diff options
| -rw-r--r-- | calculator-javacc/Calculator.jj | 74 |
1 files changed, 59 insertions, 15 deletions
diff --git a/calculator-javacc/Calculator.jj b/calculator-javacc/Calculator.jj index 6cc78f5..9222654 100644 --- a/calculator-javacc/Calculator.jj +++ b/calculator-javacc/Calculator.jj @@ -1,15 +1,36 @@ -options{DEBUG_PARSER = true; DEBUG_TOKEN_MANAGER = true;} +options{ + //DEBUG_PARSER = true; DEBUG_TOKEN_MANAGER = true; + STATIC=false; +} PARSER_BEGIN(Calculator) +import java.util.Scanner; +import java.io.StringReader; + public class Calculator { - public static void main(String[] args) { - try{ - Calculator parser = new Calculator(System.in); - parser.Start(); - }catch (ParseException e){ - System.out.println(e.getMessage()); - } - } + + private static double currentNumber; + + public static double fromString(String stringToParse) throws ParseException{ + currentNumber = 0.0; + + Calculator parser = new Calculator(new StringReader(stringToParse)); + parser.parse(); + return currentNumber; + } + + public static void main(String[] args) { + Scanner scanner = new Scanner(System.in); + while (true){ + System.out.print("Type your expression: "); + String expression = scanner.nextLine(); + try{ + System.out.println("Returned: " + fromString(expression)); + }catch (Throwable t){ + System.out.println(t); + } + } + } } PARSER_END(Calculator) @@ -22,14 +43,37 @@ SKIP : { } TOKEN : { - <SPACE: " "|"\t">| - <HELLO: "hello">| - <WORLD: "world">| - <HELLOWORLD: <HELLO> ( <SPACE> ) + <WORLD>> + <PAL: "(">| + <PAR: ")">| + <ADD: "+">| + <SUB: "-">| + <MUL: "*">| + <DIV: "/">| + <EQU: "=">| + <LET: "let">| + <END: "exit">| + <NUM: (["0"-"9"])+("."((["0"-"9"])+))?>| + <ID: (["a"-"z"]|["A"-"Z"])+> +} + + + +double factor() : +{ + Token t; + double i; +} +{ + t = <NUM> + { + i = Double.parseDouble(t.image); + currentNumber += i; + return i; + } } -void Start() : { +void parse() : { } { - (<HELLOWORLD>)* <EOF> + (factor())* <EOF> }
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