From df2a36c84bf25bdbe197d876c84843d557d2444a Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 7 Oct 2024 13:14:40 +0200
Subject: [PATCH 1/5] draft function

---
 R/label-glue.R | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 R/label-glue.R

diff --git a/R/label-glue.R b/R/label-glue.R
new file mode 100644
index 00000000..0f755296
--- /dev/null
+++ b/R/label-glue.R
@@ -0,0 +1,8 @@
+
+label_glue <- function(pattern = "{x}", ..., .envir = caller_env()) {
+  args <- list2(...)
+  force_all(pattern, .envir)
+  function(x) {
+    inject(glue::glue_data(list(x = x), pattern, !!!args, .envir = .envir))
+  }
+}

From 29402b4d94e0b9d7022739b627905e53daef8560 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 7 Oct 2024 13:20:20 +0200
Subject: [PATCH 2/5] add test

---
 tests/testthat/test-label-glue.R | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 tests/testthat/test-label-glue.R

diff --git a/tests/testthat/test-label-glue.R b/tests/testthat/test-label-glue.R
new file mode 100644
index 00000000..82701e4f
--- /dev/null
+++ b/tests/testthat/test-label-glue.R
@@ -0,0 +1,10 @@
+test_that("label_glue environments work out as intended", {
+
+  x <- LETTERS[1:3]
+  y <- "foo"
+
+  # Note `{x}` should mask the `x <- LETTERS[1:3]` above
+  f <- label_glue("{x} and {y}")
+  expect_equal(f(letters[1:3]), c("a and foo", "b and foo", "c and foo"))
+
+})

From 0a94bcc17a7d7b748ccd249ef1d6e740ec64b51b Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 7 Oct 2024 13:21:10 +0200
Subject: [PATCH 3/5] document

---
 DESCRIPTION              |  2 +-
 NAMESPACE                |  1 +
 R/label-glue.R           | 28 +++++++++++++++++++-
 man/label_bytes.Rd       |  1 +
 man/label_currency.Rd    |  1 +
 man/label_glue.Rd        | 56 ++++++++++++++++++++++++++++++++++++++++
 man/label_number_auto.Rd |  1 +
 man/label_number_si.Rd   |  1 +
 man/label_ordinal.Rd     |  1 +
 man/label_parse.Rd       |  2 ++
 man/label_percent.Rd     |  1 +
 man/label_pvalue.Rd      |  1 +
 man/label_scientific.Rd  |  1 +
 man/label_wrap.Rd        |  1 +
 14 files changed, 96 insertions(+), 2 deletions(-)
 create mode 100644 man/label_glue.Rd

diff --git a/DESCRIPTION b/DESCRIPTION
index 38d99259..0ee8fe58 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -39,4 +39,4 @@ Config/testthat/edition: 3
 Encoding: UTF-8
 LazyLoad: yes
 Roxygen: list(markdown = TRUE, r6 = FALSE)
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.2
diff --git a/NAMESPACE b/NAMESPACE
index 323e34ba..f0872ff3 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -116,6 +116,7 @@ export(label_currency)
 export(label_date)
 export(label_date_short)
 export(label_dollar)
+export(label_glue)
 export(label_log)
 export(label_math)
 export(label_number)
diff --git a/R/label-glue.R b/R/label-glue.R
index 0f755296..94765ca3 100644
--- a/R/label-glue.R
+++ b/R/label-glue.R
@@ -1,4 +1,30 @@
-
+#' Interpolated labels
+#'
+#' Use `label_glue()` to perform string interpolation using the \pkg{glue}
+#' package. Enclosed expressions will be evaluated as R code.
+#'
+#' @param pattern A glue string used for formatting. The `x` variable holds the
+#'   breaks, so that `"{x}"` (default) returns the breaks as-is.
+#' @param ... Arguments passed on to [`glue::glue()`].
+#' @inheritParams glue::glue
+#'
+#' @return A labeller function that takes a vector of breaks and returns a
+#'   character vector of labels.
+#' @export
+#' @family labels for continuous scales
+#' @family labels for discrete scales
+#'
+#' @examples
+#' # Example variables
+#' animal  <- "penguin"
+#' species <- c("Adelie",  "Chinstrap", "Emperor", "Gentoo")
+#'
+#' # Typical use, note that {x} will become the breaks
+#' demo_discrete(species, labels = label_glue("The {x}\n{animal}"))
+#' # It adapts to the breaks that are present
+#' demo_discrete(species[-3], labels =  label_glue("The {x}\n{animal}"))
+#' # Contrary to directly glueing species + animal, which results in mislabelling!
+#' demo_discrete(species[-3], labels = glue::glue("The {species}\n{animal}"))
 label_glue <- function(pattern = "{x}", ..., .envir = caller_env()) {
   args <- list2(...)
   force_all(pattern, .envir)
diff --git a/man/label_bytes.Rd b/man/label_bytes.Rd
index 02054433..7c6d9561 100644
--- a/man/label_bytes.Rd
+++ b/man/label_bytes.Rd
@@ -105,6 +105,7 @@ demo_continuous(c(1, 1024^2),
 \seealso{
 Other labels for continuous scales: 
 \code{\link{label_currency}()},
+\code{\link{label_glue}()},
 \code{\link{label_number_auto}()},
 \code{\link{label_number_si}()},
 \code{\link{label_ordinal}()},
diff --git a/man/label_currency.Rd b/man/label_currency.Rd
index a29feb17..ec8ee2e8 100644
--- a/man/label_currency.Rd
+++ b/man/label_currency.Rd
@@ -127,6 +127,7 @@ demo_log10(c(1, 1e12), breaks = log_breaks(5, 1e3), labels = gbp)
 \seealso{
 Other labels for continuous scales: 
 \code{\link{label_bytes}()},
+\code{\link{label_glue}()},
 \code{\link{label_number_auto}()},
 \code{\link{label_number_si}()},
 \code{\link{label_ordinal}()},
diff --git a/man/label_glue.Rd b/man/label_glue.Rd
new file mode 100644
index 00000000..ed10e3f8
--- /dev/null
+++ b/man/label_glue.Rd
@@ -0,0 +1,56 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/label-glue.R
+\name{label_glue}
+\alias{label_glue}
+\title{Interpolated labels}
+\usage{
+label_glue(pattern = "{x}", ..., .envir = caller_env())
+}
+\arguments{
+\item{pattern}{A glue string used for formatting. The \code{x} variable holds the
+breaks, so that \code{"{x}"} (default) returns the breaks as-is.}
+
+\item{...}{Arguments passed on to \code{\link[glue:glue]{glue::glue()}}.}
+
+\item{.envir}{[\code{environment}: \code{parent.frame()}]\cr Environment to evaluate each expression in. Expressions are
+evaluated from left to right. If \code{.x} is an environment, the expressions are
+evaluated in that environment and \code{.envir} is ignored. If \code{NULL} is passed, it is equivalent to \code{\link[=emptyenv]{emptyenv()}}.}
+}
+\value{
+A labeller function that takes a vector of breaks and returns a
+character vector of labels.
+}
+\description{
+Use \code{label_glue()} to perform string interpolation using the \pkg{glue}
+package. Enclosed expressions will be evaluated as R code.
+}
+\examples{
+# Example variables
+animal  <- "penguin"
+species <- c("Adelie",  "Chinstrap", "Emperor", "Gentoo")
+
+# Typical use, note that {x} will become the breaks
+demo_discrete(species, labels = label_glue("The {x}\n{animal}"))
+# It adapts to the breaks that are present
+demo_discrete(species[-3], labels =  label_glue("The {x}\n{animal}"))
+# Contrary to directly glueing species + animal, which results in mislabelling!
+demo_discrete(species[-3], labels = glue::glue("The {species}\n{animal}"))
+}
+\seealso{
+Other labels for continuous scales: 
+\code{\link{label_bytes}()},
+\code{\link{label_currency}()},
+\code{\link{label_number_auto}()},
+\code{\link{label_number_si}()},
+\code{\link{label_ordinal}()},
+\code{\link{label_parse}()},
+\code{\link{label_percent}()},
+\code{\link{label_pvalue}()},
+\code{\link{label_scientific}()}
+
+Other labels for discrete scales: 
+\code{\link{label_parse}()},
+\code{\link{label_wrap}()}
+}
+\concept{labels for continuous scales}
+\concept{labels for discrete scales}
diff --git a/man/label_number_auto.Rd b/man/label_number_auto.Rd
index a660cbec..401c72dc 100644
--- a/man/label_number_auto.Rd
+++ b/man/label_number_auto.Rd
@@ -30,6 +30,7 @@ demo_log10(c(1, 1e7), labels = label_number_auto())
 Other labels for continuous scales: 
 \code{\link{label_bytes}()},
 \code{\link{label_currency}()},
+\code{\link{label_glue}()},
 \code{\link{label_number_si}()},
 \code{\link{label_ordinal}()},
 \code{\link{label_parse}()},
diff --git a/man/label_number_si.Rd b/man/label_number_si.Rd
index fd8c8ece..f35d160e 100644
--- a/man/label_number_si.Rd
+++ b/man/label_number_si.Rd
@@ -90,6 +90,7 @@ units, \code{label_number(scale_cut = cut_si("unit"))}.
 Other labels for continuous scales: 
 \code{\link{label_bytes}()},
 \code{\link{label_currency}()},
+\code{\link{label_glue}()},
 \code{\link{label_number_auto}()},
 \code{\link{label_ordinal}()},
 \code{\link{label_parse}()},
diff --git a/man/label_ordinal.Rd b/man/label_ordinal.Rd
index 471c0ebd..7ee2deb7 100644
--- a/man/label_ordinal.Rd
+++ b/man/label_ordinal.Rd
@@ -118,6 +118,7 @@ demo_continuous(c(1, 10),
 Other labels for continuous scales: 
 \code{\link{label_bytes}()},
 \code{\link{label_currency}()},
+\code{\link{label_glue}()},
 \code{\link{label_number_auto}()},
 \code{\link{label_number_si}()},
 \code{\link{label_parse}()},
diff --git a/man/label_parse.Rd b/man/label_parse.Rd
index 7dd7d29d..4d4ad9da 100644
--- a/man/label_parse.Rd
+++ b/man/label_parse.Rd
@@ -48,6 +48,7 @@ demo_continuous(c(1, 5), labels = label_math())
 Other labels for continuous scales: 
 \code{\link{label_bytes}()},
 \code{\link{label_currency}()},
+\code{\link{label_glue}()},
 \code{\link{label_number_auto}()},
 \code{\link{label_number_si}()},
 \code{\link{label_ordinal}()},
@@ -56,6 +57,7 @@ Other labels for continuous scales:
 \code{\link{label_scientific}()}
 
 Other labels for discrete scales: 
+\code{\link{label_glue}()},
 \code{\link{label_wrap}()}
 }
 \concept{labels for continuous scales}
diff --git a/man/label_percent.Rd b/man/label_percent.Rd
index a705538c..ac7c2905 100644
--- a/man/label_percent.Rd
+++ b/man/label_percent.Rd
@@ -106,6 +106,7 @@ demo_continuous(c(0, .01), labels = french_percent)
 Other labels for continuous scales: 
 \code{\link{label_bytes}()},
 \code{\link{label_currency}()},
+\code{\link{label_glue}()},
 \code{\link{label_number_auto}()},
 \code{\link{label_number_si}()},
 \code{\link{label_ordinal}()},
diff --git a/man/label_pvalue.Rd b/man/label_pvalue.Rd
index ae9e2b83..55faf7c6 100644
--- a/man/label_pvalue.Rd
+++ b/man/label_pvalue.Rd
@@ -55,6 +55,7 @@ demo_continuous(c(0, 1), labels = label_pvalue(prefix = prefix))
 Other labels for continuous scales: 
 \code{\link{label_bytes}()},
 \code{\link{label_currency}()},
+\code{\link{label_glue}()},
 \code{\link{label_number_auto}()},
 \code{\link{label_number_si}()},
 \code{\link{label_ordinal}()},
diff --git a/man/label_scientific.Rd b/man/label_scientific.Rd
index 97db3367..ae22a6b9 100644
--- a/man/label_scientific.Rd
+++ b/man/label_scientific.Rd
@@ -55,6 +55,7 @@ demo_log10(c(1, 1e9))
 Other labels for continuous scales: 
 \code{\link{label_bytes}()},
 \code{\link{label_currency}()},
+\code{\link{label_glue}()},
 \code{\link{label_number_auto}()},
 \code{\link{label_number_si}()},
 \code{\link{label_ordinal}()},
diff --git a/man/label_wrap.Rd b/man/label_wrap.Rd
index 94862292..0e160437 100644
--- a/man/label_wrap.Rd
+++ b/man/label_wrap.Rd
@@ -34,6 +34,7 @@ demo_discrete(x, labels = label_wrap(20))
 }
 \seealso{
 Other labels for discrete scales: 
+\code{\link{label_glue}()},
 \code{\link{label_parse}()}
 }
 \concept{labels for discrete scales}

From 317b4a427463bf0eb404643cfe4d46ff6f599b7a Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 7 Oct 2024 13:22:07 +0200
Subject: [PATCH 4/5] add news bullet

---
 NEWS.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/NEWS.md b/NEWS.md
index 9646d4a5..04315d22 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,7 @@
 # scales (development version)
 
+* New `label_glue()` labelling function for interpolated strings (#457).
+
 # scales 1.3.0
 
 ## Better type support

From 55959408c3ffda218fb85844541fa371e4e5b75d Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Fri, 11 Oct 2024 09:39:25 +0200
Subject: [PATCH 5/5] add option to parse

---
 R/label-glue.R    | 11 ++++++++---
 man/label_glue.Rd |  4 +++-
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/R/label-glue.R b/R/label-glue.R
index 94765ca3..156d4be9 100644
--- a/R/label-glue.R
+++ b/R/label-glue.R
@@ -6,6 +6,7 @@
 #' @param pattern A glue string used for formatting. The `x` variable holds the
 #'   breaks, so that `"{x}"` (default) returns the breaks as-is.
 #' @param ... Arguments passed on to [`glue::glue()`].
+#' @param parse Whether to return labels as expressions.
 #' @inheritParams glue::glue
 #'
 #' @return A labeller function that takes a vector of breaks and returns a
@@ -25,10 +26,14 @@
 #' demo_discrete(species[-3], labels =  label_glue("The {x}\n{animal}"))
 #' # Contrary to directly glueing species + animal, which results in mislabelling!
 #' demo_discrete(species[-3], labels = glue::glue("The {species}\n{animal}"))
-label_glue <- function(pattern = "{x}", ..., .envir = caller_env()) {
+label_glue <- function(pattern = "{x}", ..., parse = FALSE, .envir = caller_env()) {
   args <- list2(...)
-  force_all(pattern, .envir)
+  force_all(pattern, parse, .envir)
   function(x) {
-    inject(glue::glue_data(list(x = x), pattern, !!!args, .envir = .envir))
+    x <- inject(glue::glue_data(list(x = x), pattern, !!!args, .envir = .envir))
+    if (parse) {
+      x <- parse_safe(x)
+    }
+    x
   }
 }
diff --git a/man/label_glue.Rd b/man/label_glue.Rd
index ed10e3f8..3b88d0ca 100644
--- a/man/label_glue.Rd
+++ b/man/label_glue.Rd
@@ -4,7 +4,7 @@
 \alias{label_glue}
 \title{Interpolated labels}
 \usage{
-label_glue(pattern = "{x}", ..., .envir = caller_env())
+label_glue(pattern = "{x}", ..., parse = FALSE, .envir = caller_env())
 }
 \arguments{
 \item{pattern}{A glue string used for formatting. The \code{x} variable holds the
@@ -12,6 +12,8 @@ breaks, so that \code{"{x}"} (default) returns the breaks as-is.}
 
 \item{...}{Arguments passed on to \code{\link[glue:glue]{glue::glue()}}.}
 
+\item{parse}{Whether to return labels as expressions.}
+
 \item{.envir}{[\code{environment}: \code{parent.frame()}]\cr Environment to evaluate each expression in. Expressions are
 evaluated from left to right. If \code{.x} is an environment, the expressions are
 evaluated in that environment and \code{.envir} is ignored. If \code{NULL} is passed, it is equivalent to \code{\link[=emptyenv]{emptyenv()}}.}