From 4968424d5aceefcf5ab6af1c6c0f7d23b9cbfadf Mon Sep 17 00:00:00 2001 From: Cliff Click Date: Tue, 26 Sep 2023 17:43:36 +0100 Subject: Chapter 2: Arithmetic MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Co-authored-by: Dibyendu Majumdar Co-authored-by: Thalia Archibald Co-authored-by: Yichen Yan Co-authored-by: Tamás Hadházy <85063808+Hels15@users.noreply.github.com> Co-authored-by: XmiliaH <45106915+XmiliaH@users.noreply.github.com> Co-authored-by: Hsiang-Ying Fu <66062782+fuhsnn@users.noreply.github.com> Co-authored-by: hadha Co-authored-by: RobertObkircher Co-authored-by: Jun Kawasaki --- src/main/java/com/seaofnodes/simple/Parser.java | 81 +++++++++++-- src/main/java/com/seaofnodes/simple/Utils.java | 39 ++++++ .../java/com/seaofnodes/simple/node/AddNode.java | 30 +++++ .../com/seaofnodes/simple/node/ConstantNode.java | 30 +++-- .../java/com/seaofnodes/simple/node/DivNode.java | 28 +++++ .../java/com/seaofnodes/simple/node/MinusNode.java | 23 ++++ .../java/com/seaofnodes/simple/node/MulNode.java | 26 ++++ src/main/java/com/seaofnodes/simple/node/Node.java | 131 ++++++++++++++++++++- .../com/seaofnodes/simple/node/ReturnNode.java | 19 +++ .../java/com/seaofnodes/simple/node/StartNode.java | 24 +++- .../java/com/seaofnodes/simple/node/SubNode.java | 27 +++++ .../simple/print/SimpleGraphAdapter.java | 2 +- .../simple/print/SimpleGraphObserver.java | 4 +- src/main/java/com/seaofnodes/simple/type/Type.java | 45 +++++++ .../com/seaofnodes/simple/type/TypeInteger.java | 41 +++++++ 15 files changed, 524 insertions(+), 26 deletions(-) create mode 100644 src/main/java/com/seaofnodes/simple/Utils.java create mode 100644 src/main/java/com/seaofnodes/simple/node/AddNode.java create mode 100644 src/main/java/com/seaofnodes/simple/node/DivNode.java create mode 100644 src/main/java/com/seaofnodes/simple/node/MinusNode.java create mode 100644 src/main/java/com/seaofnodes/simple/node/MulNode.java create mode 100644 src/main/java/com/seaofnodes/simple/node/SubNode.java create mode 100644 src/main/java/com/seaofnodes/simple/type/Type.java create mode 100644 src/main/java/com/seaofnodes/simple/type/TypeInteger.java (limited to 'src/main') diff --git a/src/main/java/com/seaofnodes/simple/Parser.java b/src/main/java/com/seaofnodes/simple/Parser.java index c2ea3734..f59b0f25 100644 --- a/src/main/java/com/seaofnodes/simple/Parser.java +++ b/src/main/java/com/seaofnodes/simple/Parser.java @@ -1,6 +1,9 @@ package com.seaofnodes.simple; +import com.seaofnodes.graph.GraphObserver; + import com.seaofnodes.simple.node.*; +import com.seaofnodes.simple.type.*; /** * The Parser converts a Simple source program to the Sea of Nodes intermediate @@ -11,6 +14,9 @@ import com.seaofnodes.simple.node.*; */ public class Parser { + // Current compilation context; the observer belongs to the parser. + public static Parser PARSER; + public GraphObserver _obs; public int pos() { return _lexer._position; } @@ -29,10 +35,13 @@ public class Parser { public Parser(String source) { _lexer = new Lexer(source); + PARSER = this; Node.reset(); START = new StartNode(); } + String src() { return new String( _lexer._input ); } + public ReturnNode parse() { var ret = (ReturnNode) parseStatement(); if (!_lexer.isEOF()) throw error("Syntax error, unexpected " + _lexer.getAnyNextToken()); @@ -60,20 +69,61 @@ public class Parser { * * @return an expression {@link Node}, never {@code null} */ - private ReturnNode parseReturn() { + private Node parseReturn() { var expr = require(parseExpression(), ";"); - return new ReturnNode(START, expr); + return new ReturnNode(START, expr).peephole(); } /** * Parse an expression of the form: * * 
-     *     expr : primaryExpr
+     *     expr : additiveExpr
      *
* @return an expression {@link Node}, never {@code null} */ - private Node parseExpression() { + private Node parseExpression() { return parseAddition(); } + + /** + * Parse an additive expression + * + * 
+     *     additiveExpr : multiplicativeExpr (('+' | '-') multiplicativeExpr)*
+     *
+ * @return an add expression {@link Node}, never {@code null} + */ + private Node parseAddition() { + var lhs = parseMultiplication(); + if (match("+")) return new AddNode(lhs, parseAddition()).peephole(); + if (match("-")) return new SubNode(lhs, parseAddition()).peephole(); + return lhs; + } + + /** + * Parse an multiplicativeExpr expression + * + * 
+     *     multiplicativeExpr : unaryExpr (('*' | '/') unaryExpr)*
+     *
+ * @return a multiply expression {@link Node}, never {@code null} + */ + private Node parseMultiplication() { + var lhs = parseUnary(); + if (match("*")) return new MulNode(lhs, parseMultiplication()).peephole(); + if (match("/")) return new DivNode(lhs, parseMultiplication()).peephole(); + return lhs; + } + + /** + * Parse a unary minus expression. + * + * 
+     *     unaryExpr : ('-') unaryExpr | primaryExpr
+     *
+ * @return a unary expression {@link Node}, never {@code null} + */ + private Node parseUnary() { + if (match("-")) return new MinusNode(parseUnary()).peephole(); return parsePrimary(); } @@ -81,14 +131,14 @@ public class Parser { * Parse a primary expression: * * 
-     *     primaryExpr : integerLiteral
+     *     primaryExpr : integerLiteral | Identifier | '(' expression ')'
      *
+ * @return a primary {@link Node}, never {@code null} */ private Node parsePrimary() { - _lexer.skipWhiteSpace(); - if (_lexer.isNumber()) - return parseIntegerLiteral(); - throw error("Syntax error, expected integer literal"); + if( _lexer.isNumber() ) return parseIntegerLiteral(); + if( match("(") ) return require(parseExpression(), ")"); + throw errorSyntax("integer literal"); } /** @@ -99,7 +149,7 @@ public class Parser { * */ private ConstantNode parseIntegerLiteral() { - return new ConstantNode(_lexer.parseNumber()); + return (ConstantNode) new ConstantNode(_lexer.parseNumber()).peephole(); } ////////////////////////////////// @@ -149,6 +199,12 @@ public class Parser { _input = buf; } + // Very handy in the debugger, shows the unparsed program + @Override + public String toString() { + return new String(_input, _position, _input.length - _position); + } + // True if at EOF private boolean isEOF() { return _position >= _input.length; @@ -212,11 +268,11 @@ public class Parser { boolean isNumber() {return isNumber(peek());} boolean isNumber(char ch) {return Character.isDigit(ch);} - private long parseNumber() { + private Type parseNumber() { String snum = parseNumberString(); if (snum.length() > 1 && snum.charAt(0) == '0') throw error("Syntax error: integer values cannot start with '0'"); - return Long.parseLong(snum); + return TypeInteger.constant(Long.parseLong(snum)); } private String parseNumberString() { int start = _position; @@ -249,5 +305,4 @@ public class Parser { return new String(_input, start, 1); } } - } diff --git a/src/main/java/com/seaofnodes/simple/Utils.java b/src/main/java/com/seaofnodes/simple/Utils.java new file mode 100644 index 00000000..45f15327 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/Utils.java @@ -0,0 +1,39 @@ +package com.seaofnodes.simple; + +import java.util.ArrayList; + +public class Utils { + public static RuntimeException TODO() { return TODO("Not yet implemented"); } + public static RuntimeException TODO(String msg) { return new RuntimeException(msg); } + + /** + * Fast, constant-time, element removal. Does not preserve order + * + * @param array ArrayList to modify + * @param i element to be removed + * @return element removed + */ + public static E del(ArrayList array, int i) { + if ( i >= 0 && i < array.size() ) { + E tmp = array.get(i); + E last = array.removeLast(); + if (i < array.size()) array.set(i, last); + return tmp; + } + return null; + } + + /** + * Search a list for an element by reference + * + * @param ary List to search in + * @param x Object to be searched + * @return >= 0 on success, -1 on failure + */ + public static int find( ArrayList ary, E x ) { + for( int i=0; i _print1(ExprPrinter p) { + return p.p(_con); } + + @Override + public Type compute() { return _con; } + + @Override + public Node idealize() { return null; } + } diff --git a/src/main/java/com/seaofnodes/simple/node/DivNode.java b/src/main/java/com/seaofnodes/simple/node/DivNode.java new file mode 100644 index 00000000..d1a554bc --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/node/DivNode.java @@ -0,0 +1,28 @@ +package com.seaofnodes.simple.node; + + +import com.seaofnodes.simple.type.Type; +import com.seaofnodes.simple.type.TypeInteger; + +public class DivNode extends Node { + public DivNode(Node lhs, Node rhs) { super(null, lhs, rhs); } + + @Override public String label() { return "Div"; } + + @Override protected String format() { return "(%1/%2)"; } + + @Override + public Type compute() { + if (in(1)._type instanceof TypeInteger i0 && + in(2)._type instanceof TypeInteger i1) { + if (i0.isConstant() && i1.isConstant()) + return i1.value() == 0 + ? TypeInteger.ZERO + : TypeInteger.constant(i0.value()/i1.value()); + } + return Type.BOTTOM; + } + + @Override + public Node idealize() { return null; } +} diff --git a/src/main/java/com/seaofnodes/simple/node/MinusNode.java b/src/main/java/com/seaofnodes/simple/node/MinusNode.java new file mode 100644 index 00000000..11769935 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/node/MinusNode.java @@ -0,0 +1,23 @@ +package com.seaofnodes.simple.node; + + +import com.seaofnodes.simple.type.Type; +import com.seaofnodes.simple.type.TypeInteger; + +public class MinusNode extends Node { + public MinusNode(Node in) { super(null, in); } + + @Override public String label() { return "Minus"; } + + @Override protected String format() { return "(-%1)"; } + + @Override + public Type compute() { + if (in(1)._type instanceof TypeInteger i0) + return i0.isConstant() ? TypeInteger.constant(-i0.value()) : i0; + return Type.BOTTOM; + } + + @Override + public Node idealize() { return null; } +} diff --git a/src/main/java/com/seaofnodes/simple/node/MulNode.java b/src/main/java/com/seaofnodes/simple/node/MulNode.java new file mode 100644 index 00000000..abae6925 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/node/MulNode.java @@ -0,0 +1,26 @@ +package com.seaofnodes.simple.node; + + +import com.seaofnodes.simple.type.Type; +import com.seaofnodes.simple.type.TypeInteger; + +public class MulNode extends Node { + public MulNode(Node lhs, Node rhs) { super(null, lhs, rhs); } + + @Override public String label() { return "Mul"; } + + @Override protected String format() { return "(%1*%2)"; } + + @Override + public Type compute() { + if (in(1)._type instanceof TypeInteger i0 && + in(2)._type instanceof TypeInteger i1) { + if (i0.isConstant() && i1.isConstant()) + return TypeInteger.constant(i0.value()*i1.value()); + } + return Type.BOTTOM; + } + + @Override + public Node idealize() { return null; } +} diff --git a/src/main/java/com/seaofnodes/simple/node/Node.java b/src/main/java/com/seaofnodes/simple/node/Node.java index ed88e86e..3c0c3905 100644 --- a/src/main/java/com/seaofnodes/simple/node/Node.java +++ b/src/main/java/com/seaofnodes/simple/node/Node.java @@ -2,6 +2,11 @@ package com.seaofnodes.simple.node; import com.seaofnodes.print.BaseNode; +import com.seaofnodes.simple.Parser; + +import com.seaofnodes.simple.Utils; +import com.seaofnodes.simple.type.Type; + import java.util.*; /** @@ -31,6 +36,12 @@ public abstract class Node extends BaseNode { */ public final ArrayList _outputs; + /** + * Current computed type for this Node. This value changes as the graph + * changes and more knowledge is gained about the program. + */ + public Type _type; + /** * A private Global Static mutable counter, for unique node id generation. * To make the compiler multi-threaded, this field will have to move into a TLS. @@ -45,9 +56,14 @@ public abstract class Node extends BaseNode { _outputs = new ArrayList<>(); for( Node n : _inputs ) if( n != null ) - n._outputs.add( this ); + n.addUse( this ); } + // Easy reading label for debugger, e.g. "Add" or "Region" or "EQ" + public abstract String label(); + + @Override public String typeName() { return _type==null ? null : _type.toString(); } + /** * Gets the ith input node * @param i Offset of the input node @@ -63,6 +79,119 @@ public abstract class Node extends BaseNode { public boolean isUnused() { return nOuts() == 0; } + /** + * Change a def into a Node. Keeps the edges correct, by removing + * the corresponding use->def edge. This may make the original + * def go dead. This function is co-recursive with {@link #kill}. + * + * @param idx which def to set + * @param new_def the new definition + * @return new_def for flow coding + */ + Node setDef(int idx, Node new_def ) { + Node old_def = in(idx); + if( old_def == new_def ) return this; // No change + // If new def is not null, add the corresponding def->use edge + // This needs to happen before removing the old node's def->use edge as + // the new_def might get killed if the old node kills it recursively. + if( new_def != null ) + new_def.addUse(this); + if( old_def != null && // If the old def exists, remove a def->use edge + old_def.delUse(this) ) // If we removed the last use, the old def is now dead + old_def.kill(); // Kill old def + // Set the new_def over the old (killed) edge + _inputs.set(idx,new_def); + // Return self for easy flow-coding + return new_def; + } + + // Breaks the edge invariants, used temporarily + protected void addUse(N n) { _outputs.add(n); } + + // Remove node 'use' from 'def's (i.e. our) output list, by compressing the list in-place. + // Return true if the output list is empty afterward. + // Error is 'use' does not exist; ok for 'use' to be null. + protected boolean delUse( Node use ) { + Utils.del(_outputs, Utils.find(_outputs, use)); + return _outputs.size() == 0; + } + + /** + * Kill a Node with no uses, by setting all of its defs + * to null. This may recursively kill more Nodes and is basically dead + * code elimination. This function is co-recursive with {@link #setDef}. + */ + public void kill( ) { + assert isUnused(); // Has no uses, so it is dead + for( int i=0; i + *
  • if the Type {@link Type#isConstant}, we replace with a {@link ConstantNode}
    • + *
  • in a future chapter we will look for a + * Common Subexpression + * to eliminate.
    • + *
  • we ask the Node for a better replacement (again, none enabled in this chapter)
    • + * + */ + public final Node peephole() { + var obs = Parser.PARSER == null ? null : Parser.PARSER._obs; + if( obs != null ) obs.before(this); + Type old = _type; + Node n = peepholeOpt(); + Node rez = n == null ? this : n; + if( obs != null ) obs.after(this, n == null && old == _type ? null : rez, false); + return rez; + } + + private Node peepholeOpt() { + // Compute initial or improved Type + Type type = _type = compute(); + + // Replace constant computations from non-constants with a constant node + if (!(this instanceof ConstantNode) && type.isConstant()) { + kill(); // Kill `this` because replacing with a Constant + return new ConstantNode(type).peephole(); + } + + // Future chapter: Global Value Numbering goes here + + // Ask each node for a better replacement + Node n = idealize(); + if( n != null ) return n; + + return null; // No progress + } + + /** + * This function needs to be + * Monotonic + * as it is part of a Monotone Analysis Framework. + * See for example this set of slides. + *

    + * For Chapter 2, all our Types are really integer constants, and so all + * the needed properties are trivially true, and we can ignore the high + * theory. Much later on, this will become important and allow us to do + * many fancy complex optimizations trivially... because theory. + *

    + * compute() needs to be stand-alone, and cannot recursively call compute + * on its inputs programs are cyclic (have loops!) and this will just + * infinitely recurse until stack overflow. Instead, compute typically + * computes a new type from the {@link #_type} field of its inputs. + */ + public abstract Type compute(); + + public abstract Node idealize(); + /** * Used to allow repeating tests in the same JVM. This just resets the * Node unique id generator, and is done as part of making a new Parser. diff --git a/src/main/java/com/seaofnodes/simple/node/ReturnNode.java b/src/main/java/com/seaofnodes/simple/node/ReturnNode.java index 85bbc83f..b48682ca 100644 --- a/src/main/java/com/seaofnodes/simple/node/ReturnNode.java +++ b/src/main/java/com/seaofnodes/simple/node/ReturnNode.java @@ -1,5 +1,9 @@ package com.seaofnodes.simple.node; +import com.seaofnodes.print.ExprPrinter; + +import com.seaofnodes.simple.type.*; + /** * The Return node has two inputs. The first input is a control node and the * second is the data node that supplies the return value. @@ -18,6 +22,21 @@ public class ReturnNode extends Node { public Node ctrl() { return in(0); } public Node expr() { return in(1); } + @Override + public String label() { return "Return"; } + + @Override + protected ExprPrinter _print1(ExprPrinter p) { + return p.p("return ").n(expr()).p(";"); + } + @Override public boolean isCFG() { return true; } + @Override + public Type compute() { + return Type.BOTTOM; + } + + @Override + public Node idealize() { return null; } } diff --git a/src/main/java/com/seaofnodes/simple/node/StartNode.java b/src/main/java/com/seaofnodes/simple/node/StartNode.java index 04bd6bb4..12f35736 100644 --- a/src/main/java/com/seaofnodes/simple/node/StartNode.java +++ b/src/main/java/com/seaofnodes/simple/node/StartNode.java @@ -1,9 +1,15 @@ package com.seaofnodes.simple.node; +import com.seaofnodes.print.ExprPrinter; + +import com.seaofnodes.simple.type.Type; + /** - * The Start node represents the start of the function. For now, we do not have any inputs to Start because our function does not - * yet accept parameters. When we add parameters the value of Start will be a tuple, and will require Projections to extract the values. - * We discuss this in detail in Chapter 9: Functions and Calls. + * The Start node represents the start of the function. For now, we do not + * have any inputs to Start because our function does not yet accept + * parameters. When we add parameters the value of Start will be a tuple, and + * will require Projections to extract the values. We discuss this in detail + * in Chapter 9: Functions and Calls. */ public class StartNode extends Node { @@ -11,6 +17,18 @@ public class StartNode extends Node { super(); } + @Override + public String label() { return "Start"; } + + @Override protected ExprPrinter _print1(ExprPrinter p) { + return p.p(label()); + } + @Override public boolean isCFG() { return true; } + @Override + public Type compute() { return Type.BOTTOM; } + + @Override + public Node idealize() { return null; } } diff --git a/src/main/java/com/seaofnodes/simple/node/SubNode.java b/src/main/java/com/seaofnodes/simple/node/SubNode.java new file mode 100644 index 00000000..88106018 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/node/SubNode.java @@ -0,0 +1,27 @@ +package com.seaofnodes.simple.node; + + +import com.seaofnodes.simple.type.Type; +import com.seaofnodes.simple.type.TypeInteger; + +public class SubNode extends Node { + public SubNode(Node lhs, Node rhs) { super(null, lhs, rhs); } + + @Override public String label() { return "Sub"; } + + @Override protected String format() { return "(%1-%2)"; } + + @Override + public Type compute() { + if (in(1)._type instanceof TypeInteger i0 && + in(2)._type instanceof TypeInteger i1) { + if (i0.isConstant() && i1.isConstant()) + return TypeInteger.constant(i0.value()-i1.value()); + } + return Type.BOTTOM; + } + + @Override + public Node idealize() { return null; } + +} diff --git a/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java b/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java index 20ee6aed..8f2f31ec 100644 --- a/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java +++ b/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java @@ -5,7 +5,7 @@ import com.seaofnodes.graph.GraphSnapshot.*; import com.seaofnodes.simple.node.*; import com.seaofnodes.simple.node.Node; -/** Chapter 1's view of the IR; browser, transport and layout are shared. */ +/** Chapter 2's view of the IR; browser, transport and layout are shared. */ public class SimpleGraphAdapter extends GraphAdapter { @Override protected Kind kind(Node n) { diff --git a/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java b/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java index 1c78e4dd..a17bf796 100644 --- a/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java +++ b/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java @@ -7,7 +7,7 @@ import com.seaofnodes.simple.node.Node; import java.util.ArrayList; import java.io.IOException; -/** Chapter 1's compilation context; capture and event bookkeeping are shared. */ +/** Chapter 2's compilation context; capture and event bookkeeping are shared. */ public class SimpleGraphObserver extends GraphCapture { private Parser _parser; private Node _ret; @@ -18,6 +18,7 @@ public class SimpleGraphObserver extends GraphCapture { } @Override protected void compile(String src) { _parser = new Parser(src); + _parser._obs = this; _phase = "Parse"; _ret = _parser.parse(); phase(_phase); @@ -25,6 +26,7 @@ public class SimpleGraphObserver extends GraphCapture { @Override protected String phase() { return _phase; } @Override protected int pos() { return "Parse".equals(_phase) ? _parser.pos() : -1; } @Override protected void detach() { + if( _parser != null ) _parser._obs = null; _parser = null; _ret = null; } diff --git a/src/main/java/com/seaofnodes/simple/type/Type.java b/src/main/java/com/seaofnodes/simple/type/Type.java new file mode 100644 index 00000000..b98ce6de --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/type/Type.java @@ -0,0 +1,45 @@ +package com.seaofnodes.simple.type; + + +/** + * These types are part of a Monotone Analysis Framework, + * @see see for example this set of slides. + *

    + * The types form a lattice; @see a symmetric complete bounded (ranked) lattice. + *

    + * This wild lattice theory will be needed later to allow us to easily beef up + * the analysis and optimization of the Simple compiler... but we don't need it + * now, just know that it is coming along in a later Chapter. + *

    g + * One of the fun things here is that while the theory is deep and subtle, the + * actual implementation is darn near trivial and is generally really obvious + * what we're doing with it. Right now, it's just simple integer math to do + * simple constant folding e.g. 1+2 == 3 stuff. + */ + +public class Type { + + // ---------------------------------------------------------- + // Simple types are implemented fully here. "Simple" means: the code and + // type hierarchy are simple, not that the Type is conceptually simple. + static final byte TBOT = 0; // Bottom (ALL) + static final byte TTOP = 1; // Top (ANY) + static final byte TSIMPLE = 2; // End of the Simple Types + static final byte TINT = 3; // All Integers; see TypeInteger + public final byte _type; + + public boolean is_simple() { return _type < TSIMPLE; } + private static final String[] STRS = new String[]{"Bot","Top"}; + protected Type(byte type) { _type = type; } + + public static final Type BOTTOM = new Type( TBOT ); // ALL + + public boolean isConstant() { return _type == TTOP; } + + @Override + public String toString() { + return print(new StringBuilder()).toString(); + } + + public StringBuilder print(StringBuilder sb) {return is_simple() ? sb.append(STRS[_type]) : sb;} +} diff --git a/src/main/java/com/seaofnodes/simple/type/TypeInteger.java b/src/main/java/com/seaofnodes/simple/type/TypeInteger.java new file mode 100644 index 00000000..e0324da5 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/type/TypeInteger.java @@ -0,0 +1,41 @@ +package com.seaofnodes.simple.type; + +/** + * Integer Type + */ +public class TypeInteger extends Type { + + public final static TypeInteger ZERO= new TypeInteger(0); + + /** + * The constant value observed for this type + */ + private final long _con; + + public TypeInteger(long con) { + super(TINT); + _con = con; + } + + public static TypeInteger constant(long con) { return new TypeInteger(con); } + + @Override + public String toString() { + return print(new StringBuilder()).toString(); + } + + @Override + public StringBuilder print(StringBuilder sb) { return sb.append(_con); } + + @Override + public boolean isConstant() { return true; } + + public long value() { return _con; } + + @Override + public boolean equals( Object o ) { + if( o==this ) return true; + if( !(o instanceof TypeInteger i) ) return false; + return _con==i._con; + } +} -- cgit v1.2.3