Support && and ||.

* gash/script.scm (and-terms, or-terms): New macros.
* gash/peg.scm (transform): Transform to use them.
(parse-): Parse && and || as binary term operator.
* test/20-and.sh: Test it.
* test/20-or.sh: Test it.
* check.sh (tests): Run it.

check.sh

@@ -48,6 +48,8 @@ tests="
 11-for-split-sequence
 
 20-semi.sh
+20-or.sh
+20-and.sh
 20-pipe-exit-0
 20-pipe-exit-1
 20-pipe-sed

gash/peg.scm

@@ -152,9 +152,9 @@
 
   (define-peg-string-patterns
     "script           <-- ws* (term (separator term)* separator?)?
-     term             <-  pipeline (sp* (and / or) ws* pipeline)*
-     and              <-- '&&'
-     or               <-- '||'
+     term             <-  (and / or / pipeline) (sp* (and / or /pipeline))*
+     and              <-- pipeline sp* amp-amp ws* pipeline
+     or               <-- pipeline sp* pipe-pipe ws* pipeline
      pipe             <   '|'
      pipeline         <-- negate? pipeline-head pipeline-tail*
      pipeline-head    <-  sp* command
@@ -223,7 +223,7 @@
      rhs              <-  (substitution / word)*
      assign           <   '='
      dollar           <   '$'
-     literal          <-- backslash? (!ws !tick !dollar !pipe !semi !par !nl !sp !rbrace .)+
+     literal          <-- backslash? (!ws !amp !tick !dollar !pipe !semi !par !nl !sp !rbrace .)+
      variable         <-- dollar ('$' / '*' / '?' / '@' / [0-9] / identifier / lbrace identifier rbrace)
      variable-and-or  <-  dollar lbrace (variable-or / variable-and ) rbrace
      variable-and     <-- identifier plus rhs
@@ -238,6 +238,8 @@
      separator        <-  (sp* break ws*) / ws+
      sequential-sep   <-  (semi !semi ws*) / ws+
      amp              <-  '&'
+     amp-amp          <   '&&'
+     pipe-pipe        <   '||'
      backslash        <-  '\\'
      semi             <   ';'
      lpar             <   '('
@@ -326,6 +328,9 @@
     (('sequence o ...)
      `(sequence (quote ,(map transform o))))
 
+    (('and l r) `(and-terms ,(transform l) ,(transform r)))
+    (('or l r) `(or-terms ,(transform l) ,(transform r)))
+
     (('substitution o) `(substitution ,(transform o)))
     (('if-clause expr then) `(if-clause ,(transform expr) ,(transform then)))
     (('if-clause expr then else) `(if-clause ,(transform expr) ,(transform then) ,(transform else)))

gash/script.scm

@@ -39,6 +39,7 @@
   #:use-module (gash util)
 
   #:export (
+            and-terms
             background
             builtin
             command
@@ -48,6 +49,7 @@
             if-clause
             ignore-error
             literal
+            or-terms
             pipeline
             run
             script
@@ -177,6 +179,22 @@
          #'(let ((it (ignore-error expr)))
              (if (zero? it) then else)))))))
 
+(define-syntax and-terms
+  (lambda (x)
+    (syntax-case x ()
+      ((_ left right)
+       (with-syntax ((it (datum->syntax x 'it)))
+         #'(let ((it left))
+             (if (zero? it) right it)))))))
+
+(define-syntax or-terms
+  (lambda (x)
+    (syntax-case x ()
+      ((_ left right)
+       (with-syntax ((it (datum->syntax x 'it)))
+         #'(let ((it (ignore-error left)))
+             (if (zero? it) it right)))))))
+
 (define (pipeline . commands)
   (define (handle job)
     (when (> %debug-level 1)

test/20-and.exit

@@ -0,0 +1 @@
+2

test/20-and.sh

@@ -0,0 +1 @@
+true && exit 2

test/20-or.sh

@@ -0,0 +1 @@
+false || true