Reorganized the project as multi-maven module

Updated README
Added language module with grammar
Split the code into common and chapter01 modules.
Removed a number of utility classes that were imported from AA.
Added github workflow file.

4 files changed, 0 insertions, 630 deletions

diff --git a/src/main/java/com/seaofnodes/simple/common/CompilerException.java b/src/main/java/com/seaofnodes/simple/common/CompilerException.java
deleted file mode 100644
index 518dcde6..00000000
--- a/src/main/java/com/seaofnodes/simple/common/CompilerException.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package com.seaofnodes.simple.common;
-
-public class CompilerException extends RuntimeException {
-    public CompilerException(String message) {
-        super(message);
-    }
-
-    public CompilerException(String message, Throwable cause) {
-        super(message, cause);
-    }
-}
diff --git a/src/main/java/com/seaofnodes/simple/lexer/aa/Lexer.java b/src/main/java/com/seaofnodes/simple/lexer/aa/Lexer.java
deleted file mode 100644
index 162cdea1..00000000
--- a/src/main/java/com/seaofnodes/simple/lexer/aa/Lexer.java
+++ /dev/null
@@ -1,228 +0,0 @@
-/**
- * DO NOT REMOVE COPYRIGHT NOTICES OR THIS HEADER.
- *
- * Contributor(s):
- *
- * The Initial Developer of the Original Software is Cliff Click.
- *
- * This file is part of the Sea Of Nodes Simple Programming language
- * implementation. See https://github.com/SeaOfNodes/Simple
- *
- * The contents of this file are subject to the terms of the
- * Apache License Version 2 (the "APL"). You may not use this
- * file except in compliance with the License. A copy of the
- * APL may be obtained from:
- * http://www.apache.org/licenses/LICENSE-2.0
- */
-package com.seaofnodes.simple.lexer.aa;
-
-import com.seaofnodes.util.AryInt;
-import com.seaofnodes.util.SB;
-
-import java.text.NumberFormat;
-import java.text.ParsePosition;
-
-public class Lexer {
-    private final String _srcName;    // Source for error messages; usually a file name
-    private final byte[] _buf;
-    private int _x;               // Parser index
-    private int _lastNWS;         // Index of last non-white-space char
-    private final AryInt _lines;  // char offset of each line
-
-    private final NumberFormat _nf;
-    private final ParsePosition _pp;
-    private final String _str;
-
-    public Lexer(String srcName, String source)
-    {
-        _srcName = srcName;
-        _buf = source.getBytes();
-        _x   = 0;
-
-        // Set fields strictly for Java number parsing
-        _nf = NumberFormat.getInstance();
-        _nf.setGroupingUsed(false);
-        _pp = new ParsePosition(0);
-        _str = source;           // Keep a complete string copy for java number parsing
-        _lines = new AryInt();//
-        _lines.push(0);       // Line 0 at offset 0
-    }
-
-    // Skip WS, return true&skip if match, false & do not skip if miss.
-    public boolean peek( char c ) { return peek1(skipWS(),c); }
-    public boolean peek_noWS( char c ) { return peek1(_x >= _buf.length ? -1 : _buf[_x],c); }
-    // Already skipped WS & have character;
-    // return true & skip if a match, false& do not skip if a miss.
-    public boolean peek1( byte c0, char c ) {
-        assert c0==-1 || c0== _buf[_x];
-        if( c0!=c ) return false;
-        _x++;                       // Skip peeked character
-        return true;
-    }
-    // Already skipped WS & have character;
-    // return true&skip if match, false & do not skip if miss.
-    public boolean peek2( byte c0, String s2 ) {
-        if( c0 != s2.charAt(0) ) return false;
-        if( _x+1 >= _buf.length || _buf[_x+1] != s2.charAt(1) ) return false;
-        _x+=2;                      // Skip peeked characters
-        return true;
-    }
-    public boolean peek( String s ) {
-        if( !peek(s.charAt(0)) ) return false;
-        if( !peek_noWS(s.charAt(1)) ) {  _x--; return false; }
-        return true;
-    }
-    // Peek 'c' and NOT followed by 'no'
-    public boolean peek_not( char c, char no ) {
-        byte c0 = skipWS();
-        if( c0 != c || (_x+1 < _buf.length && _buf[_x+1] == no) ) return false;
-        _x++;
-        return true;
-    }
-    // Match any of these, and return the match or null
-    public String peek(String[] toks) {
-        for( String tok : toks ) if( peek1(tok) ) return tok;
-        return null;
-    }
-    public boolean peek1(String tok) {
-        for( int i=0; i<tok.length(); i++ )
-            if( _x+i >= _buf.length || _buf[_x+i] != tok.charAt(i) )
-                return false;
-        return true;
-    }
-
-
-    /** Advance parse pointer to the first non-whitespace character, and return
-     *  that character, -1 otherwise.  */
-    public byte skipWS() {
-        int oldx = _x;
-        while( _x < _buf.length ) {
-            byte c = _buf[_x];
-            if( c=='/' && _x+1 < _buf.length && _buf[_x+1]=='/' ) { skipEOL()  ; continue; }
-            if( c=='/' && _x+1 < _buf.length && _buf[_x+1]=='*' ) { skipBlock(); continue; }
-            if( c=='\n' && _x+1 > _lines.last() ) _lines.push(_x+1);
-            if( !isWS(c) ) {
-                if( oldx-1 > _lastNWS && !isWS(_buf[oldx-1]) ) _lastNWS = oldx-1;
-                return c;
-            }
-            _x++;
-        }
-        return -1;
-    }
-    public void skipEOL  () { while( _x < _buf.length && _buf[_x] != '\n' ) _x++; }
-    public void skipBlock() { throw new UnsupportedOperationException("Block comments not yet implemented"); }
-    // Advance parse pointer to next WS.  Used for parser syntax error recovery.
-    public void skipNonWS() {
-        while( _x < _buf.length && !isWS(_buf[_x]) ) _x++;
-    }
-
-    /** Return true if `c` passes a test */
-    public static boolean isWS    (byte c) { return c == ' ' || c == '\t' || c == '\n' || c == '\r'; }
-    public static boolean isAlpha0(byte c) { return ('a'<=c && c <= 'z') || ('A'<=c && c <= 'Z') || (c=='_'); }
-    public static boolean isAlpha1(byte c) { return isAlpha0(c) || ('0'<=c && c <= '9'); }
-    public static boolean isJava  (byte c) { return isAlpha1(c) || (c=='$') || (c=='.'); }
-    public  static boolean isDigit (byte c) { return '0' <= c && c <= '9'; }
-
-    public String token() { skipWS();  return token0(); }
-    // Lexical tokens.  Any alpha, followed by any alphanumerics is a alpha-
-    // token; alpha-tokens end with WS or any operator character.  Any collection
-    // of the classic operator characters are a token, except that they will break
-    // un-ambiguously.
-    public String token0() {
-        if( _x >= _buf.length ) return null;
-        byte c=_buf[_x];  int x = _x;
-        if( isOp0(c) || (c=='_' && _x+1 < _buf.length && isOp0(_buf[_x+1])) )
-            while( _x < _buf.length && isOp1(_buf[_x]) ) _x++;
-        else if( isAlpha0(c) )
-            while( _x < _buf.length && isAlpha1(_buf[_x]) ) _x++;
-        else return null; // Not a token; specifically excludes e.g. all bytes >= 128, or most bytes < 32
-        if( (c==':' || c==',') && _x-x==1 ) // Disallow bare ':' as a token; ambiguous with ?: and type annotations; same for ','
-        { _x=x; return null; } // Unwind, not a token
-        if( c=='-' && _x-x>2 && _buf[x+1]=='>' ) // Disallow leading "->", confusing with function parameter list end; eg "not={x->!x}"
-            _x=x+2;                                // Just return the "->"
-        return new String(_buf,x,_x-x);
-    }
-    public boolean isOp(String s) {
-        if( s==null || s.isEmpty() ) return false;
-        byte c = (byte)s.charAt(0);
-        if( !isOp0(c) && (c!='_' || !isOp0((byte)s.charAt(1))) ) return false;
-        for( int i=1; i<s.length(); i++ )
-            if( !isOp1((byte)s.charAt(i)) ) return false;
-        return true;
-    }
-
-    // Parse a number; WS already skipped and sitting at a digit.  Relies on
-    // Javas number parsing.
-    public Number number() {
-        _pp.setIndex(_x);
-        Number n = _nf.parse(_str,_pp);
-        _x = _pp.getIndex();
-        if( n instanceof Long   ) {
-            if( _buf[_x-1]=='.' ) _x--; // Java default parser allows "1." as an integer; pushback the '.'
-        }
-        return n;
-    }
-
-    public int field_number() {
-        byte c = _buf[_x];
-        if( !isDigit(c) ) return -1;
-        _x++;
-        int sum = c-'0';
-        while( _x < _buf.length && isDigit(c=_buf[_x]) ) {
-            _x++;
-            sum = sum*10+c-'0';
-        }
-        return sum;
-    }
-
-    /** Parse a String; _x is at '"'.
-     *  str  = [.\%]*               // String contents; \t\n\r\% standard escapes
-     *  str  = %[num]?[.num]?fact   // Percent escape embeds a 'fact' in a string; "name=%name\n"
-     */
-    public String string() {
-        int oldx = ++_x;
-        byte c;
-        while( (c=_buf[_x++]) != '"' ) {
-            if( c=='%' ) throw new UnsupportedOperationException("Not implemented");
-            if( c=='\\' ) throw new UnsupportedOperationException("Not implemented");
-            if( _x == _buf.length ) return null;
-        }
-        return new String(_buf,oldx,_x-oldx-1).intern();
-    }
-
-    public static boolean isOp0(byte c) { return "!#$%*+-=<>^[]~/&|".indexOf(c) != -1; }
-    public static boolean isOp1(byte c) { return isOp0(c) || ":?_{}".indexOf(c) != -1; }
-
-    public String errLocMsg(String s) {
-        if( s.charAt(0)=='\n' ) return s;
-        // find line start
-        int a=_x;
-        while( a > 0 && _buf[a-1] != '\n' ) --a;
-        if( _buf[a]=='\r' ) a++; // do not include leading \n or \n\r
-        // find line end
-        int b=_x;
-        while( b < _buf.length && _buf[b] != '\n' ) b++;
-        if( b < _buf.length ) b--; // do not include trailing \n or \n\r
-        // Find line number.  Bin-search returns the insertion-point, which is the NEXT
-        // line unless _x is exactly a line start.
-        int line = _lines.binary_search(_x); // Find zero-based line insertion point
-        if( line == _lines._len ||  _lines.at(line)>_x ) line--;
-        // error message using 1-based line
-        SB sb = new SB().p(_srcName).p(':').p(line+1).p(':').p(s).nl();
-        sb.p(new String(_buf,a,b-a)).nl();
-        int line_start = a;
-        for( int i=line_start; i<_x; i++ )
-            sb.p(' ');
-        return sb.p('^').nl().toString();
-    }
-
-    @Override public String toString() { return new String(_buf,_x,_buf.length-_x); }
-    @Override public boolean equals(Object loc) {
-        if( this==loc ) return true;
-        if( !(loc instanceof Lexer p) ) return false;
-        return _x==p._x && _srcName.equals(p._srcName);
-    }
-    @Override public int hashCode() {
-        return _srcName.hashCode()+_x;
-    }
-}
diff --git a/src/main/java/com/seaofnodes/simple/parser/Ast.java b/src/main/java/com/seaofnodes/simple/parser/Ast.java
deleted file mode 100644
index a93b230f..00000000
--- a/src/main/java/com/seaofnodes/simple/parser/Ast.java
+++ /dev/null
@@ -1,132 +0,0 @@
-package com.seaofnodes.simple.parser;
-
-import com.seaofnodes.simple.common.CompilerException;
-import com.seaofnodes.simple.lexer.ecstasy.Token;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public abstract class Ast {
-
-    public static class Node {
-    }
-
-    public static class Expr extends Node {
-        public final Token op;
-
-        public Expr(Token op) {
-            this.op = op;
-        }
-    }
-
-    public static class Identifier extends Expr {
-        public final String name;
-        public Identifier(Token op) {
-            super(op);
-            name = op.getValueText();
-        }
-    }
-
-    public static class Symbol extends Expr {
-        public final String name;
-        public Symbol(Token op) {
-            super(op);
-            name = op.getValueText();
-        }
-    }
-
-    public static class Binary extends Expr {
-        public final Expr expr1, expr2;
-
-        public Binary(Token op, Expr expr1, Expr expr2) {
-            super(op);
-            this.expr1 = expr1;
-            this.expr2 = expr2;
-        }
-    }
-
-    public static class Unary extends Expr {
-        public final Expr expr;
-
-        public Unary(Token op, Expr expr) {
-            super(op);
-            this.expr = expr;
-        }
-    }
-
-    public static class Constant extends Expr {
-        public Constant(Token op) {
-            super(op);
-        }
-    }
-
-    public static class Statement extends Node {
-    }
-
-    public static class IfElse extends Statement {
-        public final Expr expr;
-        public final Statement ifStmt, elseStmt;
-
-        public IfElse(Expr expr, Statement ifStmt, Statement elseStmt) {
-            this.expr = expr;
-            this.ifStmt = ifStmt;
-            this.elseStmt = elseStmt;
-        }
-    }
-
-    public static class While extends Statement {
-        public Expr expr;
-        public Statement stmt;
-
-        public While() {
-        }
-        public void init(Expr expr, Statement stmt) {
-            this.expr = expr;
-            this.stmt = stmt;
-        }
-    }
-
-    public static class Break extends Statement {
-        public final Statement stmt;
-
-        public Break(Statement stmt) {
-            if (stmt == null)
-            {
-                throw new CompilerException("uneclosed break");
-            }
-            this.stmt = stmt;
-        }
-    }
-
-    public static class Assign extends Statement {
-        public final Identifier identifier;
-        public final Expr expr;
-
-        public Assign(Identifier identifier, Expr expr) {
-            this.identifier = identifier;
-            this.expr = expr;
-        }
-    }
-
-    public static class Type extends Node {
-        public final Token.Id typeId;
-
-        public Type(Token.Id typeId) {
-            this.typeId = typeId;
-        }
-    }
-
-    public static class Declare extends Statement {
-        public final Type type;
-        public final Identifier identifier;
-
-        public Declare(Type type, Identifier identifier) {
-            this.type = type;
-            this.identifier = identifier;
-        }
-    }
-
-    public static class Block extends Statement {
-        public final List<Statement> stmtList = new ArrayList<>();
-    }
-}
diff --git a/src/main/java/com/seaofnodes/simple/parser/Parser.java b/src/main/java/com/seaofnodes/simple/parser/Parser.java
deleted file mode 100644
index f7b29f40..00000000
--- a/src/main/java/com/seaofnodes/simple/parser/Parser.java
+++ /dev/null
@@ -1,259 +0,0 @@
-/**
- * DO NOT REMOVE COPYRIGHT NOTICES OR THIS HEADER.
- *
- * Contributor(s):
- *
- * The Initial Developer of the Original Software is Dibyendu Majumdar.
- *
- * This file is part of the Sea Of Nodes Simple Programming language
- * implementation. See https://github.com/SeaOfNodes/Simple
- *
- * The contents of this file are subject to the terms of the
- * Apache License Version 2 (the "APL"). You may not use this
- * file except in compliance with the License. A copy of the
- * APL may be obtained from:
- * http://www.apache.org/licenses/LICENSE-2.0
- */
-package com.seaofnodes.simple.parser;
-
-import com.seaofnodes.simple.common.CompilerException;
-import com.seaofnodes.simple.lexer.ecstasy.Lexer;
-import com.seaofnodes.simple.lexer.ecstasy.Token;
-import com.seaofnodes.util.Severity;
-
-public class Parser {
-    final Lexer lexer;
-    Token look;
-    Ast.Statement statementEnclosing;
-
-    public Parser(Lexer lexer) {
-        this.lexer = lexer;
-    }
-
-    Token nextOrEof() {
-        if (lexer.hasNext())
-            return lexer.next();
-        return new Token(look.getStartPosition(), look.getEndPosition(), Token.Id.EOF);
-    }
-
-    void nextToken() {
-        look = nextOrEof();
-        while (look.isComment()) {
-            look = nextOrEof();
-        }
-        if (look.isContextSensitive() &&
-                look.getId() == Token.Id.IDENTIFIER) {
-            look = look.convertToKeyword();
-        }
-    }
-
-    void error(Token t, String errorMessage) {
-        lexer.log(Severity.ERROR, errorMessage, t.getStartPosition(), t.getEndPosition());
-        throw new CompilerException(errorMessage + ": " + t.toDebugString());
-    }
-
-    void match(Token.Id tag) {
-        if (look.getId() == tag) {
-            nextToken();
-        } else {
-            error(look, "syntax error, expected " + tag);
-        }
-    }
-
-    public Ast.Node parse() {
-        nextToken();
-        return parseProgram();
-    }
-
-    Ast.Statement parseProgram() {
-        var block = new Ast.Block();
-        parseDeclarations(block);
-        parseStatements(block);
-        return block;
-    }
-
-    void parseDeclarations(Ast.Block block) {
-        while (look.getId() == Token.Id.VAR) {
-            nextToken();
-            var tok = look;
-            match(Token.Id.IDENTIFIER);
-            match(Token.Id.COLON);
-            var type = parseType();
-            match(Token.Id.SEMICOLON);
-            var identifier = new Ast.Identifier(tok);
-            block.stmtList.add(new Ast.Declare(type, identifier));
-        }
-    }
-
-    Ast.Type parseType() {
-        if (look.getId() == Token.Id.LIT_INTA) {
-            nextToken();
-            return new Ast.Type(look.getId());
-        }
-        error(look, "syntax error: unsupported type (at present only Int type is allowed)");
-        return null;
-    }
-
-    void parseStatements(Ast.Block block) {
-        while (look.getId() != Token.Id.EOF &&
-                look.getId() != Token.Id.R_CURLY) {
-            block.stmtList.add(parseStatement());
-        }
-    }
-
-    Ast.Statement parseStatement() {
-        Ast.Expr x;
-        Ast.Statement s1;
-        Ast.Statement s2;
-
-        switch (look.getId()) {
-            case IF -> {
-                match(Token.Id.IF);
-                match(Token.Id.L_PAREN);
-                x = parseBool();
-                match(Token.Id.R_PAREN);
-                s1 = parseStatement();
-                if (look.getId() != Token.Id.ELSE) {
-                    return new Ast.IfElse(x, s1, null);
-                }
-                s2 = parseStatement();
-                return new Ast.IfElse(x, s1, s2);
-            }
-            case WHILE -> {
-                var whilenode = new Ast.While();
-                var savedStmt = statementEnclosing;
-                statementEnclosing = whilenode;
-                match(Token.Id.WHILE);
-                match(Token.Id.L_PAREN);
-                x = parseBool();
-                match(Token.Id.R_PAREN);
-                s1 = parseStatement();
-                whilenode.init(x, s1);
-                statementEnclosing = savedStmt;
-                return whilenode;
-            }
-            case BREAK -> {
-                match(Token.Id.BREAK);
-                match(Token.Id.SEMICOLON);
-                return new Ast.Break(statementEnclosing);
-            }
-            case L_CURLY -> {
-                return parseBlock();
-            }
-            default -> {
-                return parseAssign();
-            }
-        }
-    }
-
-    Ast.Statement parseBlock() {
-        match(Token.Id.L_CURLY);
-        var block = new Ast.Block();
-        parseDeclarations(block);
-        parseStatements(block);
-        match(Token.Id.R_CURLY);
-        return block;
-    }
-
-    Ast.Statement parseAssign() {
-        match(Token.Id.IDENTIFIER);
-        Ast.Identifier identifier = new Ast.Identifier(look);
-        match(Token.Id.ASN);
-        var s = new Ast.Assign(identifier, parseBool());
-        match(Token.Id.SEMICOLON);
-        return s;
-    }
-
-    Ast.Expr parseBool() {
-        var x = parseAnd();
-        while (look.getId() == Token.Id.COND_OR) {
-            var tok = look;
-            nextToken();
-            x = new Ast.Binary(tok, x, parseAnd());
-        }
-        return x;
-    }
-
-    Ast.Expr parseAnd() {
-        var x = parseRelational();
-        while (look.getId() == Token.Id.COND_AND) {
-            var tok = look;
-            nextToken();
-            x = new Ast.Binary(tok, x, parseRelational());
-        }
-        return x;
-    }
-
-    Ast.Expr parseRelational() {
-        var x = parseAddition();
-        while (look.getId() == Token.Id.COMP_EQ ||
-                look.getId() == Token.Id.COMP_NEQ ||
-                look.getId() == Token.Id.COMP_LT ||
-                look.getId() == Token.Id.COMP_GT ||
-                look.getId() == Token.Id.COMP_GTEQ ||
-                look.getId() == Token.Id.COMP_LTEQ) {
-            var tok = look;
-            nextToken();
-            x = new Ast.Binary(tok, x, parseAddition());
-        }
-        return x;
-    }
-
-    Ast.Expr parseAddition() {
-        var x = parseMultiplication();
-        while (look.getId() == Token.Id.ADD ||
-                look.getId() == Token.Id.SUB) {
-            var tok = look;
-            nextToken();
-            x = new Ast.Binary(tok, x, parseMultiplication());
-        }
-        return x;
-    }
-
-    Ast.Expr parseMultiplication() {
-        var x = parseUnary();
-        while (look.getId() == Token.Id.MUL ||
-                look.getId() == Token.Id.DIV) {
-            var tok = look;
-            nextToken();
-            x = new Ast.Binary(tok, x, parseUnary());
-        }
-        return x;
-    }
-
-    Ast.Expr parseUnary() {
-        if (look.getId() == Token.Id.SUB ||
-                look.getId() == Token.Id.NOT) {
-            var tok = look;
-            nextToken();
-            return new Ast.Unary(tok, parseUnary());
-        } else {
-            return parsePrimary();
-        }
-    }
-
-    Ast.Expr parsePrimary() {
-        switch (look.getId()) {
-            case L_PAREN -> {
-                nextToken();
-                var x = parseBool();
-                match(Token.Id.R_PAREN);
-                return x;
-            }
-            case LIT_INT -> {
-                var x = new Ast.Constant(look);
-                nextToken();
-                return x;
-            }
-            case IDENTIFIER -> {
-                var x = new Ast.Symbol(look);
-                nextToken();
-                return x;
-            }
-            default -> {
-                error(look, "syntax error, expected nested expr, integer value or variable");
-                return null;
-            }
-        }
-    }
-}