Init next project

Project-02/triplayacc.py

@@ -0,0 +1,45 @@
+
+# ------------------------------------------------------------
+# triplayacc.py
+#
+# Yacc grammar of the TRIPLA language
+''' Here an initial grammar
+    E ->  while E do { E }
+       | CONST
+
+    CONST: Positive, integer numbers = 0 | [1-9][0-9]*
+
+'''
+
+# Note: For LALR(1) left recursion is preferred
+# ------------------------------------------------------------
+
+import ply.yacc as yacc
+import syntax as ast
+
+# Get the token map from the lexer.  This is required.
+from triplalex import tokens
+
+precedence = (
+
+)
+
+def p_expression_const(p):
+    'expression : CONST'
+    p[0] = ast.CONST(p[1])
+
+
+def p_expression_while(p):
+    'expression : WHILE expression DO LBRACE expression RBRACE'
+    p[0] = ast.WHILE(p[2],p[5])
+
+#def p_empty(p):
+#    'empty :'
+#    pass
+
+# Error rule for syntax errors
+def p_error(p):
+    print("Syntax error in input!")
+
+# Build the parser
+parser = yacc.yacc()  # debug=True