baum: c31b5bb6d493 baum.1

45 Source code are plain text files with one node per line representing the tree. The indention controls in which level in the tree the node is. Indention can be made with SPACE or with TAB characters. Every character means one level.

47 Empty lines and everything vom the hash symbol (`#') to the end of the line is ignored.

49 .B An example that echoes (and returns) `42':

51 .nf

52 # comment

53 print(0)

54 sum(0) #comment

55 number(40)

56 number(2)

57 .fi

61 .SH CONCEPT

63 baum programs are represented as nodes in a tree structure. Nodes are of specific kind and contain a value.

65 The tree is processed recursive starting at the root node. Every node controls it's sons and should only know them; while most nodes only use their leftmost son.

67 Each node returns a value to it's parent. (The root node returns an exit code to the shell.) The internal value of the node could be used in any useful way, but only inside the node.

69 All values in the language (return values, expected return values and in-node values) should be of the same type, so that every combination of nodes is possible.

71 Nodes can modify the tree, but should do this only on it's brothers or better only through it's rightmost brother.

74 .SH ERRORS

76 You have to keep in mind, that valid programs that run successful can return exit codes different from zero too! Each program returns the return value of the root node to the shell. If you don't want your program doing this, just set a `number(0)' node as root, and put everything else below.

78 .TP

79 .BI 1

80 common error

82 .TP

83 .BI 3

84 no or more than one source file given

86 .TP

87 .BI 4

88 invalid node

90 .TP

91 .BI 5

92 indention over more than one level