From b35a7c9822f2c88388c80be9788beb9fe3f7760e Mon Sep 17 00:00:00 2001
From: channa <cdiasperera@gmail.com>
Date: Sun, 21 Jan 2024 15:53:40 +0100
Subject: [PATCH] Added keyword reservation to Syntax

---
 src/main/rascal/Syntax.rsc | 19 +++++++++++++------
 src/main/rascal/Test.rsc   |  6 +++---
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/src/main/rascal/Syntax.rsc b/src/main/rascal/Syntax.rsc
index c6fbdc7..572b7c5 100644
--- a/src/main/rascal/Syntax.rsc
+++ b/src/main/rascal/Syntax.rsc
@@ -1,7 +1,6 @@
 module Syntax
 
 extend lang::std::Whitespace;
-extend lang::std::Id;
 extend lang::std::ASCII;
 
 /*
@@ -108,7 +107,7 @@ syntax Lhs                = Id ("[" Expr "]")?
 
 syntax SubProgCall        = 'readln'"(" LhsList ")"
                           | 'writeln'"(" ExprList ")"
-                          > Id \ 'writeln' \ 'readln' \ 'skip' ("(" ExprList ")")?
+                          > Id ("(" ExprList ")")?
                           ;
 
 syntax ExprList           = Expr ("," Expr)*
@@ -138,10 +137,18 @@ syntax Expr               = "(" Expr ")"
 /*
   Basic lexical constructs. 
 */
-lexical Relop   = "\<"|"\<="|"\>"|"\>="|"="|"\<\>";
-lexical Number  = Digit+
-                | Digit* "." Digit+
-                ;
+keyword Reserved  = 'program' | 'const' | 'var' | 'array' | 'of' | 'integer' 
+                  | 'real' | 'function' | 'procedure' | 'begin' | 'end'
+                  | 'skip' | 'if' | 'then' | 'else' | 'while' | 'do' | 'not'
+                  | 'or' | 'and' | 'readln' | 'writeln'
+                  ;
+lexical Id        = ([a-z A-Z 0-9 _] !<< [a-z A-Z][a-z A-Z 0-9 _]* !>> [a-z A-Z 0-9 _]) \ Reserved
+                  ;
+
+lexical Relop     = "\<"|"\<="|"\>"|"\>="|"="|"\<\>";
+lexical Number    = Digit+
+                  | Digit* "." Digit+
+                  ;
 /*
   A comment is anything between a "{" and a "}"
 */
diff --git a/src/main/rascal/Test.rsc b/src/main/rascal/Test.rsc
index 740338a..a9b53a0 100644
--- a/src/main/rascal/Test.rsc
+++ b/src/main/rascal/Test.rsc
@@ -1,6 +1,7 @@
 module Test
 
 import ParseTree;
+import Exception;
 import Syntax;
 import IO;
 
@@ -17,9 +18,8 @@ void main() {
 */
 start[Program] runSyntaxTestOn(loc file) {
   println("Parsing: <file>");
-  pt = parse(#start[Program], file);
-
-  return pt;
+  return parse(#start[Program], file);
+  
 }
 
 list[loc] getFilesIn(loc dir) {