Chapter 2 in the Textbook but in java instead of scheme
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1op: “”intval: 0children:
top = sub = 1nodeStack
1
Parse {+ 3 {+ 4 5 } 6}
Abstract Syntax TreeBeginning
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After recognizing {+
top = 1
sub = 2
11op: “”intval: 0children: 2
22op: “+”intval: 0children:
nodeStack
2
1
Abstract Syntax Tree
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After recognizing {+ 3
top = 1
sub = 2
1op: “”intval: 0children: 2
2op: “+”intval: 0children: 3
nodeStack
2
1
Abstract Syntax Tree
3op: “int”intval: 3children:
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After recognizing {+ 3 {+
top = 1
sub = 4
1op: “”intval: 0children: 2
2op: “+”intval: 0children: 3, 4
nodeStack
4
2
1
Abstract Syntax Tree
3op: “int”intval: 3children:
4op: “+”intval: 0children:
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After recognizing {+ 3 {+ 4
top = 1
sub = 4
1op: “”intval: 0children: 2
2op: “+”intval: 0children: 3, 4
nodeStack
4
2
1
Abstract Syntax Tree
3op: “int”intval: 3children:
4op: “+”intval: 0children: 5
5op: “int”intval: 4children:
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After recognizing {+ 3 {+ 4 5
top = 1
sub = 4
1op: “”intval: 0children: 2
2op: “+”intval: 0children: 3, 4
nodeStack
4
2
1
Abstract Syntax Tree
3op: “int”intval: 3children:
4op: “+”intval: 0children: 5, 6
5op: “int”intval: 4children:
6op: “int”intval: 5children:
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After recognizing {+ 3 {+ 4 5 }
top = 1
sub = 2
1op: “”intval: 0children: 2
2op: “+”intval: 0children:3, 4
nodeStack
2
1
Abstract Syntax Tree
3op: “int”intval: 3children:
4op: “+”intval: 0children: 5, 6
5op: “int”intval: 4children:
6op: “int”intval: 5children:
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After recognizing {+ 3 {+ 4 5 } 6
top = 1
sub = 2
1op: “”intval: 0children: 2
2op: “+”intval: 0children: 3, 4, 7
nodeStack
2
1
Abstract Syntax Tree
3op: “int”intval: 3children:
4op: “+”intval: 0children: 5, 6
5op: “int”intval: 4children:
6op: “int”intval: 5children:
7op: “int”intval: 6children:
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After recognizing {+ 3 {+ 4 5 } 6 }
top = 1
sub = 1
1op: “”intval: 0children: 2
2op: “+”intval: 0children: 3, 4, 7
nodeStack
1
Abstract Syntax Tree
3op: “int”intval: 3children:
4op: “+”intval: 0children: 5, 6
5op: “int”intval: 4children:
6op: “int”intval: 5children:
7op: “int”intval: 6children:
Now print the Abstract Syntax Tree starting with top
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$ lsAbstractSyntax.java Makefile Parser.jj calc.sh test
$ cat calc.shcat testcat test | java Parser
$ ./calc.sh{+ 4 5 {- {+ 1 2 3} {+ 200 300 400} 6} 101 {+ 102}}
Binary: top Binary: + 4 Binary: + 5 Binary: - Binary: + 1 Binary: + 2 Binary: + 3 Binary: + 200 Binary: + 300 Binary: + 400 Binary: - 6 Binary: + 101 Binary: + 102
Different
Parser Files – javacc demo3 – Building a simple AST
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