Absent variable on left side of boolean OR (||) expression makes it absent

Makefile

@@ -11,6 +11,9 @@ build:
 	@echo "Build complete. The Miller executable is ./mlr (or .\mlr.exe on Windows)."
 	@echo "You can use 'make check' to run tests".
 
+quiet:
+	@go build github.com/johnkerl/miller/cmd/mlr
+
 # For interactive use, 'mlr regtest' offers more options and transparency.
 check: unit-test regression-test
 	@echo "Tests complete. You can use 'make install' if you like, optionally preceded"

docs/src/data/filenames.txt

@@ -0,0 +1,2 @@
+data/a.csv
+data/b.csv

docs/src/manpage.md

@@ -178,6 +178,7 @@ MILLER(1)                                                            MILLER(1)
          mlr help mlrrc
          mlr help output-colorization
          mlr help type-arithmetic-info
+         mlr help type-arithmetic-info-extended
        Shorthands:
          mlr -g = mlr help flags
          mlr -l = mlr help list-verbs
@@ -3648,5 +3649,5 @@ MILLER(1)                                                            MILLER(1)
 
 
 
-                                  2023-11-12                         MILLER(1)
+                                  2023-12-02                         MILLER(1)
 </pre>

docs/src/manpage.txt

@@ -157,6 +157,7 @@ MILLER(1)                                                            MILLER(1)
          mlr help mlrrc
          mlr help output-colorization
          mlr help type-arithmetic-info
+         mlr help type-arithmetic-info-extended
        Shorthands:
          mlr -g = mlr help flags
          mlr -l = mlr help list-verbs
@@ -3627,4 +3628,4 @@ MILLER(1)                                                            MILLER(1)
 
 
 
-                                  2023-11-12                         MILLER(1)
+                                  2023-12-02                         MILLER(1)

docs/src/online-help.md

@@ -86,6 +86,7 @@ Other:
   mlr help mlrrc
   mlr help output-colorization
   mlr help type-arithmetic-info
+  mlr help type-arithmetic-info-extended
 Shorthands:
   mlr -g = mlr help flags
   mlr -l = mlr help list-verbs

docs/src/record-heterogeneity.md

@@ -154,8 +154,7 @@ with 1) for too-long rows:
 },
 {
   "a": 4,
-  "b": 5,
-  "c": ""
+  "b": 5
 },
 {
   "a": 7,
@@ -455,7 +454,9 @@ Miller handles explicit header changes as just shown. If your CSV input contains
 <pre class="pre-non-highlight-in-pair">
 a,b,c
 1,2,3
-4,5,
+
+a,b
+4,5
 
 a,b,c,4
 7,8,9,10

docs/src/reference-main-null-data.md

@@ -239,17 +239,44 @@ resource=/some/other/path,loadsec=0.97,ok=false,loadmillis=970
 
 ## Arithmetic rules
 
-If you're interested in a formal description of how empty and absent fields participate in arithmetic, here's a table for plus (other arithmetic/boolean/bitwise operators are similar):
+If you're interested in a formal description of how empty and absent fields participate in arithmetic, here's a table for `+`, `&&, and `||`. Notes:
+
+* Other arithmetic, boolean, and bitwise operators besides `&&` and `||` are similar to `+`.
+* The `&&` and `||` obey _short-circuiting semantics_. That is:
+  * `false && X` is `false` and `X` is not evaluated even if it is a complex expression (maybe including function calls)
+  * `true || X` is `true` and `X` is not evaluated even if it is a complex expression (maybe including function calls)
+* This means in particular that:
+  * `false && X` is false even if `X` is an error, a non-boolean type, etc.
+  * `true || X` is true even if `X` is an error, a non-boolean type, etc.
 
 <pre class="pre-highlight-in-pair">
-<b>mlr help type-arithmetic-info</b>
+<b>mlr help type-arithmetic-info-extended</b>
 </pre>
 <pre class="pre-non-highlight-in-pair">
-(+)        | 1          2.5       (empty)    (absent)   (error)   
-------     + ------     ------     ------     ------     ------    
-1          | 2          3.5        1          1          (error)   
-2.5        | 3.5        5          2.5        2.5        (error)   
-(empty)    | 1          2.5        (empty)    (absent)   (error)   
-(absent)   | 1          2.5        (absent)   (absent)   (error)   
-(error)    | (error)    (error)    (error)    (error)    (error)   
+(+)        | 1          2.5        true      (empty)    (absent)   (error)   
+------     + ------     ------     ------     ------     ------     ------    
+1          | 2          3.5        (error)    1          1          (error)   
+2.5        | 3.5        5          (error)    2.5        2.5        (error)   
+true       | (error)    (error)    (error)    (error)    (error)    (error)   
+(empty)    | 1          2.5        (error)    (empty)    (absent)   (error)   
+(absent)   | 1          2.5        (error)    (absent)   (absent)   (error)   
+(error)    | (error)    (error)    (error)    (error)    (error)    (error)   
+
+(&&)       | true       false      3         (empty)    (absent)   (error)   
+------     + ------     ------     ------     ------     ------     ------    
+true       | true       false      (error)    (error)    (absent)   (error)   
+false      | false      false      false      false      false      false     
+3          | (error)    (error)    (error)    (error)    (absent)   (error)   
+(empty)    | true       false      (error)    (error)    (absent)   (error)   
+(absent)   | true       false      (error)    (absent)   (absent)   (error)   
+(error)    | (error)    (error)    (error)    (error)    (error)    (error)   
+
+(||)       | true       false      3         (empty)    (absent)   (error)   
+------     + ------     ------     ------     ------     ------     ------    
+true       | true       true       true       true       true       true      
+false      | true       false      (error)    (error)    (absent)   (error)   
+3          | (error)    (error)    (error)    (error)    (absent)   (error)   
+(empty)    | true       false      (error)    (error)    (absent)   (error)   
+(absent)   | true       false      (error)    (absent)   (absent)   (error)   
+(error)    | (error)    (error)    (error)    (error)    (error)    (error)   
 </pre>

docs/src/reference-main-null-data.md.in

@@ -119,8 +119,16 @@ GENMD-EOF
 
 ## Arithmetic rules
 
-If you're interested in a formal description of how empty and absent fields participate in arithmetic, here's a table for plus (other arithmetic/boolean/bitwise operators are similar):
+If you're interested in a formal description of how empty and absent fields participate in arithmetic, here's a table for `+`, `&&, and `||`. Notes:
+
+* Other arithmetic, boolean, and bitwise operators besides `&&` and `||` are similar to `+`.
+* The `&&` and `||` obey _short-circuiting semantics_. That is:
+  * `false && X` is `false` and `X` is not evaluated even if it is a complex expression (maybe including function calls)
+  * `true || X` is `true` and `X` is not evaluated even if it is a complex expression (maybe including function calls)
+* This means in particular that:
+  * `false && X` is false even if `X` is an error, a non-boolean type, etc.
+  * `true || X` is true even if `X` is an error, a non-boolean type, etc.
 
 GENMD-RUN-COMMAND
-mlr help type-arithmetic-info
+mlr help type-arithmetic-info-extended
 GENMD-EOF

man/manpage.txt

@@ -157,6 +157,7 @@ MILLER(1)                                                            MILLER(1)
          mlr help mlrrc
          mlr help output-colorization
          mlr help type-arithmetic-info
+         mlr help type-arithmetic-info-extended
        Shorthands:
          mlr -g = mlr help flags
          mlr -l = mlr help list-verbs
@@ -3627,4 +3628,4 @@ MILLER(1)                                                            MILLER(1)
 
 
 
-                                  2023-11-12                         MILLER(1)
+                                  2023-12-02                         MILLER(1)

man/mlr.1

@@ -2,12 +2,12 @@
 .\"     Title: mlr
 .\"    Author: [see the "AUTHOR" section]
 .\" Generator: ./mkman.rb
-.\"      Date: 2023-11-11
+.\"      Date: 2023-12-02
 .\"    Manual: \ \&
 .\"    Source: \ \&
 .\"  Language: English
 .\"
-.TH "MILLER" "1" "2023-11-11" "\ \&" "\ \&"
+.TH "MILLER" "1" "2023-12-02" "\ \&" "\ \&"
 .\" -----------------------------------------------------------------
 .\" * Portability definitions
 .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -192,6 +192,7 @@ Other:
   mlr help mlrrc
   mlr help output-colorization
   mlr help type-arithmetic-info
+  mlr help type-arithmetic-info-extended
 Shorthands:
   mlr -g = mlr help flags
   mlr -l = mlr help list-verbs