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Use str_view htmlwidget

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hadley 2015-10-27 11:03:27 -05:00
parent 4ca5cdbaab
commit 5e65371942
3 changed files with 7 additions and 9 deletions
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2
.travis.yml
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@ -23,7 +23,7 @@ install:
# Install R packages # Install R packages
- ./travis-tool.sh r_binary_install knitr png - ./travis-tool.sh r_binary_install knitr png
- ./travis-tool.sh r_install ggplot2 dplyr tidyr pryr stringr - ./travis-tool.sh r_install ggplot2 dplyr tidyr pryr stringr
- ./travis-tool.sh github_package hadley/bookdown garrettgman/DSR hadley/readr gaborcsardi/rcorpora - ./travis-tool.sh github_package hadley/bookdown garrettgman/DSR hadley/readr gaborcsardi/rcorpora hadley/stringr
script: jekyll build script: jekyll build

10
strings.Rmd
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@ -176,7 +176,7 @@ common <- rcorpora::corpora("words/common")$commonWords
### Match anything and escaping ### Match anything and escaping
```{r} ```{r}
str_subset(c("abc", "adc", "bef"), "a.c") str_view(c("abc", "adc", "bef"), "a.c")
``` ```
But if "`.`" matches any character, how do you match an actual "`.`"? You need to use an "escape" to tell the regular expression you want to match it exactly, not use the special behaviour. The escape character used by regular expressions is `\`. Unfortunately, that's also the escape character used by strings, so to match a literal "`.`" you need to use `\\.`. But if "`.`" matches any character, how do you match an actual "`.`"? You need to use an "escape" to tell the regular expression you want to match it exactly, not use the special behaviour. The escape character used by regular expressions is `\`. Unfortunately, that's also the escape character used by strings, so to match a literal "`.`" you need to use `\\.`.
@ -189,7 +189,7 @@ dot <- "\\."
cat(dot, "\n") cat(dot, "\n")
# And this tells R to look for explicit . # And this tells R to look for explicit .
str_subset(c("abc", "a.c", "bef"), "a\\.c") str_view(c("abc", "a.c", "bef"), "a\\.c")
``` ```
If `\` is used an escape character, how do you match a literal `\`? Well you need to escape it, creating the regular expression `\\`. And in R that needs to be in a string, so you need to write `"\\\\"` - that's right, you need four backslashes to match one! If `\` is used an escape character, how do you match a literal `\`? Well you need to escape it, creating the regular expression `\\`. And in R that needs to be in a string, so you need to write `"\\\\"` - that's right, you need four backslashes to match one!
@ -218,7 +218,7 @@ Regular expressions can also match things that are not characters. The most impo
To force a regular expression to only match a complete string, anchor it with both `^` and `$`.: To force a regular expression to only match a complete string, anchor it with both `^` and `$`.:
```{r} ```{r}
str_detect(c("abcdef", "bcd"), "^bcd$") str_view(c("abcdef", "bcd"), "^bcd$")
``` ```
My favourite mneomic for rememember which is which (from [Evan Misshula](https://twitter.com/emisshula/status/323863393167613953): begin with power (`^`), end with money (`$`). My favourite mneomic for rememember which is which (from [Evan Misshula](https://twitter.com/emisshula/status/323863393167613953): begin with power (`^`), end with money (`$`).
@ -246,13 +246,13 @@ Remember, to create a regular expression containing `\d` or `\s`, you'll need to
A similar idea is alternation: `x|y` matches either x or y. Note that the precedence for `|` is low, so that `abc|xyz` matches either `abc` or `xyz` not `abcyz` or `abxyz`: A similar idea is alternation: `x|y` matches either x or y. Note that the precedence for `|` is low, so that `abc|xyz` matches either `abc` or `xyz` not `abcyz` or `abxyz`:
```{r} ```{r}
str_detect(c("abc", "xyz"), "abc|xyz") str_view(c("abc", "xyz"), "abc|xyz")
``` ```
Like with mathematical expression, if precedence ever gets confusing, use parentheses to make it clear what you want: Like with mathematical expression, if precedence ever gets confusing, use parentheses to make it clear what you want:
```{r} ```{r}
str_detect(c("grey", "gray"), "gr(e|a)y") str_view(c("grey", "gray"), "gr(e|a)y")
``` ```
Practice these by finding: Practice these by finding:

4
www/.gitignore vendored
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@ -1,3 +1 @@
bootstrap-2.3.2/ *
highlight/
jquery-1.11.0/