Renamed the lexer

5 files changed, 110 insertions, 103 deletions

diff --git a/lib/analyzer.ml b/lib/analyzer.ml
index b422b24..e4fc272 100644
--- a/lib/analyzer.ml
+++ b/lib/analyzer.ml
@@ -17,7 +17,7 @@ let format_error : Format.formatter -> error -> unit =
   else Format.fprintf f "Line %d %d:%d %s" start_line start_c end_c e.message
 
 (** 
-    Run the QSP parser and apply the analyzer over it. 
+    Run the QSP parser and apply the analyzer over it.
 
     See [syntax/S]
  *)
@@ -33,7 +33,7 @@ let parse :
     Interpreter.Interpreter (Parser.MenhirInterpreter) in
   fun lexbuf ->
     IncrementalParser.of_lexbuf lexbuf
-      (UTF16.lexer (module E))
+      (Lexer.lexer (module E))
       Parser.Incremental.main
     |> Result.map_error (fun e ->
            let message =
diff --git a/lib/expression_parser.messages b/lib/expression_parser.messages
index 6907c43..e9a83c6 100644
--- a/lib/expression_parser.messages
+++ b/lib/expression_parser.messages
@@ -2,7 +2,7 @@ main: LOCATION_START EOL IDENT SET
 ##
 ## Ends in an error in state: 12.
 ##
-## variable -> IDENT . option(delimited(L_BRACKET,option(expression),R_BRACKET)) [ STAR R_PAREN R_BRACKET PLUS OR MOD MINUS LT INCR GT EXCLAMATION EQUAL EOL ELSE DIV DECR COMA COLUMN AND AMPERSAND ]
+## variable -> IDENT . option(delimited(L_BRACKET,option(expression),R_BRACKET)) [ STAR R_PAREN R_BRACKET PLUS OR MULT_EQUAL MOD MINUS LT INCR GT EXCLAMATION EQUAL EOL ELSE DIV DECR COMA COLUMN AND AMPERSAND ]
 ##
 ## The known suffix of the stack is as follows:
 ## IDENT
@@ -40,7 +40,7 @@ Unexpected '('. Did you forgot a function before ?
 
 main: LOCATION_START EOL IF INTEGER SET
 ##
-## Ends in an error in state: 85.
+## Ends in an error in state: 86.
 ##
 ## expression -> expression . EQUAL expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL DIV COLUMN AND ]
 ## expression -> expression . LT GT expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL DIV COLUMN AND ]
@@ -66,11 +66,11 @@ main: LOCATION_START EOL IF INTEGER SET
 ## IF expression
 ##
 
-Invalid `IF` condition. You probably missed a ':'
+The `IF` expression does not end properly. A `:` is expected before any instruction.
 
 main: LOCATION_START EOL COLUMN STAR
 ##
-## Ends in an error in state: 90.
+## Ends in an error in state: 91.
 ##
 ## line_statement -> COLUMN . IDENT list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ##
@@ -82,7 +82,7 @@ A location is expected after ':' not an expression
 
 main: LOCATION_START EOL ACT INTEGER SET
 ##
-## Ends in an error in state: 94.
+## Ends in an error in state: 95.
 ##
 ## expression -> expression . EQUAL expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL DIV COLUMN AND ]
 ## expression -> expression . LT GT expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL DIV COLUMN AND ]
@@ -112,7 +112,7 @@ Invalid `ACT` label. You probably missed a ':'
 
 main: LOCATION_START EOL ACT IDENT COLUMN EOL LOCATION_END
 ##
-## Ends in an error in state: 96.
+## Ends in an error in state: 97.
 ##
 ## line_statement -> ACT expression COLUMN nonempty_list(EOL) . list(line_statement) empty_body END option(ACT) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> ACT expression COLUMN nonempty_list(EOL) . list(line_statement) empty_body END option(ACT) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -132,7 +132,7 @@ If there are nested blocks, the error will points the highest block.
 
 main: LOCATION_START EOL IF IDENT COLUMN ELSE R_PAREN
 ##
-## Ends in an error in state: 102.
+## Ends in an error in state: 103.
 ##
 ## option(preceded(ELSE,instruction)) -> ELSE . instruction [ EOL ELSE AMPERSAND ]
 ##
@@ -144,7 +144,7 @@ Too manies instructions on a single line.
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL IDENT AMPERSAND LOCATION_END
 ##
-## Ends in an error in state: 150.
+## Ends in an error in state: 151.
 ##
 ## line_statement -> IF expression COLUMN nonempty_list(EOL) list(line_statement) . elif_else_body END option(IF) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> IF expression COLUMN nonempty_list(EOL) list(line_statement) . elif_else_body END option(IF) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -156,19 +156,18 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL IDENT AMPERSAND LOCATION_END
 ## This implies that, although the LR(1) items shown above provide an
 ## accurate view of the past (what has been recognized so far), they
 ## may provide an INCOMPLETE view of the future (what was expected next).
-## In state 121, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
-## In state 130, spurious reduction of production list(EOL) ->
-## In state 131, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
-## In state 126, spurious reduction of production list(line_statement) ->
-## In state 127, spurious reduction of production list(line_statement) -> line_statement list(line_statement)
+## In state 122, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
+## In state 131, spurious reduction of production list(EOL) ->
+## In state 132, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
+## In state 127, spurious reduction of production list(line_statement) ->
+## In state 128, spurious reduction of production list(line_statement) -> line_statement list(line_statement)
 ##
 
-Unclosed statement. 
-(The error may be above in the code, for example a missing `END` after an `IF`)
+Unclosed `IF` block.
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL ELSE EOL LOCATION_END
 ##
-## Ends in an error in state: 158.
+## Ends in an error in state: 159.
 ##
 ## else_ -> ELSE nonempty_list(EOL) . list(line_statement) [ END ]
 ##
@@ -187,7 +186,7 @@ If there are nested blocks, the error will points the highest block.
 
 main: LOCATION_START EOL IDENT AMPERSAND END
 ##
-## Ends in an error in state: 170.
+## Ends in an error in state: 171.
 ##
 ## main -> list(EOL) LOCATION_START nonempty_list(EOL) list(line_statement) . LOCATION_END list(EOL) EOF [ # ]
 ##
@@ -198,11 +197,11 @@ main: LOCATION_START EOL IDENT AMPERSAND END
 ## This implies that, although the LR(1) items shown above provide an
 ## accurate view of the past (what has been recognized so far), they
 ## may provide an INCOMPLETE view of the future (what was expected next).
-## In state 121, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
-## In state 130, spurious reduction of production list(EOL) ->
-## In state 131, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
-## In state 126, spurious reduction of production list(line_statement) ->
-## In state 127, spurious reduction of production list(line_statement) -> line_statement list(line_statement)
+## In state 122, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
+## In state 131, spurious reduction of production list(EOL) ->
+## In state 132, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
+## In state 127, spurious reduction of production list(line_statement) ->
+## In state 128, spurious reduction of production list(line_statement) -> line_statement list(line_statement)
 ##
 
 Unexpected `END`.
@@ -222,7 +221,7 @@ Missing location name
 
 main: LOCATION_START EOL INTEGER SET
 ##
-## Ends in an error in state: 113.
+## Ends in an error in state: 114.
 ##
 ## expression -> expression . EQUAL expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV AND AMPERSAND ]
 ## expression -> expression . LT GT expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV AND AMPERSAND ]
@@ -289,7 +288,7 @@ main: LOCATION_START EOL IDENT L_BRACKET STAR
 ##
 ## Ends in an error in state: 13.
 ##
-## option(delimited(L_BRACKET,option(expression),R_BRACKET)) -> L_BRACKET . option(expression) R_BRACKET [ STAR R_PAREN R_BRACKET PLUS OR MOD MINUS LT INCR GT EXCLAMATION EQUAL EOL ELSE DIV DECR COMA COLUMN AND AMPERSAND ]
+## option(delimited(L_BRACKET,option(expression),R_BRACKET)) -> L_BRACKET . option(expression) R_BRACKET [ STAR R_PAREN R_BRACKET PLUS OR MULT_EQUAL MOD MINUS LT INCR GT EXCLAMATION EQUAL EOL ELSE DIV DECR COMA COLUMN AND AMPERSAND ]
 ##
 ## The known suffix of the stack is as follows:
 ## L_BRACKET
@@ -1133,7 +1132,7 @@ main: LOCATION_START EOL SET IDENT STAR
 
 main: LOCATION_START EOL SET IDENT DECR STAR
 ##
-## Ends in an error in state: 77.
+## Ends in an error in state: 78.
 ##
 ## let_assignation -> SET variable assignation_operator . expression [ EOL ELSE AMPERSAND ]
 ##
@@ -1145,7 +1144,7 @@ main: LOCATION_START EOL SET IDENT DECR STAR
 
 main: LOCATION_START EOL SET IDENT DECR INTEGER SET
 ##
-## Ends in an error in state: 78.
+## Ends in an error in state: 79.
 ##
 ## expression -> expression . EQUAL expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV AND AMPERSAND ]
 ## expression -> expression . LT GT expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV AND AMPERSAND ]
@@ -1173,7 +1172,7 @@ main: LOCATION_START EOL SET IDENT DECR INTEGER SET
 
 main: LOCATION_START EOL LET STAR
 ##
-## Ends in an error in state: 79.
+## Ends in an error in state: 80.
 ##
 ## let_assignation -> LET . variable assignation_operator expression [ EOL ELSE AMPERSAND ]
 ##
@@ -1185,7 +1184,7 @@ main: LOCATION_START EOL LET STAR
 
 main: LOCATION_START EOL LET IDENT STAR
 ##
-## Ends in an error in state: 80.
+## Ends in an error in state: 81.
 ##
 ## let_assignation -> LET variable . assignation_operator expression [ EOL ELSE AMPERSAND ]
 ##
@@ -1204,7 +1203,7 @@ main: LOCATION_START EOL LET IDENT STAR
 
 main: LOCATION_START EOL LET IDENT DECR STAR
 ##
-## Ends in an error in state: 81.
+## Ends in an error in state: 82.
 ##
 ## let_assignation -> LET variable assignation_operator . expression [ EOL ELSE AMPERSAND ]
 ##
@@ -1216,7 +1215,7 @@ main: LOCATION_START EOL LET IDENT DECR STAR
 
 main: LOCATION_START EOL LET IDENT DECR INTEGER SET
 ##
-## Ends in an error in state: 82.
+## Ends in an error in state: 83.
 ##
 ## expression -> expression . EQUAL expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV AND AMPERSAND ]
 ## expression -> expression . LT GT expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV AND AMPERSAND ]
@@ -1244,7 +1243,7 @@ main: LOCATION_START EOL LET IDENT DECR INTEGER SET
 
 main: LOCATION_START EOL IF STAR
 ##
-## Ends in an error in state: 84.
+## Ends in an error in state: 85.
 ##
 ## line_statement -> IF . expression COLUMN nonempty_list(EOL) list(line_statement) elif_else_body END option(IF) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> IF . expression COLUMN nonempty_list(EOL) list(line_statement) elif_else_body END option(IF) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1258,7 +1257,7 @@ main: LOCATION_START EOL IF STAR
 
 main: LOCATION_START EOL IF IDENT COLUMN R_PAREN
 ##
-## Ends in an error in state: 86.
+## Ends in an error in state: 87.
 ##
 ## line_statement -> IF expression COLUMN . nonempty_list(EOL) list(line_statement) elif_else_body END option(IF) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> IF expression COLUMN . nonempty_list(EOL) list(line_statement) elif_else_body END option(IF) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1272,7 +1271,7 @@ main: LOCATION_START EOL IF IDENT COLUMN R_PAREN
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL LOCATION_END
 ##
-## Ends in an error in state: 87.
+## Ends in an error in state: 88.
 ##
 ## line_statement -> IF expression COLUMN nonempty_list(EOL) . list(line_statement) elif_else_body END option(IF) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> IF expression COLUMN nonempty_list(EOL) . list(line_statement) elif_else_body END option(IF) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1291,7 +1290,7 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL LOCATION_END
 
 main: LOCATION_START EOL COMMENT STAR
 ##
-## Ends in an error in state: 88.
+## Ends in an error in state: 89.
 ##
 ## line_statement -> COMMENT . nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ##
@@ -1303,7 +1302,7 @@ main: LOCATION_START EOL COMMENT STAR
 
 main: LOCATION_START EOL COLUMN IDENT R_PAREN
 ##
-## Ends in an error in state: 91.
+## Ends in an error in state: 92.
 ##
 ## line_statement -> COLUMN IDENT . list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ##
@@ -1315,7 +1314,7 @@ main: LOCATION_START EOL COLUMN IDENT R_PAREN
 
 main: LOCATION_START EOL ACT STAR
 ##
-## Ends in an error in state: 93.
+## Ends in an error in state: 94.
 ##
 ## line_statement -> ACT . expression COLUMN nonempty_list(EOL) list(line_statement) empty_body END option(ACT) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> ACT . expression COLUMN nonempty_list(EOL) list(line_statement) empty_body END option(ACT) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1329,7 +1328,7 @@ main: LOCATION_START EOL ACT STAR
 
 main: LOCATION_START EOL ACT IDENT COLUMN R_PAREN
 ##
-## Ends in an error in state: 95.
+## Ends in an error in state: 96.
 ##
 ## line_statement -> ACT expression COLUMN . nonempty_list(EOL) list(line_statement) empty_body END option(ACT) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> ACT expression COLUMN . nonempty_list(EOL) list(line_statement) empty_body END option(ACT) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1343,7 +1342,7 @@ main: LOCATION_START EOL ACT IDENT COLUMN R_PAREN
 
 main: LOCATION_START EOL IDENT R_PAREN
 ##
-## Ends in an error in state: 97.
+## Ends in an error in state: 98.
 ##
 ## expression -> variable . [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV AND AMPERSAND ]
 ## let_assignation -> variable . assignation_operator expression [ EOL ELSE AMPERSAND ]
@@ -1363,7 +1362,7 @@ main: LOCATION_START EOL IDENT R_PAREN
 
 main: LOCATION_START EOL IDENT DECR STAR
 ##
-## Ends in an error in state: 98.
+## Ends in an error in state: 99.
 ##
 ## let_assignation -> variable assignation_operator . expression [ EOL ELSE AMPERSAND ]
 ##
@@ -1375,7 +1374,7 @@ main: LOCATION_START EOL IDENT DECR STAR
 
 main: LOCATION_START EOL IDENT DECR INTEGER SET
 ##
-## Ends in an error in state: 99.
+## Ends in an error in state: 100.
 ##
 ## expression -> expression . EQUAL expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV AND AMPERSAND ]
 ## expression -> expression . LT GT expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV AND AMPERSAND ]
@@ -1403,7 +1402,7 @@ main: LOCATION_START EOL IDENT DECR INTEGER SET
 
 main: LOCATION_START EOL IF IDENT COLUMN COMMENT STAR
 ##
-## Ends in an error in state: 101.
+## Ends in an error in state: 102.
 ##
 ## inline_action -> onliner(IF) . option(preceded(ELSE,instruction)) [ EOL ELSE AMPERSAND ]
 ##
@@ -1415,7 +1414,7 @@ main: LOCATION_START EOL IF IDENT COLUMN COMMENT STAR
 
 main: LOCATION_START EOL KEYWORD STAR
 ##
-## Ends in an error in state: 104.
+## Ends in an error in state: 105.
 ##
 ## single_instruction -> keyword . qsp_instruction_argument(expression) [ EOL ELSE AMPERSAND ]
 ##
@@ -1427,7 +1426,7 @@ main: LOCATION_START EOL KEYWORD STAR
 
 main: LOCATION_START EOL KEYWORD L_PAREN STAR
 ##
-## Ends in an error in state: 105.
+## Ends in an error in state: 106.
 ##
 ## expression -> L_PAREN . expression R_PAREN [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV COMA AND AMPERSAND ]
 ## optionnal_delimited(L_PAREN,arguments(expression),R_PAREN) -> L_PAREN . arguments(expression) R_PAREN [ EOL ELSE AMPERSAND ]
@@ -1440,7 +1439,7 @@ main: LOCATION_START EOL KEYWORD L_PAREN STAR
 
 main: LOCATION_START EOL KEYWORD L_PAREN IDENT COMA IDENT EOL
 ##
-## Ends in an error in state: 106.
+## Ends in an error in state: 107.
 ##
 ## optionnal_delimited(L_PAREN,arguments(expression),R_PAREN) -> L_PAREN arguments(expression) . R_PAREN [ EOL ELSE AMPERSAND ]
 ##
@@ -1462,7 +1461,7 @@ main: LOCATION_START EOL KEYWORD L_PAREN IDENT COMA IDENT EOL
 
 main: LOCATION_START EOL KEYWORD INTEGER SET
 ##
-## Ends in an error in state: 110.
+## Ends in an error in state: 111.
 ##
 ## arguments(expression) -> expression . COMA separated_nonempty_list(COMA,expression) [ EOL ELSE AMPERSAND ]
 ## expression -> expression . EQUAL expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL EOL ELSE DIV COMA AND AMPERSAND ]
@@ -1491,7 +1490,7 @@ main: LOCATION_START EOL KEYWORD INTEGER SET
 
 main: LOCATION_START EOL ACT IDENT COLUMN EOL IDENT AMPERSAND LOCATION_END
 ##
-## Ends in an error in state: 117.
+## Ends in an error in state: 118.
 ##
 ## line_statement -> ACT expression COLUMN nonempty_list(EOL) list(line_statement) empty_body . END option(ACT) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> ACT expression COLUMN nonempty_list(EOL) list(line_statement) empty_body . END option(ACT) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1503,19 +1502,19 @@ main: LOCATION_START EOL ACT IDENT COLUMN EOL IDENT AMPERSAND LOCATION_END
 ## This implies that, although the LR(1) items shown above provide an
 ## accurate view of the past (what has been recognized so far), they
 ## may provide an INCOMPLETE view of the future (what was expected next).
-## In state 121, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
-## In state 130, spurious reduction of production list(EOL) ->
-## In state 131, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
-## In state 126, spurious reduction of production list(line_statement) ->
-## In state 127, spurious reduction of production list(line_statement) -> line_statement list(line_statement)
-## In state 116, spurious reduction of production empty_body ->
+## In state 122, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
+## In state 131, spurious reduction of production list(EOL) ->
+## In state 132, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
+## In state 127, spurious reduction of production list(line_statement) ->
+## In state 128, spurious reduction of production list(line_statement) -> line_statement list(line_statement)
+## In state 117, spurious reduction of production empty_body ->
 ##
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
 main: LOCATION_START EOL ACT IDENT COLUMN EOL END STAR
 ##
-## Ends in an error in state: 118.
+## Ends in an error in state: 119.
 ##
 ## line_statement -> ACT expression COLUMN nonempty_list(EOL) list(line_statement) empty_body END . option(ACT) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> ACT expression COLUMN nonempty_list(EOL) list(line_statement) empty_body END . option(ACT) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1528,7 +1527,7 @@ main: LOCATION_START EOL ACT IDENT COLUMN EOL END STAR
 
 main: LOCATION_START EOL ACT IDENT COLUMN EOL END ACT STAR
 ##
-## Ends in an error in state: 120.
+## Ends in an error in state: 121.
 ##
 ## line_statement -> ACT expression COLUMN nonempty_list(EOL) list(line_statement) empty_body END option(ACT) . nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> ACT expression COLUMN nonempty_list(EOL) list(line_statement) empty_body END option(ACT) . nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1541,7 +1540,7 @@ main: LOCATION_START EOL ACT IDENT COLUMN EOL END ACT STAR
 
 main: LOCATION_START EOL IDENT AMPERSAND R_PAREN
 ##
-## Ends in an error in state: 121.
+## Ends in an error in state: 122.
 ##
 ## nonempty_list(AMPERSAND) -> AMPERSAND . [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION EOL END ELSE ELIF COMMENT COLUMN AMPERSAND ACT ]
 ## nonempty_list(AMPERSAND) -> AMPERSAND . nonempty_list(AMPERSAND) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION EOL END ELSE ELIF COMMENT COLUMN AMPERSAND ACT ]
@@ -1554,7 +1553,7 @@ main: LOCATION_START EOL IDENT AMPERSAND R_PAREN
 
 main: LOCATION_START EOL IDENT AMPERSAND EOL EOF
 ##
-## Ends in an error in state: 126.
+## Ends in an error in state: 127.
 ##
 ## list(line_statement) -> line_statement . list(line_statement) [ LOCATION_END END ELSE ELIF ]
 ##
@@ -1567,14 +1566,14 @@ main: LOCATION_START EOL IDENT AMPERSAND EOL EOF
 ## may provide an INCOMPLETE view of the future (what was expected next).
 ## In state 1, spurious reduction of production list(EOL) ->
 ## In state 2, spurious reduction of production list(EOL) -> EOL list(EOL)
-## In state 131, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
+## In state 132, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
 ##
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
 main: LOCATION_START EOL IDENT ELSE
 ##
-## Ends in an error in state: 128.
+## Ends in an error in state: 129.
 ##
 ## line_statement -> instruction . nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> instruction . nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1588,16 +1587,16 @@ main: LOCATION_START EOL IDENT ELSE
 ## may provide an INCOMPLETE view of the future (what was expected next).
 ## In state 12, spurious reduction of production option(delimited(L_BRACKET,option(expression),R_BRACKET)) ->
 ## In state 72, spurious reduction of production variable -> IDENT option(delimited(L_BRACKET,option(expression),R_BRACKET))
-## In state 97, spurious reduction of production expression -> variable
-## In state 113, spurious reduction of production single_instruction -> expression
-## In state 100, spurious reduction of production instruction -> single_instruction
+## In state 98, spurious reduction of production expression -> variable
+## In state 114, spurious reduction of production single_instruction -> expression
+## In state 101, spurious reduction of production instruction -> single_instruction
 ##
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
 main: LOCATION_START EOL ACT IDENT COLUMN COMMENT STAR
 ##
-## Ends in an error in state: 132.
+## Ends in an error in state: 133.
 ##
 ## line_statement -> inline_action . nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> inline_action . nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1610,7 +1609,7 @@ main: LOCATION_START EOL ACT IDENT COLUMN COMMENT STAR
 
 main: LOCATION_START EOL ACT IDENT COLUMN IDENT AMPERSAND LOCATION_END
 ##
-## Ends in an error in state: 136.
+## Ends in an error in state: 137.
 ##
 ## final_inline_instruction -> inline_instruction . instruction [ EOL ELSE AMPERSAND ]
 ## final_inline_instruction -> inline_instruction . inline_action [ EOL ELSE AMPERSAND ]
@@ -1625,15 +1624,15 @@ main: LOCATION_START EOL ACT IDENT COLUMN IDENT AMPERSAND LOCATION_END
 ## This implies that, although the LR(1) items shown above provide an
 ## accurate view of the past (what has been recognized so far), they
 ## may provide an INCOMPLETE view of the future (what was expected next).
-## In state 121, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
-## In state 147, spurious reduction of production inline_instruction -> inline_instruction single_instruction nonempty_list(AMPERSAND)
+## In state 122, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
+## In state 148, spurious reduction of production inline_instruction -> inline_instruction single_instruction nonempty_list(AMPERSAND)
 ##
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
 main: LOCATION_START EOL ACT IDENT COLUMN IF STAR
 ##
-## Ends in an error in state: 137.
+## Ends in an error in state: 138.
 ##
 ## onliner(IF) -> IF . expression COLUMN final_inline_instruction [ EOL ELSE AMPERSAND ]
 ##
@@ -1645,7 +1644,7 @@ main: LOCATION_START EOL ACT IDENT COLUMN IF STAR
 
 main: LOCATION_START EOL ACT IDENT COLUMN IF INTEGER SET
 ##
-## Ends in an error in state: 138.
+## Ends in an error in state: 139.
 ##
 ## expression -> expression . EQUAL expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL DIV COLUMN AND ]
 ## expression -> expression . LT GT expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL DIV COLUMN AND ]
@@ -1673,7 +1672,7 @@ main: LOCATION_START EOL ACT IDENT COLUMN IF INTEGER SET
 
 main: LOCATION_START EOL ACT IDENT COLUMN ACT STAR
 ##
-## Ends in an error in state: 142.
+## Ends in an error in state: 143.
 ##
 ## onliner(ACT) -> ACT . expression COLUMN final_inline_instruction [ EOL ELSE AMPERSAND ]
 ##
@@ -1685,7 +1684,7 @@ main: LOCATION_START EOL ACT IDENT COLUMN ACT STAR
 
 main: LOCATION_START EOL ACT IDENT COLUMN ACT INTEGER SET
 ##
-## Ends in an error in state: 143.
+## Ends in an error in state: 144.
 ##
 ## expression -> expression . EQUAL expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL DIV COLUMN AND ]
 ## expression -> expression . LT GT expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL DIV COLUMN AND ]
@@ -1713,7 +1712,7 @@ main: LOCATION_START EOL ACT IDENT COLUMN ACT INTEGER SET
 
 main: LOCATION_START EOL ACT IDENT COLUMN KEYWORD L_PAREN R_PAREN STAR
 ##
-## Ends in an error in state: 146.
+## Ends in an error in state: 147.
 ##
 ## inline_instruction -> inline_instruction single_instruction . nonempty_list(AMPERSAND) [ STAR SET PLUS OBJ NO MINUS L_PAREN LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION EOL ELSE COMMENT AMPERSAND ACT ]
 ## instruction -> single_instruction . [ EOL ELSE AMPERSAND ]
@@ -1726,7 +1725,7 @@ main: LOCATION_START EOL ACT IDENT COLUMN KEYWORD L_PAREN R_PAREN STAR
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL ELIF STAR
 ##
-## Ends in an error in state: 151.
+## Ends in an error in state: 152.
 ##
 ## elif -> ELIF . expression COLUMN nonempty_list(EOL) list(line_statement) [ END ELSE ELIF ]
 ##
@@ -1738,7 +1737,7 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL ELIF STAR
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL ELIF INTEGER SET
 ##
-## Ends in an error in state: 152.
+## Ends in an error in state: 153.
 ##
 ## elif -> ELIF expression . COLUMN nonempty_list(EOL) list(line_statement) [ END ELSE ELIF ]
 ## expression -> expression . EQUAL expression [ STAR PLUS OR MOD MINUS LT GT EXCLAMATION EQUAL DIV COLUMN AND ]
@@ -1762,11 +1761,11 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL ELIF INTEGER SET
 ## ELIF expression
 ##
 
-<YOUR SYNTAX ERROR MESSAGE HERE>
+The `ELIF` expression does not end properly. A `:` is expected before any instruction.
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL ELIF IDENT COLUMN STAR
 ##
-## Ends in an error in state: 153.
+## Ends in an error in state: 154.
 ##
 ## elif -> ELIF expression COLUMN . nonempty_list(EOL) list(line_statement) [ END ELSE ELIF ]
 ##
@@ -1778,7 +1777,7 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL ELIF IDENT COLUMN STAR
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL ELIF IDENT COLUMN EOL LOCATION_END
 ##
-## Ends in an error in state: 154.
+## Ends in an error in state: 155.
 ##
 ## elif -> ELIF expression COLUMN nonempty_list(EOL) . list(line_statement) [ END ELSE ELIF ]
 ##
@@ -1796,7 +1795,7 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL ELIF IDENT COLUMN EOL LOCATION_END
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL ELSE STAR
 ##
-## Ends in an error in state: 157.
+## Ends in an error in state: 158.
 ##
 ## else_ -> ELSE . nonempty_list(EOL) list(line_statement) [ END ]
 ##
@@ -1808,7 +1807,7 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL ELSE STAR
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL ELSE EOL IDENT AMPERSAND LOCATION_END
 ##
-## Ends in an error in state: 161.
+## Ends in an error in state: 162.
 ##
 ## line_statement -> IF expression COLUMN nonempty_list(EOL) list(line_statement) elif_else_body . END option(IF) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> IF expression COLUMN nonempty_list(EOL) list(line_statement) elif_else_body . END option(IF) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1820,20 +1819,20 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL ELSE EOL IDENT AMPERSAND LOCATION_E
 ## This implies that, although the LR(1) items shown above provide an
 ## accurate view of the past (what has been recognized so far), they
 ## may provide an INCOMPLETE view of the future (what was expected next).
-## In state 121, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
-## In state 130, spurious reduction of production list(EOL) ->
-## In state 131, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
-## In state 126, spurious reduction of production list(line_statement) ->
-## In state 127, spurious reduction of production list(line_statement) -> line_statement list(line_statement)
-## In state 159, spurious reduction of production else_ -> ELSE nonempty_list(EOL) list(line_statement)
-## In state 160, spurious reduction of production elif_else_body -> list(elif) else_
+## In state 122, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
+## In state 131, spurious reduction of production list(EOL) ->
+## In state 132, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
+## In state 127, spurious reduction of production list(line_statement) ->
+## In state 128, spurious reduction of production list(line_statement) -> line_statement list(line_statement)
+## In state 160, spurious reduction of production else_ -> ELSE nonempty_list(EOL) list(line_statement)
+## In state 161, spurious reduction of production elif_else_body -> list(elif) else_
 ##
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL END STAR
 ##
-## Ends in an error in state: 162.
+## Ends in an error in state: 163.
 ##
 ## line_statement -> IF expression COLUMN nonempty_list(EOL) list(line_statement) elif_else_body END . option(IF) nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> IF expression COLUMN nonempty_list(EOL) list(line_statement) elif_else_body END . option(IF) nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1846,7 +1845,7 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL END STAR
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL END IF STAR
 ##
-## Ends in an error in state: 164.
+## Ends in an error in state: 165.
 ##
 ## line_statement -> IF expression COLUMN nonempty_list(EOL) list(line_statement) elif_else_body END option(IF) . nonempty_list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
 ## line_statement -> IF expression COLUMN nonempty_list(EOL) list(line_statement) elif_else_body END option(IF) . nonempty_list(AMPERSAND) list(EOL) [ STAR SET PLUS OBJ NO MINUS L_PAREN LOCATION_END LITERAL LET KEYWORD INTEGER IF IDENT FUNCTION END ELSE ELIF COMMENT COLUMN ACT ]
@@ -1859,7 +1858,7 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL END IF STAR
 
 main: LOCATION_START EOL IF IDENT COLUMN EOL ELIF IDENT COLUMN EOL IDENT AMPERSAND LOCATION_END
 ##
-## Ends in an error in state: 168.
+## Ends in an error in state: 169.
 ##
 ## list(elif) -> elif . list(elif) [ END ELSE ]
 ##
@@ -1870,19 +1869,19 @@ main: LOCATION_START EOL IF IDENT COLUMN EOL ELIF IDENT COLUMN EOL IDENT AMPERSA
 ## This implies that, although the LR(1) items shown above provide an
 ## accurate view of the past (what has been recognized so far), they
 ## may provide an INCOMPLETE view of the future (what was expected next).
-## In state 121, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
-## In state 130, spurious reduction of production list(EOL) ->
-## In state 131, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
-## In state 126, spurious reduction of production list(line_statement) ->
-## In state 127, spurious reduction of production list(line_statement) -> line_statement list(line_statement)
-## In state 155, spurious reduction of production elif -> ELIF expression COLUMN nonempty_list(EOL) list(line_statement)
+## In state 122, spurious reduction of production nonempty_list(AMPERSAND) -> AMPERSAND
+## In state 131, spurious reduction of production list(EOL) ->
+## In state 132, spurious reduction of production line_statement -> instruction nonempty_list(AMPERSAND) list(EOL)
+## In state 127, spurious reduction of production list(line_statement) ->
+## In state 128, spurious reduction of production list(line_statement) -> line_statement list(line_statement)
+## In state 156, spurious reduction of production elif -> ELIF expression COLUMN nonempty_list(EOL) list(line_statement)
 ##
 
-<YOUR SYNTAX ERROR MESSAGE HERE>
+Unclosed `ELIF` block.
 
 main: LOCATION_START EOL LOCATION_END STAR
 ##
-## Ends in an error in state: 171.
+## Ends in an error in state: 172.
 ##
 ## main -> list(EOL) LOCATION_START nonempty_list(EOL) list(line_statement) LOCATION_END . list(EOL) EOF [ # ]
 ##
@@ -1894,7 +1893,7 @@ main: LOCATION_START EOL LOCATION_END STAR
 
 main: LOCATION_START EOL LOCATION_END EOL STAR
 ##
-## Ends in an error in state: 172.
+## Ends in an error in state: 173.
 ##
 ## main -> list(EOL) LOCATION_START nonempty_list(EOL) list(line_statement) LOCATION_END list(EOL) . EOF [ # ]
 ##
diff --git a/lib/interpreter.ml b/lib/interpreter.ml
index 346ceb5..7fc0413 100644
--- a/lib/interpreter.ml
+++ b/lib/interpreter.ml
@@ -5,7 +5,7 @@
 
     Refer to the menhir manual in order to see the values.
 
-    The interresting function here is [of_lexer] which return the error code in
+    The interresting function here is [of_lexbuf] which return the error code in
     case of invalid syntax.
  *)
 
@@ -17,7 +17,6 @@ struct
     code : error_code;
     start_pos : Lexing.position;
     end_pos : Lexing.position;
-
   }
 
   module E = MenhirLib.ErrorReports
@@ -31,6 +30,8 @@ struct
   let get_parse_error lexbuf env : error =
     match MI.stack env with
     | (lazy Nil) ->
+        (* The parser is in its initial state. We should not get an
+           error here *)
         let positions = Sedlexing.lexing_positions lexbuf in
         range_message positions InvalidSyntax
     | (lazy (Cons (MI.Element (state, _, start_pos, end_pos), _))) ->
diff --git a/lib/UTF16.ml b/lib/lexer.ml
index e325011..324171f 100644
--- a/lib/UTF16.ml
+++ b/lib/lexer.ml
@@ -84,7 +84,6 @@ let rec read_long_string level buf lexbuf =
           Buffer.add_string buf (Sedlexing.Utf8.lexeme lexbuf);
           read_long_string (level - 1) buf lexbuf)
   | eol ->
-      Sedlexing.new_line lexbuf;
       Buffer.add_string buf (Sedlexing.Utf8.lexeme lexbuf);
       read_long_string level buf lexbuf
   | any ->
@@ -111,7 +110,6 @@ let rec read_quoted_string buf lexbuf =
   | '\'' -> Buffer.contents buf
   | eol ->
       Buffer.add_string buf (Sedlexing.Utf8.lexeme lexbuf);
-      Sedlexing.new_line lexbuf;
       read_quoted_string buf lexbuf
   | any ->
       Buffer.add_string buf (Sedlexing.Utf8.lexeme lexbuf);
@@ -181,7 +179,6 @@ let rec token : (module Encoding.S) -> Sedlexing.lexbuf -> token =
   | ident -> build_ident lexbuf
   | eol ->
       Bucket.add is_expression lexbuf 0;
-      Sedlexing.new_line lexbuf;
       EOL
   | '&' ->
       Bucket.add is_expression lexbuf 0;
diff --git a/lib/lexer.mli b/lib/lexer.mli
new file mode 100644
index 0000000..41c7c11
--- /dev/null
+++ b/lib/lexer.mli
@@ -0,0 +1,10 @@
+module type Encoding = sig
+  val lexeme : Sedlexing.lexbuf -> string
+end
+
+val lexer :
+  (module Encoding) ->
+  Sedlexing.lexbuf ->
+  unit ->
+  Tokens.token * Lexing.position * Lexing.position
+(** Apply the lexer to the source *)