getParseData
Get Detailed Parse Information from Object
Description
Given a parsed expression, produce a data.frame containing detailed
information about the parsed expression, including comments.
Usage
getParseData(x, includeText = NA)
getParseText(parseData, id)
Arguments
| x |
A parsed expression, as returned by parse. The parsing
must be done with the keep.source argument equal to TRUE,
to keep the parsing information used by getParseData.
|
| includeText |
A logical value.
|
| parseData |
A data.frame returned by getParseData.
|
| id |
A vector of integers.
|
Details
The includeText argument specifies whether the data.frame produced
by getParseData contains the text for each of the parsed tokens.
- If includeText is TRUE, then the data.frame contains a column named
'text' with the text corresponding to each row.
- If includeText is FALSE, then the data.frame has no 'text' column.
- If includeText is NA, then there is a 'text' column, but it has only text
values for terminal tokens.
Value
| getParseData | returns a data.frame with one row for each of
the tokens in the parsed expression. The data.frame columns are
the following:
- "line1" Line number of the first character of the token text.
- "col1" Column number of the first character of the token text.
- "line2" Line number of the last character of the token text.
- "col2" Column number of the last character of the token text.
- "id" An integer identifying the token.
- "parent" The ID of the parent token of this token.
- "token" S string giving the token type.
- "terminal" A logical value, TRUE if the token has no children.
- "text" The text string for this token. If the includeText
argument is FALSE, this column is not present.
|
| getParseText | returns a vector of strings, giving the token
strings corresponding to the specified ID numbers. |
See Also
Examples
ex <- parse(text="#comm1\nx<-function(x) {\n#comm2\n x+1\n}\n",
keep.source=TRUE)
pd <- getParseData(ex)
# line1 col1 line2 col2 id parent token terminal text
# 1 1 1 1 6 1 0 COMMENT TRUE #comm1
# 20 2 1 5 1 20 0 expr FALSE
# 3 2 1 2 1 3 4 SYMBOL TRUE x
# ...
getParseText(pd, 1)
# [1] "#comm1"