Mercurial > hg > compilers
comparison lab2/tree.mli @ 0:bfdcc3820b32
Basis
| author | Mike Spivey <mike@cs.ox.ac.uk> |
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| date | Thu, 05 Oct 2017 08:04:15 +0100 |
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| -1:000000000000 | 0:bfdcc3820b32 |
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| 1 (* lab2/tree.mli *) | |
| 2 (* Copyright (c) 2017 J. M. Spivey *) | |
| 3 | |
| 4 open Dict | |
| 5 | |
| 6 (* | |
| 7 This module describes the type of abstract syntax trees that is used | |
| 8 as the main interface between parts of the comipler. A tree is built | |
| 9 by the parser, then checked by the semantic analyser, which annotates | |
| 10 identifiers in the tree with their definitions. The intermediate code | |
| 11 generator finally traverses the tree, emitting code for each | |
| 12 expression or statement. | |
| 13 | |
| 14 The module also contains some functions that are used to build the | |
| 15 tree initially; they construct nodes with default values for the | |
| 16 annotations. Proper values are filled in later during semantic | |
| 17 analysis. | |
| 18 *) | |
| 19 | |
| 20 (* |name| -- type for applied occurrences with annotations *) | |
| 21 type name = | |
| 22 { x_name: ident; (* Name of the reference *) | |
| 23 x_line: int; (* Line number *) | |
| 24 mutable x_def: def option } (* Definition in scope *) | |
| 25 | |
| 26 | |
| 27 (* Abstract syntax *) | |
| 28 | |
| 29 type program = Program of decl list * stmt | |
| 30 | |
| 31 and decl = Decl of name list * ptype | |
| 32 | |
| 33 and stmt = | |
| 34 Skip | |
| 35 | Seq of stmt list | |
| 36 | Assign of expr * expr | |
| 37 | Print of expr | |
| 38 | Newline | |
| 39 | IfStmt of expr * stmt * stmt | |
| 40 | WhileStmt of expr * stmt | |
| 41 | |
| 42 and expr = | |
| 43 { e_guts: expr_guts; | |
| 44 mutable e_type: ptype } | |
| 45 | |
| 46 and expr_guts = | |
| 47 Constant of int * ptype | |
| 48 | Variable of name | |
| 49 | Sub of expr * expr | |
| 50 | Monop of Keiko.op * expr | |
| 51 | Binop of Keiko.op * expr * expr | |
| 52 | |
| 53 | |
| 54 (* seq -- neatly join a list of statements into a sequence *) | |
| 55 val seq : stmt list -> stmt | |
| 56 | |
| 57 (* |makeName| -- construct a name node with dummy annotations *) | |
| 58 val makeName : ident -> int -> name | |
| 59 | |
| 60 (* |get_def| -- rerieve definition from name *) | |
| 61 val get_def : name -> def | |
| 62 | |
| 63 (* |makeExpr| -- construct an expr node with dummy annotations *) | |
| 64 val makeExpr : expr_guts -> expr | |
| 65 | |
| 66 (* |print_tree| -- pretty-print a tree *) | |
| 67 val print_tree : out_channel -> program -> unit |