glue 1.7.0

• If rlang is installed, glue will generate more informative errors if an
  interpolated expression either can't be parsed or fails to evaluate (#229).

• + now works in more situations, and gives errors when one side isn't a
  character vector. It no longer automatically applies glue interpolation to
  a non-glue input, if there is one. You'll need to do that yourself (#286).

• glue_collapse(character()) (and hence glue_sql_collapse(character())) now
  return "", so that they always return a single string (#88).

• glue_sql() now collapses an empty vector to "" not "NULL" (#272).

• glue_sql() now uses DBI::dbQuoteLiteral() for all object types. This
  should increase fidelity of escaping for different object types (#279).

• The "Speed of glue" vignette has been converted to an article, which allows
  several package to be removed from Suggests (and re-located to
  Config/Needs/website). The code got a light refresh, including a switch
  from microbenchmark to bench and more modern use of ggplot2.

• Add $(C_VISIBILITY) to compiler flags to hide internal symbols from the dll (#284 @lionel-).

glue 1.6.2

• Modify a test for better forward compatibility with R.

glue 1.6.1

• glue now registers its custom knitr engines in a way that is more robust to namespace-loading edge cases that can arise during package installation (#254).

glue 1.6.0

• glue(), glue_data(), glue_col(), and glue_data_col() gain a new .literal argument, which controls how quotes and the comment character are treated when parsing the expression string (#235). This is mostly useful when using a custom transformer.

• Trailing whitespace-only lines don't interfere with indentation (#247).

glue 1.5.1

• Jennifer Bryan is now the maintainer.

• The existing custom language engines for knitr, glue and glue_sql, are documented in a new vignette (#71).

• glue_col() gives special treatment to styling functions from the crayon package, e.g. glue_col("{blue foo}") "just works" now, even if crayon is not attached (but is installed) (#241).

• Unterminated backticks trigger the same error as unterminated single or double quotes (#237).

• glue_sql() collapses zero-length DBI::SQL object into DBI::SQL("NULL") (#244 @shrektan).

glue 1.5.0

Breaking changes

• Long deprecated function collapse() has been removed (#213)

New functions and arguments

• New glue_sql_collapse() function to collapse inputs and return a DBI::SQL() object (#103).

• glue() gains a new .comment argument, to control the comment character (#193).

• glue() gains a new .null argument, to control the value to replace NULL values with (#217, @echasnovski).

Bugfixes and minor changes

• sql_quote_transformer() is now allows whitespace after the trailing * (#218).
• compare_proxy.glue() method defined so glue objects can be compared to strings in testthat 3e without errors (#212)
• print.glue() no longer prints an empty newline for 0 length inputs (#214)
• Unterminated comments in glue expression now throw an error (#227, @gaborcsardi)
• Unterminated quotes in glue expressions now throw an error (#226, @gaborcsardi)

glue v1.4.2

• glue_safe() gives a slightly nicer error message
• The required version of R is now 3.2 (#189)
• glue_sql() now collapses DBI::SQL() elements correctly (#192 @shrektan)
• The internal compare() method gains a ... argument, for compatibility with testthat 3.0.0

glue 1.4.1

• Internal changes for compatibility with vctrs 0.3.0 (#187).
• glue_sql() now replaces missing values correctly when collapsing values (#185).
• glue_sql() now always preserves the type of the column even in the presence of missing values (#130)

glue 1.4.0

• .envir = NULL is now supported and is equivalent to passing .envir = emptyenv() (#140)

• New glue_safe() and glue_data_safe() functions, safer versions of
  glue() that do not execute code, only look up values (using get()). These
  alternatives are useful for things like shiny applications where you do not
  have control of the input for your glue expressions. (#140)

• Fixed memory access issue and memory leaks found by valgrind.

glue 1.3.2

• glue now implements vctrs methods. This ensures that vectors of glue
  strings are compatible with tidyverse packages like tidyr
  (r-lib/tidyselect#170, tidyverse/tidyr#773, @lionel-).

• Fix a LTO type mismatch warning (#146)

• glue_sql() now quotes lists of values appropriate to their type, rather
  than coercing all values to characters (#153)

• glue_data() now implicitly coerces .x to a list.

• glue() gains the .trim argument, like glue_data().

• single_quote() double_quote() and backtick() all return NA for NA
  inputs (#135).

• Improve trim()'s handling of lines containing only indentation (#162, #163, @alandipert)