Differences

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--- at:tutorial:basic [2007/04/17 16:40] – tvcutsem
+++ at:tutorial:basic [2007/04/17 16:51] – tvcutsem
@@ Line 10: / Line 10: @@
 As usual, one can define, assign and refer to a variable. Variable definitions are made with the keyword **def**. Note that AmbientTalk is a dynamically typed language, so variables do not have a type but can contain any value.
-In the examples we use the interactive AmbientTalk shell (iat) where the input and output prompt are represented by > and <code>>></code> respectively.
+In the examples we use the interactive AmbientTalk shell (iat) where the input and output prompt are represented by > and %%>>%% respectively.
 <code>
@@ Line 35: / Line 35: @@
 <note>
-When using the '':='' assignment operator, beware of the following syntactic annoyance: the expression ''a := 1'' denotes an assignment to the variable "a", while ''a:= 1'' is misunderstood by the parser as "a: = 1", which is the invocation of a keyworded message named ''a:''. Keyworded message sends will be explained later on in this chapter. Hence, as a general rule, don't forget to always put a space between the variable name and the '':='' operator.
+When using the '':='' assignment operator, beware of the following syntactic annoyance: the expression ''a := 1'' denotes an assignment to the variable ''a'', while ''a:= 1'' is misunderstood by the parser as ''a: = 1'', which is the invocation of a keyworded message named ''a:''. Keyworded message sends will be explained later on in this chapter. Hence, as a general rule, don't forget to always put a space between the variable name and the '':='' operator.
 </note>
 ===== Tables =====
-Indexed tables represent what other languages call arrays or lists. Tables are unidimensional and their indexes range from 1 to the size of the table. As variables, one can define, assign and refer to a table. Table definition is also made  with the keyword **def** in the following form:
+The //table// is AmbientTalk's native compound data type. It is akin to what other languages call //arrays//. The main difference is that tables are indexed from ''1'' up to their ''length'', while arrays are indexed from ''0'' up to ''length-1''. Like with variables, one can define, assign and refer to a table. Table definitions are also formed with the keyword **def** in the following format:
 <code>
-def t[ <size> ] { <expression> }
+def t[ <sizeexpression> ] { <initexpression> }
 </code>
-This means that the <expression> will be evaluated <size> times, i.e., one for each slot of the table. This allows expressions such as initializing a table of ascending numbers as shown below:
+This constructs a table, the size of which is determined by ''<sizeexpression>''. The content of each slot is the result of evaluating ''<initexpression>''. This means that ''<initexpression>'' is evaluated for each slot in the table! Tables of e.g. ascending numbers are easily formed:
 <code>
 >def z := 0
@@ Line 52: / Line 53: @@
 </code>
-Although there is no special constructor for definition of multidimensional tables, a table entry can contain another table. This is internally stored as a unidimensional table whose entries are other tables.
+Although there is no special constructor for definition of multidimensional tables, a table entry can contain another table. This is internally stored as a one-dimensional table whose entries are other tables.
 <code>
 >def vowels := ["a", "e", "i", "o", "u"]
@@ Line 62: / Line 63: @@
 </code>
-As shown in the definition of the varible //vowels//, evaluating a series of comma-separated data types between square brackets (aka a tabulation) results in a table.
+As shown in the definition of the variable ''vowels'', AmbientTalk provides literal syntax to encode in-line tables. Table assignment and indexation work as usual, but recall that table indices range from ''1'' up to ''table.length''. Some more examples of literal tables:
 <code>