diff options
Diffstat (limited to 'main/core/parser/Parser.java')
| -rw-r--r-- | main/core/parser/Parser.java | 155 |
1 files changed, 119 insertions, 36 deletions
diff --git a/main/core/parser/Parser.java b/main/core/parser/Parser.java index af62f7e..416c3f0 100644 --- a/main/core/parser/Parser.java +++ b/main/core/parser/Parser.java @@ -2,9 +2,12 @@ package com.jantuomi.interpreter.main.core.parser; import com.jantuomi.interpreter.main.core.parser.ast.*; import com.jantuomi.interpreter.main.core.tokenizer.token.Token; +import com.jantuomi.interpreter.main.exception.ExceptionManager; +import com.jantuomi.interpreter.main.exception.InterpreterException; import com.jantuomi.interpreter.main.utils.Counter; import java.util.ArrayList; +import java.util.Arrays; import java.util.List; /** @@ -24,6 +27,18 @@ public class Parser { } + private Token getTokenAt(Counter c) { + if (c.getValue() >= tokens.size()) { + return new Token(Token.Type.NotAToken); + } + + return tokens.get(c.getValue()); + } + + private boolean isTooDeep(Counter c) { + return c.getRecursionDepth() > tokens.size(); + } + public List<ASTNode> parse(List<Token> tokens) { this.tokens = tokens; this.statementSequence = new ArrayList<>(); @@ -40,6 +55,11 @@ public class Parser { statementSequence.add(adn); continue; } + + Token failed = tokens.get(c.getValue()); + ExceptionManager.raise(InterpreterException.Exception.SyntaxError, failed.getLine(), + Arrays.asList(failed.toString())); + break; } return statementSequence; @@ -47,8 +67,13 @@ public class Parser { public AssignmentNode expectAssignmentRoutine(Counter c) { Counter d = c.clone(); + d.deeper(); - SymbolNode lhs = expectLHS(d); + if (isTooDeep(d)) { + return null; + } + + SymbolNode lhs = expectAssignmentLHS(d); if (lhs == null) { return null; } @@ -56,27 +81,98 @@ public class Parser { if (!isAssign) { return null; } - ExpressionNode rhs = expectRHS(d); + ExpressionNode rhs = expectAssignmentRHS(d); if (rhs == null) { return null; } AssignmentNode an = new AssignmentNode(lhs, rhs); - c.setValue(d.getValue()); + d.shallower(); + c.assign(d); return an; } - public SymbolNode expectLHS(Counter c) { - SymbolNode sn = parseSymbolAndAdvance(c); + private AdditionNode expectAdditionRoutine(Counter c) { + Counter d = c.clone(); + d.deeper(); + + if (isTooDeep(d)) { + return null; + } + + ExpressionNode lhs = expectExpression(d); + if (lhs == null) { + return null; + } + boolean isAddition = expectAdditionAndAdvance(d); + if (!isAddition) { + return null; + } + ExpressionNode rhs = expectExpression(d); + if (rhs == null) { + return null; + } + + AdditionNode an = new AdditionNode(lhs, rhs); + d.shallower(); + c.assign(d); + return an; + } + +// private ExpressionNode expectAdditionLHS(Counter c) { +// Counter d = c.clone(); +// d.deeper(); +// +// if (isTooDeep(d)) { +// return null; +// } +// +// IntegerLiteralNode in = parseIntegerLiteralAndAdvance(d); +// if (in != null) { +// d.shallower(); +// c.assign(d); +// return in; +// } +// SymbolNode sn = parseSymbolAndAdvance(d); +// if (sn != null) { +// d.shallower(); +// c.assign(d); +// return sn; +// } +// +// return null; +// } + + + public SymbolNode expectAssignmentLHS(Counter c) { + Counter d = c.clone(); + d.deeper(); + + if (isTooDeep(d)) { + return null; + } + + SymbolNode sn = parseSymbolAndAdvance(d); if (sn != null) { + d.shallower(); + c.assign(d); return sn; } return null; } - public ExpressionNode expectRHS(Counter c) { + public ExpressionNode expectAssignmentRHS(Counter c) { + Counter d = c.clone(); + d.deeper(); + + if (isTooDeep(d)) { + return null; + } + ExpressionNode en = expectExpression(c); if (en != null) { + d.shallower(); + c.assign(d); return en; } return null; @@ -84,49 +180,36 @@ public class Parser { private ExpressionNode expectExpression(Counter c) { Counter d = c.clone(); + d.deeper(); + + if (isTooDeep(d)) { + return null; + } AdditionNode an = expectAdditionRoutine(d); if (an != null) { - c.setValue(d.getValue()); + d.shallower(); + c.assign(d); return an; } IntegerLiteralNode in = parseIntegerLiteralAndAdvance(d); if (in != null) { - c.setValue(d.getValue()); + d.shallower(); + c.assign(d); return in; } SymbolNode sn = parseSymbolAndAdvance(d); if (sn != null) { - c.setValue(d.getValue()); + d.shallower(); + c.assign(d); return sn; } return null; } - private AdditionNode expectAdditionRoutine(Counter c) { - Counter d = c.clone(); - - ExpressionNode lhs = expectLHS(d); - if (lhs == null) { - return null; - } - boolean isAddition = expectAdditionAndAdvance(d); - if (!isAddition) { - return null; - } - ExpressionNode rhs = expectRHS(d); - if (rhs == null) { - return null; - } - - AdditionNode an = new AdditionNode(lhs, rhs); - c.setValue(d.getValue()); - return an; - } - private boolean expectAdditionAndAdvance(Counter c) { - if (tokens.get(c.getValue()).is(Token.Type.AdditionToken)) { + if (getTokenAt(c).is(Token.Type.AdditionToken)) { c.advance(); return true; } else { @@ -135,8 +218,8 @@ public class Parser { } private IntegerLiteralNode parseIntegerLiteralAndAdvance(Counter c) { - if (tokens.get(c.getValue()).is(Token.Type.IntegerLiteralToken)) { - IntegerLiteralNode in = new IntegerLiteralNode(tokens.get(c.getValue())); + if (getTokenAt(c).is(Token.Type.IntegerLiteralToken)) { + IntegerLiteralNode in = new IntegerLiteralNode(getTokenAt(c)); c.advance(); return in; } else { @@ -145,7 +228,7 @@ public class Parser { } public boolean expectAssignmentAndAdvance(Counter c) { - if (tokens.get(c.getValue()).is(Token.Type.AssignmentToken)) { + if (getTokenAt(c).is(Token.Type.AssignmentToken)) { c.advance(); return true; } else { @@ -154,8 +237,8 @@ public class Parser { } public SymbolNode parseSymbolAndAdvance(Counter c) { - if (tokens.get(c.getValue()).is(Token.Type.SymbolToken)) { - SymbolNode sn = new SymbolNode(tokens.get(c.getValue())); + if (getTokenAt(c).is(Token.Type.SymbolToken)) { + SymbolNode sn = new SymbolNode(getTokenAt(c)); c.advance(); return sn; } else { |