Merge remote-tracking branch 'upstream/master'

1 files changed, 74 insertions, 0 deletions

diff --git a/third_party/ply/example/BASIC/basiclex.py b/third_party/ply/example/BASIC/basiclex.py
new file mode 100644
index 00000000..3d27cdee
--- /dev/null
+++ b/third_party/ply/example/BASIC/basiclex.py
@@ -0,0 +1,74 @@
+# An implementation of Dartmouth BASIC (1964)
+
+from ply import *
+
+keywords = (
+    'LET','READ','DATA','PRINT','GOTO','IF','THEN','FOR','NEXT','TO','STEP',
+    'END','STOP','DEF','GOSUB','DIM','REM','RETURN','RUN','LIST','NEW',
+)
+
+tokens = keywords + (
+     'EQUALS','PLUS','MINUS','TIMES','DIVIDE','POWER',
+     'LPAREN','RPAREN','LT','LE','GT','GE','NE',
+     'COMMA','SEMI', 'INTEGER','FLOAT', 'STRING',
+     'ID','NEWLINE'
+)
+
+t_ignore = ' \t'
+
+def t_REM(t):
+    r'REM .*'
+    return t
+
+def t_ID(t):
+    r'[A-Z][A-Z0-9]*'
+    if t.value in keywords:
+        t.type = t.value
+    return t
+    
+t_EQUALS  = r'='
+t_PLUS    = r'\+'
+t_MINUS   = r'-'
+t_TIMES   = r'\*'
+t_POWER   = r'\^'
+t_DIVIDE  = r'/'
+t_LPAREN  = r'\('
+t_RPAREN  = r'\)'
+t_LT      = r'<'
+t_LE      = r'<='
+t_GT      = r'>'
+t_GE      = r'>='
+t_NE      = r'<>'
+t_COMMA   = r'\,'
+t_SEMI    = r';'
+t_INTEGER = r'\d+'    
+t_FLOAT   = r'((\d*\.\d+)(E[\+-]?\d+)?|([1-9]\d*E[\+-]?\d+))'
+t_STRING  = r'\".*?\"'
+
+def t_NEWLINE(t):
+    r'\n'
+    t.lexer.lineno += 1
+    return t
+
+def t_error(t):
+    print("Illegal character %s" % t.value[0])
+    t.lexer.skip(1)
+
+lex.lex(debug=0)
+
+
+
+
+
+
+
+       
+   
+  
+            
+
+
+
+
+
+