1Parsing(3) OCaml library Parsing(3)
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6 Parsing - The run-time library for parsers generated by ocamlyacc.
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9 Module Parsing
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12 Module Parsing
13 : sig end
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16 The run-time library for parsers generated by ocamlyacc .
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24 val symbol_start : unit -> int
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27 symbol_start and Parsing.symbol_end are to be called in the action part
28 of a grammar rule only. They return the offset of the string that
29 matches the left-hand side of the rule: symbol_start() returns the off‐
30 set of the first character; symbol_end() returns the offset after the
31 last character. The first character in a file is at offset 0.
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36 val symbol_end : unit -> int
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38 See Parsing.symbol_start .
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43 val rhs_start : int -> int
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45 Same as Parsing.symbol_start and Parsing.symbol_end , but return the
46 offset of the string matching the n th item on the right-hand side of
47 the rule, where n is the integer parameter to rhs_start and rhs_end .
48 n is 1 for the leftmost item.
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53 val rhs_end : int -> int
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55 See Parsing.rhs_start .
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60 val symbol_start_pos : unit -> Lexing.position
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62 Same as symbol_start , but return a position instead of an offset.
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67 val symbol_end_pos : unit -> Lexing.position
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69 Same as symbol_end , but return a position instead of an offset.
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74 val rhs_start_pos : int -> Lexing.position
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76 Same as rhs_start , but return a position instead of an offset.
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81 val rhs_end_pos : int -> Lexing.position
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83 Same as rhs_end , but return a position instead of an offset.
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88 val clear_parser : unit -> unit
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90 Empty the parser stack. Call it just after a parsing function has
91 returned, to remove all pointers from the parser stack to structures
92 that were built by semantic actions during parsing. This is optional,
93 but lowers the memory requirements of the programs.
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98 exception Parse_error
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101 Raised when a parser encounters a syntax error. Can also be raised
102 from the action part of a grammar rule, to initiate error recovery.
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107 val set_trace : bool -> bool
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109 Control debugging support for ocamlyacc -generated parsers. After
110 Parsing.set_trace true , the pushdown automaton that executes the
111 parsers prints a trace of its actions (reading a token, shifting a
112 state, reducing by a rule) on standard output. Parsing.set_trace false
113 turns this debugging trace off. The boolean returned is the previous
114 state of the trace flag.
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121OCamldoc 2017-03-22 Parsing(3)