Rework test expressions

Fixes #11

README.md

@@ -10,3 +10,4 @@ Bash grammar for [tree-sitter](https://github.com/tree-sitter/tree-sitter).
 
 * [Bash man page](http://man7.org/linux/man-pages/man1/bash.1.html#SHELL_GRAMMAR)
 * [Shell command language specification](http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html)
+* [mvdnan/sh - a shell parser in go](https://github.com/mvdan/sh)

corpus/commands.txt

@@ -22,21 +22,6 @@ git diff --word-diff=color -- file1.txt file2.txt
   (command (command_name (word)) (word))
   (command (command_name (word)) (word) (word) (word) (word) (word)))
 
-===============================
-Commands with quoted arguments
-===============================
-
-echo "hello $(whoami), this is $(uname)"
-echo 'hi'
-
----
-
-(program
-  (command (command_name (word)) (string
-    (command_substitution (command (command_name (word))))
-    (command_substitution (command (command_name (word))))))
-  (command (command_name (word)) (raw_string)))
-
 ===============================
 Quoted command names
 ===============================
@@ -94,43 +79,6 @@ VAR2= echo
   (variable_assignment (variable_name))
   (command (variable_assignment (variable_name)) (command_name (word))))
 
-===================================
-Pipelines
-===================================
-
-whoami | cat
-cat foo | grep -v bar
-
----
-
-(program
-  (pipeline
-    (command (command_name (word)))
-    (command (command_name (word))))
-  (pipeline
-    (command (command_name (word)) (word))
-    (command (command_name (word)) (word) (word))))
-
-===================================
-Lists
-===================================
-
-a | b && c && d; d e f || e g
-
----
-
-(program
-  (list
-    (list
-      (pipeline
-        (command (command_name (word)))
-        (command (command_name (word))))
-      (command (command_name (word))))
-    (command (command_name (word))))
-  (list
-    (command (command_name (word)) (word) (word))
-    (command (command_name (word)) (word))))
-
 ===============================
 File redirects
 ===============================

corpus/literals.txt

@@ -26,35 +26,6 @@ echo ]]] ===
   (command (command_name (word)) (word))
   (command (command_name (word)) (word) (word)))
 
-=============================
-The regex operator
-=============================
-
-[[ "35d8b" =~ ^[0-9a-fA-F] ]]
-[[ $CMD =~ (^|;)update_terminal_cwd($|;) ]]
-[[ ! " ${completions[*]} " =~ " $alias_cmd " ]]
-! [[ "$a" =~ ^a|b\ *c|d$ ]]
-
----
-
-(program
-  (bracket_command
-    (string)
-    (regex))
-  (bracket_command
-    (simple_expansion (variable_name))
-    (regex))
-  (bracket_command
-    (word)
-    (string (expansion (subscript (variable_name) (word))))
-    (string (simple_expansion (variable_name))))
-  (command
-    (command_name (word))
-    (word)
-    (string (simple_expansion (variable_name)))
-    (regex)
-    (word)))
-
 =============================
 Simple variable expansions
 =============================

corpus/statements.txt

@@ -1,3 +1,40 @@
+===================================
+Pipelines
+===================================
+
+whoami | cat
+cat foo | grep -v bar
+
+---
+
+(program
+  (pipeline
+    (command (command_name (word)))
+    (command (command_name (word))))
+  (pipeline
+    (command (command_name (word)) (word))
+    (command (command_name (word)) (word) (word))))
+
+===================================
+Lists
+===================================
+
+a | b && c && d; d e f || e g
+
+---
+
+(program
+  (list
+    (list
+      (pipeline
+        (command (command_name (word)))
+        (command (command_name (word))))
+      (command (command_name (word))))
+    (command (command_name (word))))
+  (list
+    (command (command_name (word)) (word) (word))
+    (command (command_name (word)) (word))))
+
 ====================================
 While statements
 ====================================
@@ -103,9 +140,9 @@ fi
 
 (program
   (if_statement
-    (bracket_command
+    (test_command (binary_expression
       (string (command_substitution (command (command_name (word)))))
-      (raw_string))
+      (raw_string)))
     (command (command_name (word)) (word))))
 
 ====================================
@@ -146,6 +183,60 @@ esac
     (case_item (concatenation (word) (word))
       (command (command_name (word)) (simple_expansion (special_variable_name))))))
 
+=============================
+Test commands
+=============================
+
+if [[ "$lsb_dist" != 'Ubuntu' || $(ver_to_int "$lsb_release") < $(ver_to_int '14.04') ]]; then
+	return 1
+fi
+
+---
+
+(program
+  (if_statement
+    (test_command (binary_expression
+      (binary_expression
+        (binary_expression
+          (string (simple_expansion (variable_name)))
+          (raw_string))
+        (command_substitution (command
+          (command_name (word))
+          (string (simple_expansion (variable_name))))))
+      (command_substitution (command (command_name (word)) (raw_string)))))
+    (command (command_name (word)) (word))))
+
+=============================
+Test commands with regexes
+=============================
+
+[[ "35d8b" =~ ^[0-9a-fA-F] ]]
+[[ $CMD =~ (^|;)update_terminal_cwd($|;) ]]
+[[ ! " ${completions[*]} " =~ " $alias_cmd " ]]
+! [[ "$a" =~ ^a|b\ *c|d$ ]]
+
+---
+
+(program
+  (test_command
+    (binary_expression
+      (string)
+      (regex)))
+  (test_command
+    (binary_expression
+      (simple_expansion (variable_name))
+      (regex)))
+  (test_command
+    (unary_expression
+      (binary_expression
+        (string (expansion (subscript (variable_name) (word))))
+        (string (simple_expansion (variable_name))))))
+  (negated_command
+    (test_command
+      (binary_expression
+        (string (simple_expansion (variable_name)))
+        (regex)))))
+
 ===============================
 Subshells
 ===============================

grammar.js

@@ -17,7 +17,7 @@ module.exports = grammar({
   inline: $ => [
     $._statement,
     $._terminator,
-    $._expression,
+    $._literal,
     $._primary_expression,
     $._simple_variable_name,
     $._special_variable_name,
@@ -58,7 +58,8 @@ module.exports = grammar({
       $.command,
       $.declaration_command,
       $.unset_command,
-      $.bracket_command,
+      $.test_command,
+      $.negated_command,
       $.for_statement,
       $.while_statement,
       $.if_statement,
@@ -74,7 +75,7 @@ module.exports = grammar({
       $._simple_variable_name,
       optional(seq(
         'in',
-        repeat1($._expression)
+        repeat1($._literal)
       )),
       $._terminator,
       $.do_group
@@ -122,7 +123,7 @@ module.exports = grammar({
 
     case_statement: $ => seq(
       'case',
-      $._expression,
+      $._literal,
       optional($._terminator),
       'in',
       $._terminator,
@@ -134,8 +135,8 @@ module.exports = grammar({
     ),
 
     case_item: $ => seq(
-      $._expression,
+      $._literal,
-      repeat(seq('|', $._expression)),
+      repeat(seq('|', $._literal)),
       ')',
       optional(seq(
         repeat($._terminated_statement),
@@ -145,8 +146,8 @@ module.exports = grammar({
     ),
 
     last_case_item: $ => seq(
-      $._expression,
+      $._literal,
-      repeat(seq('|', $._expression)),
+      repeat(seq('|', $._literal)),
       ')',
       optional(seq(
         repeat($._terminated_statement),
@@ -192,6 +193,43 @@ module.exports = grammar({
 
     // Commands
 
+    negated_command: $ => seq(
+      '!',
+      choice(
+        $.command,
+        $.test_command
+      )
+    ),
+
+    test_command: $ => seq(
+      choice(
+        seq('[', $._expression, ']'),
+        seq('[[', $._expression, ']]')
+      ),
+      repeat(choice(
+        $.file_redirect,
+        $.heredoc_redirect,
+        $.herestring_redirect
+      ))
+    ),
+
+    declaration_command: $ => prec.left(seq(
+      choice('declare', 'typeset', 'export', 'readonly', 'local'),
+      repeat(choice(
+        $._literal,
+        $._simple_variable_name,
+        $.variable_assignment
+      ))
+    )),
+
+    unset_command: $ => prec.left(seq(
+      choice('unset', 'unsetenv'),
+      repeat(choice(
+        $._literal,
+        $._simple_variable_name
+      ))
+    )),
+
     command: $ => prec.left(seq(
       repeat(choice(
         $.variable_assignment,
@@ -199,10 +237,10 @@ module.exports = grammar({
       )),
       $.command_name,
       repeat(choice(
-        $._expression,
+        $._literal,
         seq(
           choice('=~', '=='),
-          choice($.regex, $._expression)
+          choice($.regex, $._literal)
         )
       )),
       repeat(choice(
@@ -213,62 +251,19 @@ module.exports = grammar({
       optional($.heredoc_body)
     )),
 
-    command_name: $ => $._expression,
+    command_name: $ => $._literal,
-
-    bracket_command: $ => {
-      const args = repeat1(choice(
-        $._expression,
-        seq(
-          choice('=~', '=='),
-          choice($.regex, $._expression)
-        )
-      ))
-
-      return seq(
-        choice(
-          seq('[', args, ']'),
-          seq('[[', args, ']]')
-        ),
-        repeat(choice(
-          $.file_redirect,
-          $.heredoc_redirect,
-          $.herestring_redirect
-        ))
-      )
-    },
 
     variable_assignment: $ => seq(
       choice(
         $.variable_name,
         $.subscript
       ),
-      $._assignment
-    ),
-
-    declaration_command: $ => prec.left(seq(
-      choice('declare', 'typeset', 'export', 'readonly', 'local'),
-      repeat(choice(
-        $._expression,
-        $._simple_variable_name,
-        $.variable_assignment
-      ))
-    )),
-
-    unset_command: $ => prec.left(seq(
-      choice('unset', 'unsetenv'),
-      repeat(choice(
-        $._expression,
-        $._simple_variable_name
-      ))
-    )),
-
-    _assignment: $ => seq(
       choice(
         '=',
         '+='
       ),
       choice(
-        $._expression,
+        $._literal,
         $.array,
         $._empty_value
       )
@@ -277,7 +272,7 @@ module.exports = grammar({
     subscript: $ => seq(
       $.variable_name,
       '[',
-      $._expression,
+      $._literal,
       optional($._concat),
       ']',
       optional($._concat)
@@ -286,7 +281,7 @@ module.exports = grammar({
     file_redirect: $ => prec.left(seq(
       optional($.file_descriptor),
       choice('<', '>', '>>', '&>', '&>>', '<&', '>&'),
-      $._expression
+      $._literal
     )),
 
     heredoc_redirect: $ => seq(
@@ -309,12 +304,45 @@ module.exports = grammar({
 
     herestring_redirect: $ => seq(
       '<<<',
-      $._expression
+      $._literal
     ),
 
     // Expressions
 
     _expression: $ => choice(
+      $._literal,
+      $.unary_expression,
+      $.binary_expression,
+      $.parenthesized_expression
+    ),
+
+    binary_expression: $ => prec.left(choice(
+      seq(
+        $._expression,
+        choice('==', '=', '=~', '!=', '<', '>', '||', '&&', $.test_operator),
+        $._expression
+      ),
+      seq(
+        $._expression,
+        choice('==', '=~'),
+        $.regex
+      )
+    )),
+
+    unary_expression: $ => prec.right(seq(
+      choice('!', $.test_operator),
+      $._expression
+    )),
+
+    parenthesized_expression: $ => seq(
+      '(',
+      $._expression,
+      ')'
+    ),
+
+    // Literals
+
+    _literal: $ => choice(
       $.concatenation,
       $._primary_expression,
       alias(prec(-2, $._special_characters), $.word)
@@ -365,7 +393,7 @@ module.exports = grammar({
 
     array: $ => seq(
       '(',
-      repeat($._expression),
+      repeat($._literal),
       ')'
     ),
 
@@ -389,7 +417,7 @@ module.exports = grammar({
         seq(
           $.variable_name,
           '=',
-          optional($._expression)
+          optional($._literal)
         ),
         seq(
           choice(
@@ -402,7 +430,7 @@ module.exports = grammar({
             alias($.regex_without_right_brace, $.regex)
           )),
           repeat(choice(
-            $._expression,
+            $._literal,
             ':', ':?', '=', ':-', '%', '-', '#'
           ))
         ),
@@ -432,7 +460,10 @@ module.exports = grammar({
       seq('\\', noneOf('\\s'))
     ))),
 
+    test_operator: $ => token(prec(1, seq('-', /[a-zA-Z]+/))),
+
     regex: $ => /([^"\s]|\\.)([^\s]|\\.)*/,
+
     regex_without_right_brace: $ => /([^"\s}]|\\.)([^\s}]|\\.)*/,
 
     _terminator: $ => choice(';', ';;', '\n', '&')

script/known-failures.txt

@@ -1,24 +1,19 @@
 examples/bash-it/plugins/available/git.plugin.bash
 examples/bash-it/plugins/available/extract.plugin.bash
-examples/bash-it/plugins/available/z_autoenv.plugin.bash
 examples/bash-it/plugins/available/sshagent.plugin.bash
 examples/bash-it/plugins/available/go.plugin.bash
 examples/bash-it/install.sh
-examples/bash-it/completion/available/terraform.completion.bash
 examples/bash-it/completion/available/go.completion.bash
 examples/bash-it/completion/available/maven.completion.bash
 examples/bash-it/completion/available/svn.completion.bash
 examples/bash-it/completion/available/docker-compose.completion.bash
 examples/bash-it/completion/available/jboss7.completion.bash
-examples/bash-it/completion/available/todo.completion.bash
 examples/bash-it/completion/available/gh.completion.bash
 examples/bash-it/completion/available/bundler.completion.bash
 examples/bash-it/completion/available/gradle.completion.bash
 examples/bash-it/completion/available/drush.completion.bash
-examples/bash-it/completion/available/test_kitchen.completion.bash
 examples/bash-it/completion/available/hub.completion.bash
 examples/bash-it/completion/available/docker-machine.completion.bash
-examples/bash-it/completion/available/fabric-completion.bash
 examples/bash-it/completion/available/git.completion.bash
 examples/bash-it/completion/available/vagrant.completion.bash
 examples/bash-it/completion/available/defaults.completion.bash
@@ -27,7 +22,6 @@ examples/bash-it/completion/available/salt.completion.bash
 examples/bash-it/completion/available/vault.completion.bash
 examples/bash-it/completion/available/docker.completion.bash
 examples/bash-it/completion/available/tmux.completion.bash
-examples/bash-it/completion/available/projects.completion.bash
 examples/bash-it/completion/available/virsh.completion.bash
 examples/bash-it/completion/available/apm.completion.bash
 examples/bash-it/completion/available/git_flow.completion.bash
@@ -39,7 +33,6 @@ examples/bash-it/test_lib/bats-support/src/output.bash
 examples/bash-it/test_lib/bats-assert/src/assert.bash
 examples/bash-it/test_lib/bats-file/src/temp.bash
 examples/bash-it/themes/hawaii50/hawaii50.theme.bash
-examples/bash-it/themes/iterate/iterate.theme.bash
 examples/bash-it/themes/dulcie/dulcie.theme.bash
 examples/bash-it/themes/colors.theme.bash
 examples/bash-it/themes/rana/rana.theme.bash

src/grammar.json

@@ -42,7 +42,11 @@
         },
         {
           "type": "SYMBOL",
-          "name": "bracket_command"
+          "name": "test_command"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "negated_command"
         },
         {
           "type": "SYMBOL",
@@ -103,7 +107,7 @@
                   "type": "REPEAT1",
                   "content": {
                     "type": "SYMBOL",
-                    "name": "_expression"
+                    "name": "_literal"
                   }
                 }
               ]
@@ -288,7 +292,7 @@
         },
         {
           "type": "SYMBOL",
-          "name": "_expression"
+          "name": "_literal"
         },
         {
           "type": "CHOICE",
@@ -350,7 +354,7 @@
       "members": [
         {
           "type": "SYMBOL",
-          "name": "_expression"
+          "name": "_literal"
         },
         {
           "type": "REPEAT",
@@ -363,7 +367,7 @@
               },
               {
                 "type": "SYMBOL",
-                "name": "_expression"
+                "name": "_literal"
               }
             ]
           }
@@ -419,7 +423,7 @@
       "members": [
         {
           "type": "SYMBOL",
-          "name": "_expression"
+          "name": "_literal"
         },
         {
           "type": "REPEAT",
@@ -432,7 +436,7 @@
               },
               {
                 "type": "SYMBOL",
-                "name": "_expression"
+                "name": "_literal"
               }
             ]
           }
@@ -684,6 +688,184 @@
         ]
       }
     },
+    "negated_command": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "!"
+        },
+        {
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "SYMBOL",
+              "name": "command"
+            },
+            {
+              "type": "SYMBOL",
+              "name": "test_command"
+            }
+          ]
+        }
+      ]
+    },
+    "test_command": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "SEQ",
+              "members": [
+                {
+                  "type": "STRING",
+                  "value": "["
+                },
+                {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                },
+                {
+                  "type": "STRING",
+                  "value": "]"
+                }
+              ]
+            },
+            {
+              "type": "SEQ",
+              "members": [
+                {
+                  "type": "STRING",
+                  "value": "[["
+                },
+                {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                },
+                {
+                  "type": "STRING",
+                  "value": "]]"
+                }
+              ]
+            }
+          ]
+        },
+        {
+          "type": "REPEAT",
+          "content": {
+            "type": "CHOICE",
+            "members": [
+              {
+                "type": "SYMBOL",
+                "name": "file_redirect"
+              },
+              {
+                "type": "SYMBOL",
+                "name": "heredoc_redirect"
+              },
+              {
+                "type": "SYMBOL",
+                "name": "herestring_redirect"
+              }
+            ]
+          }
+        }
+      ]
+    },
+    "declaration_command": {
+      "type": "PREC_LEFT",
+      "value": 0,
+      "content": {
+        "type": "SEQ",
+        "members": [
+          {
+            "type": "CHOICE",
+            "members": [
+              {
+                "type": "STRING",
+                "value": "declare"
+              },
+              {
+                "type": "STRING",
+                "value": "typeset"
+              },
+              {
+                "type": "STRING",
+                "value": "export"
+              },
+              {
+                "type": "STRING",
+                "value": "readonly"
+              },
+              {
+                "type": "STRING",
+                "value": "local"
+              }
+            ]
+          },
+          {
+            "type": "REPEAT",
+            "content": {
+              "type": "CHOICE",
+              "members": [
+                {
+                  "type": "SYMBOL",
+                  "name": "_literal"
+                },
+                {
+                  "type": "SYMBOL",
+                  "name": "_simple_variable_name"
+                },
+                {
+                  "type": "SYMBOL",
+                  "name": "variable_assignment"
+                }
+              ]
+            }
+          }
+        ]
+      }
+    },
+    "unset_command": {
+      "type": "PREC_LEFT",
+      "value": 0,
+      "content": {
+        "type": "SEQ",
+        "members": [
+          {
+            "type": "CHOICE",
+            "members": [
+              {
+                "type": "STRING",
+                "value": "unset"
+              },
+              {
+                "type": "STRING",
+                "value": "unsetenv"
+              }
+            ]
+          },
+          {
+            "type": "REPEAT",
+            "content": {
+              "type": "CHOICE",
+              "members": [
+                {
+                  "type": "SYMBOL",
+                  "name": "_literal"
+                },
+                {
+                  "type": "SYMBOL",
+                  "name": "_simple_variable_name"
+                }
+              ]
+            }
+          }
+        ]
+      }
+    },
     "command": {
       "type": "PREC_LEFT",
       "value": 0,
@@ -717,7 +899,7 @@
               "members": [
                 {
                   "type": "SYMBOL",
-                  "name": "_expression"
+                  "name": "_literal"
                 },
                 {
                   "type": "SEQ",
@@ -744,7 +926,7 @@
                         },
                         {
                           "type": "SYMBOL",
-                          "name": "_expression"
+                          "name": "_literal"
                         }
                       ]
                     }
@@ -790,149 +972,7 @@
     },
     "command_name": {
       "type": "SYMBOL",
-      "name": "_expression"
+      "name": "_literal"
-    },
-    "bracket_command": {
-      "type": "SEQ",
-      "members": [
-        {
-          "type": "CHOICE",
-          "members": [
-            {
-              "type": "SEQ",
-              "members": [
-                {
-                  "type": "STRING",
-                  "value": "["
-                },
-                {
-                  "type": "REPEAT1",
-                  "content": {
-                    "type": "CHOICE",
-                    "members": [
-                      {
-                        "type": "SYMBOL",
-                        "name": "_expression"
-                      },
-                      {
-                        "type": "SEQ",
-                        "members": [
-                          {
-                            "type": "CHOICE",
-                            "members": [
-                              {
-                                "type": "STRING",
-                                "value": "=~"
-                              },
-                              {
-                                "type": "STRING",
-                                "value": "=="
-                              }
-                            ]
-                          },
-                          {
-                            "type": "CHOICE",
-                            "members": [
-                              {
-                                "type": "SYMBOL",
-                                "name": "regex"
-                              },
-                              {
-                                "type": "SYMBOL",
-                                "name": "_expression"
-                              }
-                            ]
-                          }
-                        ]
-                      }
-                    ]
-                  }
-                },
-                {
-                  "type": "STRING",
-                  "value": "]"
-                }
-              ]
-            },
-            {
-              "type": "SEQ",
-              "members": [
-                {
-                  "type": "STRING",
-                  "value": "[["
-                },
-                {
-                  "type": "REPEAT1",
-                  "content": {
-                    "type": "CHOICE",
-                    "members": [
-                      {
-                        "type": "SYMBOL",
-                        "name": "_expression"
-                      },
-                      {
-                        "type": "SEQ",
-                        "members": [
-                          {
-                            "type": "CHOICE",
-                            "members": [
-                              {
-                                "type": "STRING",
-                                "value": "=~"
-                              },
-                              {
-                                "type": "STRING",
-                                "value": "=="
-                              }
-                            ]
-                          },
-                          {
-                            "type": "CHOICE",
-                            "members": [
-                              {
-                                "type": "SYMBOL",
-                                "name": "regex"
-                              },
-                              {
-                                "type": "SYMBOL",
-                                "name": "_expression"
-                              }
-                            ]
-                          }
-                        ]
-                      }
-                    ]
-                  }
-                },
-                {
-                  "type": "STRING",
-                  "value": "]]"
-                }
-              ]
-            }
-          ]
-        },
-        {
-          "type": "REPEAT",
-          "content": {
-            "type": "CHOICE",
-            "members": [
-              {
-                "type": "SYMBOL",
-                "name": "file_redirect"
-              },
-              {
-                "type": "SYMBOL",
-                "name": "heredoc_redirect"
-              },
-              {
-                "type": "SYMBOL",
-                "name": "herestring_redirect"
-              }
-            ]
-          }
-        }
-      ]
     },
     "variable_assignment": {
       "type": "SEQ",
@@ -950,107 +990,6 @@
             }
           ]
         },
-        {
-          "type": "SYMBOL",
-          "name": "_assignment"
-        }
-      ]
-    },
-    "declaration_command": {
-      "type": "PREC_LEFT",
-      "value": 0,
-      "content": {
-        "type": "SEQ",
-        "members": [
-          {
-            "type": "CHOICE",
-            "members": [
-              {
-                "type": "STRING",
-                "value": "declare"
-              },
-              {
-                "type": "STRING",
-                "value": "typeset"
-              },
-              {
-                "type": "STRING",
-                "value": "export"
-              },
-              {
-                "type": "STRING",
-                "value": "readonly"
-              },
-              {
-                "type": "STRING",
-                "value": "local"
-              }
-            ]
-          },
-          {
-            "type": "REPEAT",
-            "content": {
-              "type": "CHOICE",
-              "members": [
-                {
-                  "type": "SYMBOL",
-                  "name": "_expression"
-                },
-                {
-                  "type": "SYMBOL",
-                  "name": "_simple_variable_name"
-                },
-                {
-                  "type": "SYMBOL",
-                  "name": "variable_assignment"
-                }
-              ]
-            }
-          }
-        ]
-      }
-    },
-    "unset_command": {
-      "type": "PREC_LEFT",
-      "value": 0,
-      "content": {
-        "type": "SEQ",
-        "members": [
-          {
-            "type": "CHOICE",
-            "members": [
-              {
-                "type": "STRING",
-                "value": "unset"
-              },
-              {
-                "type": "STRING",
-                "value": "unsetenv"
-              }
-            ]
-          },
-          {
-            "type": "REPEAT",
-            "content": {
-              "type": "CHOICE",
-              "members": [
-                {
-                  "type": "SYMBOL",
-                  "name": "_expression"
-                },
-                {
-                  "type": "SYMBOL",
-                  "name": "_simple_variable_name"
-                }
-              ]
-            }
-          }
-        ]
-      }
-    },
-    "_assignment": {
-      "type": "SEQ",
-      "members": [
         {
           "type": "CHOICE",
           "members": [
@@ -1069,7 +1008,7 @@
           "members": [
             {
               "type": "SYMBOL",
-              "name": "_expression"
+              "name": "_literal"
             },
             {
               "type": "SYMBOL",
@@ -1096,7 +1035,7 @@
         },
         {
           "type": "SYMBOL",
-          "name": "_expression"
+          "name": "_literal"
         },
         {
           "type": "CHOICE",
@@ -1181,7 +1120,7 @@
           },
           {
             "type": "SYMBOL",
-            "name": "_expression"
+            "name": "_literal"
           }
         ]
       }
@@ -1259,11 +1198,164 @@
         },
         {
           "type": "SYMBOL",
-          "name": "_expression"
+          "name": "_literal"
         }
       ]
     },
     "_expression": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "_literal"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "unary_expression"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "binary_expression"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "parenthesized_expression"
+        }
+      ]
+    },
+    "binary_expression": {
+      "type": "PREC_LEFT",
+      "value": 0,
+      "content": {
+        "type": "CHOICE",
+        "members": [
+          {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "SYMBOL",
+                "name": "_expression"
+              },
+              {
+                "type": "CHOICE",
+                "members": [
+                  {
+                    "type": "STRING",
+                    "value": "=="
+                  },
+                  {
+                    "type": "STRING",
+                    "value": "="
+                  },
+                  {
+                    "type": "STRING",
+                    "value": "=~"
+                  },
+                  {
+                    "type": "STRING",
+                    "value": "!="
+                  },
+                  {
+                    "type": "STRING",
+                    "value": "<"
+                  },
+                  {
+                    "type": "STRING",
+                    "value": ">"
+                  },
+                  {
+                    "type": "STRING",
+                    "value": "||"
+                  },
+                  {
+                    "type": "STRING",
+                    "value": "&&"
+                  },
+                  {
+                    "type": "SYMBOL",
+                    "name": "test_operator"
+                  }
+                ]
+              },
+              {
+                "type": "SYMBOL",
+                "name": "_expression"
+              }
+            ]
+          },
+          {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "SYMBOL",
+                "name": "_expression"
+              },
+              {
+                "type": "CHOICE",
+                "members": [
+                  {
+                    "type": "STRING",
+                    "value": "=="
+                  },
+                  {
+                    "type": "STRING",
+                    "value": "=~"
+                  }
+                ]
+              },
+              {
+                "type": "SYMBOL",
+                "name": "regex"
+              }
+            ]
+          }
+        ]
+      }
+    },
+    "unary_expression": {
+      "type": "PREC_RIGHT",
+      "value": 0,
+      "content": {
+        "type": "SEQ",
+        "members": [
+          {
+            "type": "CHOICE",
+            "members": [
+              {
+                "type": "STRING",
+                "value": "!"
+              },
+              {
+                "type": "SYMBOL",
+                "name": "test_operator"
+              }
+            ]
+          },
+          {
+            "type": "SYMBOL",
+            "name": "_expression"
+          }
+        ]
+      }
+    },
+    "parenthesized_expression": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "("
+        },
+        {
+          "type": "SYMBOL",
+          "name": "_expression"
+        },
+        {
+          "type": "STRING",
+          "value": ")"
+        }
+      ]
+    },
+    "_literal": {
       "type": "CHOICE",
       "members": [
         {
@@ -1501,7 +1593,7 @@
           "type": "REPEAT",
           "content": {
             "type": "SYMBOL",
-            "name": "_expression"
+            "name": "_literal"
           }
         },
         {
@@ -1605,7 +1697,7 @@
                   "members": [
                     {
                       "type": "SYMBOL",
-                      "name": "_expression"
+                      "name": "_literal"
                     },
                     {
                       "type": "BLANK"
@@ -1674,7 +1766,7 @@
                     "members": [
                       {
                         "type": "SYMBOL",
-                        "name": "_expression"
+                        "name": "_literal"
                       },
                       {
                         "type": "STRING",
@@ -1872,6 +1964,26 @@
         }
       }
     },
+    "test_operator": {
+      "type": "TOKEN",
+      "content": {
+        "type": "PREC",
+        "value": 1,
+        "content": {
+          "type": "SEQ",
+          "members": [
+            {
+              "type": "STRING",
+              "value": "-"
+            },
+            {
+              "type": "PATTERN",
+              "value": "[a-zA-Z]+"
+            }
+          ]
+        }
+      }
+    },
     "regex": {
       "type": "PATTERN",
       "value": "([^\"\\s]|\\\\.)([^\\s]|\\\\.)*"
@@ -1978,7 +2090,7 @@
   "inline": [
     "_statement",
     "_terminator",
-    "_expression",
+    "_literal",
     "_primary_expression",
     "_simple_variable_name",
     "_special_variable_name"

src/tree_sitter/parser.h

@@ -9,13 +9,14 @@ extern "C" {
 #include <stdint.h>
 #include <stdlib.h>
 
-typedef uint16_t TSSymbol;
-typedef uint16_t TSStateId;
-
 #define ts_builtin_sym_error ((TSSymbol)-1)
 #define ts_builtin_sym_end 0
 #define TREE_SITTER_SERIALIZATION_BUFFER_SIZE 1024
 
+typedef uint16_t TSSymbol;
+
+typedef uint16_t TSStateId;
+
 typedef struct {
   bool visible : 1;
   bool named : 1;
@@ -129,6 +130,7 @@ typedef struct TSLanguage {
  */
 
 #define STATE(id) id
+
 #define ACTIONS(id) id
 
 #define SHIFT(state_value)              \