preserving whitespace

[Enrique Pérez]

I am writing a parser for a grammar, and I want to allow Python sections
(delimitd by '\n<-\n' and '\n->\n') within code generated from that
grammar. I do not want to parse Python; I will feed it to exec. I just want
to get the whole lines, including whitespace.

This is in my lexer:

def t_begin_pycode(self, t):
r'<-'
t.lexer.begin('pycode')

def t_pycode_newline(self, t):
r'\n+'
t.lexer.lineno += len(t.value)

def t_pycode_IMPLIES(self, t):
r'->'
t.lexer.begin('INITIAL')
return t

def t_pycode_PYCODE(self, t):
r'.+'
return t

t_pycode_ignore = ''

However, somewhere between this and the parser, the leading whitespace is
lost...
What am I doing wrong?

I have looked at the GardenSnake parser by Andrew Dalke but I do not need
to parse indentation or distinguish types of whitespace.

[Enrique Pérez Arnaud]

The problem was elsewhere, not in my usage of ply.

Sorry about the noise

Post by Enrique Pérez
I am writing a parser for a grammar, and I want to allow Python sections
(delimitd by '\n<-\n' and '\n->\n') within code generated from that
grammar. I do not want to parse Python; I will feed it to exec. I just want
to get the whole lines, including whitespace.
r'<-'
t.lexer.begin('pycode')
r'\n+'
t.lexer.lineno += len(t.value)
r'->'
t.lexer.begin('INITIAL')
return t
r'.+'
return t
t_pycode_ignore = ''
However, somewhere between this and the parser, the leading whitespace is
lost...
What am I doing wrong?
I have looked at the GardenSnake parser by Andrew Dalke but I do not need
to parse indentation or distinguish types of whitespace.
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